U.S. patent application number 12/589323 was filed with the patent office on 2013-05-23 for fluid-surfaced electrode.
This patent application is currently assigned to Searete LLC. The applicant listed for this patent is Geoffrey Deane, Bran Ferren, William Gates, W. Daniel Hillis, Roderick Hyde, Muriel Ishikawa, Edward Jung, Jordin Kare, Nathan Myhrvold, Clarence Tegreene, David Tuckerman, Thomas Weaver, Charles Whitmer, Lowell Wood, Jr., Victoria Wood. Invention is credited to Geoffrey Deane, Bran Ferren, William Gates, W. Daniel Hillis, Roderick Hyde, Muriel Ishikawa, Edward Jung, Jordin Kare, Nathan Myhrvold, Clarence Tegreene, David Tuckerman, Thomas Weaver, Charles Whitmer, Lowell Wood, Jr., Victoria Wood.
Application Number | 20130130067 12/589323 |
Document ID | / |
Family ID | 43527336 |
Filed Date | 2013-05-23 |
United States Patent
Application |
20130130067 |
Kind Code |
A2 |
Deane; Geoffrey ; et
al. |
May 23, 2013 |
FLUID-SURFACED ELECTRODE
Abstract
An electrochemical device (such as a battery) includes at least
one electrode having a fluid surface, which may employ a surface
energy effect to maintain a position of the fluid surface and/or to
modulate flow within the fluid. Fluid-directing structures may also
modulate flow or retain fluid in a predetermined pattern. An
electrolyte within the device may also include an ion-transport
fluid, for example infiltrated into a porous solid support.
Inventors: |
Deane; Geoffrey; (Bellevue,
WA) ; Ferren; Bran; (Beverly Hills, CA) ;
Gates; William; (Redmond, WA) ; Hillis; W.
Daniel; (Encino, CA) ; Hyde; Roderick;
(Redmond, WA) ; Ishikawa; Muriel; (Livermore,
CA) ; Jung; Edward; (Bellevue, WA) ; Kare;
Jordin; (Seattle, WA) ; Myhrvold; Nathan;
(Bellevue, WA) ; Tegreene; Clarence; (Bellevue,
WA) ; Tuckerman; David; (Lafayette, CA) ;
Weaver; Thomas; (San Mateo, CA) ; Whitmer;
Charles; (North Bend, WA) ; Wood, Jr.; Lowell;
(Bellevue, WA) ; Wood; Victoria; (Livermore,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Deane; Geoffrey
Ferren; Bran
Gates; William
Hillis; W. Daniel
Hyde; Roderick
Ishikawa; Muriel
Jung; Edward
Kare; Jordin
Myhrvold; Nathan
Tegreene; Clarence
Tuckerman; David
Weaver; Thomas
Whitmer; Charles
Wood, Jr.; Lowell
Wood; Victoria |
Bellevue
Beverly Hills
Redmond
Encino
Redmond
Livermore
Bellevue
Seattle
Bellevue
Bellevue
Lafayette
San Mateo
North Bend
Bellevue
Livermore |
WA
CA
WA
CA
WA
CA
WA
WA
WA
WA
CA
CA
WA
WA
CA |
US
US
US
US
US
US
US
US
US
US
US
US
US
US
US |
|
|
Assignee: |
Searete LLC
Bellevue
WA
|
Prior
Publication: |
|
Document Identifier |
Publication Date |
|
US 20110027627 A1 |
February 3, 2011 |
|
|
Family ID: |
43527336 |
Appl. No.: |
12/589323 |
Filed: |
October 20, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12462205 |
Jul 29, 2009 |
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12589323 |
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12589310 |
Oct 20, 2009 |
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12462205 |
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12589322 |
Oct 20, 2009 |
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12589310 |
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12589309 |
Oct 20, 2009 |
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12589322 |
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Current U.S.
Class: |
429/50 ;
29/623.1; 320/137; 429/101; 429/120; 429/209 |
Current CPC
Class: |
H01M 10/613 20150401;
H01M 2004/021 20130101; Y02E 60/10 20130101; H01M 4/36 20130101;
H01M 10/617 20150401; H01M 10/44 20130101; H01M 10/6567 20150401;
H01M 4/02 20130101; Y10T 29/49108 20150115; H01M 4/366 20130101;
H01M 10/654 20150401 |
Class at
Publication: |
429/50 ; 429/209;
429/101; 429/120; 29/623.1; 320/137 |
International
Class: |
H01M 10/44 20060101
H01M010/44; H02J 7/00 20060101 H02J007/00; H01M 10/50 20060101
H01M010/50; H01M 10/04 20060101 H01M010/04; H01M 4/02 20060101
H01M004/02; H01M 4/36 20060101 H01M004/36 |
Claims
1.-129. (canceled)
130. An electrochemical device, comprising: two electrodes
including a cathode and an anode; and an electrolyte arranged to
conduct an ionic current from a first electrolyte surface in
contact with one of the electrodes to a second electrolyte surface
in contact with another of the electrodes, wherein at least one of
the electrodes includes an electrochemically active fluid layer
having a surface in contact with the electrolyte; and a
micropatterned support including a fluid-directing structure
configured to retain the electrochemically active fluid at a
predetermined location.
131. A method of supplying electrochemical energy, comprising:
connecting an electrical load to a first and second electrode
separated by an electrolyte arranged to conduct an ionic current
from a first electrolyte surface in contact with the first
electrode to a second electrolyte surface in contact with the
second electrode, wherein at least one of the first and second
electrodes includes a micropatterned support including a
fluid-directing structure; and flowing an electrochemically active
fluid along the micropatterned support in a configuration in which
the electrochemically active fluid contacts the electrolyte and is
retained by the fluid-directing structure at a predetermined
location.
132. A method of charging a battery, comprising: connecting an
electrical potential to a first and second electrode separated by
an electrolyte arranged to conduct an ionic current from a first
electrolyte surface in contact with the first electrode to a second
electrolyte surface in contact with the second electrode, wherein
at least one of the first and second electrodes includes a
micropatterned support including a fluid-directing structure; and
flowing an electrochemically active fluid along the micropatterned
support in a configuration in which the electrochemically active
fluid contacts the electrolyte and is retained by the
fluid-directing structure at a predetermined location.
133. A method of charging a battery having an electrode including
an electrochemically active fluid layer that flows along a
micropatterned solid support and contacts an electrolyte, the
method comprising: refreshing the electrochemically active fluid
layer by flowing the electrochemically active fluid along the solid
support while retaining electrochemically active fluid at a
predetermined location.
134. The method of claim 133, wherein refreshing the
electrochemically active fluid layer includes removing
electrochemically active fluid depleted of an electrochemical
species and introducing electrochemically active fluid containing
the electrochemical species.
135. The method of claim 133, wherein flowing the electrochemically
active fluid includes flowing the electrochemically active fluid in
a substantially laminar flow.
136. An electrode for a battery, comprising: an electrochemically
active fluid layer that clings to a micropatterned solid support by
a surface energy effect, the electrochemically active fluid layer
being configured for contact with an electrolyte, and the
micropatterned solid support including a fluid-directing structure
configured to retain electrochemically active fluid at a
predetermined location.
137. A method of making a battery, comprising: coupling an
electrolyte with two electrodes including an anode and a cathode,
wherein at least one of the electrodes is configured to support an
electrochemically active fluid layer in ionic communication with
the electrolyte on a micropatterned solid support, the
micropatterned solid support including a fluid-directing structure
configured to retain the electrochemically active fluid at a
predetermined location.
138.-197. (canceled)
198. The electrochemical device of claim 130, wherein the
micropatterned support includes fluid-directing structures
configured to retain a plurality of fluids, each at a predetermined
location.
199. The electrochemical device of claim 130, wherein the
micropatterned support includes a first fluid-directing structure
configured to retain an electrochemically active fluid of the
anode, and a second fluid-directing structure configured to retain
an electrochemically active fluid of the cathode.
200. (canceled)
201. The electrochemical device of claim 130, wherein the
micropatterned support is configured to spatially vary the contact
between the electrochemically active fluid layer and the
electrolyte.
202. The electrochemical device of claim 130, wherein the
micropatterned support includes a fluid channel.
203. The electrochemical device of claim 202, wherein the fluid
channel has a surface that wets the electrochemically active
fluid.
204. The electrochemical device of claim 202, wherein the fluid
channel is configured to retain the electrochemically active fluid
by surface tension.
205. The electrochemical device of claim 202, wherein a dimension
of the fluid channel varies along its length.
206. (canceled)
207. (canceled)
208. The electrochemical device of claim 130, wherein the
micropatterned support includes a plurality of fluid channels, and
wherein at least two of the fluid channels are connected.
209. The electrochemical device of claim 130, wherein the
micropatterned support includes a first region and a second region,
the first and second regions having different wetting behavior with
the electrochemically active fluid layer.
210.-211. (canceled)
212. The electrochemical device of claim 130, wherein the
electrochemical device is configured to dynamically change a
property of the fluid-directing structure.
213.-214. (canceled)
215. The electrochemical device of claim 212, wherein the
electrochemical device is configured to dynamically change the
property of the fluid-directing structure in response to a property
of the device.
216.-219. (canceled)
220. The electrochemical device of claim 130, wherein the
electrolyte is further arranged to conduct an ionic current from
the second electrolyte surface to the first electrolyte
surface.
221. The electrochemical device of claim 130, wherein the
electrolyte includes a solid surface impervious to the
electrochemically active fluid.
222. The electrochemical device of claim 130, wherein the
electrolyte includes a fluid-directing structure configured to
direct fluid flow of the electrochemically active fluid layer.
223. The electrochemical device of claim 130, wherein the
electrolyte includes an ion-transport fluid through which an ion
can move to produce the ionic current.
224. The electrochemical device of claim 223, wherein the
electrolyte further includes a solid structure.
225. The electrochemical device of claim 224, wherein the solid
structure includes a porous structure infiltrated by the
ion-transport fluid.
226.-231. (canceled)
232. The electrochemical device of claim 223, wherein the
ion-transport fluid is supercritical.
