CA2102065C - Alkaline manganese dioxide cells - Google Patents
Alkaline manganese dioxide cellsInfo
- Publication number
- CA2102065C CA2102065C CA002102065A CA2102065A CA2102065C CA 2102065 C CA2102065 C CA 2102065C CA 002102065 A CA002102065 A CA 002102065A CA 2102065 A CA2102065 A CA 2102065A CA 2102065 C CA2102065 C CA 2102065C
- Authority
- CA
- Canada
- Prior art keywords
- separator
- barrier
- hot melt
- cathode
- cell
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- NUJOXMJBOLGQSY-UHFFFAOYSA-N manganese dioxide Inorganic materials O=[Mn]=O NUJOXMJBOLGQSY-UHFFFAOYSA-N 0.000 title claims abstract description 9
- GOPYZMJAIPBUGX-UHFFFAOYSA-N [O-2].[O-2].[Mn+4] Chemical compound [O-2].[O-2].[Mn+4] GOPYZMJAIPBUGX-UHFFFAOYSA-N 0.000 title abstract description 3
- 230000004888 barrier function Effects 0.000 claims abstract description 129
- 239000000565 sealant Substances 0.000 claims abstract description 81
- 239000012943 hotmelt Substances 0.000 claims abstract description 68
- 230000002745 absorbent Effects 0.000 claims abstract description 12
- 239000002250 absorbent Substances 0.000 claims abstract description 12
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 claims abstract description 11
- 239000011701 zinc Substances 0.000 claims abstract description 11
- 229910052725 zinc Inorganic materials 0.000 claims abstract description 11
- 238000000034 method Methods 0.000 claims description 36
- 239000000463 material Substances 0.000 claims description 5
- 239000007788 liquid Substances 0.000 claims description 2
- 238000002844 melting Methods 0.000 claims description 2
- 230000008018 melting Effects 0.000 claims description 2
- 239000007787 solid Substances 0.000 claims description 2
- 239000011800 void material Substances 0.000 claims 12
- 230000002093 peripheral effect Effects 0.000 claims 6
- 239000003292 glue Substances 0.000 claims 2
- 230000002401 inhibitory effect Effects 0.000 claims 2
- 239000004831 Hot glue Substances 0.000 claims 1
- 238000007789 sealing Methods 0.000 claims 1
- 230000001351 cycling effect Effects 0.000 abstract description 2
- 238000013461 design Methods 0.000 description 8
- 238000013459 approach Methods 0.000 description 4
- 239000003792 electrolyte Substances 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 238000012360 testing method Methods 0.000 description 3
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 2
- 229910052748 manganese Inorganic materials 0.000 description 2
- 239000011572 manganese Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- SGTNSNPWRIOYBX-UHFFFAOYSA-N 2-(3,4-dimethoxyphenyl)-5-{[2-(3,4-dimethoxyphenyl)ethyl](methyl)amino}-2-(propan-2-yl)pentanenitrile Chemical compound C1=C(OC)C(OC)=CC=C1CCN(C)CCCC(C#N)(C(C)C)C1=CC=C(OC)C(OC)=C1 SGTNSNPWRIOYBX-UHFFFAOYSA-N 0.000 description 1
- 241000905957 Channa melasoma Species 0.000 description 1
- 240000001973 Ficus microcarpa Species 0.000 description 1
- 241000206607 Porphyra umbilicalis Species 0.000 description 1
- 229920002472 Starch Polymers 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 230000005012 migration Effects 0.000 description 1
- 238000013508 migration Methods 0.000 description 1
- GWUSZQUVEVMBPI-UHFFFAOYSA-N nimetazepam Chemical compound N=1CC(=O)N(C)C2=CC=C([N+]([O-])=O)C=C2C=1C1=CC=CC=C1 GWUSZQUVEVMBPI-UHFFFAOYSA-N 0.000 description 1
- 230000037361 pathway Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 235000019698 starch Nutrition 0.000 description 1
- 239000008107 starch Substances 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/24—Alkaline accumulators
- H01M10/28—Construction or manufacture
- H01M10/283—Cells or batteries with two cup-shaped or cylindrical collectors
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
- H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
- H01M50/409—Separators, membranes or diaphragms characterised by the material
- H01M50/449—Separators, membranes or diaphragms characterised by the material having a layered structure
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/49108—Electric battery cell making
- Y10T29/4911—Electric battery cell making including sealing
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/49108—Electric battery cell making
- Y10T29/49114—Electric battery cell making including adhesively bonding
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Primary Cells (AREA)
- Sealing Battery Cases Or Jackets (AREA)
Abstract
During repeated cycling of alkaline manganese dioxide cells, it is critical to ensure that adequate barrier protection is formed and maintained between the anode and cathode of the cell to prevent shorts from occurring between the cathode and the anode. However, the potential also exists for anodic zinc to migrate via the absorbent separator and create a short path to the cathode. To prevent this, cells can be fabricated whereby a separator barrier is placed into the cells, a hot melt sealant is metered into the cell so that the sealant flows under the separator barrier, the separator barrier is pushed down and seated into the hot melt. The end result is a separator barrier which is sealed at the bottom of the cell and at both sides of the separator barrier and virtually eliminates shorts from developing between the electrodes.
Description
~1 02065 ALKALINE ;~'IANGANESE DIOXIDE CELLS
FIELD OF THE INVFI~ITI~N
The present invention relates generally to alkaline m~ng~nese dioxide cells, and more particularly to rechargeable alkaline zinc m~ng~nese dioxide 5 batteries having separator barriers and a meltable sealant between the anode and cathode such that the number of shorts developing between the electrodes of such cells upon repeated charge/discharge cycles is substantially reduced.
BACKGROUND OF THE I~IVE~IT101~
~Ikaline electrochemical cells having zinc anodes and m~ng~nese dioxide cathodes have achieved commercial- success in recent years.
Particularly when manufactured in the cylindrical configuration, such cells constitute important sources of portable- electrical energy. Alkaline zinc nlanE~nese dioxide cells provide substantially more energy vis-a-vis Leclanche 15 cells when used in high current continuous discharge applications.
Historically, alkaline _inc m~nganese dioxide cells have been used mainly in primary batteries. To date, significant reductions in battery performance after a few recharge cycles delayed the commerc-ali7~tion of ~1 02065 second~rv ~l~;aline zinc manuanese ~ioxide cells. Several principal problems contributed to Ihis delav.
One problem endemic to such cells arises from the frequency at which they fail due to shorts developinu between the metallic anode and the 5 manganese based cathode. Shorts develop because on repeated discharge anodic zinc tends to migrate towards the cathode. Although the electrodes are separated from one another by a barrier-type separator, pathways may develop between the electrodes. For example, if the physical contact between the separator barrier and the bottom of the cell is disrupted, a sfiort can 10 easily develop.
