U.S. patent application number 17/150835 was filed with the patent office on 2021-06-03 for multilayer separator and methods of manufacture and use.
The applicant listed for this patent is Daramic, LLC. Invention is credited to Eric H. Miller, J. Kevin Whear.
Application Number | 20210167464 17/150835 |
Document ID | / |
Family ID | 1000005387662 |
Filed Date | 2021-06-03 |
United States Patent
Application |
20210167464 |
Kind Code |
A1 |
Whear; J. Kevin ; et
al. |
June 3, 2021 |
MULTILAYER SEPARATOR AND METHODS OF MANUFACTURE AND USE
Abstract
A multilayer deep cycle battery separator comprising at least
two layers of an automotive-sized separator bonded or welded
together. The automotive-sized separator layers include a backweb
having a backweb thickness between 6 to 10 mils, an overall
thickness of between 25 to 65 mils, and a rib base width of between
20 to 35 mils. The automotive-sized separator layers also have an
extraction time of between 45 to 75 seconds, thereby providing an
overall extraction time of less than a standard deep cycle battery
separator.
Inventors: |
Whear; J. Kevin; (Utica,
KY) ; Miller; Eric H.; (Philpot, KY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Daramic, LLC |
Charlotte |
NC |
US |
|
|
Family ID: |
1000005387662 |
Appl. No.: |
17/150835 |
Filed: |
January 15, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16398622 |
Apr 30, 2019 |
10923700 |
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17150835 |
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14584109 |
Dec 29, 2014 |
10276850 |
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16398622 |
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61923051 |
Jan 2, 2014 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01M 50/463 20210101;
H01M 50/411 20210101; H01M 2220/20 20130101; H01M 10/12 20130101;
H01M 50/403 20210101; Y02P 70/50 20151101; Y02E 60/10 20130101;
H01M 50/449 20210101; Y10T 29/49108 20150115 |
International
Class: |
H01M 50/463 20060101
H01M050/463; H01M 50/403 20060101 H01M050/403; H01M 50/411 20060101
H01M050/411; H01M 50/449 20060101 H01M050/449 |
Claims
1. A multilayer deep cycle battery separator.
2. The multilayer deep cycle battery separator of claim 1
comprising at least two layers of an automotive-sized battery
separator connected or bonded or welded together.
3. The multilayer deep cycle battery separator of claim 2
comprising two layers of automotive-sized separator.
4. The multilayer deep cycle battery separator of claim 2 wherein
said automotive-sized battery separator layers comprise: a backweb
having a backweb thickness of between 5 and 10 mils, an overall
thickness of between 25 and 65 mils, and a rib having a rib base
width of between 20 and 35 mils.
5. The multilayer deep cycle battery separator of claim 2 wherein
said automotive-sized battery separator layers have an extraction
time of between 45 to 75 seconds.
6. The multilayer deep cycle battery separator of claim 2 wherein
said automotive-sized battery separator layers are selected from
the group consisting of: a PE separator; a PVC separator; a rubber
separator; a phenolic resin separator; a PP separator; a cellulosic
materials separator; and combinations thereof.
7. The multilayer deep cycle battery separator of claim 2 wherein
said automotive-sized battery separator layers comprise at least
one layer of PE separator.
8. The multilayer deep cycle battery separator of claim 7 wherein
said automotive-sized battery separator layers comprise two layers
of PE separators.
9. The multilayer deep cycle battery separator of claim 2 wherein
said layers of automotive-sized separator are welded together.
10. The multilayer deep cycle battery separator of claim 9 wherein
said layers of automotive-sized separator are welded together by
welding techniques selected from the group consisting of: heat;
pressure; heat and pressure; sonic welding; vibration; crimping;
laser; and combinations thereof.
11. The multilayer deep cycle battery separator of claim 2 wherein
said layers of automotive-sized separator are connected together by
a layer of adhesive.
12. The multilayer deep cycle battery separator of claim 11 wherein
said adhesive is selected from the group consisting of: a standard
adhesive; latex rubber; a coating with a basic solution of sodium
silicate that is ultimately neutralized with acid; and combinations
thereof.
13. The multilayer deep cycle battery separator of claim 2 further
including an additive.
14. The multilayer deep cycle battery separator of claim 13 wherein
said additive is selected from the group consisting of: ground
rubber; latex rubber; one or more lignins; sodium sulfate; and
combinations thereof.
15. The multilayer deep cycle battery separator of claim 2 wherein
said layers of automotive-sized separator are without any welding
or other means of attachment.
16. The multilayer deep cycle battery separator of claim 2 wherein
said layers of automotive-sized separator are positioned together
by being enveloped, wrapped, sleeved or stacked.
