U.S. patent application number 13/341052 was filed with the patent office on 2013-07-04 for rechargeable battery and method.
The applicant listed for this patent is Roger BULL, James SUDWORTH, Paul SUDWORTH, Stuart TOWLE. Invention is credited to Roger BULL, James SUDWORTH, Paul SUDWORTH, Stuart TOWLE.
Application Number | 20130171487 13/341052 |
Document ID | / |
Family ID | 47358022 |
Filed Date | 2013-07-04 |
United States Patent
Application |
20130171487 |
Kind Code |
A1 |
BULL; Roger ; et
al. |
July 4, 2013 |
RECHARGEABLE BATTERY AND METHOD
Abstract
A method of assembling a rechargeable battery is disclosed. The
method includes inserting rechargeable energy storage cells into a
battery housing, the battery housing having a base portion, a side
portion extending from the base portion, and an aperture defined by
the side portion, wherein the rechargeable energy storage cells are
inserted into the battery housing through the aperture; installing
an insulator on the rechargeable energy storage cells; and securing
a housing cover to the battery housing such that the insulator and
the rechargeable energy storage cells are maintained in compression
between the housing cover and the housing base portion. Also
disclosed is a rechargeable battery including a battery housing, a
housing cover, a plurality of rechargeable energy storage cells
disposed within the battery housing, and an insulator disposed
between the rechargeable energy storage cells and the housing cover
and maintained in compression.
Inventors: |
BULL; Roger; (Staffordshire,
GB) ; SUDWORTH; James; (Staffordshire, GB) ;
SUDWORTH; Paul; (Staffordshire, GB) ; TOWLE;
Stuart; (Staffordshire, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BULL; Roger
SUDWORTH; James
SUDWORTH; Paul
TOWLE; Stuart |
Staffordshire
Staffordshire
Staffordshire
Staffordshire |
|
GB
GB
GB
GB |
|
|
Family ID: |
47358022 |
Appl. No.: |
13/341052 |
Filed: |
December 30, 2011 |
Current U.S.
Class: |
429/99 ;
29/623.1 |
Current CPC
Class: |
H01M 10/658 20150401;
H01M 2/1077 20130101; H01M 10/399 20130101; H01M 10/0481 20130101;
H01M 10/653 20150401; H01M 10/3909 20130101; H01M 10/615 20150401;
Y10T 29/49108 20150115; H01M 2/1088 20130101; H01M 2/1094 20130101;
Y02E 60/10 20130101 |
Class at
Publication: |
429/99 ;
29/623.1 |
International
Class: |
H01M 2/10 20060101
H01M002/10; H01M 10/04 20060101 H01M010/04; H01M 2/22 20060101
H01M002/22; H01M 10/02 20060101 H01M010/02; H01M 2/04 20060101
H01M002/04 |
Claims
1. A method of assembling a rechargeable battery comprising:
inserting rechargeable energy storage cells into a battery housing,
the battery housing having a base portion, a side portion extending
from the base portion, and an aperture defined by the side portion,
wherein the rechargeable energy storage cells are inserted into the
battery housing through the aperture; installing an insulator on
the rechargeable energy storage cells; and securing a housing cover
to the battery housing such that the insulator and the rechargeable
energy storage cells are maintained in compression between the
housing cover and the housing base portion.
2. The method of assembling a rechargeable battery as claimed in
claim 1, wherein the insulator comprises a plurality of mica
sheets.
3. The method of assembling a rechargeable battery as claimed in
claim 2, wherein installing the insulator on the rechargeable
energy storage cells further comprises installing the plurality of
mica sheets such that the mica sheets extend through a plane
defined by the perimeter of the aperture of the battery
housing.
4. The method of assembling a rechargeable battery as claimed in
claim 1, wherein the insulator is compressed at least 5% in the
direction between the base portion and the housing cover when the
housing cover is secured to the battery housing.
5. The method of assembling a rechargeable battery as claimed in
claim 1, wherein securing the housing cover to the battery housing
comprises applying at least 1.7 kpa of force to the housing cover
to compress the insulator.
