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TEPZZ￥54Z8￥7A_T
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EP3 540 837A1
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(43)Date of publication:
EUROPEAN PATENT APPLICATION
(51)Int Cl.:
H01M6/04(2006.01)H01M4/24(2006.01)
H01M10/24(2006.01)H01M4/62(2006.01)
18.09.2024Bulletin2024/38
(21)Application number: 19163002.9(22)Date of filing: 14.03.2024(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TRDesignated Extension States: BA ME
Designated Validation States: KH MA MD TN
(72)Inventors:
?Liu, Zhufang
Westlake, OH Ohio 44145 (US)?Freeman, Dawn Marie
Westlake, OH Ohio 44145 (US)
(74)Representative: Bradley, Josephine Mary
Marks & Clerk LLP 40 Torphichen StreetEdinburgh EH3 8JB (GB)
Remarks:
Claims filed after the date of filing of the application (Rule 68(4) EPC).
(30)Priority:15.03.2024US 202415922530(71)Applicant: Energizer Brands, LLC
St. Louis, Missouri 63141 (US)
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LONG-CHAIN SURFACTANTS FOR IMRPOVING BATTERY PERFORMANCE
Alkaline electrochemical cells are provided, wherein a long-chain surfactant is included in at least one component
of the cell in order to delay anode shutdown. Methods for preparing such cells are also provided.
EP3 540 837A1Printed by Jouve, 75001 PARIS (FR)
EP3 540 837A1
DescriptionBACKGROUND
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[0001]Alkaline electrochemical cells are commercially available in cell sizes commonly known as LR6 (AA), LR03(AAA), LR14 (C) and LR20 (D). The cells have a cylindrical shape that must comply with the dimensional standards thatare set by organizations such as the International Electrotechnical Commission. The electrochemical cells are utilizedby consumers to power a wide range of electrical devices, for example, clocks, radios, toys, electronic games, filmcameras generally including a flashbulb unit, as well as digital cameras. Such electrical devices possess a wide rangeof electrical discharge conditions, such as from low drain to relatively high drain.
[0002]As the shape and size of the batteries are often fixed, battery manufacturers must modify cell characteristicsto provide increased performance. Attempts to address the problem of how to improve a battery’s performance in aparticular device, such as a digital camera, have usually involved changes to the cell’s internal construction. For example,cell construction has been modified by increasing the quantity of active materials utilized within the cell.
[0003]Early anode shutdown is one of the major causes of poor service in moderate-drain tests. In anode shutdown,the anode discharge products (i.e. ZnO) passivate the Zn particle surface and block the Zn discharge. In addition, thedense discharge/reaction zone close to the anode/separator interface could also block the H2O and OH- transport andcause early anode shutdown. Anode shutdown becomes even more problematic for designs with low anode KOHconcentration (i.e. 24-28 Wt.% KOH) or coarse zinc materials.
[0004]Generally, anode shutdown can be mitigated by adding more electrolytes in the alkaline cells, but this willreduce the volumetric space for active materials (Zn and MnO2) and negatively impact the cell capacity. Anode shutdownissues can also be mitigated by increasing the concentration of KOH electrolyte, but this will increase the cell leakagerate and the cell direct-short temperature.
[0005]It is in an effort to overcome the limitations of the above-described cells, and other such cells, that the presentembodiments were designed.BRIEF SUMMARY[0006]
An embodiment is an alkaline electrochemical cell, comprising:
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a) a container; and
b) an electrode assembly disposed within the container and comprising a cathode, an anode, a separator locatedbetween the cathode and the anode, an alkaline electrolyte solution, and a long-chain surfactant.
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[0007]An embodiment is a method of producing the above-described electrochemical cell, wherein the anode com-prises the long-chain surfactant, said method comprising combining the long-chain surfactant with i) anode dry mixcontaining Zn powder and ii) gelled electrolyte, or with anode paste comprising Zn and gelled electrolyte.
[0008]An embodiment is a method of producing the above-described electrochemical cell, wherein the anode com-prises the long-chain surfactant, comprising the steps:
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1) adding the long-chain surfactant to anode dry mix containing Zn powder; and2) blending the anode dry mix with gelled electrolyte;
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orii)
1) adding the long-chain surfactant to gelled electrolyte; and
2) blending anode dry mix comprising Zn with the gelled electrolyte;oriii)
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1) adding the long-chain surfactant to anode paste comprising Zn and gelled electrolyte;oriv)
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EP3540837A1LONGCHAINSURFACTANTSFORIMRPOVINGBATTE