17. The multilayer deep cycle battery separator of claim 2 wherein
said layers of automotive-sized separator are embossed
together.
18. The multilayer deep cycle battery separator of claim 17 wherein
said layers are embossed together by two or more layers being fed
through a pair of mated rollers with a three-dimensional pattern,
whereby when the two or more layers are embossed, the original
shape of ribs being modified in the pattern of the embossed
roll.
19. The multi-layer deep cycle battery separator of claim 18
wherein points of connectivity of said embossed layers are across
an entire face of the separator.
20. The multilayer deep cycle battery separator of claim 2
comprising two layers of automotive-sized separator connected in a
back to back configuration by which backwebs of each layer are
positioned adjacent to one another.
21. The multilayer deep cycle battery separator of claim 2
comprising two separators stacked on top of one another.
22. The multi-layer deep cycle battery separator of claim 20
comprising two layers of automotive-sized separator connected in a
back to back configuration and wherein at least one of the layers
further includes negative ribs, which negative ribs are thereby
positioned between the two backwebs of the two layers.
23. The multilayer deep cycle battery separator of claim 2
comprising two layers of automotive-sized separator together in a
rib to rib configuration with ribs stacked on top of each other or
with ribs offset from one another, a ribbed separator and a flat
sheet, wherein at least one of the layers comprises ribs.
24. The multilayer deep cycle battery separator of claim 23 wherein
said ribs are selected from the group consisting of: straight
vertical ribs; sinusoidal; diagonal; discontinuous; embattlement;
cross rib patterns; and combinations thereof, or wherein said ribs
are straight vertical ribs.
25. The multilayer deep cycle battery separator of claim 2 having
an extraction time of less than a standard deep cycle battery
separator, having an extraction time of at least 2/3 less than a
standard deep cycle battery separator, having an extraction time of
between and 2/3 less than a standard deep cycle battery separator,
having a stiffness greater than a standard deep cycle battery
separator, having a compression greater than a standard deep cycle
battery separator, having a rib mass less than a standard deep
cycle battery separator, and/or having fewer pinholes than a
standard deep cycle battery separator.
26. The multilayer deep cycle battery separator of claim 13 wherein
said additive or additives are between the layers, and/or wherein
said additive or additives are pocketed into a welded region.
27. The multilayer deep cycle battery separator of claim 2
comprising a composite structure.
28. The multilayer deep cycle battery separator of claim 27 wherein
said composite structure includes a stiffening material between the
layers.
29. The multilayer deep cycle battery separator of claim 28 wherein
said stiffening material is selected from the group consisting of:
a glass mat; glass fibers; a synthetic mat; synthetic fibers; and
combinations thereof.
30. A battery comprising a multilayer deep cycle battery separator,
and/or deep cycle battery comprising a multilayer separator
according to claim 2.
31. In the manufacturing of a battery, the improvement comprising a
multi-layer deep cycle battery separator according to claim 2.
32. A method of separating a battery's positive and negative
electrodes including using at least one of the multi-layer deep
cycle battery separators according to claim 2.
33. A method of manufacturing a deep cycle battery separator
comprising the step of assembling a multi-layer deep cycle battery
separator according to claim 2.
34. A method of producing a lead acid battery where two layers of
automotive-sized separator are used in such a manner to replace a
thicker deep cycle battery separator.
35. The method of producing a lead acid battery of claim 34, where
a positive electrode is enveloped, wrapped or sleeved with one
separator while a negative electrode is enveloped, wrapped or
sleeved with another separator.
36. The multilayer deep cycle battery separator of claim 4, wherein
the separator comprises two layers of automotive-sized separators
which are connected in a back to back manner such that the backweb
of each of the two layers are adjacent.
37. The multilayer deep cycle battery separator of claim 36,
wherein the backwebs of the two layers are connected by a plurality
of welds.
38. The multilayer deep cycle battery separator of claim 4, wherein
the separator comprises two layers of automotive-sized separators
which are connected in a stacked manner such that the ribs of one
of the layers faces the backweb of the other of the layers and
wherein the layers are connected with welds at one or more edge of
the layers.
39. The multilayer deep cycle battery separator of claim 36,
wherein one of the two layers comprises negative ribs which are
thereby positioned between the two layers.
40. The multilayer deep cycle battery separator of claim 4, wherein
the separator comprises two layers of automotive-sized separators
which are connected rib to rib with the ribs of one of the two
layer aligned with the ribs on the other of the two layers.
41. The multilayer deep cycle battery separator of claim 2, wherein
the separator comprises two layers, a first of the two layers
comprising a backweb having a backweb thickness of between 5 and 10
mils, an overall thickness of between 25 and 65 mils, and a rib
having a rib base width of between 20 and 35 mils, a second of the
two layers comprising a backweb and wherein the two layers are
connected in a manner such that the ribs of the first of the two
layers faces the backweb of the second layer of the two layers.