233. (canceled)
234. The electrochemical device of claim 223, wherein the cathode
and the anode each include an electrochemically active fluid layer,
and wherein the ion-transport fluid is in contact with the
respective electrochemically active fluid layer at each of the two
electrodes.
235. The electrochemical device of claim 223, wherein the
ion-transport fluid is immiscible with the electrochemically active
fluid.
236. The electrochemical device of claim 223, wherein the
ion-transport fluid is connected to an external reservoir.
237.-255. (canceled)
256. The electrochemical device of claim 130, wherein the
electrochemically active fluid layer includes a fluid selected from
the group consisting of a liquid, a paste, a gel, an emulsion, a
supercritical fluid, and a non-Newtonian fluid.
257. The electrochemical device of claim 130, wherein the
electrochemically active fluid layer is an ionic conductor.
258. The electrochemical device of claim 130, wherein the
electrochemically active fluid layer is an electronic
conductor.
259. The electrochemical device of claim 130, wherein the
electrochemically active fluid layer includes a carrier fluid that
is not electrochemically active.
260. (canceled)
261. The electrochemical device of claim 130, wherein the
electrochemically active fluid layer wets the electrolyte.
262. The electrochemical device of claim 130, wherein the
electrochemically active fluid layer clings to the electrolyte.
263. The electrochemical device of claim 130, wherein the anode
includes at least one element selected from the group consisting of
lithium, sodium, mercury, tin, cesium, rubidium, and potassium.
264. (canceled)
265. The electrochemical device of claim 130, wherein the cathode
includes at least one element selected from the group consisting of
gallium, iron, mercury, tin, sulfur, and chlorine.
266. (canceled)
267. The electrochemical device of claim 130, wherein the
electrolyte includes at least one material selected from the group
consisting of perchlorate, ether, graphene, polyimide,
succinonitrile, polyacrylonitrile, polyethylene oxide, polyethylene
glycol, ethylene carbonate, beta-alumina, and an ion-conducting
glass.
268. (canceled)
269. (canceled)
270. The electrochemical device of claim 130, wherein the fluid
layer includes a liquid metal.
271.-275. (canceled)
276. The electrochemical device of claim 130, wherein the
electrochemically active fluid layer is connected to an external
reservoir.
277. The electrochemical device of claim 130, wherein the fluid
layer is configured to transport heat energy away from the
battery.
278. (canceled)
279. (canceled)
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] For purposes of the USPTO extra-statutory requirements, the
present application constitutes a continuation-in-part of U.S.
patent application Ser. No. 12/589,309, entitled FLUID-SURFACED
ELECTRODE, naming Geoffrey F. Deane, Bran Ferren, William Gates, W.
Daniel Hillis, Roderick A. Hyde, Muriel Y. Ishikawa, Edward K. Y.
Jung, Jordin T. Kare, Nathan P. Myhrvold, Clarence T. Tegreene,
David B. Tuckerman, Thomas A. Weaver, Charles Whitmer, Lowell L.
Wood, Jr., Victoria Y. H. Wood as inventors, filed 20 Oct. 2009,
which is currently co-pending, or is an application of which a
currently co-pending application is entitled to the benefit of the
filing date.
[0002] For purposes of the USPTO extra-statutory requirements, the
present application constitutes a continuation-in-part of U.S.
patent application Ser. No. 12/589,322, entitled FLUID-SURFACED
ELECTRODE, naming Geoffrey F. Deane, Bran Ferren, William Gates, W.
Daniel Hillis, Roderick A. Hyde, Muriel Y. Ishikawa, Edward K. Y.
Jung, Jordin T. Kare, Nathan P. Myhrvold, Clarence T. Tegreene,
David B. Tuckerman, Thomas A. Weaver, Charles Whitmer, Lowell L.
Wood, Jr., Victoria Y. H. Wood as inventors, filed 20 Oct. 2009,
which is currently co-pending, or is an application of which a
currently co-pending application is entitled to the benefit of the
filing date.
[0003] For purposes of the USPTO extra-statutory requirements, the
present application constitutes a continuation-in-part of U.S.
patent application Ser. No. 12/589,310, entitled FLUID-SURFACED
ELECTRODE, naming Geoffrey F. Deane, Bran Ferren, William Gates, W.
Daniel Hillis, Roderick A. Hyde, Muriel Y. Ishikawa, Edward K. Y.
Jung, Jordin T. Kare, Nathan P. Myhrvold, Clarence T. Tegreene,
David B. Tuckerman, Thomas A. Weaver, Charles Whitmer, Lowell L.
Wood, Jr., Victoria Y. H. Wood as inventors, filed 20 Oct. 2009,
which is currently co-pending, or is an application of which a
currently co-pending application is entitled to the benefit of the
filing date.
BACKGROUND
[0004] Recent attention to "green" generation of energy has
produced a variety of new processes and refinements of existing
methods for providing electrical power. However, many renewable
energy sources (e.g., solar power and wind power) may be only
intermittently available, thus possibly requiring substantial
storage capacity in order to provide electricity on demand. Even
continuously-available power sources (e.g., nuclear) may benefit
from electrical storage allowing intermittent peak loading in
excess of continuously-available average capacity. Existing
batteries for these purposes can be expensive, especially on a
lifetime basis (considering limited cycle lifetimes).
[0005] Further, existing batteries may have energy densities
substantially below those of fossil fuels, thus motivating
continued primary use of hydrocarbon fuels for personal transport
despite known negative effects of the use of hydrocarbons for such
purposes Improved battery technology could enable more widespread
use of electric vehicles and "green" power generation.
SUMMARY
[0006] In one aspect, an electrochemical device includes two
electrodes (an anode and a cathode) and an electrolyte arranged to
conduct an ionic current from a surface in contact with one
electrode to a surface in contact with the other electrode. At
least one (or optionally both) of the electrodes includes an
electrochemically active fluid layer having fluid properties that
permit at least a portion of it to cling to a substantially smooth
solid support by a surface energy effect, a surface of the
electrochemically active fluid layer being in contact with the
electrolyte.
[0007] If both electrodes include an electrochemically active fluid
layer, these layers may be in contact with a common surface of the
solid support. The solid support may include a fluid-directing
structure such as a surface channel, conduit, or pattern of regions
having different wetting properties, any of which may be configured
to direct fluid flow via surface tension. The fluid-directing
structure may be configured to adjust a fluid surface area in
response to pressure, and may be configured to control flow rate or
flow direction of a fluid. The fluid-directing structure may be
configured to distribute fluid according to a flow pattern selected
to optimize an electrical property of the electrochemical device
(e.g., by maximizing or minimizing the property, or by adjusting it
to obtain a selected value). The device may be configured to
dynamically change a property of the fluid-directing structure,
such as surface energy, wetting behavior, shape, or temperature,
for example in response to a property of the device such as global
current, global voltage, local current, local voltage, current
density, amount or composition of electrochemically active fluid,
or amount or composition of reaction products, and such dynamic
change may alter a flow characteristic of the electrochemically
active fluid layer.
[0008] At least a portion of the electrochemically active fluid
layer may cling to the substantially smooth solid support in a
manner that varies spatially. The substantially smooth solid
support may include an electrical contact, and may be curved. The
solid support and the fluid layer may differ in composition.
[0009] The electrolyte may conduct an ionic current by motion of
positive ions, negative ions, or both, and may conduct current from
cathode to anode, anode to cathode, or both. The electrolyte may
include a solid surface which may be impervious to the
electrochemically active fluid, and may include a fluid-directing
structure configured to direct fluid flow of the electrochemically
active fluid layer. The electrolyte may include an ion-transport
fluid through which an ion can move to produce the ionic current,
and may further include a solid structure, such as a porous
structure infiltrated by the ion-transport fluid (e.g., a sponge, a
wick, a plurality of fibers, a fabric, a partially sintered body, a
mesh, a perforated sheet, a textured surface, or an agglomeration
of particles). The ion-transport fluid may wet the porous
structure, and the electrochemically active fluid may wet the
ion-transport fluid more than it wets the solid structure,
including not wetting the solid structure. If the cathode and the
anode each include an electrochemically active fluid layer, the
ion-transport fluid may wet each of the electrochemically active
fluid layers more than they wet one another (including a case in
which they do not wet one another). The ion-transport fluid may be
supercritical, and may contact an electrochemically active fluid at
one or both electrodes. The ion-transport fluid may be immiscible
with the electrochemically active fluid. The ion-transport fluid
may be connected to an external reservoir, and may be configured to
remove heat by flow of the ion-transport fluid.
[0010] The electrolyte may have a thickness of less than about 1
cm, 1 mm, 100 .mu.m, 10 .mu.m, 1 .mu.m, 100 nm, or 10 nm. It may
include a reaction product of at least a portion of the cathode
with at least a portion of the anode. If the reaction product is a
fluid, it may wet a solid surface of the electrolyte or of at least
one of the electrodes, or may cling to a solid surface of at least
one of the electrodes. The reaction product may be connected to a
reservoir, and the electrolyte may be configured to remove heat by
flow of the reaction product. A reaction product of at least a
portion of the cathode with at least a portion of the anode may be
intermixed with the electrochemically active fluid. Either the
electrolyte or one of the electrodes may include a fluid-reacting
structure configured to direct a reaction product of at least a
portion of the cathode with at least a portion of the anode.
[0011] The electrochemically active fluid layer may include a
liquid, a paste, a gel, an emulsion, a thixotropic fluid, a
supercritical fluid, or a non-Newtonian fluid, and may be an ionic
or an electronic conductor. It may include a carrier fluid that is
not electrochemically active. It may wet or cling to the
electrolyte. The fluid layer may include a dissolved gas such as
oxygen, or a liquid metal such as an alloy. The liquid metal may be
liquid at about 100.degree. C., 50.degree. C., 25.degree. C., or
0.degree. C. The electrochemically active fluid may be connected to
an external reservoir, and may be configured to transport heat
energy away from the battery.