6. The method of assembling a rechargeable battery as claimed in
claim 1, wherein the compression of the insulator inhibits movement
of the energy storage cells in a direction between the housing
cover and the housing base portion.
7. The method of assembling a rechargeable battery as claimed in
claim 1, wherein the side portion of the battery housing comprises
four sides forming a substantially rectangular cross-section of the
battery housing.
8. The method of assembling a rechargeable battery as claimed in
claim 1, wherein the battery housing comprises a deep drawn
enclosure.
9. The method of assembling a rechargeable battery as claimed in
claim 1, wherein the side portion of the battery housing is welded
to the base portion to form the battery housing.
10. The method of assembling a rechargeable battery as claimed in
claim 1, wherein the housing cover is secured to the battery
housing by welding.
11. The method of assembling a rechargeable battery as claimed in
claim 1, wherein the housing cover is secured to the battery
housing by mechanical fasteners.
12. The method of assembling a rechargeable battery as claimed in
claim 1, further comprising the step of evacuating the rechargeable
battery after securing the housing cover to the battery
housing.
13. The method of assembling a rechargeable battery as claimed in
claim 1, wherein the rechargeable energy storage cells are
sodium-halide cells.
14. A rechargeable battery comprising: a battery housing having a
base portion, a side portion extending from the base portion, and
an aperture defined by the side portions; a housing cover secured
to the battery housing; a plurality of rechargeable energy storage
cells disposed within the battery housing with at least a portion
of the energy storage cells electrically connected to one another;
and an insulator disposed between the rechargeable energy storage
cells and the housing cover; wherein the insulator and the energy
storage cells are maintained in compression between the housing
cover and the housing base portion.
15. The rechargeable battery as claimed in claim 14, wherein the
insulator comprises a plurality of mica sheets.
16. The rechargeable battery as claimed in claim 14, wherein the
insulator is maintained in compression with at least 1.7 kpa of
compressive force.
17. The rechargeable battery as claimed in claim 14, wherein the
compression of the insulator inhibits movement of the energy
storage cells between the housing cover and the housing base
portion.
18. The rechargeable battery as claimed in claim 14, wherein said
at least the portion of the energy storage cells are electrically
connected by welded connections.
19. A rechargeable battery comprising: a battery housing having a
base portion, a side portion extending from the base portion, and
an aperture defined by the side portions; a housing cover secured
to the side portion of the battery housing and covering the
aperture; a plurality of electrically interconnected, rechargeable
energy storage cells disposed within the battery housing; and a
plurality of mica sheets disposed between the rechargeable energy
storage cells and the housing cover; wherein the plurality of mica
sheets and the energy storage cells are maintained in compression
between the housing cover and the housing base portion, for
inhibiting movement of the energy storage cells between the housing
cover and the housing base portion, and wherein said compression
comprises at least one of 1.7 kpa or more of compressive force or a
compressive force suitable to compress the plurality of mica sheets
by at least 5% in the vertical dimension from its uncompressed
state.
20. The rechargeable battery as claimed in claim 19, wherein the
energy storage cells are sodium-halide cells having an operating
temperature of at least 100 degrees C.
Description
BACKGROUND
[0001] 1. Technical Field
[0002] Embodiments of the invention relate to rechargeable
batteries. Other embodiments relate to a method and apparatus for
assembling a rechargeable battery.
[0003] 2. Background
[0004] Energy storage devices may have challenges with damage and
manufacturability. Loosely packaged batteries may result in
vibration or shaking, which may damage the energy storage cells or
connections between the energy storage cells, especially when the
batteries are used in vehicles or other moving platforms.
[0005] It may be desirable to have a battery package that differs
from those packages that are currently available.
SUMMARY
[0006] Presently disclosed is a method of assembling a rechargeable
battery. In an embodiment, the method includes inserting
rechargeable energy storage cells into a battery housing, the
battery housing having a base portion, a side portion extending
from the base portion, and an aperture defined by the side portion,
wherein the rechargeable energy storage cells are inserted into the
battery housing through the aperture; installing an insulator on
the rechargeable energy storage cells; and securing a housing cover
to the battery housing such that the insulator and the rechargeable
energy storage cells are maintained in compression between the
housing cover and the housing base portion.