42. The multilayer deep cycle battery separator of claim 4, wherein
the separator comprises two layers of automotive-sized separators
which are connected rib to rib with the ribs of one of the two
layer are offset from the ribs on the other of the two layers.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a Divisional of U.S. application Ser.
No. 16/398,622, filed Apr. 30, 2019, which claims the benefit of
U.S. Divisional application Ser. No. 14/584,109, filed Dec. 29,
2014, and issued as U.S. Pat. No. 10,276,850 on Apr. 30, 2019,
which claims the benefit of U.S. Provisional Patent Application
Ser. No. 61/923,051, filed Jan. 2, 2014, the disclosures of which
are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The instant invention is directed to a new, improved or
optimized separator for a battery, such as a deep cycling storage
battery, and/or related methods. In accordance with at least
selected embodiments, the instant invention is directed to a
multilayer separator for an industrial storage battery, a deep
cycling or deep cycle storage battery, or the like, and/or to
methods of manufacture and/or use thereof.
BACKGROUND OF THE INVENTION
[0003] A battery separator is used to separate the battery's
positive and negative electrodes or plates in order to prevent an
electrical short. Such a battery separator is typically microporous
so that ions may pass therethrough between the positive and
negative electrodes or plates. In lead/acid storage batteries,
either automotive batteries or industrial and/or deep cycle
batteries, the battery separator is typically a microporous
polyethylene separator having a backweb and a plurality of ribs
standing on the backweb. See: Besenhard, J. O., Editor, Handbook of
Battery Materials, Wiley-VCH Verlag GmbH, Weinheim, Germany (1999),
Chapter 9, pp. 245-292. The separators for automotive batteries are
typically made in continuous lengths and rolled, subsequently
folded, and sealed along the edges to form pouches or envelopes
that receive the electrodes for the batteries. The separators for
industrial (or traction or deep cycle storage) batteries are
typically cut to a size about the same as an electrode plate
(pieces or leaves).
[0004] In a typical lead/acid microporous polyethylene battery
separator, the separator has a ribbed face (i.e., with the primary
ribs) and a back face (i.e., without ribs or a plurality of small
or secondary ribs). The negative electrode (or plate) may be placed
adjacent to the back face, while the positive electrode (or plate)
may rest on the ribs of the ribbed face. U.S. Pat. No. 3,917,772
illustrates a method of making a lead/acid battery separator sheet
from a plastic material and is hereby incorporated by reference
herein. In this method, the sheet is calender molded to form ribs
and/or projections. Referring to FIGS. 2 and 3 of U.S. Pat. No.
3,917,772, ribs 29 and 31 have a solid profile. Referring to FIGS.
4 and 5 of U.S. Pat. No. 3,917,772, discrete projections 45 and 49
are formed by rounded pits in the calendering rolls 12 and 13. U.S.
Pat. No. 4,000,352, which is hereby incorporated by reference
herein, illustrates a lead/acid battery separator characterized by
an interrupted pattern of discrete separator projections standing
on a backweb. Each projection has a circular or oval shape. U.S.
Pat. No. 5,558,952, which is hereby incorporated by reference
herein, illustrates a lead/acid battery separator having a
plurality of discrete ribs with no intermediate connecting walls.
U.S. Pat. No. 5,716,734, which is also hereby incorporated by
reference herein, illustrates a lead/acid battery separator having
a plurality of ribs, each with a solid profile. PCT Publication WO
01/13442, which is hereby incorporated by reference herein,
illustrates a lead/acid battery separator having at least one
vertical rib and a plurality of studs. The studs are truncated
cones, and their bases are flush with the backweb. The ribs have a
solid profile.
[0005] The typical separator for lead/acid batteries is made from
polyethylene ("PE") resin. The manufacturing of the PE separator
used in lead/acid batteries, like flooded lead acid batteries, may
include extruding a mixture of precipitated silica, PE, such as
Ultra High Molecular Weight polyethylene (UHMWPE) or some other
type of PE, and mineral oil, along with some other minor
ingredients into a profile sheet or film. This profile sheet is
then solvent extracted where the bulk of the mineral oil is removed
or extracted to create porosity in the sheet or film. The last step
of the process is often called finishing, where the profile sheet
is mechanically adjusted to the desired width, overall thickness
and length.
[0006] The aforementioned process produces a PE separator that may
be used in a variety of applications including automotive,
stationary and deep cycling (or traction or industrial) batteries.