In prior art cells, the seating of the separator barrier within the cell to reduce shorts between the electrodes in alkaline manganese dioxide cells was accomplished in several ways. U.S. Patent No. 5,108,852 for a Manganese Dioxide Cathode for a Rechargeable Alkaline Cell and Cell Containing the 5 Same discloses one such method. In this method, a plastic disk is placed in the bottom of the cell. Then a convolute separator barrier is placed on the disk and a hot melt material is metered to the inside of the separator barrier so that a seal forms only at the interior surface of the separator barrier. An example of a cell constructed in this way is depicted in FIG. 1. Battery 20 Technologies, Inc. of Richmond Hill, Ontario, Canada has manufactured batteries having such a structure.
During repeat cycling of alkaline m~ng~nese dry cells, it is critical to ensure that adequate barrier protection is formed and m~int~ined between the cathode and the anode. With the design depicted in FIG. 1, it is possible for anodic zinc to migrate through the absoll~n~ and over the top of the plastic disk thereby creating a shorting p~lhw~y to the cathode, as depicted in FIG. 2. Additionally, the m~nllf~ctl-re of this type of cell involves additional steps, e.g., the disk must be constructed and then placed within the cell and the cell must be spun during metering of the hot melt.
Another method to prevent shorting (specifically in recllalgeable ~lk~lin~ zinc m~ng~qnese dioxide cells) utilizes a separator tube as part of a barrier system to prevent an abrupt capacity loss due to shorting experienced in cells after extended cycle life. There are three separate approaches, all using a barrier system assembled outside the cell and kept in place in the cell by a hot melt sealant. The first approach involves using a separator tube having only one open end. The closed end of the ~epa~lor tube is affixed to the bottom of the cell with a hot melt sealant. The second approach affixes a separator tube on a plastic disk which is affixed to the bottom of the cell with a hot melt sealant, whereas in the third approach the s~al~l~r tube is bent inward before being affixed to the plastic disk.
Since the s~or tubes all involve completely sealed arrangements, difficulties are encountered in obtaining a sufficient distribution of electrolyte, i.e., the apl)ropliate electrolyte gradient between the electrodes. In order to overcome this problem, several additional m~nllf~cturing steps must be taken. Additionally, the insertion of a separator assembly into ~e cell fi~her reduces ~e speed in wl~ich b~tt~ri~ can be manufactured l.~ 7in~ the above me~od.
Therefore, an object of the present invention is to provide a S rechargeable ~Ik~line m~ng~n.~se dry cell with an in~ tin~ barrier at the positive (cathode) end of the cell that completely separates the cathode and anode compartments.
Another objea of the present invention is to provide continuous protection against shorting on cycled discharges in rechargeable ?l~ ine m~n~anese dry cells and batteries.
Yet another object of the present invention is to provide re-:hafgeable ~Ik~line mang~nese dioxide cells and batteries having a simplified overall desigrL
Still another object of the present invention is to provide rechargeable ~Ik~line m~ngan~ose dioxide cells and batteries that are easy to m~n~lf~c~lre~
Other objects and advamages of the present invention will be apparent from the drawings and the description of the invention.
SUMMARY OF T~E INVENllOI~
The present invention achieves these and other objects by placing a separator barrier into the cell. metering a hot melt sealant into the cell so that the sealant flows under the separator barrier, and pushing the separator barrier down. and seating the separator barrier into the hot melt. The end result is a sealed tube formed at ~e bottom of the cell. I;~el s~parator ~arrier should be placed above the bottom ot the cell.
The present invention eliminates the possibilitv of a short path developing between the anode and the cathode via a space bet~een the cell S bottom and a plastic disk that e.Yists in prior art designs. Furthermore, the present invention greatly simplifies the manufacturing process, since the plastic disk is eliminated -- there is no need to form or place the disk in the bottom of the cell and there is no longer any requirement to spin the cell during hot melt metering.
10 BRIEF DESCRIPl~ON OF T~IE DRAWINGS
FIG l depicts a prior art cell design in cross section.
FIG 2 depicts the shor~t path in the prior art cell depicted in FIG l.
FIG 3 illustrates a cell design of the present invention shown in cross section.
FIG ~ depicts the blocking of the short path m the cell depicted in FIG 3 according to the present invention.
FIG S depicts the test results of the amount of charge required to recharge a cell for several charge/discharge cycles when the cell was discharged by 300 mAHr, for a cell constructed according to the present 20 invention and a cell constructed according to FIG 1.
FIG 6 depicts the test results of the amount of charge required to recharge a cell for several charge/discharge cycles when the cell was ~1 02065 disch~ged by 60OrnAHr, for a cell co~11u~d accol~l~ to the present invention and a cell cons~ucted a~ .lillg to FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 3 and 4 depict a cell co~l~u~,1ed accordillg to ~e present invention.
5 The cell is disposed w~thin a ~;ylill~;cal can 20, in coll~ ,tional manner.
The ~I;~"]. ;r~1 anode 1 is separated from the .;~ I ca~ode 3 by the se~t~
barrier 5 having an ~~ t layer 6. The sepa~tor balrier S having an al)s~ layer 6 is formed by winding m~t~n~l fiom a fi~t roll of separator m ~ Wi~ m~7,-i~l from a second roll of alK~rl~ t ...~ l onto a 10 cylindrical mandrel of appropriate ~ neter such that both the absorbent material and the separator material are wound ~wice around the mandrel.
thereby forming a convolute separator barrier. The separator barrier and the absorbent are wound together in convolute fashion so that the outside diameter of the cylindrically shaped separator barrier is less than the inner diameter of the cathode. This allows the separator barrier- to be easily 15 inserted into the central cavity ~luring manu&cturing. During and after the manufacturing process, the convolute separator barrier terids to unra~el and push against the inner cathode wall, which ensures that the electrolyte functions properly since the electrolyte becomes in contact with the- anode and cathode. It is to be understood that other types of separator barriers 20 having absorbent layers or absorbent properties are contemplated in the present invention. ~vhich is not contine(3 to separator barriers of the convolute tvpe.
~,a The separator barrier 5 is then placed into the cell, e.g., a~ro~ lately 1/8 inch off the bottom of the cell. A hot melt type sealant 7 is then metered directly onto the bottom of the cell. In this step, hot melt type sealant No. 34/2771 manufactured by National Starch, Inc. of Bridgewater, New Jersey, and which is an undirrelc~ teA, subst~nti~lly homogeneous liquid at tempe,dl-ues exceeAing its melting te~llpeld~ule and an undiffer~nti~t~A, subst~nti~lly homogeneous solid at room ten~cldlu~, is metered directly into the cell at a telll~eldlule of about 340~F and at a l,res~ule of about 200 p.s.i. The te",l)e,dlule range over which this sealant operates for the purposes described herein is between 300~F and 370~F.