[0007] Also disclosed is a rechargeable battery. In an embodiment,
a battery housing having a base portion, a side portion extending
from the base portion, and an aperture defined by the side
portions; a housing cover secured to the battery housing; a
plurality of rechargeable energy storage cells disposed within the
battery housing with at least a portion of the energy storage cells
electrically connected to one another; and an insulator disposed
between the rechargeable energy storage cells and the housing
cover; wherein the insulator and the energy storage cells are
maintained in compression between the housing cover and the housing
base portion.
[0008] In another embodiment, the rechargeable battery comprises a
battery housing having a base portion, a side portion extending
from the base portion, and an aperture defined by the side
portions. The rechargeable battery further comprises a housing
cover secured to the side portion of the battery housing and
covering the aperture. The rechargeable battery further comprises a
plurality of electrically interconnected, rechargeable energy
storage cells disposed within the battery housing. The rechargeable
battery further comprises a plurality of mica sheets disposed
between the rechargeable energy storage cells and the housing
cover. The plurality of mica sheets and the energy storage cells
are maintained in compression between the housing cover and the
housing base portion, for inhibiting movement of the energy storage
cells between the housing cover and the housing base portion. The
amount of compression comprises: 1.7 kpa or more of compressive
force; and/or a compressive force suitable to compress the
plurality of mica sheets by at least 5% in the vertical dimension
from an uncompressed state of the plurality of mica sheets.
BRIEF DESCRIPTION OF DRAWINGS
[0009] Reference is made to the accompanying drawings in which
particular embodiments and further benefits of the invention are
illustrated as described in more detail in the description below,
in which:
[0010] FIG. 1 is a perspective view of an energy storage
device;
[0011] FIG. 2 is a perspective view of an enclosure for an energy
storage device;
[0012] FIG. 3 is a perspective view of another enclosure for an
energy storage device;
[0013] FIG. 4 is a perspective view of another enclosure for an
energy storage device;
[0014] FIG. 5 is a perspective view of another enclosure for an
energy storage device;
[0015] FIG. 6 is a perspective view of a cover for an energy
storage device enclosure;
[0016] FIG. 7 is a perspective view of another cover for an energy
storage device enclosure;
[0017] FIG. 8 is a perspective view of another cover for an energy
storage device enclosure;
[0018] FIG. 9 is a perspective view of another cover for an energy
storage device enclosure; and
[0019] FIG. 10 is a cross-section view of an energy storage
device.
DETAILED DESCRIPTION
[0020] The subject matter disclosed herein relates to an enclosure
for an energy storage device, such as a rechargeable battery.
Referring generally to FIGS. 1 through 10, embodiments of an
enclosure for an energy storage device and a method for packaging
an energy storage device are disclosed. The enclosure for an energy
storage device may support a wide variety of electrochemical cells,
such as sodium-halide (e.g., sodium-metal-halide), sodium-sulfur,
lithium-sulfur, and other available electrochemical cells used for
energy storage. In one embodiment, the electrochemical cells have
an operating temperature determined by the melting point of the
materials utilized in the cells. For example, the operating
temperature may be at least or greater than about 100 degrees
Celsius, such as between 250 degrees Celsius and 400 degrees
Celsius, or between 400 degrees Celsius and 700 degrees Celsius,
but other desired operating temperatures are possible. In one
embodiment, the operating temperature is between 250 and 350
degrees Celsius.
[0021] In some embodiments, the rechargeable energy storage cells
have dimensions of about 37 mm.times.27 mm.times.240 mm, any of
which dimensions may vary by up to +/-50%, in accordance with
various embodiments. In other embodiments, the energy storage cells
may have a diameter of about 10 mm and a length of between 110 mm
and 210 mm. In embodiments, the chemistry of a cell is of the
sodium-metal-halide type, in which NaCl and Ni are converted to Na
and NiCl.sub.2 during battery charging. The energy capacity of an
energy storage cell can range from about 2 amp*hours to about 250
amp*hours. The rechargeable battery includes a plurality of energy
storage cells with the battery housing sized to accommodate the
plurality of energy storage cells. In one embodiment, the
rechargeable battery includes one hundred energy storage cells and
the battery housing has dimensions of about 400 mm.times.300
mm.times.300 mm. In other embodiments, the rechargeable battery may
include at least 20 cells, at least 50 cells, or at least 150
cells, with the battery housing sized accordingly. In some
embodiments, the battery housing is sized to accommodate more
energy storage cells than are provided in the rechargeable battery.