In general, the automotive separators are thinner in backweb and
overall thickness as compared to those separators used in deep
cycling and/or industrial batteries. The following table, Table 1,
highlights the typical differences in mechanical dimensions of the
automotive battery separators versus the deep cycling and/or
industrial battery separators.
TABLE-US-00001 TABLE 1 Automotive Deep Cycle Units Separator
Separator Backweb Thickness (mils) 6 to 10 12 to 25 Overall
Thickness (mils) 12 to 65 65 to 140 Rib Base Width (mils) 12 to 50
35 to 80 Extraction Time (seconds) 45 to 75 180 to 300
To better understand the numbers in Table 1 above, FIG. 1, which
shows a typical deep cycle battery separator, also shows backweb 20
having a certain backweb thickness (or height) and rib 22 having a
certain rib base width (where rib 22 meets backweb 20). The
separator shown in FIG. 1 has an overall thickness that includes
the backweb thickness as well as the height of the rib 22 above the
backweb.
[0007] Because of the structural differences between a typical deep
cycle battery separator and a typical automotive battery separator,
the deep cycle battery separator usually takes longer to make, for
example, it may take approximately 3 to 5 times longer in the
extraction process to remove the oil to the proper level than a
typical automotive separator. The time in the extraction process is
defined by diffusion principles where the oil is removed from the
separator. As the deep cycling separator has a thicker backweb
thickness and larger ribs, the rate of diffusion of the oil out of
the separator is substantially longer than the time required to
extract oil out of the automotive separator.
[0008] As such, there is a need or desire to produce a deep cycling
separator or a separator for a deep cycle storage battery or an
industrial or traction battery with the desired backweb thickness
and overall thickness as well as rib shape that is useful for a
deep cycle battery separator, while also reducing the manufacturing
time for such a separator, reducing the extraction time for such a
separator and/or simplifying the manufacturing process for such a
separator.
SUMMARY OF THE INVENTION
[0009] In accordance with various embodiments herein, the instant
invention is designed to address at least some of the above
mentioned needs or problems, and/or the invention is directed to a
multilayer or composite separator for use with a deep cycle storage
battery and/or an industrial storage battery. The multilayer
separator may comprise at least two layers bonded or welded
together, wherein each layer preferably comprises a layer of
automotive-sized separator or separator that is typically used in
an automotive battery. In certain instances, a layer of
automotive-sized separator may comprise a backweb and one or more
ribs. In some embodiments, the backweb thickness may range from
about 5 to about 10 mils, and in other embodiments, from about 6
mils to about 10 mils. In various embodiments, the overall
thickness of the layer of automatize-sized separator, which overall
thickness includes the backweb thickness and the height of a rib,
may range from about 12 mils to about 65 mils, in some embodiments,
about 15 mils to about 65 mils, and in other embodiments, about 25
mils to about 65 mils. Additionally, the base of a rib may have a
width of from about 12 to about 50 mils, in some embodiments, about
20 mils to about 35 mils.
[0010] The multilayer or composite separator described herein may
have an extraction time of from about 45 seconds to about 75
seconds, where such an extraction time refers to the time it takes
for oil to be extracted from the separator as pores are being
formed.
[0011] Each layer of automotive-sized separator may comprise
polyethylene, PVC, rubber, a phenolic resin, polypropylene,
cellulosic material, and combinations thereof.
[0012] In various embodiments, the layers may be welded together by
welding techniques selected from the group consisting of: heat;
pressure; heat and pressure; sonic welding; vibration; crimping;
laser; the like; and/or any combination thereof. In other
embodiments, the layers may be connected together by a layer of
adhesive. In such embodiments, the adhesive may be selected from
the group consisting of: a standard adhesive, latex rubber, coating
with the basic solution of sodium silicate that is ultimately
neutralized with acid; the like; and/or combinations thereof.
[0013] In some aspects of the present invention, the multilayer
separator further includes one or more additives. In various
instances, such an additive may be selected from the group
consisting of: ground rubber; latex rubber; lignin; sodium sulfate;
the like; and/or combinations thereof. In various embodiments, the
additive or additives are between the layers. In certain instances,
the multilayer deep cycle battery separator may include one or more
additives pocketed into a welded region of the separator (such as
is done in the nonwoven industry as they add super absorbent
polymers to incontinence products).
[0014] The multilayer separator in some instances may comprise the
at least two layers, wherein each layer comprises a layer of
automotive-sized separator or separator that is typically used in
an automotive battery, wherein the layers are not bonded or welded
or otherwise attached to each other using some means of attachment.
In such cases, the layers of automotive-sized separator are
positioned together by being enveloped, wrapped, sleeved or
stacked.
