WO2021193407A1 - Zinc secondary battery - Google Patents

Abstract

This zinc secondary battery is configured such that electrical short-circuiting of a positive electrode current collector and a negative electrode current collector is suppressed. This zinc secondary battery comprises a layered body, a positive electrode current collector tab, and a negative electrode current collector tab. The layered body comprises a positive electrode plate and a negative electrode plate. The positive electrode plate comprises a positive electrode current collector and a positive electrode active material layer. The negative electrode plate comprises a negative electrode current collector and a negative electrode active material layer. The positive electrode active material layer is disposed around the positive electrode current collector. The negative electrode active material layer is disposed around the negative electrode current collector. The positive electrode current collector tab is connected to the positive electrode current collector and protrudes in a first direction from the layered body. The negative electrode current collector tab is connected to the negative electrode current collector and protrudes in a second direction from the layered body. The first direction and the second direction are opposite directions to each other. The center of a range in which the negative electrode active material layer is disposed in the direction that is parallel to the first direction and the second direction is offset in the second direction from the center of a range in which the positive electrode active material layer is disposed.

Description

Zinc secondary battery

The present invention relates to a zinc secondary battery.

The laminated zinc secondary battery includes a laminated body in which a plurality of positive electrode plates and a plurality of negative electrode plates are laminated (see, for example, Patent Document 1). In the zinc secondary battery described in Patent Document 1, positive electrode plates and negative electrode plates are alternately laminated (paragraph 0012). Further, the positive electrode current collecting tab and the negative electrode current collecting tab project in opposite directions (paragraph 0011). Further, in the direction parallel to the direction in which the positive electrode current collecting tab and the negative electrode current collecting tab protrude, the center of the arrangement range of the positive electrode active material layer and the center of the arrangement range of the negative electrode active material layer coincide with each other ( Paragraph 0011 and FIG. 2).

Like the zinc secondary battery disclosed in Patent Document 1, the positive electrode activity is such that the positive electrode current collecting tab and the negative electrode current collecting tab protrude from the laminate in opposite directions and are parallel to the protruding directions of both. When the center of the arrangement range of the material layer and the center of the arrangement range of the negative electrode active material layer coincide with each other, the negative electrode current collector is near the base of the negative electrode current collector tab and near the end of the positive electrode current collector. The peripheral part is exposed, and the positive electrode current collector and the negative electrode current collector are likely to be electrically short-circuited.

International Publication No. 2019/077953

The present invention has been made to solve the above problems. An object to be solved by the present invention is to prevent an electrical short circuit between a positive electrode current collector and a negative electrode current collector in a zinc secondary battery.

The zinc secondary battery includes a laminate, a positive electrode current collecting tab, and a negative electrode current collecting tab.

The laminate includes a positive electrode plate and a negative electrode plate. The positive electrode plate includes a positive electrode current collector and a positive electrode active material layer. The negative electrode plate includes a negative electrode current collector and a negative electrode active material layer. The positive electrode active material layer is arranged around the positive electrode current collector. The negative electrode active material layer is arranged around the negative electrode current collector.

The positive electrode current collector tab is connected to the positive electrode current collector and protrudes from the laminated body in the first direction.

The negative electrode current collector tab is connected to the negative electrode current collector and protrudes from the laminated body in the second direction. The first direction and the second direction are opposite to each other.

Regarding the first direction and the direction parallel to the second direction, the center of the arrangement range of the negative electrode active material layer is deviated from the center of the arrangement range of the positive electrode active material layer in the second direction.

According to the present invention, it is possible to prevent the peripheral portion of the negative electrode current collector, which is near the base of the negative electrode current collector tab and near the end of the positive electrode current collector, from being exposed. As a result, it is possible to prevent the positive electrode current collector and the negative electrode current collector from being electrically short-circuited.

The purpose, features, aspects and advantages of the present invention will be made clearer by the following detailed description and accompanying drawings.

It is a perspective view which shows typically the zinc secondary battery. It is sectional drawing which shows typically the zinc secondary battery. It is sectional drawing which shows typically the zinc secondary battery. It is sectional drawing which shows typically the 1st structural example of the main part of the laminated battery provided in the zinc secondary battery. It is sectional drawing which shows typically the 2nd structural example of the main part of the laminated battery provided in the zinc secondary battery. It is sectional drawing which shows typically the main part of the laminated battery provided in the zinc secondary battery of a reference example. It is sectional drawing which shows typically the main part of the laminated battery provided in the zinc secondary battery. It is sectional drawing which shows typically the 1st structural example of the main part of the laminated battery provided in the zinc secondary battery. It is sectional drawing which shows typically the 2nd structural example of the main part of the laminated battery provided in the zinc secondary battery. It is sectional drawing which shows typically the main part of the laminated battery provided in the zinc secondary battery of a reference example.