[0012] The anode may include lithium, sodium, mercury, tin, cesium,
rubidium, potassium, or an alloy, solution, amalgam, or
intermetallic compound of any of these. The cathode may include
gallium, iron, mercury, tin, sulfur, chlorine, or an alloy,
solution, amalgam, or intermetallic compound of any of these. The
electrolyte may include perchlorate, ether, graphene, polyimide,
succinonitrile, polyacrylonitrile, polyethylene oxide, polyethylene
glycol, ethylene carbonate, beta-alumina, or an ion-conducting
glass. The electrochemical device may include a cooling system,
which may include a heat pipe, a heat exchanger, or a
microchannel
[0013] In another aspect, a method of supplying electrochemical
energy includes connecting an electrical load to a first and a
second electrode separated by an electrolyte arranged to conduct an
ionic current from a first electrolyte surface in contact with the
first electrode to a second electrolyte surface in contact with the
second electrode. At least one of the electrodes includes an
electrochemically active fluid sheet that clings to a solid support
by a surface energy effect in opposition to an acceleration field,
such as a gravitational field. A surface of the fluid sheet is in
contact with the electrolyte.
[0014] In another aspect, a method of charging a battery includes
connecting an electrical potential to a first and a second
electrode separated by an electrolyte arranged to conduct an ionic
current from a first electrolyte surface in contact with the first
electrode to a second electrolyte surface in contact with the
second electrode. At least one of the electrodes includes an
electrochemically active fluid sheet that clings to a solid support
by a surface energy effect in opposition to an acceleration field,
such as a gravitational field. A surface of the fluid sheet is in
contact with the electrolyte.
[0015] In another aspect, a method of charging a battery having an
electrode including an electrochemically active fluid layer that
clings to a substantially smooth solid support by a surface energy
effect includes refreshing the electrochemically active fluid layer
by flowing the electrochemically active fluid along the
substantially smooth solid support. Refreshing may include removing
fluid depleted of an electrochemical species and introducing fluid
containing the electrochemical species, and may include flowing the
fluid in a substantially laminar flow.
[0016] In another aspect, a method of refreshing a battery having
an electrolyte layer including an ion transport fluid includes
refreshing the ion transport fluid by flowing it through the
electrolyte layer. Refreshing the ion transport fluid may include
removing fluid depleted of an electrochemical species and
introducing fluid containing the electrochemical species.
[0017] In another aspect, a method of refreshing a battery that
produces a fluid reaction product of an electrochemical reaction
includes refreshing the battery by flowing the fluid reaction
product.
[0018] In another aspect, an electrode for a battery includes an
electrochemically active fluid layer that clings to a substantially
smooth solid support by a surface energy effect, the
electrochemically active fluid layer being configured for contact
with an electrolyte.
[0019] In another aspect, a method of making a battery includes
coupling an electrolyte with two electrodes, at least one of the
electrodes being configured to support an electrochemically active
fluid layer in ionic communication with the electrolyte by a
surface energy effect on a substantially smooth solid support.
[0020] In another aspect, an electrochemical device includes two
electrodes (an anode and a cathode), and an electrolyte arranged to
conduct an ionic current from one electrode to the other. At least
one of the electrodes includes an electrochemically active fluid
layer having a surface in contact with the electrolyte, and a
micropatterned support including a fluid-directing structure
configured to direct the electrochemically active fluid according
to a predetermined flow pattern. The micropatterned support may be
constructed by micromachining, lithography, molding, printing,
stamping, or replica-printing, and may include fluid-directing
structures configured to direct a plurality of fluids, each
according to a predetermined flow pattern. It may include a first
fluid-directing structure configured to direct an electrochemically
active fluid of the anode, and a second fluid-directing structure
configured to direct an electrochemically active fluid of the
cathode. The micropatterned support may include a first
fluid-directing structure configured to wet an electrochemically
active fluid of the anode, and a second fluid-directing structure
configured to wet an electrochemically active fluid of the cathode.
It may be configured to spatially vary the contact between the
electrochemically active fluid and the electrolyte.
[0021] The micropatterned support may include a fluid channel,
which may have a surface that wets the electrochemically active
fluid or may be configured to retain the electrochemically active
fluid by surface tension. A dimension of the fluid channel may vary
along its length, and it may be parallel to the surface of the
electrochemically active fluid in contact with the electrolyte or
not parallel to it (e.g., perpendicular). The micropatterned
support may include a plurality of fluid channels, which may be
interconnected. The micropatterned support may include first and
second regions that differ in their wetting behavior with the
electrochemically active fluid layer. The fluid-directing structure
may include a defined surface topology on the micropatterned
support, such as a plurality of surface projections.
[0022] The electrochemical device may be configured to dynamically
change a property of the fluid-directing structure, such as surface
energy, wetting behavior, shape, or temperature, for example to
alter a flow characteristic of the electrochemically active fluid
layer. Dynamically changing the property of the fluid-directing
structure may be in response to a property of the device, such as
global current, global voltage, local current, local voltage,
current density, amount or composition of electrochemically active
fluid, or amount or composition of reaction products.
[0023] In another aspect, a method of supplying electrochemical
energy includes connecting an electrical load to first and second
electrodes separated by an electrolyte arranged to conduct an ionic
current from a first electrolyte surface in contact with the first
electrode to a second electrolyte surface in contact with the
second electrode, at least one of the electrodes including a
micropatterned support including an fluid-directing structure, and
flowing an electrochemically active fluid along the micropatterned
support in a configuration in which the electrochemically active
fluid contacts the electrolyte and is directed by the
fluid-directing structure to flow according to a predetermined flow
pattern.
[0024] In another aspect, a method of charging a battery includes
connecting an electrical potential to first and second electrodes
separated by an electrolyte arranged to conduct an ionic current
from a first electrolyte surface in contact with the first
electrode to a second electrolyte surface in contact with the
second electrode, at least one of the electrodes including a
micropatterned support including an fluid-directing structure, and
flowing an electrochemically active fluid along the micropatterned
support in a configuration in which the electrochemically active
fluid contacts the electrolyte and is directed by the
fluid-directing structure to flow according to a predetermined flow
pattern.
[0025] In another aspect, a method of charging a battery having an
electrode including an electrochemically active fluid layer that
flows along a micropatterned solid support and contacts an
electrolyte includes refreshing the electrochemically active fluid
by flowing it along the solid support according to a predetermined
flow pattern. Refreshing the electrochemically active fluid may
include removing electrochemically active fluid depleted of an
electrochemical species and introducing electrochemically active
fluid containing the electrochemical species. Flowing the
electrochemically active fluid may include flowing it in a
substantially laminar flow.
[0026] In another aspect, an electrode for a battery includes an
electrochemically active fluid layer that clings to a
micropatterned solid support by a surface energy effect, the
electrochemically active fluid being configured for contact with an
electrolyte, and the micropatterned solid support including a
fluid-directing structure configured to direct the
electrochemically active fluid according to a predetermined flow
pattern.
[0027] In another aspect, a method of making a battery includes
coupling an electrolyte with two electrodes including an anode and
a cathode, wherein at least one of the electrodes is configured to
support an electrochemically active fluid layer in ionic
communication with the electrolyte on a micropatterned solid
support, the micropatterned solid support including a
fluid-directing structure configured to direct the
electrochemically active fluid according to a predetermined flow
pattern.
[0028] In another aspect, an electrochemical device includes two
electrodes (a cathode and an anode), and an electrolyte arranged to
conduct an ionic current from a first electrolyte surface in
contact with one of the electrodes to a second electrolyte surface
in contact with another of the electrodes. At least one of the
electrodes includes an electrochemically active fluid layer having
a surface in contact with the electrolyte and a micropatterned
support including a fluid-directing structure configured to retain
the electrochemically active fluid at a predetermined location.
[0029] In another aspect, a method of supplying electrochemical
energy includes connecting an electrical load to a first and second
electrode separated by an electrolyte arranged to conduct an ionic
current from a first electrolyte surface in contact with the first
electrode to a second electrolyte surface in contact with the
second electrode. At least one of the first and second electrodes
includes a micropatterned support including a fluid-directing
structure. The method further includes flowing an electrochemically
active fluid along the micropatterned support in a configuration in
which the electrochemically active fluid contacts the electrolyte
and is retained by the fluid-directing structure at a predetermined
location.
[0030] In another aspect, a method of charging a battery includes
connecting an electrical potential to a first and second electrode
separated by an electrolyte arranged to conduct an ionic current
from a first electrolyte surface in contact with the first
electrode to a second electrolyte surface in contact with the
second electrode. At least one of the first and second electrodes
includes a micropatterned support including a fluid-directing
structure. The method further includes flowing an electrochemically
active fluid along the micropatterned support in a configuration in
which the electrochemically active fluid contacts the electrolyte
and is retained by the fluid-directing structure at a predetermined
location.
[0031] In another aspect, a method of charging a battery having an
electrode including an electrochemically active fluid layer that
flows along a micropatterned solid support and contacts an
electrolyte includes refreshing the electrochemically active fluid
layer by flowing the electrochemically active fluid along the solid
support while retaining electrochemically active fluid at a
predetermined location. Refreshing the electrochemically active
fluid layer may include removing electrochemically active fluid
depleted of an electrochemical species and introducing
electrochemically active fluid containing the electrochemical
species. Flowing the electrochemically active fluid may include
flowing the electrochemically active fluid in a substantially
laminar flow.
[0032] In another aspect, an electrode for a battery includes an
electrochemically active fluid layer that clings to a
micropatterned solid support by a surface energy effect, the
electrochemically active fluid layer being configured for contact
with an electrolyte, and the micropatterned solid support including
a fluid-directing structure configured to retain electrochemically
active fluid at a predetermined location.
[0033] In another aspect, a method of making a battery includes
coupling an electrolyte with two electrodes (an anode and a
cathode). At least one of the electrodes is configured to support
an electrochemically active fluid layer in ionic communication with
the electrolyte on a micropatterned solid support, the
micropatterned solid support including a fluid-directing structure
configured to retain the electrochemically active fluid at a
predetermined location.