For example, a battery housing may accommodate up to 50 cells, but
the rechargeable battery may be populated with only 40 cells based
on the electrical requirements, and the remaining space within the
housing may be occupied by a packing material or other support to
inhibit movement of the battery cells disposed within the battery
housing.
[0022] In various embodiments, a rechargeable battery includes a
battery housing having a base portion, side portions extending from
the base portion, and an aperture defined by the side portions. The
rechargeable battery also includes a housing cover secured to the
battery housing with a plurality of rechargeable energy storage
cells disposed within the battery housing. In one embodiment, the
energy storage cells are electrically connected by welded
connections between the respective positive and negative terminals
of the energy storage cells. The rechargeable battery also includes
an insulator disposed between the rechargeable battery cells and
the housing cover that inhibits movement of the energy storage
cells and avoid stress to the welded intercell connections. In one
embodiment, the housing includes a peripheral edge defining an
aperture distal from the base portion through which the
rechargeable energy storage cells are inserted into the interior
volume of the battery housing. The aperture is sized to receive the
one or more electrochemical cells during assembly of the
rechargeable battery. In various embodiments, the insulator
disposed between the energy storage cells and the housing cover is
formed of one or more materials that are electrically or thermally
insulating, or both. In one embodiment, the insulator includes
discrete portions where a first portion such as an outer covering
of the insulator is electrically insulating, while a second portion
such as an interior portion of the insulator is thermally
insulating. In one embodiment, the housing cover is securable to
the peripheral edge of the battery housing. In this manner, the
housing and cover are configured to contain at least one
electrochemical cell at an operating temperature that is greater
than about 100 degrees Celsius. In some embodiments, the housing
and cover are configured to house electrochemical cells operating
at temperatures greater than about 250 degrees Celsius, or greater
than about 400 degrees Celsius.
[0023] Referring to FIG. 1, a cutaway of an embodiment of a
rechargeable battery assembly 100 is illustrated. In the embodiment
shown, the rechargeable battery includes a battery housing 102 for
receiving one or more rechargeable energy storage cells 104. A
cover 108 is secured to the battery housing 102 to enclose the
cells 104 within the housing. An insulator 106 is provided between
the housing cover 108 and the cells 104. In one embodiment, the
insulator 106 includes a material having sufficient thickness in
the direction "D" (see FIG. 10) between the housing cover and the
housing base such that when the cover 108 is secured to the battery
housing 102, pressure is applied to the insulator and to the cells
104 to inhibit movement of the cells. In some embodiments, when the
housing 102 is enclosed by the cover 108, the insulator 106 is
compressed.
[0024] FIG. 2 illustrates a perspective view of an embodiment of
the battery housing 102. The housing 102 includes a base portion
110 and side portions 112 extending substantially perpendicular to
the base portion 110 to form an aperture 114. In the embodiment
illustrated, the base portion 110 is a rectangle and the battery
housing 102 includes four side portions 112 arranged about the
perimeter of the base portion 110. The aperture 114 therefore has a
rectangular profile. Further, according to the illustrated
embodiment, the side portions 112 are joined to one another in an
abutting relationship.
[0025] According to various other embodiments of the battery
housing 102 the base portion 110 may have a circular, hexagonal,
oval, or other shaped profile and the side portions 112 extend from
the perimeter of the base portion 110 to form the aperture 114.
According to further variations, the side portions 112 may extend
at an angle other than perpendicular to the base portion 110, or
may be of unequal height, defining an irregular aperture 114.