After a short delay, e.g., al~p~ illlately one to ten seconds, which short delay depends on the viscosity and initial l~"ll)eldlure of the hot melt sealant, while the sealant 7 is still in fluid form, the se~ald~or barrier 5 is pushed down and seated directly into the sealant 7, but does not engage the boKom of the cell. The act of pushing the separator barrier down causes the sealant 70 trapped between the cathode 3 and the barrier 5 to deform the boKom of the barrier 50 radially inwardly, as shown in Figure 3. Thus, a continuous seal is formed around and under the separator barrier. Thus, hot melt sealant forms on both the outer circumference and the inner cir.;ulllfelellce of the separator barrier, as well as urlA~ th the separator barrier. Thus, all short paths 10 existing in prior art designs are elimin~te l It is to be understood that the length of the short delay will depend on the viscosity of the sealant used, and the tt;~ eldlule at which the sealant is metered into the cell, however, three to five seconds has also proved advantageous.
. ~
'~- 21 02065 The reason for the short delay is that the hot melt sealant cools faster at the bottom of the cell and at lhe surface that touches the cathode than - 7a-melt sealant. the separator barrier will not touch the bottom ot the cell because the lowest laver of hot melt sealant has alreadv solidified.
As depicted in FIG ~, for a cell constructed as shown in FIG 1, with the sealant 7 applied only within the inner circumference of the separator S barrier 5, anodic zinc can migrate into the porous absorbent layer 6 of the - se~ lol balTier and above ~e bottom disk to reach ~e ca~ode. The present invention ~)lCVt;lll~ is short path 11 from developing by en.~lrin~ that hot melt exists between the exterior and the interior surfaces of the separator barrier as well as underneath the separator barrier. As depicted in FIG 4, the 10 sealant blocks the migration of the anodic zinc to the cathode.
The present invention also yrGve~ a short from occuI~ing at ~e edges or bottom of the separator barrier. Although the separator and absorbent are wound together, they do not perfec~ly overlie one another. Interstitial gaps occur at the edges of the bottom of the separator barrier. When the 15 separator barrier is pushed down into the hot melt sealant, the hot melt sealant goes up into these interstitial gaps and fills them, thus preventing shorts from occurring at these interstitial voids.
The manufacturing of the rechargeable alkaline manganese cell is significantly improved by eliminating the bottom disk described in U.S. Patent ~0 ~'o. 5,108,852. ~o forming or placing of the disk is required, and there is no longer any requirement to spin the cell during hot melt metering, as was required in the prior art. Thus, the present invention removes the possibility of shorting be~ween the cathode and anode that was present in prior art b ~
designs, yet simultaneously reduces the complexitv of the manufacturing process.
To determine the effectiveness of the short protection provided by batteries constructed according to the present invention as compared to 5 batteries constructed according to the design illustrated in FIG 1, cells of both designs were discharged by 300 mAhr and 600 mAhr. After being discharged by the requisite amount, the batteries were taken off load for four hours to allow shorts to develop. The batteries were then recharged for ten hours. If batteries do not have shorts between their electrodes, the charge 10 necessary to recharge should be equal to the charge removed during discharge.
Figures S and 6 show the results of these discharge tests. Cells constructed according to the present invention (denoted as seated seal in FlGs 5 and 6) required approximately the same charge as that removed 15 during discharge, i.e., they exhibited no shorting after eight cycles when discharged by 300 mAHr, and after five cycles when discharged by 600 mAHr. In contrast, cells constructed according to FIG I (denoted as ID seal in FIGs 5 and 6) required significantly more charge than that removed during discharge under both discharge conditions, even after a few charge/discharge ~0 cycles, i.e., they exhibited evidence of significant shorting after very few cycles. For example, after only eight charge discharge cycles, the cells constructed according FIG 1, required over four times the amount of charge than that removed during discharge, i.e., 1,200 mAHr were required to charge the cell when it had been discharged by 300 mAHr. Thus, cells constructed 21~2~6~
according lo the present invention do not contain the shorts that develop in cells constructed according lo the designed depicted in FIG 1.
While the invenliOn has been described with reference to specific embodiments, it will be apparent to those skilled in the art that many modifications and variations may be made. Accordingly, the present invention is intended to embrace all such alternatives~ modifications and variations that may fall within the spirit and scope of the appended claims and e~uivalents thereof.
FIELD OF THE INVFI~ITI~N
The present invention relates generally to alkaline m~ng~nese dioxide cells, and more particularly to rechargeable alkaline zinc m~ng~nese dioxide 5 batteries having separator barriers and a meltable sealant between the anode and cathode such that the number of shorts developing between the electrodes of such cells upon repeated charge/discharge cycles is substantially reduced.
BACKGROUND OF THE I~IVE~IT101~
~Ikaline electrochemical cells having zinc anodes and m~ng~nese dioxide cathodes have achieved commercial- success in recent years.
Particularly when manufactured in the cylindrical configuration, such cells constitute important sources of portable- electrical energy. Alkaline zinc nlanE~nese dioxide cells provide substantially more energy vis-a-vis Leclanche 15 cells when used in high current continuous discharge applications.
Historically, alkaline _inc m~nganese dioxide cells have been used mainly in primary batteries. To date, significant reductions in battery performance after a few recharge cycles delayed the commerc-ali7~tion of ~1 02065 second~rv ~l~;aline zinc manuanese ~ioxide cells. Several principal problems contributed to Ihis delav.
One problem endemic to such cells arises from the frequency at which they fail due to shorts developinu between the metallic anode and the 5 manganese based cathode. Shorts develop because on repeated discharge anodic zinc tends to migrate towards the cathode. Although the electrodes are separated from one another by a barrier-type separator, pathways may develop between the electrodes. For example, if the physical contact between the separator barrier and the bottom of the cell is disrupted, a sfiort can 10 easily develop.
In prior art cells, the seating of the separator barrier within the cell to reduce shorts between the electrodes in alkaline manganese dioxide cells was accomplished in several ways. U.S. Patent No. 5,108,852 for a Manganese Dioxide Cathode for a Rechargeable Alkaline Cell and Cell Containing the 5 Same discloses one such method. In this method, a plastic disk is placed in the bottom of the cell. Then a convolute separator barrier is placed on the disk and a hot melt material is metered to the inside of the separator barrier so that a seal forms only at the interior surface of the separator barrier. An example of a cell constructed in this way is depicted in FIG. 1. Battery 20 Technologies, Inc. of Richmond Hill, Ontario, Canada has manufactured batteries having such a structure.