[0034] In another aspect, an electrochemical device includes two
electrodes (a cathode and an anode), and an electrolyte arranged to
conduct an ionic current from a first electrolyte surface in
contact with one of the electrodes to a second electrolyte surface
in contact with another of the electrodes. The cathode includes a
first electrochemically active fluid layer configured to cling to a
first microfeatured fluid-directing structure arranged to engage
the electrolyte, and the anode includes a second electrochemically
active fluid layer configured to cling to a second microfeatured
fluid-directing structure arranged to engage the electrolyte. The
first microfeatured fluid-directing structure may be configured to
direct the first electrochemically active fluid according to a
first predetermined flow pattern, while the second microfeatured
fluid-directing structure may be configured to direct the second
electrochemically active fluid according to a second predetermined
flow pattern. The first microfeatured fluid-directing structure may
be configured to retain the first electrochemically active fluid at
a first predetermined location, while the second microfeatured
fluid-directing structure may be configured to retain the second
electrochemically active fluid at a second predetermined location.
The first microfeatured fluid-directing structure may be
micromachined, constructed by lithography, or constructed by
molding, printing, stamping, or replica-printing.
[0035] The first microfeatured fluid-directing structure may
include a plurality of fibers or a plurality of particles, which
may be affixed to a surface of the electrolyte. The first
microfeatured fluid-directing structure may includes a fluid
channel, which may have a dimension that varies along its length,
and may be parallel or not parallel to a surface of the
electrolyte. The first microfeatured fluid-directing structure may
include a plurality of fluid channels, at least two of which may be
interconnected. It may have a property that varies spatially. The
electrochemical device may be configured to dynamically change a
property of the first microfeatured fluid-directing structure.
[0036] In another aspect, a method of supplying electrochemical
energy includes connecting an electrical load to a cathode and an
anode separated by an electrolyte, the electrolyte arranged to
conduct an ionic current from a first electrolyte surface in
contact with the cathode to a second electrolyte surface in contact
with the anode. The cathode includes a first microfeatured
fluid-directing structure arranged to engage the electrolyte and
the anode includes a second microfeatured fluid-directing structure
arranged to engage the electrolyte. The method further includes
flowing a first electrochemically active fluid along the first
microfeatured fluid-directing structure in engagement with the
electrolyte, and flowing a second electrochemically active fluid
along the second microfeatured fluid-directing structure in
engagement with the electrolyte.
[0037] In another aspect, a method of charging a battery includes
connecting an electrical potential to a cathode and an anode
separated by an electrolyte, the electrolyte arranged to conduct an
ionic current from a first electrolyte surface in contact with the
cathode to a second electrolyte surface in contact with the anode.
The cathode includes a first microfeatured fluid-directing
structure arranged to engage the electrolyte and the anode includes
a second microfeatured fluid-directing structure arranged to engage
the electrolyte. The method further includes flowing a first
electrochemically active fluid along the first microfeatured
fluid-directing structure in engagement with the electrolyte, and
flowing a second electrochemically active fluid along the second
microfeatured fluid-directing structure in engagement with the
electrolyte.
[0038] In another aspect, a method of charging a battery having an
electrode including a first electrochemically active fluid layer
that clings to a first microfeatured fluid-directing structure
arranged to engage an electrolyte and a second electrochemically
active fluid layer that clings to a second microfeatured
fluid-directing structure arranged to engage the electrolyte
includes refreshing the first electrochemically active fluid layer
by flowing the first electrochemically active fluid along the first
microfeatured fluid-directing structure. Refreshing the first
electrochemically active fluid layer may include removing
electrochemically active fluid depleted of a charge carrier and
introducing electrochemically active fluid containing the charge
carrier. Flowing the first electrochemically active fluid may
include flowing the first electrochemically active fluid in a
substantially laminar flow.
[0039] In another aspect, a pair of electrodes for a battery
includes a first microfeatured fluid-directing structure arranged
to engage an electrolyte and to support a first electrochemically
active fluid layer, and a second microfeatured fluid-directing
structure arranged to engage the electrolyte and to support a
second electrochemically active fluid layer.
[0040] In another aspect, a method of making a battery includes
coupling an electrolyte with two electrodes (a cathode and an
anode), the cathode including a first microfeatured fluid-directing
structure arranged to engage the electrolyte and to support a first
electrochemically active fluid layer and the anode including a
second microfeatured fluid-directing structure arranged to engage
the electrolyte and to support a second electrochemically active
fluid layer.
[0041] In another aspect, an electrochemical device includes two
electrodes (a cathode including a first electrochemically active
fluid layer and an anode including a second electrochemically
active fluid layer), an electrolyte arranged to conduct an ionic
current from a first electrolyte surface in contact with one of the
electrodes to a second electrolyte surface in contact with another
of the electrodes via an ion-transport fluid, and a fluid control
structure configured to engage a controlled fluid through surface
tension, the controlled fluid being the first electrochemically
active fluid, the second electrochemically active fluid, or the
ion-transport fluid. The cathode and/or the anode may further
include a solid support, and the electrochemically active fluid
layer(s) may cling to the solid support by a surface energy effect.
The first and/or second electrochemically active fluid layer may be
configured to flow along a surface of the electrolyte. The
ion-transport fluid may be configured to flow within or through the
device. The electrolyte may further include a solid structure, such
as a porous structure infiltrated by the ion-transport fluid. The
porous structure may include a sponge, a wick, a plurality of
fibers, a fabric, a partially sintered body, a mesh, a perforated
sheet, a textured surface, or an agglomeration of particles. The
ion-transport liquid may wet the porous structure. At least one of
the first and second electrochemically active fluids may wet the
ion-transport fluid more than it wets the solid structure,
including not wetting the solid structure. The ion-transport fluid
may wetseach of the first and second electrochemically active fluid
layers more than the electrochemically active fluid layers wet one
another, and the electrochemically active fluid layers may not wet
one another. The ion-transport fluid may be supercritical. The
ion-transport fluid may be in contact with only one of or with both
of the first and second electrochemically active fluid layers. It
may be immiscible with the electrochemically active fluid, and may
be connected to an external reservoir.
[0042] The electrolyte may be configured to remove heat by flow of
the ion-transport fluid. The fluid control structure may configured
to retain or to direct flow of the controlled fluid, and may be
microfeatured, micropatterned, or substantially smooth.
[0043] In another aspect, a method of supplying electrochemical
energy includes connecting an electrical load to a first and second
electrode separated by an electrolyte arranged to conduct an ionic
current from a first electrolyte surface in contact with the first
electrode to a second electrolyte surface in contact with the
second electrode via an ion-transport fluid. The first electrode
includes a first electrochemically active fluid layer and the
second electrode includes a second electrochemically active fluid
layer. The method further includes controlling via surface tension
flow of the ion-transport fluid, the first electrochemically active
fluid layer, or the second electrochemically active fluid
layer.
[0044] In another aspect, a method of charging a battery includes
connecting an electrical potential to a first and second electrode
separated by an electrolyte arranged to conduct an ionic current
from a first electrolyte surface in contact with the first
electrode to a second electrolyte surface in contact with the
second electrode via an ion-transport fluid. The first electrode
includes a first electrochemically active fluid layer and the
second electrode includes a second electrochemically active fluid
layer. The method further includes controlling via surface tension
flow the ion-transport fluid, the first electrochemically active
fluid layer, or the second electrochemically active fluid
layer.
[0045] In another aspect, a method of charging a battery having a
first electrode including a first electrochemically active fluid
layer, a second electrode including a second electrochemically
active fluid layer, and an electrolyte including an ion-transport
fluid includes refreshing by flowing the ion-transport fluid, the
first electrochemically active fluid layer, or the second
electrochemically active fluid layer. Refreshing by flowing may
include removing fluid depleted of an electrochemical species and
introducing fluid containing the electrochemical species, and may
include flowing the fluid in a substantially laminar flow.
[0046] In another aspect, a method of making a battery includes
coupling an electrolyte with two electrodes (an anode and a
cathode), the first electrode being configured to support a first
electrochemically active fluid layer in ionic communication with
the electrolyte and the second electrode being configured to
support a second electrochemically active fluid layer in ionic
communication with the electrolyte.
[0047] The foregoing summary is illustrative only and is not
intended to be in any way limiting. In addition to the illustrative
aspects, embodiments, and features described above, further
aspects, embodiments, and features will become apparent by
reference to the drawings and the following detailed
description.
BRIEF DESCRIPTION OF THE FIGURES
[0048] FIG. 1 is a schematic of an electrochemical device.
[0049] FIG. 2 is a schematic of an electrode surface for another
electrochemical device.
[0050] FIG. 3 is a schematic of another electrode surface for an
electrochemical device.
[0051] FIG. 4 is a schematic of another electrochemical device.
DETAILED DESCRIPTION
[0052] In the following detailed description, reference is made to
the accompanying drawings, which form a part hereof In the
drawings, similar symbols typically identify similar components,
unless context dictates otherwise. The illustrative embodiments
described in the detailed description, drawings, and claims are not
meant to be limiting. Other embodiments may be utilized, and other
changes may be made, without departing from the spirit or scope of
the subject matter presented here.
[0053] As used herein, the term "fluid" includes any condensed
phase lacking substantial shear strength, including liquids,
pastes, gels, emulsions, and supercritical fluids. Unless context
dictates otherwise, materials within electrochemical devices that
are described as "fluids" have a fluidic character at the working
temperature and pressure of the device, which may be room
temperature or another temperature (e.g., 0.degree. C., 25.degree.
C., 50.degree. C., 75.degree. C., 100.degree. C., or any other
suitable temperature), and ambient pressure or another suitable
working pressure.
[0054] As used herein, the term "smooth," when used to describe a
surface wetted by a fluid layer, includes a surface having a local
radius of curvature significantly greater than the thickness of the
fluid layer.
[0055] As used herein, the term "cling," when used to describe a
fluid in contact with a solid, includes a fluid that wets or
otherwise substantially adheres to the solid, for example with a
force sufficient to maintain contact with the solid in opposition
to a gravitational force.