[0026] Further embodiments of the battery housing 102 are shown and
described with reference to FIGS. 3-6. According to the embodiment
shown in FIG. 3, the side portions 112 of the housing 102 terminate
at a top edge. According to a second embodiment, such as that shown
in FIG. 4, attached to the side portions 112 may be a perimeter
edge 116 extending about the open side of the aperture 114.
According to the embodiment illustrated in FIG. 5 the perimeter
edge 116 extends away from the aperture 114 and may be
perpendicular to the side portion 112. According to the embodiment
illustrated in FIG. 6, the perimeter edge 116 may extend into the
aperture 114 and be perpendicular to the side portion 112. In
various alternative embodiments, the perimeter edge 116 may extend
at an acute or obtuse angle relative to the side portion 112 and
may be bent, rolled, curved, or otherwise extend into or away from
the aperture 114.
[0027] According to one embodiment, the housing 102 is constructed
of a single stamped piece of metal. However, other fabrication
methods are contemplated, including welding, extrusion, assembly
with fasteners, casting, or other metal fabrication method or
combination of fabrication methods. In one embodiment, the battery
housing is a deep drawn enclosure. A deep drawn enclosure is formed
from material, such as a section of sheet metal, that is press
formed one or more times to achieve the desired configuration. In
one embodiment, press forming includes stamping a section of steel
metal using a die to alter the shape of the metal. The resulting
deep drawn enclosure retains the continuity of the original
material avoiding the formation of seams or other discontinuities.
A deep drawn enclosure is a monolithic structure consisting of a
single unbroken component.
[0028] Shown in FIGS. 7-10 are a variety of embodiments
illustrating various covers. According to an embodiment, shown in
FIG. 7, the cover 108 may be a planar member that has a profile
matching the aperture 114. According to another embodiment, the
cover 108 may include a channel 118 as shown in FIG. 8 for engaging
the perimeter edge 116, for example in a sliding arrangement.
According to another aspect shown in FIG. 9, the cover 108 may
include a plug 120 to be received within the aperture 114 and the
planar portion of the cover 108 may engage the side portions 112 or
perimeter edge 116. According to yet another aspect, the cover 108
may include a lip edge 122 which may surround the side portion 112
when the cover 108 is positioned over the aperture 114.
[0029] According to the embodiment illustrated in FIG. 1, the
rechargeable battery assembly 100 also includes an insulator 106
that provides thermal and electrical insulation between at least
the cover 108 and rechargeable energy storage cells 104. According
to various aspects of this embodiment, the insulator 106 may be
constructed from Teflon.RTM. or other brand PTFE, fiberglass, mica,
or other thermal and/or electrical insulator.
[0030] According to a first arrangement, the insulator 106 includes
sheets of a substantially rigid insulating material that resists
deformation when compressed, such as one or more mica sheets,
arranged either in an overlapping, side-by-side, or stacked
arrangement. According to alternative arrangements, the insulator
106 is a deformable insulation, such as woven fiberglass, that may
compress, deform, and change in shape when a force is applied.
[0031] With regard to the first embodiment, the insulator 106 is
positioned between the rechargeable energy storage cells 104 and
cover 108 and a compressive force is applied to the cover 108.
According to one aspect, this compressive force is at least 0.25
pounds per square inch ("psi") (at least 1.7 kpa). Alternatively or
additionally, the compressive force may be sufficient to compress
the insulator 106 at least 5% in the vertical dimension from its
uncompressed state. Various methods for achieving this arrangement
may be used, as will be described later with reference to the
various arrangements of the housing 102 and cover 108.
[0032] Also disclosed is a method of assembling a rechargeable
battery. Rechargeable energy storage cells 104 are inserted into a
battery housing 102 having a base portion 110 and side portions 112
extending from the base portion 110 defining an aperture 114. The
rechargeable energy storage cells 104 may be inserted through the
aperture 114. An insulator 106 is provided on the rechargeable
energy storage cells 104 and a housing cover 108 is secured to the
housing 102 so as to compress the insulator 106. The method of
assembling a rechargeable battery may also include evacuating the
rechargeable battery after securing the housing cover to the
battery housing. In an embodiment, the battery housing includes a
sealable port configured for evacuating the interior of the battery
housing such that the rechargeable energy storage cells are
maintained at a reduced pressure. In one embodiment, the reduced
pressure is a substantial vacuum that is maintained once the
sealable port is sealed after evacuating the battery housing.