During repeat cycling of alkaline m~ng~nese dry cells, it is critical to ensure that adequate barrier protection is formed and m~int~ined between the cathode and the anode. With the design depicted in FIG. 1, it is possible for anodic zinc to migrate through the absoll~n~ and over the top of the plastic disk thereby creating a shorting p~lhw~y to the cathode, as depicted in FIG. 2. Additionally, the m~nllf~ctl-re of this type of cell involves additional steps, e.g., the disk must be constructed and then placed within the cell and the cell must be spun during metering of the hot melt.
Another method to prevent shorting (specifically in recllalgeable ~lk~lin~ zinc m~ng~qnese dioxide cells) utilizes a separator tube as part of a barrier system to prevent an abrupt capacity loss due to shorting experienced in cells after extended cycle life. There are three separate approaches, all using a barrier system assembled outside the cell and kept in place in the cell by a hot melt sealant. The first approach involves using a separator tube having only one open end. The closed end of the ~epa~lor tube is affixed to the bottom of the cell with a hot melt sealant. The second approach affixes a separator tube on a plastic disk which is affixed to the bottom of the cell with a hot melt sealant, whereas in the third approach the s~al~l~r tube is bent inward before being affixed to the plastic disk.
Since the s~or tubes all involve completely sealed arrangements, difficulties are encountered in obtaining a sufficient distribution of electrolyte, i.e., the apl)ropliate electrolyte gradient between the electrodes. In order to overcome this problem, several additional m~nllf~cturing steps must be taken. Additionally, the insertion of a separator assembly into ~e cell fi~her reduces ~e speed in wl~ich b~tt~ri~ can be manufactured l.~ 7in~ the above me~od.
Therefore, an object of the present invention is to provide a S rechargeable ~Ik~line m~ng~n.~se dry cell with an in~ tin~ barrier at the positive (cathode) end of the cell that completely separates the cathode and anode compartments.
Another objea of the present invention is to provide continuous protection against shorting on cycled discharges in rechargeable ?l~ ine m~n~anese dry cells and batteries.
Yet another object of the present invention is to provide re-:hafgeable ~Ik~line mang~nese dioxide cells and batteries having a simplified overall desigrL
Still another object of the present invention is to provide rechargeable ~Ik~line m~ngan~ose dioxide cells and batteries that are easy to m~n~lf~c~lre~
Other objects and advamages of the present invention will be apparent from the drawings and the description of the invention.
SUMMARY OF T~E INVENllOI~
The present invention achieves these and other objects by placing a separator barrier into the cell. metering a hot melt sealant into the cell so that the sealant flows under the separator barrier, and pushing the separator barrier down. and seating the separator barrier into the hot melt. The end result is a sealed tube formed at ~e bottom of the cell. I;~el s~parator ~arrier should be placed above the bottom ot the cell.
The present invention eliminates the possibilitv of a short path developing between the anode and the cathode via a space bet~een the cell S bottom and a plastic disk that e.Yists in prior art designs. Furthermore, the present invention greatly simplifies the manufacturing process, since the plastic disk is eliminated -- there is no need to form or place the disk in the bottom of the cell and there is no longer any requirement to spin the cell during hot melt metering.
10 BRIEF DESCRIPl~ON OF T~IE DRAWINGS
FIG l depicts a prior art cell design in cross section.
FIG 2 depicts the shor~t path in the prior art cell depicted in FIG l.
FIG 3 illustrates a cell design of the present invention shown in cross section.
FIG ~ depicts the blocking of the short path m the cell depicted in FIG 3 according to the present invention.
FIG S depicts the test results of the amount of charge required to recharge a cell for several charge/discharge cycles when the cell was discharged by 300 mAHr, for a cell constructed according to the present 20 invention and a cell constructed according to FIG 1.
FIG 6 depicts the test results of the amount of charge required to recharge a cell for several charge/discharge cycles when the cell was ~1 02065 disch~ged by 60OrnAHr, for a cell co~11u~d accol~l~ to the present invention and a cell cons~ucted a~ .lillg to FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIGS. 3 and 4 depict a cell co~l~u~,1ed accordillg to ~e present invention.
5 The cell is disposed w~thin a ~;ylill~;cal can 20, in coll~ ,tional manner.
The ~I;~"]. ;r~1 anode 1 is separated from the .;~ I ca~ode 3 by the se~t~
barrier 5 having an ~~ t layer 6. The sepa~tor balrier S having an al)s~ layer 6 is formed by winding m~t~n~l fiom a fi~t roll of separator m ~ Wi~ m~7,-i~l from a second roll of alK~rl~ t ...~ l onto a 10 cylindrical mandrel of appropriate ~ neter such that both the absorbent material and the separator material are wound ~wice around the mandrel.
thereby forming a convolute separator barrier. The separator barrier and the absorbent are wound together in convolute fashion so that the outside diameter of the cylindrically shaped separator barrier is less than the inner diameter of the cathode. This allows the separator barrier- to be easily 15 inserted into the central cavity ~luring manu&cturing. During and after the manufacturing process, the convolute separator barrier terids to unra~el and push against the inner cathode wall, which ensures that the electrolyte functions properly since the electrolyte becomes in contact with the- anode and cathode. It is to be understood that other types of separator barriers 20 having absorbent layers or absorbent properties are contemplated in the present invention. ~vhich is not contine(3 to separator barriers of the convolute tvpe.
~,a The separator barrier 5 is then placed into the cell, e.g., a~ro~ lately 1/8 inch off the bottom of the cell. A hot melt type sealant 7 is then metered directly onto the bottom of the cell. In this step, hot melt type sealant No. 34/2771 manufactured by National Starch, Inc. of Bridgewater, New Jersey, and which is an undirrelc~ teA, subst~nti~lly homogeneous liquid at tempe,dl-ues exceeAing its melting te~llpeld~ule and an undiffer~nti~t~A, subst~nti~lly homogeneous solid at room ten~cldlu~, is metered directly into the cell at a telll~eldlule of about 340~F and at a l,res~ule of about 200 p.s.i. The te",l)e,dlule range over which this sealant operates for the purposes described herein is between 300~F and 370~F.
After a short delay, e.g., al~p~ illlately one to ten seconds, which short delay depends on the viscosity and initial l~"ll)eldlure of the hot melt sealant, while the sealant 7 is still in fluid form, the se~ald~or barrier 5 is pushed down and seated directly into the sealant 7, but does not engage the boKom of the cell. The act of pushing the separator barrier down causes the sealant 70 trapped between the cathode 3 and the barrier 5 to deform the boKom of the barrier 50 radially inwardly, as shown in Figure 3. Thus, a continuous seal is formed around and under the separator barrier. Thus, hot melt sealant forms on both the outer circumference and the inner cir.;ulllfelellce of the separator barrier, as well as urlA~ th the separator barrier. Thus, all short paths 10 existing in prior art designs are elimin~te l It is to be understood that the length of the short delay will depend on the viscosity of the sealant used, and the tt;~ eldlule at which the sealant is metered into the cell, however, three to five seconds has also proved advantageous.