[0056] As used herein, the term "ionic current" includes any
movement of electrical charge created by bulk diffusion or flow of
ions. An "ionic current" is said to flow from a positive potential
to a negative potential, even if it is produced in part or in whole
by a movement of (negatively charged) ions in the opposite
direction. A material "conducts" ionic current if it permits ions
to pass through it to create a net flow of charge. These ions may
be already present in the material or may enter through an
interface.
[0057] As used herein, the term "micropatterned" includes surfaces
exhibiting structures of roughly submillimeter size (including
micron-scale and nanoscale structures), where these structures form
predetermined shapes or have a predetermined effect on fluid flow
in their vicinity. Micropatterned surfaces may, but need not,
include repeating arrays of features, and may be constructed, for
example, by micromachining, lithography, molding (including
extrusion), printing, stamping, replica-printing, or other
processes.
[0058] As used herein, the term "microfeatured" includes surfaces
exhibiting structures of roughly submillimeter size (including
micron-scale and nanoscale structures), where the shapes or flow
characteristics of the structures may (but need not) have a random
component.
[0059] As used herein, the term "impervious" includes substances
that resist flow of a specified fluid. A substance may still be
termed "impervious" to a fluid if it is gradually degraded by the
fluid over time.
[0060] FIG. 1 is a schematic of an electrochemical device such as a
battery. As shown, the device includes cathode 100, anode 102, and
electrolyte 104. Cathode 100 includes a solid support 106 and a
fluid layer 108 that clings to the solid support. In some
embodiments, fluid layer 108 may also wet electrolyte 104. The
illustrated electrolyte 104 includes an ion-transport fluid 110
infiltrated into a porous layer 112 (e.g., a sponge, a wick, a
plurality of substantially parallel fibers, a fabric, a partially
sintered body, a mesh, a perforated sheet, a textured surface such
as a surface including a plurality of projections, or an
agglomeration of particles of any appropriate shape or size). In
some embodiments, ion-transport fluid 110 may wet porous layer 112.
In other embodiments (not shown), electrolyte 104 may be a fluid, a
solid, or a combination other than the infiltrated solid
illustrated in FIG. 1 (e.g., a fluid layer that clings to a solid
layer). While both cathode 100 and anode 102 are in contact with
electrolyte 104 during operation of the device, in some
embodiments, either electrode may be in contact only with the solid
or only with the liquid portions of the electrolyte 104, or with
both (if both are present). In the illustrated embodiment, anode
102 is a solid structure. In other embodiments (not shown), anode
102 may include a fluid layer and a solid support analogous to
those shown in the cathode 100 of FIG. 1, and may further include
one or more reservoirs as discussed below in connection with
cathode 100. While the illustrated embodiment is substantially
flat, in other embodiments the device may be curved, with one or
two radii of curvature.
[0061] In the illustrated embodiment, cathode 100 further includes
reservoirs 114 and 116 for cathode fluid layer 108. During
operation of the battery, cathode fluid may flow from reservoir 114
to reservoir 116 along support 106 (which may be a substantially
smooth support), replenishing electrochemical species which may be
depleted in the cathode fluid (note that "depleted" may include
species that are reduced in concentration, rather than totally
exhausted). In some embodiments, reservoirs 114 and 116 may be
connected, allowing recirculation of cathode fluid. The cathode
fluid may be composed primarily of the species that will
participate in the electrochemical reaction, or it may include a
carrier fluid (which may be electrochemically inert). A
complementary half-reaction occurs at anode 102. Electrolyte 104
supports transfer of at least one ionic species between cathode 100
and anode 102, while preventing transfer of electrons. The
differing chemical potentials of the two half-reactions thus
generate an electrical potential across the battery between cathode
100 and anode 102.
[0062] For example, in some embodiments, the cathode fluid may be
substantially composed of a carrier fluid that is liquid at the
desired working temperature (e.g., mercury, gallium, or a gallium
alloy such as GALINSTAN.TM., a near-eutectic alloy of gallium,
indium, and tin), doped with a lithium-containing compound such as
LiFePO.sub.4. As lithium ions are converted to neutral lithium in
the cathode fluid, depleted fluid flows into reservoir 116, while
fresh lithium ions flow from reservoir 114 into fluid layer 108.
Solid support 106 may be any of the very wide variety of materials
wetted by the cathode fluid. In an embodiment including a
fluid-surfaced anode as described above, the anode fluid may be a
sodium-potassium alloy (e.g., the eutectic NaK.sub.2) doped with
lithium metal (e.g., at a concentration of about 10 atom-%).
Electrolyte 104 may include any of a wide varieties of porous solid
supports (e.g., polytetrafluoroethylene or polyethylene
terephthalate), infiltrated with an organic solvent (e.g., diethyl
ether) containing a dissolved lithium salt such as lithium
perchlorate. In some embodiments, it may be possible to dispense
with the porous solid support, using an electrolyte layer composed
of the fluid organic solvent and (if necessary) a dissolved salt,
as long as surface tension or other forces prevent anode 100 and
cathode 102 from contacting one another to create an internal short
(for example, anode and cathode fluids may wet the electrolyte
fluid more than they wet one another, tending to reduce the
possibility of a short, or some or all of the fluids may be
immiscible). In other embodiments, the electrolyte layer may be a
solid having sufficient ion transport properties, such as
beta-alumina, a sulfide glass or another ion-conducting glass such
as Li super-ion conducting glass (LISICON), a
lithium-zinc-germanium oxide glass. Other suitable electrolyte
materials are described, for example, in Patel, et al.,
"Plastic-polymer composite electrolytes: Novel soft matter
electrolytes for recharegable lithium batteries," Electrochem.
Comm. 10(12):1912-1915 (2008); MacFarlane, et al., "Lithium-doped
plastic crystal electrolytes exhibiting fast ion conduction for
secondary batteries," Nature 402:792-794 (1999); and U.S. Pat. No.
4,237,196, "Sodium ion-conducting glass electrolyte for
sodium-sulfur batteries" (1980), all of which are incorporated by
reference herein. In the illustrated embodiment, the electrolyte
layer is connected to reservoirs 118, 120 which may be used to
refresh the electrolyte fluid in an analogous manner to the
refreshment of the cathode fluid using reservoirs 114, 116.
[0063] The electrolyte layer may be partially or fully composed of
a reaction product of the anode and cathode fluids (e.g., the anode
and cathode fluids may include monomers that participate in
interfacial polymerization). For some such embodiments, it may even
be possible to withdraw depleted electrode fluids by continuously
removing a solid or liquid reaction product during battery
operation. In some embodiments, reaction products may also be found
in either the anode or the cathode fluids, in which case they may
optionally be removed by flow of the cathode or anode fluids. In
some embodiments, reaction products may cling to solid support 106
(or an analogous structure of the anode) by a surface energy
effect, thus potentially clearing them from the
electrode-electrolyte interface. The solid support may also include
one or more fluid-directing structures that facilitate flow of a
reaction product.
[0064] In some embodiments, it is preferable to have as thin an
electrolyte as possible while still avoiding arcing between
electrodes. An electrode may be as thick as 1 cm or more, but may
also be as thin as 1 mm, 100 .mu.m, 10 .mu.m, 1 .mu.m, 100 nm, or
even 10 nm.
[0065] In another embodiment, an electrochemical device such as
that shown in FIG. 1 may be used to recharge a depleted
electrochemically active fluid. In such an embodiment, rather than
drawing electrical current from the potential difference between
the anode and the cathode, a voltage is applied to drive the
reaction in reverse, returning the electrochemically active fluid
to a higher chemical energy state for later use in the same or
another device.
[0066] In some embodiments, solid support 106 may include one or
more fluid-directing features (not shown). For example, solid
support 106 may include ripples or channels that direct fluid flow,
or areas of variable surface energy that influence wetting behavior
of the fluid. In some embodiments, surface energy may be
dynamically adjusted, for example using techniques described in
Lahann, et al., "A Reversibly Switching Surface," Science 299:5605,
pp. 371-374 (2003), which is incorporated by reference herein.
These fluid-directing features may be selected, for example, to
facilitate a flow pattern that optimizes an electrical property
(e.g., global or local current, voltage, current density, amount or
composition of electrochemically active fluid, or amount or
composition of reaction products) of the device. For example, a
flow pattern may be chosen that equalizes current flow transverse
to the electrode-electrolyte interface by presenting a larger
surface area of electrode fluid to the electrolyte as the fluid
becomes depleted of charge carriers. In some embodiments,
fluid-directing features may be responsive to pressure and/or
applied fields, and may adjust flow rate, presented area of fluid,
flow direction, or wetting behavior, for example by dynamically
changing surface energy, shape, and/or temperature.
[0067] FIG. 2 is a schematic of an electrode for use with an
electrochemical device. The electrode includes an active surface
130 which may be substantially smooth, or may have a shaped or
textured surface. In the illustrated embodiment, the device
includes a plurality of conduits 132, 134, 136, 138 through the
thickness of the electrode (in the illustrated embodiment,
perpendicular to the illustrated face of the electrode), which are
connected by surface channels 140, 142 on the electrode surface. In
use, cathodic fluids are flowed from a reservoir (not shown) up
through conduits 132, along surface channels 140, down through
conduits 136, and into the same or another reservoir (not shown).
Anodic fluids are similarly flowed up through conduits 134, along
surface channels 142, and down through conduits 138. In the
illustrated embodiment, for each set of surface channels, the
channels widen as flow proceeds along the surface, which may create
a pressure drop to facilitate flow. In some embodiments, the
conduits or surface channels may wet their respective fluids or
retain fluids via surface tension. Channels or conduits may also be
connected, either at the surface or within the electrode. The
illustrated face of the electrode is placed in contact with an
electrolyte (not shown) as described above. The electrolyte may be
fluid, solid, or a combination such as a porous solid infiltrated
with a fluid. When the electrolyte is placed in contact with the
fluids in surface channels 140, 142, an ionic current from the
cathode to the anode is produced in the electrolyte. In some
embodiments, surface channels 140, 142 are small and/or closely
spaced (e.g., on the order of millimeters or microns), allowing a
high current density through the electrolyte and a high specific
power output for a battery using the illustrated electrode. In some
embodiments, the illustrated electrode and the electrolyte may be
flexible. Electrodes and electrolyte may be stacked or arranged in
other configurations to achieve a desired form factor (for
instance, a "jellyroll" configuration of a rolled sheet of
electrode and electrolyte, which may be flexible or rigid).