[0033] According to various embodiments of the above-described
method, the battery housing 102 may include additional structure
for supporting, engaging, receiving, or locking the rechargeable
energy storage cells 104 in the housing 102. This structure may
include, without limitation, clasps, rails, lips for frictional
engagement, fasteners, openings for receiving fasteners, recesses,
or other engagement structure.
[0034] Also according to various embodiments, the insulator 106 may
include Teflon.RTM. or other brand PTFE, mica, fiberglass, or other
thermal and electrical insulator. The insulator 106 may have a low
ratio between applied force and displacement, such as woven
fiberglass, or may have a high ratio, such as mica sheets. The
compression ratio may alter the amount of force applied to the
cover 108 in order to protect the rechargeable energy storage cells
104 against displacement due to vibration or damage.
[0035] According to the first embodiment, the cover 108 is secured
to the housing 102 in order to provide a compression force to the
insulator 106, thereby securing the rechargeable battery cells 104
against vibration forces.
[0036] According to a first aspect of this embodiment, the cover
108 may be first placed on the insulator 106. Next, a force may be
applied to the cover 108 to compress the insulator 106 and
electrochemical cells 104, either by deforming the insulator 106,
some portion of the electrochemical cells 104, or some portion of
the housing 102 (such as a bottom insulating layer or springs, not
shown). This deformation will allow the cover 108 to contact the
housing 102, whereby the cover 108 is secured to the housing by
means of welding, fasteners, or other type of permanent or
semi-permanent connection. According to this aspect, the
compression force may be at least 0.25 psi (at least 1.7 kpa). In
other embodiments, the compressive force may be at least 0.5 psi,
or at least 1.0 psi. The level of compression force used in any
given application will vary depending on the expected amplitude of
the vibration of the rechargeable electrochemical cells 104.
[0037] According to another aspect, screws, nails, or other
mechanical fasteners are used to secure the cover 108 to the
housing 102. According to this aspect, the cover 108 includes
through holes (not shown) and the perimeter edge 116 includes
counter-fasteners (not shown), such as nuts, for receiving the
fasteners. The cover 108 is first placed on the insulator 106 and
screws are inserted into the through holes to engage the
counter-fasteners. The screws may then be tightened, driving the
cover 108 to the housing 102, thereby compressing the insulator 106
through displacement. According to one arrangement, the insulator
106 may be compressed by 10% of its thickness. In this aspect, the
length of the fasteners will depend on the type of insulator
chosen.
[0038] According to a further aspect of the invention, the cover
108 may include a channel 118 for slideably engaging the perimeter
edge 116 of the housing 102. A compressive force may be applied to
the insulator 106, for example at least 0.25 psi (at least 1.7
kpa), and the cover 108 may be slid on to the housing 102, thereby
maintaining the compression by means of the interaction between the
channel 118 and perimeter edge 116. According to one arrangement,
once the cover 108 is in a secured position the cover 108 may be
welded, fastened, or otherwise permanently secured to the housing
102.
[0039] According to a further aspect of the invention, the
insulator 106 may have a thermal expansion rate so that the
thickness of the insulator varies with ambient temperature. The
insulator 106 is maintained at a base temperature during assembly
whereby the insulator 106 is in an unexpanded state. Owing to the
high operating temperature of the energy storage device, the
temperature within the housing 102 will increase during operation,
thereby causing the insulator 106 to try to expand. As heated cells
expand, greater compression of the insulating material may result
depending upon the coefficient of expansion of the materials used
to construct the energy storage cells, the insulation, and the
housing. However, expansion of the insulator 106 will be resisted
by the cover 108, thereby providing the necessary compressive force
against vibration. According to one variation, once thermally
activated the insulator 106 maintains its expanded state even when
the temperature is lowered. According to an alternative variation,
the insulator 106 may be thermally responsive, expanding when
heated and contracting when cooled.