. ~
'~- 21 02065 The reason for the short delay is that the hot melt sealant cools faster at the bottom of the cell and at lhe surface that touches the cathode than - 7a-melt sealant. the separator barrier will not touch the bottom ot the cell because the lowest laver of hot melt sealant has alreadv solidified.
As depicted in FIG ~, for a cell constructed as shown in FIG 1, with the sealant 7 applied only within the inner circumference of the separator S barrier 5, anodic zinc can migrate into the porous absorbent layer 6 of the - se~ lol balTier and above ~e bottom disk to reach ~e ca~ode. The present invention ~)lCVt;lll~ is short path 11 from developing by en.~lrin~ that hot melt exists between the exterior and the interior surfaces of the separator barrier as well as underneath the separator barrier. As depicted in FIG 4, the 10 sealant blocks the migration of the anodic zinc to the cathode.
The present invention also yrGve~ a short from occuI~ing at ~e edges or bottom of the separator barrier. Although the separator and absorbent are wound together, they do not perfec~ly overlie one another. Interstitial gaps occur at the edges of the bottom of the separator barrier. When the 15 separator barrier is pushed down into the hot melt sealant, the hot melt sealant goes up into these interstitial gaps and fills them, thus preventing shorts from occurring at these interstitial voids.
The manufacturing of the rechargeable alkaline manganese cell is significantly improved by eliminating the bottom disk described in U.S. Patent ~0 ~'o. 5,108,852. ~o forming or placing of the disk is required, and there is no longer any requirement to spin the cell during hot melt metering, as was required in the prior art. Thus, the present invention removes the possibility of shorting be~ween the cathode and anode that was present in prior art b ~
designs, yet simultaneously reduces the complexitv of the manufacturing process.
To determine the effectiveness of the short protection provided by batteries constructed according to the present invention as compared to 5 batteries constructed according to the design illustrated in FIG 1, cells of both designs were discharged by 300 mAhr and 600 mAhr. After being discharged by the requisite amount, the batteries were taken off load for four hours to allow shorts to develop. The batteries were then recharged for ten hours. If batteries do not have shorts between their electrodes, the charge 10 necessary to recharge should be equal to the charge removed during discharge.
Figures S and 6 show the results of these discharge tests. Cells constructed according to the present invention (denoted as seated seal in FlGs 5 and 6) required approximately the same charge as that removed 15 during discharge, i.e., they exhibited no shorting after eight cycles when discharged by 300 mAHr, and after five cycles when discharged by 600 mAHr. In contrast, cells constructed according to FIG I (denoted as ID seal in FIGs 5 and 6) required significantly more charge than that removed during discharge under both discharge conditions, even after a few charge/discharge ~0 cycles, i.e., they exhibited evidence of significant shorting after very few cycles. For example, after only eight charge discharge cycles, the cells constructed according FIG 1, required over four times the amount of charge than that removed during discharge, i.e., 1,200 mAHr were required to charge the cell when it had been discharged by 300 mAHr. Thus, cells constructed 21~2~6~
according lo the present invention do not contain the shorts that develop in cells constructed according lo the designed depicted in FIG 1.
While the invenliOn has been described with reference to specific embodiments, it will be apparent to those skilled in the art that many modifications and variations may be made. Accordingly, the present invention is intended to embrace all such alternatives~ modifications and variations that may fall within the spirit and scope of the appended claims and e~uivalents thereof.
Claims (49)
1. A method for making a battery cell having an anode and a cathode, comprising the steps of:
a) placing a separator barrier propinquant to the cathode so that a space remains between the bottom of the separator barrier and the bottom of the cell;
b) metering a hot melt sealant into the cell so that the hot melt sealant flows under the separator barrier and completely seals off the bottom of the cell; and c) pushing the separator barrier down and seating the separator barrier into the hot melt sealant, thus forming a seal both at the exterior and the interior of the separator barrier at the bottom of the cell.
a) placing a separator barrier propinquant to the cathode so that a space remains between the bottom of the separator barrier and the bottom of the cell;
b) metering a hot melt sealant into the cell so that the hot melt sealant flows under the separator barrier and completely seals off the bottom of the cell; and c) pushing the separator barrier down and seating the separator barrier into the hot melt sealant, thus forming a seal both at the exterior and the interior of the separator barrier at the bottom of the cell.
2. The method according to claim 1, wherein said pushing step occurs following a short delay after said metering step.
3. The method according to claim 1, wherein said hot melt sealant is metered into the bottom of the cell at a temperature between about 310°F and 370°F.
4. The method according to claim 2, wherein said hot melt sealant is metered into the bottom of the cell at a temperature between about 310°F and 370°F.
5. The method according to claim 1, wherein said hot melt sealant is metered into the bottom of the cell at a temperature about 340°F.
6. The method according to claim 2, wherein said hot melt sealant is metered into the bottom of the cell at a temperature about 340°F.
7. The method according to claim 1, wherein said space is about 0.125 inches in height.
8. The method according to claim 2, wherein said space is about 0.125 inches in height.
9. The method according to claim 2, wherein said short delay is approximately one to ten seconds.
10. The method according to claim 2, wherein said short delay is approximately three to five seconds.
11. A method for making a battery cell having an inner anode and an outer cathode with an inner void, a separator barrier having a bottom edge, and having an inner anode wall and an outer cathode being disposed between the cathode and the anode, the outer cathode wall being disposed propinquant to the cathode and the inner anode wall being disposed propinquant to the anode, comprising the steps of:
a) placing the separator barrier inside the inner void and propinquant to the cathode, the region between the bottom edge of the barrier separator and the bottom of the cell forming a space therebetween;
b) metering a hot melt sealant inside the separator barrier and onto the bottom of the cell, the hot melt sealant flowing under the bottom edge of the barrier separator, engaging the inner wall of the cathode, occupying the space, and forming a complete seal on the bottom of the cell, and c) pushing separator barrier down and seating the barrier separator into the hot melt sealant, the hot melt sealant engaging and surrounding completely the bottom portions of the inner and outer walls of the separator barrier and the bottom edge of the separator barrier.
a) placing the separator barrier inside the inner void and propinquant to the cathode, the region between the bottom edge of the barrier separator and the bottom of the cell forming a space therebetween;
b) metering a hot melt sealant inside the separator barrier and onto the bottom of the cell, the hot melt sealant flowing under the bottom edge of the barrier separator, engaging the inner wall of the cathode, occupying the space, and forming a complete seal on the bottom of the cell, and c) pushing separator barrier down and seating the barrier separator into the hot melt sealant, the hot melt sealant engaging and surrounding completely the bottom portions of the inner and outer walls of the separator barrier and the bottom edge of the separator barrier.