[0068] The illustrated electrode may be produced by micromachining,
lithography, molding (including extrusion), printing, stamping,
replica-printing, or other known processes for constructing MEMS
and other microscale or nanoscale devices. Other electrode
configurations that direct fluid according to a predetermined
pattern may also be used--the arrangement illustrated in FIG. 2 is
merely exemplary. In some such embodiments, two electrodes
positioned on opposing surfaces of the electrolyte (like the
configuration of FIG. 1) may be used.
[0069] FIG. 3 is a schematic of another electrode surface for an
electrochemical device. Electrode plate 150 may be smooth or
textured. The surface is treated to produce areas with differing
wetting properties (e.g., hydrophilic, hydrophobic, oleophilic, or
oleophobic surfaces). Surface treatment may be accomplished, for
example, by binding different functional groups to different sites
(for example, using soft lithography), by etching (e.g., to change
physical properties or to expose a material overcoated with another
material), by chemical or physical vapor deposition, by laser
processing (e.g., by ablation or surface restructuring, such as by
femtosecond laser pulses) by roughening or otherwise physically
modifying the surfaces, or by a combination of these
techniques.
[0070] In the illustrated embodiment, the surface is treated at
areas 152 and 154 with two different surface treatments. Areas 152
are treated so that they will be wetted by a cathodic fluid, and
areas 154 are treated so that they will be wetted by an anodic
fluid. In one embodiment, a carrier fluid for a cathodic species is
aqueous in nature, while a carrier fluid for an anodic species is
nonaqueous, and areas 152 and 154 are each treated to be wetted by
aqueous and nonaqueous species, respectively. In use, the fluids
may be washed over the surface of electrode plate 150, and will
selectively cling to their respective areas. The electrode may then
be placed in contact with an electrolyte (not shown) to produce the
electrochemical reaction. Contacts (not shown) placed at the
surface treated areas (e.g., connected via the back of electrode
plate 150) may extract electrical energy from the electrochemical
reaction. In some embodiments, the cathodic and anodic fluids will
have a greater affinity for the electrolyte than they will for one
another, thereby reducing chances for cathodic and anodic fluids to
make direct electrical contact. As fluids become depleted in
regions 152 and 154, new fluids may be washed over the surface to
replenish them, optionally after first wiping the surface clean of
fluid. In some embodiments, this washing may be done at a
temperature that prevents excessive reaction of the fluids during
the washing process, either by slowing reaction kinetics or by
placing at least one of the fluids in a nonreactive (e.g., solid)
phase during a portion of the process. Alternatively, fluids may be
placed more selectively upon their respective areas (e.g., via
channels from the back of electrode plate 150), and are retained in
position by the differing surface energies of the different regions
of electrode plate 150. In another embodiment, two electrode plates
are used, each with retaining areas for a single species of
electrode fluid. In the illustrated embodiment, it will be noted
that there are twice as many regions for anode fluids as for
cathode fluids. In other embodiments, these proportions may be
reversed or the proportions of areas may be equal (or any other
appropriate ratio, taking into account the quantities, chemical
activities, and availabilities of the electrode species).
[0071] In another embodiment, local surface energy regions 152, 154
may be placed directly on the surface of a solid electrolyte. The
electrolyte may then be washed with the electrode fluids to deposit
them in the appropriate regions. The regions of differing surface
energy may all be placed on one common surface of the electrolyte,
or they may be on opposing surfaces.
[0072] FIG. 4 is a schematic of another electrochemical device.
Cathode 170 and anode 172 each include a sheet of substantially
parallel fibers that may be infiltrated with an electrochemically
active fluid as described above. These fibers are separated by
electrolyte 174. In use, the fibers function to guide flow of
electrochemically active fluid along the surface of the electrolyte
as shown by the arrows. In the illustrated embodiment, the fibers
are of substantially uniform thickness, but tapered fibers may also
be used to present differing surface areas of fluid to the
electrolyte, or the fibers may be curved to define a curved flow
path. In some embodiments, the fibers may be affixed to one another
or to the electrolyte 174.
[0073] In another embodiment, rather than parallel fibers, fluid
may be guided along a known path by other structures such as
particulates or a porous medium. In any of these cases, capillary
flow may draw fluid through the fibers, particulates, or other
medium.
[0074] In general, in order to extract or to store electrical
energy in any of the previously described electrochemical devices,
contacts will be used to connect the device to an electrical load
or an electrical generator. These contacts may be placed at any
convenient location in electrical contact with the electrode
fluids. In cases where the fluids themselves are conductive,
contacts may simply be immersed or otherwise placed in contact with
the fluids. In some embodiments, the electrochemically active
fluids may be nonconductive or have a relatively low conductivity.
In these cases, if there is a support structure supporting the
fluids, it may be convenient for the support structure to serve as
an electrical connection.
[0075] Any of the electrochemical devices described herein may
generate a certain amount of waste heat, and may be provided with a
cooling system. In some embodiments, the flow of electrode or
electrolyte fluids may provide cooling.
[0076] In some embodiments, electrochemical devices may further
include circuitry or other mechanisms for monitoring depletion
level of the various fluids of the electrodes or electrolyte. In
some embodiments, these devices may monitor electrical output in
order to infer depletion levels, or may directly measure chemical
concentrations or activities. These monitored depletion levels may
be used, for example, to determine remaining battery life, or to
identify an economic value for depleted fluid (for example when
recharging a battery by replacing depleted fluid with fresh
fluid).
[0077] A wide variety of chemical reactions may be used in the
electrochemical devices described herein. In principle, any pair of
the half-reactions described in a standard electrode potential
table may be used at the cathode and anode, although reactions that
are substantially separated on the table are preferred for some
embodiments as they will yield a higher device voltage. (An example
table of standard electrode potentials is appended as Appendix A;
however, reactions not listed in Appendix A may also be used in the
devices described herein.) In some embodiments, reactants that are
liquid at operating temperature (e.g., liquid metals and liquid
metal alloys) may be preferred. Exemplary anode materials include
lithium, sodium, mercury, tin, cesium, rubidium, potassium, and
compounds containing any of these, while exemplary cathode
materials include gallium, iron, mercury, tin, chlorine, and
compounds containing any of these. Suitable electrolyte materials
will generally include salts compatible with the chosen anode and
cathode materials. Any of the above materials may include dissolved
gases (e.g., oxygen), which may in some embodiments participate in
the electrochemical reaction.
[0078] Various embodiments of electrochemical devices and methods
have been described herein. In general, features that have been
described in connection with one particular embodiment may be used
in other embodiments, unless context dictates otherwise. For
example, the electrodes described in connection with FIG. 3 may be
employed in the devices described in connection with FIG. 1, or
with any of the embodiments described herein. For the sake of
brevity, descriptions of such features have not been repeated, but
will be understood to be included in the different aspects and
embodiments described herein.
[0079] It will be understood that, in general, terms used herein,
and especially in the appended claims, are generally intended as
"open" terms (e.g., the term "including" should be interpreted as
"including but not limited to," the term "having" should be
interpreted as "having at least," the term "includes" should be
interpreted as "includes but is not limited to," etc.). It will be
further understood that if a specific number of an introduced claim
recitation is intended, such an intent will be explicitly recited
in the claim, and in the absence of such recitation no such intent
is present. For example, as an aid to understanding, the following
appended claims may contain usage of introductory phrases such as
"at least one" or "one or more" to introduce claim recitations.
However, the use of such phrases should not be construed to imply
that the introduction of a claim recitation by the indefinite
articles "a" or "an" limits any particular claim containing such
introduced claim recitation to inventions containing only one such
recitation, even when the same claim includes the introductory
phrases "one or more" or "at least one" and indefinite articles
such as "a" or "an" (e.g., "an electrode" should typically be
interpreted to mean "at least one electrode"); the same holds true
for the use of definite articles used to introduce claim
recitations. In addition, even if a specific number of an
introduced claim recitation is explicitly recited, it will be
recognized that such recitation should typically be interpreted to
mean at least the recited number (e.g., the bare recitation of "two
fluid-directing structures," or "a plurality of fluid-directing
structures," without other modifiers, typically means at least two
fluid-directing structures). Furthermore, in those instances where
a phrase such as "at least one of A, B, and C," "at least one of A,
B, or C," or "an [item] selected from the group consisting of A, B,
and C," is used, in general such a construction is intended to be
disjunctive (e.g., any of these phrases would include but not be
limited to systems that have A alone, B alone, C alone, A and B
together, A and C together, B and C together, or A, B, and C
together, and may further include more than one of A, B, or C, such
as A.sub.1, A.sub.2, and C together, A, B.sub.1, B.sub.2, C.sub.1,
and C.sub.2 together, or B.sub.1 and B.sub.2 together). It will be
further understood that virtually any disjunctive word or phrase
presenting two or more alternative terms, whether in the
description, claims, or drawings, should be understood to
contemplate the possibilities of including one of the terms, either
of the terms, or both terms. For example, the phrase "A or B" will
be understood to include the possibilities of "A" or "B" or "A and
B."
[0080] While various aspects and embodiments have been disclosed
herein, other aspects and embodiments will be apparent to those
skilled in the art. The various aspects and embodiments disclosed
herein are for purposes of illustration and are not intended to be
limiting, with the true scope and spirit being indicated by the
following claims.