1 Zinc secondary battery FIG. 1 is a perspective view schematically showing a zinc secondary battery 1 according to an embodiment of the present invention. 2 and 3 are cross-sectional views schematically showing the zinc secondary battery 1. FIG. 2 is a cross-sectional view taken at the position of the cutting line BB drawn in FIG. FIG. 3 is a cross-sectional view taken at the position of the cutting line AA drawn in FIG.

The zinc secondary battery 1 shown in FIGS. 1, 2 and 3 is a nickel-zinc battery. The zinc secondary battery 1 may be a zinc secondary battery other than the nickel-zinc battery.

The zinc secondary battery 1 includes a case 11 and a lid 12 as shown in FIGS. 1, 2 and 3. Further, as shown in FIGS. 2 and 3, the zinc secondary battery 1 includes a laminated battery 13, a positive electrode current collector plate 14, and a negative electrode current collector plate 15.

The laminated battery 13 includes a laminated body 101 in which a plurality of coated positive electrodes 131 and a plurality of coated negative electrodes 132 (see FIGS. 4 and 5) are laminated, a plurality of positive electrode current collecting tabs 102, and a plurality of negative electrode collections. It is provided with an electric tab 103. That is, the zinc secondary battery 1 includes a laminate 101, a plurality of positive electrode current collecting tabs 102, and a plurality of negative electrode current collecting tabs 103.

The plurality of positive electrode current collecting tabs 102 project from the laminated body 101 in the first direction DXP. Further, the plurality of negative electrode current collecting tabs 103 project from the laminated body 101 in the second direction DXN. FIG. 2 shows how one positive electrode current collecting tab 102 and one negative electrode current collecting tab 103 protrude. The second direction DXN is the direction opposite to the first direction DXP. As will be described later, the tips of the plurality of positive electrode current collector tabs 102 are aggregated and electrically connected to the positive electrode current collector plate 14. Further, the tips of the plurality of negative electrode current collector tabs 103 are aggregated and electrically connected to the negative electrode current collector plate 15.

The case 11 has an opening 11a. The case 11 houses the laminated battery 13 (laminated body 101, a plurality of positive electrode current collecting tabs 102 and a plurality of negative electrode current collecting tabs 103), a positive electrode current collecting plate 14, and a negative electrode current collecting plate 15. The lid 12 closes the opening 11a. As a result, the case 11 and the lid 12 form a closed container having a closed space. Further, the laminated battery 13, the positive electrode current collector plate 14, and the negative electrode current collector plate 15 are arranged in a closed space.

As shown in FIGS. 1, 2 and 3, the lid 12 includes a lid main body 111, a positive electrode terminal 112, and a negative electrode terminal 113.

The case 11 and the lid body 111 are made of an insulator having resistance to an electrolytic solution. The insulator is preferably a resin, more preferably a polyolefin resin, an acrylonitrile butadiene styrene (ABS) resin or a modified polyphenylene ether resin, and particularly preferably an ABS resin or a modified polyphenylene ether resin.

The case 11 has a rectangular parallelepiped box-like shape, and the case 11 accommodates a laminated body 101 having a plate-like and rectangular planar shape. More specifically, the case 11 includes a side wall 121, a side wall 122, a side wall 123, a side wall 124, and a bottom wall 125, as shown in FIGS. 1, 2, and 3. The side wall 121 and the side wall 122 are parallel to the laminated body 101. The side wall 123, the side wall 124, and the bottom wall 125 are perpendicular to the laminated body 101. The side wall 121 and the side wall 122 face each other with the laminated battery 13, the positive electrode current collector plate 14, and the negative electrode current collector plate 15 interposed therebetween. The side wall 123 and the side wall 124 face each other with the laminated battery 13, the positive electrode current collector plate 14, and the negative electrode current collector plate 15 interposed therebetween. The opening 11a and the bottom wall 125 face each other with the laminated battery 13, the positive electrode current collector plate 14, and the negative electrode current collector plate 15 interposed therebetween. The side wall 123, the side wall 124 and the bottom wall 125 connect the end portion of the side wall 121 and the end portion of the side wall 122. The opening 11a is formed between the end of the side wall 121 and the end of the side wall 122.