[0015] In other embodiments, the layers of automotive-sized
separator are embossed together. In these cases, the layers are
embossed together by two or more layers being fed through a pair of
mated rollers with a three-dimensional pattern, whereby when the
two or more layers are embossed, the original shape of the ribs is
modified in the pattern of the embossed roller(s). In such cases,
the points of connectivity of the embossed layers may be across a
portion of the separator or across the entire face of the
separator.
[0016] The multilayer deep cycle battery separator described herein
may comprise two layers of automotive-sized separator, which two
layers are connected back to back, meaning the backwebs of the two
layers are adjacent each other. In such embodiments, one or both of
the layers may comprise a backweb having negative ribs such that
the negative ribs are thereby positioned between the backwebs of
the two layers. In other embodiments, the layers are stacked on top
of one another, wherein the backweb of one layer is stacked atop
the top of the rib or ribs of the second layer. In additional
embodiments, the layers are positioned in a rib-to-rib fashion. In
certain embodiments, the ribs are stacked on top of each other
adjacent to each other. In still other embodiments, the ribs of one
layer are offset relative to the ribs of the other layer.
[0017] In still other embodiments, the multilayer separator
comprises a ribbed separator and a flat sheet. In the embodiments
described throughout the disclosure, the ribs may be selected from
the group consisting of: straight vertical ribs; sinusoidal;
diagonal; continuous; discontinuous; embattlement; cross rib
patterns; other shapes and/or patterns; the like; and/or
combinations thereof.
[0018] The multilayer deep cycle battery separator of the invention
may have an extraction time that is less than the extraction time
for a standard deep cycle battery separator. For instance, the
multilayer deep cycle battery separator of the invention may have
an extraction time that is at least 2/3 less than the extraction
time for a standard deep cycle battery separator, in other
instances, between and 2/3 less.
[0019] Additionally, the multilayer deep cycle battery separator of
the invention may have a stiffness greater than the stiffness of a
standard deep cycle battery separator. Moreover, the multilayer
deep cycle battery separator of the invention may have a
compression greater than the compression of a standard deep cycle
battery separator. Further, the multilayer deep cycle battery
separator of the present invention may have a rib mass that is less
than the rib mass of a standard deep cycle battery separator. And
the multilayer deep cycle battery separator of the present
invention may have fewer pinholes than a standard deep cycle
battery separator.
[0020] The multilayer deep cycle battery separator may comprise a
composite structure, which composite structure may include a
stiffening material on one or both outer surfaces and/or between
the layers. Such a stiffening material may be selected from the
group consisting of: a glass mat; glass fibers; a synthetic mat;
synthetic fibers; the like; and combinations thereof.
[0021] Various aspects of the present invention include a battery
comprising the multilayer deep cycle battery separator described
herein. In such embodiments, the battery may be a deep cycle
battery, an industrial battery, an ISS battery, and/or the like.
And in the manufacture of a battery, the present invention may
include the improvement comprising providing to such battery at
least one of the multilayer deep cycle battery separators described
herein.
[0022] The present invention also is directed to a method of
separating a battery's positive and negative electrodes including
using at least one of the multilayer deep cycle battery separators
described and claimed herein. And various methods of manufacturing
a deep cycle battery separator are also disclosed herein.
[0023] A method of producing a lead acid battery is described,
where two layers of separators are used in such a manner to replace
a thicker separator, such as two automotive separators used to
replace a deep cycle battery separator. In such a method of
producing a lead acid battery, the positive electrode is enveloped,
wrapped or sleeved with one separator while the negative electrode
is enveloped, wrapped or sleeved with another separator.
[0024] Moreover, the present invention provides various new or
improved batteries, components, separators, systems, their methods
of manufacture and/or use, and/or means and/or methods of enhancing
the extrusion tooling, minimizing rib calendaring, minimizing rib
mass, improving extrusion changeover, reducing pinholes, adding
additives, providing a composite structure, providing acid
displacement, as shown or described herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 includes a cross-sectional view of a typical,
single-layer deep cycle battery separator.
[0026] FIG. 2 includes a cross-sectional view of a multilayer deep
cycle battery separator in accordance with one embodiment of the
present invention.
[0027] FIG. 3 includes a cross-sectional view of another multilayer
deep cycle battery separator in accordance with another embodiment
of the present invention.
[0028] FIG. 4 depicts a cross-sectional view of yet another
multilayer deep cycle battery separator in accordance with an
embodiment of the present invention.
[0029] FIG. 5 shows a cross-sectional view of still another
multilayer deep cycle battery separator in accordance with one
embodiment of the present invention.
[0030] FIG. 6 includes a cross-sectional view of a multilayer deep
cycle battery separator in accordance with an embodiment of the
present invention.