TABLE-US-00001 APPENDIX A Half-reaction E.degree. (V) 3/2
N.sub.2(g) + H.sup.+ + e.sup.- HN.sub.3(aq) -3.09 Li.sup.+ +
e.sup.- Li(s) -3.0401 N.sub.2(g) + 4H.sub.2O + 2e.sup.-
2NH.sub.2OH(aq) + 2OH.sup.- -3.04 Cs.sup.+ + e.sup.- Cs(s) -3.026
Rb.sup.+ + e.sup.- Rb(s) -2.98 K.sup.+ + e.sup.- K(s) -2.931
Ba.sup.2+ + 2e.sup.- Ba(s) -2.912 La(OH).sub.3(s) + 3e.sup.- La(s)
+ 3OH.sup.- -2.90 Sr.sup.2+ + 2e.sup.- Sr(s) -2.899 Ca.sup.2+ +
2e.sup.- Ca(s) -2.868 Eu.sup.2+ + 2e.sup.- Eu(s) -2.812 Ra.sup.2+ +
2e.sup.- Ra(s) -2.8 Na.sup.+ + e.sup.- Na(s) -2.71 La.sup.3+ +
3e.sup.- La(s) -2.379 Y.sup.3+ + 3e.sup.- Y(s) -2.372 Mg.sup.2+ +
2e.sup.- Mg(s) -2.372 ZrO(OH).sub.2(s) + H.sub.2O + 4e.sup.- Zr(s)
+ 4OH.sup.- -2.36 Al(OH).sub.4.sup.- + 3e.sup.- Al(s) + 4OH.sup.-
-2.33 Al(OH).sub.3(s) + 3e.sup.- Al(s) + 3OH.sup.- -2.31 H.sub.2(g)
+ 2e.sup.- 2H.sup.- -2.25 Ac.sup.3+ + 3e.sup.- Ac(s) -2.20
Be.sup.2+ + 2e.sup.- Be(s) -1.85 U.sup.3+ + 3e.sup.- U(s) -1.66
Al.sup.3+ + 3e.sup.- Al(s) -1.66 Ti.sup.2+ + 2e.sup.- Ti(s) -1.63
ZrO.sub.2(s) + 4H.sup.+ + 4e.sup.- Zr(s) + 2H.sub.2O -1.553
Zr.sup.4+ + 4e.sup.- Zr(s) -1.45 TiO(s) + 2H.sup.+ + 2e.sup.- Ti(s)
+ H.sub.2O -1.31 Ti.sub.2O.sub.3(s) + 2H.sup.+ + 2e.sup.- 2TiO(s) +
H.sub.2O -1.23 Ti.sup.3+ + 3e.sup.- Ti(s) -1.21 Mn.sup.2+ +
2e.sup.- Mn(s) -1.185 Te(s) + 2e.sup.- Te.sup.2- -1.143 V.sup.2+ +
2e.sup.- V(s) -1.13 Nb.sup.3+ + 3e.sup.- Nb(s) -1.099 Sn(s) +
4H.sup.+ + 4e.sup.- SnH.sub.4(g) -1.07 SiO.sub.2(s) + 4H.sup.+ +
4e.sup.- Si(s) + 2H.sub.2O -0.91 B(OH).sub.3(aq) + 3H.sup.+ +
3e.sup.- B(s) + 3H.sub.2O -0.89 TiO.sup.2+ + 2H.sup.+ + 4e.sup.-
Ti(s) + H.sub.2O -0.86 Bi(s) + 3H.sup.+ + 3e.sup.- BiH.sub.3 -0.8
H.sub.2O + 2e.sup.- H.sub.2(g) + 2OH.sup.- -0.8277 Zn.sup.2+ +
2e.sup.- Zn(Hg) -0.7628 Zn.sup.2+ + 2e.sup.- Zn(s) -0.7618
Ta.sub.2O.sub.5(s) + 10H.sup.+ + 10e.sup.- 2Ta(s) + 5H.sub.2O -0.75
Cr.sup.3+ + 3e.sup.- Cr(s) -0.74 [Au(CN).sub.2].sup.- + e.sup.-
Au(s) + 2CN.sup.- -0.60 Ta.sup.3+ + 3e.sup.- Ta(s) -0.6 PbO(s) +
H.sub.2O + 2e.sup.- Pb(s) + 2OH.sup.- -0.58 2TiO.sub.2(s) +
2H.sup.+ + 2e.sup.- Ti.sub.2O.sub.3(s) + H.sub.2O -0.56 Ga.sup.3+ +
3e.sup.- Ga(s) -0.53 AgI(s) + e.sup.- Ag(s) + I.sup.- -0.15224
U.sup.4+ + e.sup.- U.sup.3+ -0.52 H.sub.3PO.sub.2(aq) + H.sup.+ +
e.sup.- P(white) + 2H.sub.2O -0.508 H.sub.3PO.sub.3(aq) + 2H.sup.+
+ 2e.sup.- H.sub.3PO.sub.2(aq) + H.sub.2O -0.499
H.sub.3PO.sub.3(aq) + 3H.sup.+ + 3e.sup.- P(red) + 3H.sub.2O -0.454
Fe.sup.2+ + 2e.sup.- Fe(s) -0.44 2CO.sub.2(g) + 2H.sup.+ + 2e.sup.-
HOOCCOOH(aq) -0.43 Cr.sup.3+ + e.sup.- Cr.sup.2+ -0.42 Cd.sup.2+ +
2e.sup.- Cd(s) -0.40 GeO.sub.2(s) + 2H.sup.+ + 2e.sup.- GeO(s) +
H.sub.2O -0.37 Cu.sub.2O(s) + H.sub.2O + 2e.sup.- 2Cu(s) +
2OH.sup.+ -0.360 PbSO.sub.4(s) + 2e.sup.- Pb(s) + SO.sub.4.sup.2-
-0.3588 PbSO.sub.4(s) + 2e.sup.- Pb(Hg) + SO.sub.4.sup.2- -0.3505
Eu.sup.3+ + e.sup.- Eu.sup.2+ -0.35 In.sup.3+ + 3e.sup.- In(s)
-0.34 Tl.sup.+ + e.sup.- Tl(s) -0.34 Ge(s) + 4H.sup.+ + 4e.sup.-
GeH.sub.4(g) -0.29 Co.sup.2+ + 2e.sup.- Co(s) -0.28
H.sub.3PO.sub.4(aq) + 2H.sup.+ + 2e.sup.- H.sub.3PO.sub.3(aq) +
H.sub.2O -0.276 V.sup.3+ + e.sup.- V.sup.2+ -0.26 Ni.sup.2+ +
2e.sup.- Ni(s) -0.25 As(s) + 3H.sup.+ + 3e.sup.- AsH.sub.3(g) -0.23
MoO.sub.2(s) + 4H.sup.+ + 4e.sup.- Mo(s) + 2H.sub.2O -0.15 Si(s) +
4H.sup.+ + 4e.sup.- SiH.sub.4(g) -0.14 Sn.sup.2+ + 2e.sup.- Sn(s)
-0.13 O.sub.2(g) + H.sup.+ + e.sup.- HO.sub.2.(aq) -0.13 Pb.sup.2+
+ 2e.sup.- Pb(s) -0.13 WO.sub.2(s) + 4H.sup.+ + 4e.sup.- W(s) +
2H.sub.2O -0.12 P(red) + 3H.sup.+ + 3e.sup.- PH.sub.3(g) -0.111
CO.sub.2(g) + 2H.sup.+ + 2e.sup.- HCOOH(aq) -0.11 Se(s) + 2H.sup.+
+ 2e.sup.- H.sub.2Se(g) -0.11 CO.sub.2(g) + 2H.sup.+ + 2e.sup.-
CO(g) + H.sub.2O -0.11 SnO(s) + 2H.sup.+ + 2e.sup.- Sn(s) +
H.sub.2O -0.10 SnO.sub.2(s) + 2H.sup.+ + 2e.sup.- SnO(s) + H.sub.2O
-0.09 WO.sub.3(aq) + 6H.sup.+ + 6e.sup.- W(s) + 3H.sub.2O -0.09
P(white) + 3H.sup.+ + 3e.sup.- PH.sub.3(g) -0.063 HCOOH(aq) +
2H.sup.+ + 3e.sup.- HCHO(aq) + H.sub.2O -0.03 2H.sup.+ + 2e.sup.-
H.sub.2(g) 0.0000 AgBr(s) + e.sup.- Ag(s) + Br.sup.- +0.07133
S.sub.4O.sub.6.sup.2- + 2e.sup.- 2S.sub.2O.sub.3.sup.2- +0.08
Fe.sub.3O.sub.4(s) + 8H.sup.+ + 8e.sup.- 3Fe(s) + 4H.sub.2O +0.085
N.sub.2(g) + 2H.sub.2O + 6H.sup.+ + 6e.sup.- 2NH.sub.4OH(aq) +0.092
HgO(s) + H.sub.2O + 2e.sup.- Hg(l) + 2OH.sup.- +0.0977
Cu(NH.sub.3).sub.4.sup.2+ + e.sup.- Cu(NH.sub.3).sub.2.sup.+ +
2NH.sub.3 +0.10 Ru(NH.sub.3).sub.6.sup.3+ + e.sup.-
Ru(NH.sub.3).sub.6.sup.2+ +0.10 N.sub.2H.sub.4(aq) + 4H.sub.2O +
2e.sup.- 2NH.sub.4.sup.+ + 4OH.sup.- +0.11 H.sub.2MoO.sub.4(aq) +
6H.sup.+ + 6e.sup.- Mo(s) + 4H.sub.2O +0.11 Ge.sup.4+ + 4e.sup.-
Ge(s) +0.12 C(s) + 4H.sup.+ + 4e.sup.- CH.sub.4(g) +0.13 HCHO(aq) +
2H.sup.+ + 2e.sup.- CH.sub.3OH(aq) +0.13 S(s) + 2H.sup.+ + 2e.sup.-
H.sub.2S(g) +0.14 Sn.sup.4+ + 2e.sup.- Sn.sup.2+ +0.15 Cu.sup.2+ +
e.sup.- Cu.sup.+ +0.159 HSO.sub.4.sup.- + 3H.sup.+ + 2e.sup.-
SO.sub.2(aq) + 2H.sub.2O +0.16 UO.sub.2.sup.2+ + e.sup.-