The positive electrode terminal 112 and the negative electrode terminal 113 are made of a conductor. The conductor is preferably a metal or alloy. The positive electrode terminal 112 and the negative electrode terminal 113 are arranged so as to penetrate the lid main body 111 made of an insulator.

The positive electrode terminal 112 is connected to one end of the positive electrode current collector plate 14. The positive electrode current collector plate 14 is connected to the tips of a plurality of aggregated positive electrode current collector tabs 102. Further, the negative electrode terminal 113 is connected to one end of the negative electrode current collector plate 15. The negative electrode current collector plate 15 is connected to the tips of a plurality of integrated negative electrode current collector tabs 103. As a result, the positive electrode terminal 112 is electrically connected to the plurality of positive electrode current collecting tabs 102 via the positive electrode current collecting plate 14. Further, the negative electrode terminal 113 is electrically connected to a plurality of negative electrode current collector tabs 103 via the negative electrode current collector plate 15. By establishing these electrical connections, in the zinc secondary battery 1, in the zinc secondary battery 1, the positive electrode current collecting plate 14, the plurality of positive electrode current collecting tabs 102, the laminate 101, and the plurality of negative electrode current collecting tabs 103 are formed from the positive electrode terminal 112. A charging current flows toward the negative electrode terminal 113 via the negative electrode current collector plate 15. Further, a discharge current flowing from the negative electrode terminal 113 to the positive electrode terminal 112 via the negative electrode current collector plate 15, the plurality of negative electrode current collector tabs 103, the laminate 101, the plurality of positive electrode current collector tabs 102, and the positive electrode current collector plate 14. ..

2 Laminated Battery FIGS. 4 and 5 are cross-sectional views schematically showing first and second structural examples of the main parts of the laminated battery 13 included in the zinc secondary battery 1, respectively. 4 and 5 show a state before the charge / discharge cycle is repeated in the zinc secondary battery 1.

As shown in FIGS. 4 and 5, the laminated battery 13 includes a plurality of coated positive electrodes 131 and a plurality of coated negative electrodes 132 constituting the laminated body 101.

The plurality of coated positive electrodes 131 and the plurality of coated negative electrodes 132 are overlapped with each other by alternately arranging one of each. A coated positive electrode 131 and a coated negative electrode 132 adjacent thereto constitute one battery constituting the laminated battery 13. The number of coated positive electrodes 131 and the number of coated negative electrodes 132 may be increased or decreased according to the specifications of the zinc secondary battery 1. However, from the viewpoint of increasing power generation efficiency, the number of coated negative electrodes 132 is larger than that of the coated positive electrodes 131 as shown in FIGS. 4 and 5, rather than the same number of coated positive electrodes 131 and the number of coated negative electrodes 132. It is preferable to increase the number of the laminate 101 by one so that the coated negative electrodes 132 are located on both sides of the coated positive electrode 131.

Each coated positive electrode 131 includes a positive electrode 141 and a positive electrode coating 142 that covers the positive electrode 141. Each positive electrode 141 includes a positive electrode plate 151 and a positive electrode current collecting tab 102. Further, each coated negative electrode 132 includes a negative electrode 143 and a negative electrode coating 144 that covers the negative electrode 143. Each negative electrode 143 includes a negative electrode plate 153 and a negative electrode current collecting tab 103. That is, the laminated body 101 includes a plurality of positive electrode plates 151, each of which constitutes a positive electrode 141, and a plurality of negative electrode plates 153, each of which constitutes a negative electrode 143.

As shown in FIGS. 4 and 5, each positive electrode plate 151 includes a positive electrode current collector 171 and a positive electrode active material layer 172. Further, each negative electrode plate 153 includes a negative electrode current collector 174 and a negative electrode active material layer 175, as shown in FIGS. 4 and 5.

A positive electrode current collector tab 102 is connected to each positive electrode current collector 171. Further, a negative electrode current collector tab 103 is connected to each negative electrode current collector 174.

In each positive electrode plate 151, the positive electrode active material layer 172 is arranged around the positive electrode current collector 171. Further, in each of the negative electrode plates 153, the negative electrode active material layer 175 is arranged around the negative electrode current collector 174. However, more specifically, the positive electrode active material layer 172 is not arranged in a part of the positive electrode current collector 171 including the connecting portion of the positive electrode current collector tab 102. Further, the negative electrode active material layer 175 is not arranged in a part of the negative electrode current collector 174 including the connecting portion of the negative electrode current collector tab 103.