[0031] FIG. 7 depicts a cross-sectional view of a multilayer deep
cycle battery separator in accordance with yet another embodiment
of the present invention.
[0032] FIG. 8 illustrates a cross-sectional view of a multilayer
deep cycle battery separator in accordance with still another
embodiment of the present invention.
[0033] FIG. 9 illustrates a cross-sectional view of a rib portion
of a typical, single-layer deep cycle battery separator in FIG.
9(a) compared with a profile in FIG. 9(b) of two rib portions of a
multilayer deep cycle battery separator according to various
embodiments of the present invention, such as a battery separator
in accordance with FIG. 4 shown herein.
DETAILED DESCRIPTION OF THE INVENTION
[0034] In accordance with at least selected embodiments, the
instant invention addresses the above mentioned needs or problems
by providing two or more thinner separators, preferably two or more
automotive separators, together to provide a new multilayer
separator that may perform the function of the conventional,
thicker deep cycle battery separator, to produce a deep cycle
battery separator with the required backweb thickness and overall
thickness that reduces the manufacturing time, reduces the
extraction time, reduces complexity by reducing separator types,
and/or simplifies the manufacturing process. The instant invention
of two or more automotive separators together can be constructed in
such a way to have the same total backweb and overall thickness as
the existing deep cycle battery separator and thus provide similar
functionality. However from a process and product usage standpoint,
two or more automotive separators together can provide many
advantages when compared to the existing industrial deep cycling or
deep cycle battery separator.
[0035] In the embodiments shown and described herein, the deep
cycle separator of the instant invention may preferably include two
layers of automotive-sized separators. However, the invention is
not so limited, and the instant invention may include any number of
automotive-sized separators, like two or more multi-layers of
automotive sized-separators to provide the desired properties for
the deep cycle separator.
[0036] Two or more automotive-sized separators may be included in
the instant invention of a multilayer deep cycle battery separator.
The automotive sized-separators used in the multilayer separator of
the instant invention may include, but are not limited to, a
backweb thickness of between about 5 to about 10 mils, an overall
thickness of between about 15 to about 65 mils, and a rib base
width of between about 12 to about 50 mils. In addition, the
automotive-sized separators and/or production methods used in or to
produce the multilayer separators of the instant invention may
include, but are not limited to, having a preferred extraction time
of between about 45 to about 75 seconds.
[0037] The instant invention contemplates various embodiments of
how the two or more layers of automotive-sized separators are
together. In one embodiment, the two or more layers of
automotive-sized separators may be together by welding. As the PE
separator is highly weldable unto itself, it is contemplated that
the welding is accomplished by various welding or other similar
processes, including, but not limited to, heat, pressure, heat and
pressure, sonic welding, vibration, crimping, laser, the like, or
any combination thereof.
[0038] In other various embodiments, the multilayer structure or
separator of the instant invention could be achieved by adding a
layer of adhesive between the two layers. In one embodiment, an
additive is included with the multilayer separator, and the desired
additive may even have adhesive properties. Besides standard
adhesives, in other embodiments, the layers may be assembled with
latex rubber or via coating with a basic solution of sodium
silicate that is ultimately neutralized with acid.
[0039] In other select embodiments, to make matters even simpler, a
battery manufacturer could use two or more distinct layers of
automotive type separators in place of one deep cycling or deep
cycle battery separator without any welding or other means of
attachment. In the manufacture of batteries, electrodes may be
enveloped, wrapped, sleeved, or stacked with the multilayer
separators of the instant invention. In one embodiment, the battery
manufacturer could simply replace one deep cycle battery separator
with two automotive type separators. For instance, instead of just
sleeving the positive electrode with a deep cycle battery
separator, one could sleeve each one of the positive and negative
electrode with an automotive-type separator material.
[0040] In other select embodiments, the two or more layers of the
deep cycle separator of the instant invention may be embossed
together. For example, in this embossed embodiment, the two or more
layers may be fed through a pair of mated rollers with a three
dimensional pattern. When the two layers may be embossed, the
original shape of the ribs may be modified in the pattern of the
embossed roll. This embossing step may be an advantageous concept
for welding or connecting the two layers together because the
points of connectivity may be across the entire face of the
separator.
[0041] Referring now to the Figures, it is shown that various
combinations and orientations of automotive-sized separators are
contemplated for various embodiments of the instant invention.
However, the instant invention is not so limited, and the Figures
are merely provided as examples. In FIG. 1, this diagram shows the
prior art, typical standard deep cycle battery separator with a
backweb 20 and rib 22 as well as the required relative backweb
thickness, overall thickness and rib base width.
[0042] FIG. 2 shows one embodiment of the instant invention with
two layers of automotive-sized separators connected back to back.