12. The method according to claim 11, wherein the pushing step occurs a short delay after the metering step.
13. The method according to claim 11, wherein the pushing step occurs after the hot melt sealant has cooled where the sealant contacts the cathode and the bottom of the cell but not where the sealant contacts the separator barrier.
14. The method according to claim 12, wherein the short delay is between about one to ten seconds.
15. The method according to claim 12, wherein the short delay is between about three to five seconds.
16. The method according to claim 11, wherein said space is about 0.125 inches.
17. The method according to claim 11, wherein the metering step occurs when the hot melt sealant reaches a temperature of between about 310°F and 370°F.
18. The method according to claim 11, wherein the metering step occurs when the hot melt sealant reaches a temperature of about 340°F.
19. A method for making a battery cell having an inner anode and an outer cathode with an inner void, a separator barrier having a bottom edge, an inner wall and an outer wall with bottom portions, wherein the separator barrier is disposed between the cathode and the anode, the method comprising the steps of:
a) placing the separator barrier within the cathode void to define a region between the bottom edge of the barrier separator and the bottom of the cell;
b) metering a hot melt sealant inside the separator barrier and onto the bottom of the cell, the hot melt sealant flowing under the bottom edge of the separator barrier, engaging the inner wall of the cathode, occupying the region, and forming a complete seal on the bottom of the cell; and c) pushing the separator barrier down and seating the separator barrier into the hot melt sealant, and deforming the separator barrier bottom radially inwardly, the hot melt sealant engaging and surrounding completely the deformed bottom portions of the inner and outer walls of the separator barrier and the bottom edge of the separator barrier.
a) placing the separator barrier within the cathode void to define a region between the bottom edge of the barrier separator and the bottom of the cell;
b) metering a hot melt sealant inside the separator barrier and onto the bottom of the cell, the hot melt sealant flowing under the bottom edge of the separator barrier, engaging the inner wall of the cathode, occupying the region, and forming a complete seal on the bottom of the cell; and c) pushing the separator barrier down and seating the separator barrier into the hot melt sealant, and deforming the separator barrier bottom radially inwardly, the hot melt sealant engaging and surrounding completely the deformed bottom portions of the inner and outer walls of the separator barrier and the bottom edge of the separator barrier.
20. The method according to claim 19, wherein the pushing step occurs a short delay after the metering step.
21. The method according to claim 20, wherein the short delay is between about one to ten seconds.
22. The method according to claim 20, wherein the short delay is between about three to five seconds.
23. The method according to claim 19, wherein the pushing step occurs after the hot melt sealant has cooled where the sealant contacts the cathode and the bottom of the cell but not where the sealant contacts the separator barrier.
24. The method according to claim 19, wherein said region has a height of about 0.125 inches.
25. The method according to claim 19, wherein the metering step occurs when the hot melt sealant reaches a temperature of between about 310°F and 370°F.
26. The method according to claim 19, wherein the metering step occurs when the hot melt sealant reaches a temperature of about 340°F.
27. A method for making a battery having an anode and a cathode and a container therefor, wherein the container has a bottom, the method comprising the steps of:
a) placing a separator barrier having a bottom edge within the container so that a space remains between the bottom of the separator barrier and the bottom of the container;
b) metering a hot melt sealant into the container so that the hot melt sealant flows under the separator barrier and completely seals off the bottom of the container;
and c) pushing the separator barrier down into the hot melt sealant to deform the separator barrier bottom edge to extend radially inwardly within the sealant, thus forming a seal which surrounds the separator barrier bottom edge which is spaced above the bottom of the container.
a) placing a separator barrier having a bottom edge within the container so that a space remains between the bottom of the separator barrier and the bottom of the container;
b) metering a hot melt sealant into the container so that the hot melt sealant flows under the separator barrier and completely seals off the bottom of the container;
and c) pushing the separator barrier down into the hot melt sealant to deform the separator barrier bottom edge to extend radially inwardly within the sealant, thus forming a seal which surrounds the separator barrier bottom edge which is spaced above the bottom of the container.
28. The method of claim 27, wherein the separator barrier comprises at least one absorbent layer.
29. The method of claim 27, wherein the separator barrier is convoluted with a plurality of layers and interstitial gaps are defined between the bottom edges of the separator layers and hot melt sealant fills at least a portion of said gaps in the pushing step.
30. A method for making a battery having a container with a bottom, an inner anode, an outer cathode with an inner void, and a separator barrier having a bottom edge, an inner wall, and an outer wall with bottom portions, wherein the separator barrier is disposed between the cathode and the anode, the method comprising the steps of:
a) placing the separator barrier within the cathode void to define a region between the bottom edge of the barrier separator and the bottom of the container;
b) disposing a quantity of hot melt sealant into the container, the hot melt sealant flowing under the bottom edge of the separator barrier, occupying the region, and forming a seal on the bottom of the cell;
c) pausing to allow a portion of the hot melt sealant to solidify, from the bottom up;
and d) pushing the separator barrier down into engagement with the solidified portion of the hot melt adhesive, thus seating the separator barrier into the hot melt sealant, the hot melt sealant engaging and surrounding the inner and outer walls of the separator barrier and the bottom edge of the separator barrier.
a) placing the separator barrier within the cathode void to define a region between the bottom edge of the barrier separator and the bottom of the container;
b) disposing a quantity of hot melt sealant into the container, the hot melt sealant flowing under the bottom edge of the separator barrier, occupying the region, and forming a seal on the bottom of the cell;
c) pausing to allow a portion of the hot melt sealant to solidify, from the bottom up;
and d) pushing the separator barrier down into engagement with the solidified portion of the hot melt adhesive, thus seating the separator barrier into the hot melt sealant, the hot melt sealant engaging and surrounding the inner and outer walls of the separator barrier and the bottom edge of the separator barrier.
31. A battery cell, comprising:
a) an anode;
b) a cathode;
c) a separator barrier preventing a short from developing between the anode and cathode, and being disposed between the anode and the cathode so that a space remains between the bottom of the separator barrier and the bottom of the cell;
and d) a meltable sealant completely occupying the space between the bottom of the cell and the bottom of the separator barrier, forming a seal at both exterior and interior surfaces of the separator barrier, and completely sealing off the bottom of the cell.
a) an anode;
b) a cathode;
c) a separator barrier preventing a short from developing between the anode and cathode, and being disposed between the anode and the cathode so that a space remains between the bottom of the separator barrier and the bottom of the cell;
and d) a meltable sealant completely occupying the space between the bottom of the cell and the bottom of the separator barrier, forming a seal at both exterior and interior surfaces of the separator barrier, and completely sealing off the bottom of the cell.