UO.sub.2.sup.+ +0.163 SO.sub.4.sup.2- + 4H.sup.+ + 2e.sup.-
SO.sub.2(aq) + 2H.sub.2O +0.17 TiO.sup.2+ + 2H.sup.+ + e.sup.-
Ti.sup.3+ + H.sub.2O +0.19 Bi.sup.3+ + 2e.sup.- Bi.sup.+ +0.2
SbO.sup.+ + 2H.sup.+ + 3e.sup.- Sb(s) + H.sub.2O +0.20 AgCl(s) +
e.sup.- Ag(s) + Cl.sup.- +0.22233 H.sub.3AsO.sub.3(aq) + 3H.sup.+ +
3e.sup.- As(s) + 3H.sub.2O +0.24 GeO(s) + 2H.sup.+ + 2e.sup.- Ge(s)
+ H.sub.2O +0.26 UO.sub.2.sup.+ + 4H.sup.+ + e.sup.- U.sup.4+ +
2H.sub.2O +0.273 Re.sup.3+ + 3e.sup.- Re(s) +0.300 Bi.sup.3+ +
3e.sup.- Bi(s) +0.32 VO.sup.2+ + 2H.sup.+ + e.sup.- V.sup.3+ +
H.sub.2O +0.34 Cu.sup.2+ + 2e.sup.- Cu(s) +0.340
[Fe(CN).sub.6].sup.3- + e.sup.- [Fe(CN).sub.6].sup.4- +0.36
O.sub.2(g) + 2H.sub.2O + 4e.sup.- 4OH.sup.-(aq) +0.40
H.sub.2MoO.sub.4 + 6H.sup.+ + 3e.sup.- Mo.sup.3+ + 2H.sub.2O +0.43
Bi.sup.+ + e.sup.- Bi(s) +0.50 CH.sub.3OH(aq) + 2H.sup.+ + 2e.sup.-
CH.sub.4(g) + H.sub.2O +0.50 SO.sub.2(aq) + 4H.sup.+ + 4e.sup.-
S(s) + 2H.sub.2O +0.50 Cu.sup.+ + e.sup.- Cu(s) +0.520 CO(g) +
2H.sup.+ + 2e.sup.- C(s) + H.sub.2O +0.52 I.sub.2(s) + 2e.sup.-
2I.sup.- +0.54 I.sub.3.sup.- + 2e.sup.- 3I.sup.- +0.53
[AuI.sub.4].sup.- + 3e.sup.- Au(s) + 4I.sup.- +0.56
H.sub.3AsO.sub.4(aq) + 2H.sup.+ + 2e.sup.- H.sub.3AsO.sub.3(aq) +
H.sub.2O +0.56 [AuI.sub.2].sup.- + e.sup.- Au(s) + 2I.sup.- +0.58
MnO.sub.4.sup.- + 2H.sub.2O + 3e.sup.- MnO.sub.2(s) + 4OH.sup.-
+0.59 S.sub.2O.sub.3.sup.2- + 6H.sup.+ + 4e.sup.- 2S(s) + 3H.sub.2O
+0.60 H.sub.2MoO.sub.4(aq) + 2H.sup.+ + 2e.sup.- MoO.sub.2(s) +
2H.sub.2O +0.65 O.sub.2(g) + 2H.sup.+ + 2e.sup.- H.sub.2O.sub.2(aq)
+0.70 Tl.sup.3+ + 3e.sup.- Tl(s) +0.72 PtCl.sub.6.sup.2- + 2e.sup.-
PtCl.sub.4.sup.2- + 2Cl.sup.- +0.726 H.sub.2SeO.sub.3(aq) +
4H.sup.+ + 4e.sup.- Se(s) + 3H.sub.2O +0.74 PtCl.sub.4.sup.2- +
2e.sup.- Pt(s) + 4Cl.sup.- +0.758 Fe.sup.3+ + e.sup.- Fe.sup.2+
+0.77 Ag.sup.+ + e.sup.- Ag(s) +0.7996 Hg.sub.2.sup.2+ + 2e.sup.-
2Hg(l) +0.80 NO.sub.3.sup.-(aq) + 2H.sup.+ + e.sup.- NO.sub.2(g) +
H.sub.2O +0.80 [AuBr.sub.4].sup.- + 3e.sup.- Au(s) + 4Br.sup.-
+0.85 Hg.sup.2+ + 2e.sup.- Hg(l) +0.85 MnO.sub.4.sup.- + H.sup.+ +
e.sup.- HMnO.sub.4.sup.- +0.90 2Hg.sup.2+ + 2e.sup.-
Hg.sub.2.sup.2+ +0.91 Pd.sup.2+ + 2e.sup.- Pd(s) +0.915
[AuCl.sub.4].sup.- + 3e.sup.- Au(s) + 4C1.sup.- +0.93 MnO.sub.2(s)
+ 4H.sup.+ + e.sup.- Mn.sup.3+ + 2H.sub.2O +0.95 [AuBr.sub.2].sup.-
+ e.sup.- Au(s) + 2Br.sup.- +0.96 Br.sub.2(l) + 2e.sup.- 2Br.sup.-
+1.066 Br.sub.2(aq) + 2e.sup.- 2Br.sup.- +1.0873 IO.sub.3.sup.- +
5H.sup.+ + 4e.sup.- HIO(aq) + 2H.sub.2O +1.13 [AuCl.sub.2].sup.- +
e.sup.- Au(s) + 2C1.sup.- +1.15 HSeO.sub.4.sup.- + 3H.sup.+ +
2e.sup.- H.sub.2SeO.sub.3(aq) + H.sub.2O +1.15 Ag.sub.2O(s) +
2H.sup.+ + 2e.sup.- 2Ag(s) + H.sub.2O +1.17 ClO.sub.3.sup.- +
2H.sup.+ + e.sup.- ClO.sub.2(g) + H.sub.2O +1.18 Pt.sup.2+ +
2e.sup.- Pt(s) +1.188 ClO.sub.2(g) + H.sup.+ + e.sup.-
HClO.sub.2(aq) +1.19 2IO.sub.3.sup.- + 12H.sup.+ + 10e.sup.-
I.sub.2(s) + 6H.sub.2O +1.20 ClO.sub.4.sup.- + 2H.sup.+ + 2e.sup.-
ClO.sub.3.sup.- + H.sub.2O +1.20 O.sub.2(g) + 4H.sup.+ + 4e.sup.-
2H.sub.2O +1.23 MnO.sub.2(s) + 4H.sup.+ + 2e.sup.- Mn.sup.2+ +
2H.sub.2O +1.23 Tl.sup.3+ + 2e.sup.- Tl.sup.+ +1.25 Cl.sub.2(g) +
2e.sup.- 2Cl.sup.- +1.36 Cr.sub.2O.sub.7.sup.-- + 14H.sup.+ +
6e.sup.- 2Cr.sup.3+ + 7H.sub.2O +1.33 CoO.sub.2(s) + 4H.sup.+ +
e.sup.- Co.sup.3+ + 2 H.sub.2O +1.42 2NH.sub.3OH.sup.+ + H.sup.+ +
2e.sup.- N.sub.2H.sub.5.sup.+ + 2H.sub.2O +1.42 2HIO(aq) + 2H.sup.+
+ 2e.sup.- I.sub.2(s) + 2H.sub.2O +1.44 Ce.sup.4+ + e.sup.-
Ce.sup.3+ +1.44 BrO.sub.3.sup.- + 5H.sup.+ + 4e.sup.- HBrO(aq) +
2H.sub.2O +1.45 .beta.-PbO.sub.2(s) + 4H.sup.+ + 2e.sup.- Pb.sup.2+
+ 2H.sub.2O +1.460 .alpha.-PbO.sub.2(s) + 4H.sup.+ + 2e.sup.-
Pb.sup.2+ + 2H.sub.2O +1.468 2BrO.sub.3.sup.-+ 12H.sup.+ +
10e.sup.- Br.sub.2(l) + 6H.sub.2O +1.48 2ClO.sub.3.sup.- +
12H.sup.+ + 10e.sup.- Cl.sub.2(g) + 6H.sub.2O +1.49 MnO.sub.4.sup.-
+ 8H.sup.+ + 5e.sup.- Mn.sup.2+ + 4H.sub.2O +1.51 HO.sub.2. +
H.sup.+ + e.sup.- H.sub.2O.sub.2(aq) +1.51 Au.sup.3+ + 3e.sup.-
Au(s) +1.52 NiO.sub.2(s) + 4H.sup.+ + 2e.sup.- Ni.sup.2+ +
2OH.sup.- +1.59 2HClO(aq) + 2H.sup.+ + 2e.sup.- Cl.sub.2(g) +
2H.sub.2O +1.63 Ag.sub.2O.sub.3(s) + 6H.sup.+ + 4e.sup.- 2Ag.sup.+
+ 3H.sub.2O +1.67 HClO.sub.2(aq) + 2H.sup.+ + 2e.sup.- HClO(aq) +
H.sub.2O +1.67 Pb.sup.4+ + 2e.sup.- Pb.sup.2+ +1.69 MnO.sub.4.sup.-
+ 4H.sup.+ + 3e.sup.- MnO.sub.2(s) + 2H.sub.2O +1.70
H.sub.2O.sub.2(aq) + 2H.sup.+ + 2e.sup.- 2H.sub.2O +1.78 AgO(s) +
2H.sup.+ + e.sup.- Ag.sup.+ + H.sub.2O +1.77 Co.sup.3+ + e.sup.-
Co.sup.2+ +1.82 Au.sup.+ + e.sup.- Au(s) +1.83 BrO.sub.4.sup.- +
2H.sup.+ + 2e.sup.- BrO.sub.3.sup.+ + H.sub.2O +1.85 Ag.sup.2+ + e-
Ag.sup.+ +1.98 S.sub.2O.sub.8.sup.2- + 2e.sup.- 2SO.sub.4.sup.2-
+2.010 O.sub.3(g) + 2H.sup.+ + 2e.sup.- O.sub.2(g) + H.sub.2O
+2.075 HMnO.sub.4.sup.- + 3H.sup.+ + 2e.sup.- MnO.sub.2(s) +
2H.sub.2O +2.09 F.sub.2(g) + 2e.sup.- 2F.sup.- +2.87 F.sub.2(g) +
2H.sup.+ + 2e.sup.- 2HF(aq) +3.05
* * * * *