In such embodiment, each separator or separator layer comprises a
backweb 40 and ribs 42, and the two layers or separators are
attached via welds 30. This embodiment is also shown in FIG. 3,
however, in FIG. 3 the welds 50 are more frequent.
[0043] Referring to FIG. 4, this embodiment may show the most
straightforward approach of combining two automotive separators to
meet the needs now realized by the deep cycling separator with the
separators stacked on top of one another. In such embodiment, each
separator or separator layer comprises a backweb 40 and ribs 42,
and the two layers or separators are attached via welds 60. In the
embodiment shown in FIG. 4, the multilayer deep cycle battery
separator may provide improved stiffness when compared to known or
existing deep cycle separators (such as, for example, the separator
depicted in FIG. 1).
[0044] Referring to FIG. 5, an embodiment with two layers of
automotive-sized separator is shown with the layers back to back
and at least one of the layers including negative ribs 70, which
are thereby positioned between the two layers. This configuration
may offer a separator product with the stiffness maximized or
optimized.
[0045] Referring now to FIG. 6, this diagram shows an embodiment
with two layers of automotive-sized separator together rib to rib
with the ribs 42 aligned on top of one another. As an example, this
embodiment may offer maximum or optimum compression against the
active material to prevent shedding.
[0046] Referring now to FIG. 7, this figure shows an embodiment
with a ribbed separator that includes ribs 42 and backweb 40,
together with a flat sheet 80.
[0047] In FIG. 8, an embodiment is shown with two layers of
automotive-sized separator together in a rib to rib orientation
with the ribs 42 offset from one another.
[0048] Referring to FIG. 9, a side-by-side comparison of a typical
industrial-sized and industrial-shaped rib is shown next to a
multi-layer rib with 2 automotive ribs stacked on top of one
another. This figure illustrates a cross-sectional view of a rib
portion of a typical, single-layer deep cycle battery separator in
FIG. 9(a) compared with a profile in FIG. 9(b) of two rib portions
of a multilayer deep cycle battery separator according to various
embodiments of the present invention, such as a battery separator
in accordance with FIG. 4 shown herein. These ribs 22 and 42 plus
42 are shown with the same height (H) of 50 mils, however, the
multi-layer rib with 2 automotive ribs stacked on top of one
another has a width that is clearly reduced from the industrial
sized and shaped rib. By way of example only, in FIG. 9(a), the
width of the bottom or base of the rib 22 might be, for instance,
about 50 mils, with the top of the rib having a width of about 35
mils. In contrast, and by way of example only, in FIG. 9(b), the
width of the bottom or base of the bottom rib 42 in the stack might
be, for instance, about 30 mils, with the top of the top rib 42
having a width of about 21 mils.
[0049] The multilayer deep cycle battery separator may include ribs
on one or more of the layers. The ribs may be any ribs, including,
but not limited to straight ribs as shown in the Figures. However,
the instant invention is not so limited and could also be embodied
by not just straight vertical ribs but also by sinusoidal,
diagonal, discontinuous, embattlement, cross rib patterns, other
shapes and/or patterns, the like, and combinations thereof.
[0050] In one embodiment, the multilayer deep cycle battery
separator of the instant invention may include layers made from PE
separators. However, the invention is not so limited and in other
various embodiments could also include separators made from PVC,
rubber, phenolic resin, PP, cellulosic materials, other separator
materials known or later discovered, the like, and combinations
thereof.
[0051] One advantage of providing two layers of automotive-sized
separator to create the deep cycle separator of the instant
invention is reducing the extraction time and simplifying the
manufacturing process. For example, the two automotive separators
may require approximately 60 seconds each to process through the
extraction process or 120 seconds in total. The time to extract the
existing deep cycle or industrial battery separator takes
approximately 180 to 300 seconds. Thus with regard to extraction
time, one can expect to increase the output of the extractor by 1.5
to 2.5 times. Thus, improvement will be seen in utilization of the
extraction equipment; however, as discussed below, many other
advantages can also be obtained using the separator described
herein.
[0052] Another advantage to the instant invention may be a
reduction in cost and time required for extrusion tooling.
Currently the volume of automotive separators is approximately 10
times greater in volume, square meters, than is supplied for deep
cycling applications. However to supply the deep cycling industry,
there are often as many unique profile rolls or ribbing designs
needed. Thus the expense of constructing and maintaining calendar
rolls is similar for deep cycling applications as it is for
automotive applications even though the market volume is
approximately 1/10 the size in terms of square meters. The proposed
invention offers the potential to suppress the expense associated
with the deep cycling calendar rolls and simply utilize the product
produced from the automotive calendar rolls or combinations of
products.