32. The battery of claim 31, wherein the separator barrier extends into the meltable sealant, and the separator barrier bottom extends radially inwardly within the meltable sealant, the meltable sealant engaging and surrounding completely the bottom portions of the inner and outer walls of the separator barrier and the bottom edge of the separator barrier.
33. The battery of claim 31, wherein the separator barrier comprises at least one absorbent layer.
34. The battery of claim 31, wherein the separator barrier is convoluted with a plurality of layers and intersittial gaps are defined between the bottom edges of the separator layers and meltable sealant fills at least a portion of said gaps.
35. The battery of claim 31, wherein the separtor barrier extends down into the meltable sealant to deform the separator barrier bottom edge to extend radially inwardly within the sealant, thus forming a seal which surrounds the separator barrier bottom edge.
36. A battery cell comprising:
a) an outer cathode having an inner void;
b) an inner anode disposed in the inner void, the bottommost portion of the inner void forming a space;
c) a separator barrier having a bottom edge and inner and outer walls, the outer wall being disposed propinquant to the cathode and the inner wall being disposed propinquant to the anode, the separator barrier being disposed between the anode and cathode, the bottom edge being disposed in the space and the sealant engaging the bottommost portion of the cathode inner wall; and d) a hot melt sealant completely occupying the space, and engaging and surrounding completely the bottom portions of the inner and outer walls of the separator barrier and the bottom edge of the separator barrier and forming a complete seal in the bottom of the cell, the hot melt sealant and barrier separator inhibiting the occurrence of shorts between the anode and the cathode.
a) an outer cathode having an inner void;
b) an inner anode disposed in the inner void, the bottommost portion of the inner void forming a space;
c) a separator barrier having a bottom edge and inner and outer walls, the outer wall being disposed propinquant to the cathode and the inner wall being disposed propinquant to the anode, the separator barrier being disposed between the anode and cathode, the bottom edge being disposed in the space and the sealant engaging the bottommost portion of the cathode inner wall; and d) a hot melt sealant completely occupying the space, and engaging and surrounding completely the bottom portions of the inner and outer walls of the separator barrier and the bottom edge of the separator barrier and forming a complete seal in the bottom of the cell, the hot melt sealant and barrier separator inhibiting the occurrence of shorts between the anode and the cathode.
37. The battery of claim 36, wherein the separator barrier extends into the hot melt sealant, and the separator barrier bottom extends radially inwardly within the hot melt sealant, the hot melt sealant engaging and surrounding completely the bottom portions of the inner and outer walls of the separator barrier and the bottom edge of the separator barrier.
38. The battery of claim 36, wherein the separator barrier comprises at least one absorbent layer.
39. The battery of claim 36, wherein the separator barrier is convoluted with a plurality of layers and interstitial gaps are defined between the bottom edges of the separator layers and hot melt sealant fills at least a portion of said gaps.
40. The battery of claim 36, wherein the separator barrier extends down into the hot melt sealant to deform the separator barrier bottom edge to extend radially inwardly within the sealant, thus forming a seal which surrounds the separator barrier bottom edge.
41. A battery cell comprising:
a) a battery can having a bottom;
b) an anode disposed within the can;
c) a cathode disposed within the can;
d) a separator barrier disposed between the anode and cathode and positioned above the battery can bottom, wherein the separator barrier prevents a short from developing between the anode and cathode; and e) a hot melt glue which engages the bottom of the can and extends upwardly to engage the separator barrier, wherein the hot melt glue forms a barrier between the anode and the cathode.
a) a battery can having a bottom;
b) an anode disposed within the can;
c) a cathode disposed within the can;
d) a separator barrier disposed between the anode and cathode and positioned above the battery can bottom, wherein the separator barrier prevents a short from developing between the anode and cathode; and e) a hot melt glue which engages the bottom of the can and extends upwardly to engage the separator barrier, wherein the hot melt glue forms a barrier between the anode and the cathode.
42. The battery of claim 41, wherein the separator barrier extends into the hot melt sealant, and wherein portions of the separator barrier extend radially inwardly within the hot melt sealant, the hot melt sealant engaging and surrounding said barrier portions.
43. The battery of claim 41, wherein the separator barrier comprises at least one absorbent layer.
44. The battery of claim 41, wherein the separator barrier is convoluted with a plurality of layers and interstitial gaps are defined between bottom edges of the separator layers and hot melt sealant fills at least a portion of said gaps.
45. A rechargeable alkaline manganese dioxide round cell, comprising:
a) a cylindrical container comprising a closed first end forming a bottom, an initially open second end, and upstanding sidewalls, the bottom and upstanding sidewalls having inner surfaces, b) a cylindrically-shaped annular cathode disposed within the container and comprising manganese dioxide, the cathode having outer and inner peripheral sidewalls, the outer peripheral sidewalls being disposed propinquant to the inner surface of the upstanding sidewals, the inner peripheral sidewalls forming a central cylindrically shaped void, the bottommost portion of the void forming a space;
c) a cylindrically-shaped anode having outer peripheral sidewalls and comprising zinc, the anode being disposed within the void;
d) a cylindrically-shaped separator having a bottom edge, an inner sidewall, and an outer sidewall, the separator being disposed between the outer peripheral sidewalls of the anode and the inner peripheral sidwalls of the cathode, the bottom edge being disposed within the space; and e) a hot melt barrier disposed in the bottom of the container and completely occupying the space, the barrier engaging and surrounding completely the bottom edge and portions of the inner and outer separator sidewalls propinquant to the bottom edge, the barrier forming a seal for inhibiting the occurrence of electrical shorts between the anode and the cathode, the barrier comprising an undifferentiated, substantially homogeneous solid hot melt material at room temperature, the hot melt material being an undifferentiated, substantially homogeneous, form-fitting liquid at temperatures exceeding its melting temperature.
a) a cylindrical container comprising a closed first end forming a bottom, an initially open second end, and upstanding sidewalls, the bottom and upstanding sidewalls having inner surfaces, b) a cylindrically-shaped annular cathode disposed within the container and comprising manganese dioxide, the cathode having outer and inner peripheral sidewalls, the outer peripheral sidewalls being disposed propinquant to the inner surface of the upstanding sidewals, the inner peripheral sidewalls forming a central cylindrically shaped void, the bottommost portion of the void forming a space;
c) a cylindrically-shaped anode having outer peripheral sidewalls and comprising zinc, the anode being disposed within the void;
d) a cylindrically-shaped separator having a bottom edge, an inner sidewall, and an outer sidewall, the separator being disposed between the outer peripheral sidewalls of the anode and the inner peripheral sidwalls of the cathode, the bottom edge being disposed within the space; and e) a hot melt barrier disposed in the bottom of the container and completely occupying the space, the barrier engaging and surrounding completely the bottom edge and portions of the inner and outer separator sidewalls propinquant to the bottom edge, the barrier forming a seal for inhibiting the occurrence of electrical shorts between the anode and the cathode, the barrier comprising an undifferentiated, substantially homogeneous solid hot melt material at room temperature, the hot melt material being an undifferentiated, substantially homogeneous, form-fitting liquid at temperatures exceeding its melting temperature.