[0040] According to a further aspect of the invention, the
insulator 106 may be provided in an unexpanded state and expand
upon contact with the air or other some other accelerator, such as
a chemical accelerant. In this aspect, the cover 108 is positioned
on the housing 102 when the insulator 106 is in an unexpanded state
and the insulator 106 is allowed to expand after the cover 108 is
secured to the housing 102. According to one variation, the
insulator 106 may be provided on the rechargeable electrochemical
cells 104 prior to the cover 108 being positioned on the housing
102. The cover 108 is then secured to the housing 102 and the
insulator 106 is allowed to expand, thereby providing a compressive
force. According to another variation, the insulator 106 may
require an accelerator to expand. The insulator 106 may be provided
on the rechargeable electrochemical cells 104 and the cover 108
secured to the housing 102. The cover 108 according to this
variation includes an opening or through hole for receiving the
accelerator. Once the insulator 106 receives the accelerator, the
insulator may expand, thereby causing the desired compression force
between the rechargeable electrochemical cells 104 and cover
108.
[0041] According to a further aspect of the invention, a
combination of insulators may be provided. According to one
variation of this aspect, a first insulator 106, such as a rigid
mica sheet, is provided across the electrochemical cells 104 to
provide structural support. A second insulator, such as a foaming
insulation, is then provided between the rigid mica sheet and the
cover 108, thereby providing the necessary compression force for
securing the electrochemical cells 104 against vibration. According
to another variation of this aspect, an easily deformable insulator
106, such as fiberglass, is first provided onto the electrochemical
cells 104 to protect terminals or other components of the cells
104. A second, more rigid insulator 106, such as a mica sheet, is
then provided over the first insulator, thereby providing
additional structure and insulation. According to yet another
variation a first insulator exhibiting high electrical resistance
is provided across the electrochemical cells 104 and a second
insulator exhibiting high thermal resistance is provided between
the first insulator and the cover 108. Various other embodiments
may also be appreciated.
[0042] In the specification and claims, reference will be made to a
number of terms that have the following meanings. The singular
forms "a", "an" and "the" include plural referents unless the
context clearly dictates otherwise. Approximating language, as used
herein throughout the specification and claims, may be applied to
modify any quantitative representation that could permissibly vary
without resulting in a change in the basic function to which it is
related. Accordingly, a value modified by a term such as "about" is
not to be limited to the precise value specified. In some
instances, the approximating language may correspond to the
precision of an instrument for measuring the value. Similarly,
"free" may be used in combination with a term, and may include an
insubstantial number, or trace amounts, while still being
considered free of the modified term. Moreover, unless specifically
stated otherwise, any use of the terms "first," "second," etc., do
not denote any order or importance, but rather the terms "first,"
"second," etc., are used to distinguish one element from
another.
[0043] As used herein, the terms "may" and "may be" indicate a
possibility of an occurrence within a set of circumstances; a
possession of a specified property, characteristic or function;
and/or qualify another verb by expressing one or more of an
ability, capability, or possibility associated with the qualified
verb. Accordingly, usage of "may" and "may be" indicates that a
modified term is apparently appropriate, capable, or suitable for
an indicated capacity, function, or usage, while taking into
account that in some circumstances the modified term may sometimes
not be appropriate, capable, or suitable. For example, in some
circumstances an event or capacity can be expected, while in other
circumstances the event or capacity cannot occur--this distinction
is captured by the terms "may" and "may be." The terms "generator"
and "alternator" are used interchangeably herein (however, it is
recognized that one term or the other may be more appropriate
depending on the application). The term "instructions" as used
herein with respect to a controller or processor may refer to
computer executable instructions.
[0044] This written description uses examples to disclose the
invention, including the best mode, and also to enable one of
ordinary skill in the art to practice the invention, including
making and using any devices or systems and performing any
incorporated methods. The patentable scope of the invention is
defined by the claims, and may include other examples that occur to
one of ordinary skill in the art. Such other examples are intended
to be within the scope of the claims if they have structural
elements that do not different from the literal language of the
claims, or if they include equivalent structural elements with
insubstantial differences from the literal language of the
claims.
* * * * *