[0053] Yet another advantage to the instant invention may be to
minimize rib calendaring. To suppress cost associated with calendar
rolls, often one calendar roll will be used to make products with
varying rib height or overall thickness. As the degree of rib
filling may be relatively constant in the extrusion process, the
rib can be calendared anywhere from 1 to 25 mils. This feature may
increase the range of products in varying overall thicknesses that
can be supplied while minimizing the added costs of calendar rolls.
So when a product is calendared 25 mils, there is extra mass that
is being wasted. Therefore with the present invention, the
calendared rib mass can be saved simply by selecting appropriate
combinations of automotive profiles that allow for minimum
calendaring.
[0054] Yet another advantage of the instant invention may be to
minimize rib mass. Besides minimizing rib mass by limiting the
range of calendaring there is another aspect for decreasing the
mass associated with the ribs. In order to prevent ribs from
leaning with the manufacturing process or once inside the battery,
it has been found that the base of the rib needs to be proportional
to the height of the rib. Thus a taller rib will have a wider base
in comparison to a shorter rib with a narrower base. In the present
invention, two smaller ribs are used to achieve the overall
separator thickness instead of one tall rib as the ribs are placed
on opposite sides of the separator from one another. In this
configuration, the mass of two small ribs will provide the same
spacing as one big rib but with less mass required.
[0055] Yet another advantage of the instant invention may be with
regards to extrusion changeover. If the deep cycling separator is
replaced with two automotive separators together, the need to stop
the extrusion process and install the appropriate deep cycle
profile roll will be eliminated. As mentioned earlier, the deep
cycle separators are approximately 1/10 the volume of the
automotive product but with approximately the same number of
ribbing configurations or required calendar rolls. Due to the lower
volume of deep cycle separators, the profile tooling often only
runs 8 to 24 hours in an extruder where an automotive tooling, due
to the volume demand, may run in excess of 100 hours. Thus
replacing the deep cycle separators with two automotive separators
will eliminate the need to make frequent tooling changeovers and
decrease the material scrap.
[0056] Yet another advantage of the instant invention may be the
reduction of undesired pinholes. As PE separators are produced,
pinholes are occasionally encountered in the material and to such a
level that an entire roll will need to be scrapped. By definition,
a pinhole can be as small as 100 microns in diameter opening. As
two layers are laminated together, the frequency of observed or
detected pinholes will decrease substantially. With two layers
laminated together, any associated pinholes will have to occur in
both layers in the same location and this is highly unlikely.
[0057] Yet another advantage of the instant invention may be the
option for additives. To meet the needs of the deep cycling market,
additives are often contained in separators provided into this
market. These additives are often incorporated in the extrusion
process facility, which creates the need to purge the extrudate
going on and off the particular formula. By combining two layers,
one could imagine incorporating the various additives (or more
electrolyte) between the layers and then pocketing them into a
welded region such as is done in the nonwoven industry as they add
super absorbent polymers to incontinence products. Again this may
have the effect of standardizing the extrusion and extraction
process and then introducing the uniqueness at the last step of the
manufacturing process. Examples of additives helpful to the battery
and the battery separator could be, but are not limited to, ground
rubber, latex rubber, various lignins or compounds like sodium
sulfate, other desired additives known or later discovered, the
like, and combinations thereof.
[0058] Yet another advantage of the instant invention may be the
option to provide a composite structure. Often deep cycle
separators are assembled by hand and stiffness is a desirable
property. To enhance stiffness, it is contemplated to add between
the layers material to stiffen the structure, including, but not
limited to, a glass mat, glass fibers, a synthetic mat, synthetic
fibers, other desired materials known or later discovered, the
like, and combinations thereof.
[0059] Yet another advantage of the instant invention may relate to
acid displacement. Deep cycling batteries, such as batteries that
provide energy for an electric forktruck, golf cart, mining
vehicles, etc., are often home power supplied and are regularly
discharged deeply before recharging. As the electrolyte, sulfuric
acid, is a reactant in the discharge reaction, batteries that have
more electrolyte volume can often have deeper discharges and
delivery of more energy to the user. Thus far, this disclosure has
spoken of reducing the rib mass and ultimately the separator mass
by two automotive separators together when compared to the existing
deep cycle separator. Thus, with less separator mass, the two
automotive separators together will allow for more acid between the
electrodes thereby creating a situation where more energy can be
delivered to the user, assuming the battery is acid limited by
design.
[0060] The present invention may be embodied in other forms without
departing from the spirit and the essential attributes thereof,
and, accordingly, reference should be made to the appended claims,
rather than to the foregoing specification, as indicating the scope
of the invention. Additionally, the invention illustratively
disclosed herein suitably may be practiced in the absence of any
element which is not specifically disclosed herein.
* * * * *