46. The cell of claim 45, wherein the bottom edge is propinquant to the inner surface of the bottom of the container.
47. The cell of claim 45, wherein the separator comprises at least one absorbent layer.
48. The cell of claim 45, wherein the separator is convoluted, and has a plurality of layers, with interstitial gaps being defined between the bottom edges of the separator layers and the hot melt sealant barrier filling at least a portion of the gaps.
49. The cell of claim 45, wherein the bottom edge of the separator extends radially inwardly within the hot melt barrier.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US07/968,896 US5324332A (en) | 1992-10-30 | 1992-10-30 | Alkaline manganese dioxide cells |
| US968,896 | 1992-10-30 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2102065A1 CA2102065A1 (en) | 1994-05-01 |
| CA2102065C true CA2102065C (en) | 1998-07-21 |
Family
ID=25514909
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002102065A Expired - Fee Related CA2102065C (en) | 1992-10-30 | 1993-10-29 | Alkaline manganese dioxide cells |
Country Status (2)
| Country | Link |
|---|---|
| US (2) | US5324332A (en) |
| CA (1) | CA2102065C (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5837398A (en) * | 1996-09-26 | 1998-11-17 | Three Bond Co., Ltd. | Radiation curable sealing material for batteries |
| US5789102A (en) * | 1996-12-04 | 1998-08-04 | Rayovac Corporation | Alkaline cell and separator therefor |
| US6099987A (en) * | 1998-07-24 | 2000-08-08 | Battery Technologies Inc. | Cylindrical electrochemical cell with cup seal for separator |
| US6126704A (en) * | 1998-08-27 | 2000-10-03 | Duracell Inc. | Method of forming a terminal pip protrusion on the casing of an alkaline cell |
| US6265104B1 (en) * | 1999-08-13 | 2001-07-24 | The Gillette Company | Hot-melt seal for metal-air battery |
| US6489054B2 (en) | 2001-04-19 | 2002-12-03 | Zinc Matrix Power, Inc. | Battery case with edge seal |
| EP2352185A1 (en) * | 2003-10-28 | 2011-08-03 | Johnson Controls Techonology Company | Battery container with improved heat dissipation |
| KR20250158995A (en) * | 2023-03-06 | 2025-11-07 | 다이니폰 인사츠 가부시키가이샤 | Storage device, barrier film, cover unit, and method for manufacturing cover unit |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1370054A (en) * | 1920-05-15 | 1921-03-01 | Burgess Battery Co | Dry cell and method of manufacturing the same |
| US2389674A (en) * | 1941-04-30 | 1945-11-27 | Burgess Battery Co | Method of making dry batteries |
| US2605298A (en) * | 1949-11-05 | 1952-07-29 | Union Carbide & Carbon Corp | Dry cell |
| US3318737A (en) * | 1963-12-25 | 1967-05-09 | Matsushita Electric Industrial Co Ltd | Alkali dry cells |
| US3364073A (en) * | 1966-12-01 | 1968-01-16 | Patent Holding Corp | Primary battery |
| US3617384A (en) * | 1969-11-07 | 1971-11-02 | Hitachi Maxell | Zinc alkaline secondary cell |
| FR2123618A5 (en) * | 1971-01-25 | 1972-09-15 | Accumulateurs Fixes | |
| US4037030A (en) * | 1975-03-31 | 1977-07-19 | Gould Inc. | Storage battery and method of forming the same |
| US4075398A (en) * | 1976-10-26 | 1978-02-21 | Esb Incorporated | Means of providing pressure relief to sealed galvanic cell |
| US4174565A (en) * | 1977-06-28 | 1979-11-20 | Union Carbide Corporation | Method of precharging rechargeable metal oxide-hydrogen cells |
| US4654963A (en) * | 1979-11-21 | 1987-04-07 | General Electric Company | Method for making electrochemical cell having cast-in-place insulator |
| US4320182A (en) * | 1979-11-21 | 1982-03-16 | General Electric Company | Electrochemical cell having cast-in-place insulator |
| US4515187A (en) * | 1982-05-07 | 1985-05-07 | Gnb Batteries Inc. | Compound dispensing method and apparatus |
| US4618547A (en) * | 1983-10-06 | 1986-10-21 | Duracell Inc. | Leak resistant non-tacky sealant |
| CA1265189A (en) * | 1984-08-17 | 1990-01-30 | Gregory S. Kulibert | Seal for alkaline primary battery |
| JPS62136748A (en) * | 1985-12-10 | 1987-06-19 | Seiko Electronic Components Ltd | Manufacturing method of flat plate lithium battery |
| CH669479A5 (en) * | 1986-12-09 | 1989-03-15 | Leclanche Sa | Chargeable manganese di:oxide-zinc battery - with hot melt adhesive sealing separate membrane |
| KR920004316B1 (en) * | 1987-08-28 | 1992-06-01 | 마쯔시다덴기산교 가부시가기아샤 | Alkaline battery |
| CA1295364C (en) * | 1988-07-08 | 1992-02-04 | Battery Technologies Inc. | Rechargeable alkaline manganese cells with zinc anodes |
| US4857424A (en) * | 1988-10-11 | 1989-08-15 | Rayovac Corporation | Zinc alkaline electrochemical cells with reduced mercury anodes |
| US5001024A (en) * | 1989-10-31 | 1991-03-19 | Eberle William J | Storage battery and method of manufacturing |
| US5108852A (en) * | 1990-03-23 | 1992-04-28 | Battery Technologies Inc. | Manganese dioxide cathode for a rechargeable alkaline cell, and cell containing the same |
| HU914046D0 (en) * | 1991-12-19 | 1992-04-28 | Environmetal Batteries Systems | Cylindrical alkaline manganese dioxide zinc cell with improved lower sealing |
-
1992
- 1992-10-30 US US07/968,896 patent/US5324332A/en not_active Expired - Fee Related
-
1993
- 1993-10-29 CA CA002102065A patent/CA2102065C/en not_active Expired - Fee Related
-
1994
- 1994-06-10 US US08/257,569 patent/US5462819A/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| US5324332A (en) | 1994-06-28 |
| US5462819A (en) | 1995-10-31 |
| CA2102065A1 (en) | 1994-05-01 |
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