In the cases shown in FIGS. 4 and 5, a plurality of positive electrode current collecting tabs 102 protrude from the first end 101P of the laminated body 101, and a plurality of negative electrode current collecting tabs 103 protrude from the second end 101N. ing. However, the first end 101P is an end on the DXP side in the first direction that constitutes the first side in the rectangular planar shape formed by the laminated body 101, and the second end 101N is , The end on the DXN side in the second direction, which constitutes the second side facing the first side.

As described above, each positive electrode current collecting tab 102 projects from the laminated body 101 in the first direction DXP. Moreover, the respective positive electrode current collecting tabs 102 are arranged at the same positions when the laminated body 101 is viewed in a plan view from the thickness direction. Therefore, in the laminated body 101, the plurality of positive electrode current collecting tabs 102 project from the same position when viewed in a plan view from the thickness direction toward the same direction. The tips of the plurality of positive electrode current collector tabs 102 projecting in this embodiment are aggregated and electrically connected to each other, and further electrically connected to the positive electrode current collector plate 14.

Further, each negative electrode current collecting tab 103 projects from the laminated body 101 in the second direction DXN. Each negative electrode current collecting tab 103 is also arranged at the same position when the laminated body 101 is viewed in a plan view from the thickness direction. Therefore, in the laminated body 101, the plurality of negative electrode current collecting tabs 103 also project from the same position in the plan view from the thickness direction toward the same direction. The tips of the plurality of negative electrode current collector tabs 103 protruding in this embodiment are aggregated and electrically connected to each other, and further electrically connected to the negative electrode current collector plate 15.

The positive electrode current collector tab 102 may be a tab lead having a root portion which is overlapped with the positive electrode current collector 171 and connected to the positive electrode current collector 171 and a tip portion which is not overlapped with the positive electrode current collector 171. It may be a tab made of the same material as the material constituting the positive electrode current collector 171 and continuous from the positive electrode current collector 171. Further, the negative electrode current collector tab 103 may be a tab lead including a root portion which is overlapped with the negative electrode current collector 174 and connected to the negative electrode current collector 174 and a tip portion which is not overlapped with the negative electrode current collector 174. However, the tab may be made of the same material as the material constituting the negative electrode current collector 174 and continuous from the negative electrode current collector 174. In such cases, the tab reed is made of a conductor, preferably a metal or alloy. For example, the tab lead constituting the positive electrode current collecting tab 102 can be provided with nickel. Further, the tab lead constituting the negative electrode current collecting tab 103 can be provided with copper. The tab lead preferably has a thickness of 0.05 mm or more and 0.20 mm or less, and more preferably 0.10 mm or more and 0.15 mm or less.

Further, in the laminated battery 13, in the direction DX parallel to the first direction DXP and the second direction DXN, the entire arrangement range RP of the positive electrode active material layer 172 becomes the arrangement range RN of the negative electrode active material layer 175. include. Also in the direction perpendicular to the first direction DXP and the second direction DXN (direction perpendicular to the drawing), the entire arrangement range RP of the positive electrode active material layer 172 is included in the arrangement range RN of the negative electrode active material layer 175. It has been. By adopting these configurations, in the zinc secondary battery 1 according to the present embodiment, the entire positive electrode active material layer 172 contributes to charging / discharging. In the zinc secondary battery 1 having such a configuration, its capacity can be determined by the positive electrode capacity.

FIG. 6 is a cross-sectional view schematically showing a main part of a laminated battery provided in a zinc secondary battery of a reference example. FIG. 6 illustrates a state before the charge / discharge cycle is repeated.

In the laminated battery 93 shown in FIG. 6, in the direction DX, the center CN of the arrangement range RN of the negative electrode active material layer 175 coincides with the center CP of the arrangement range RP of the positive electrode active material layer 172.

On the other hand, in the first structural example of the laminated battery 13 shown in FIG. 4, the arrangement range RP of the positive electrode active material layer 172 is offset in the first direction DXP as compared with the laminated battery 93 shown in FIG. ing. As a result, in the direction DX, the center CN of the arrangement range RN of the negative electrode active material layer 175 is deviated from the center CP of the arrangement range RP of the positive electrode active material layer 172 to the second direction DXN. That is, in the first structural example of the laminated battery 13, the second end EP2 of the arrangement range RP of the positive electrode active material layer 172 from the end EN2 of the arrangement range RN of the negative electrode active material layer 175 in the second direction DXN. Is longer than the distance from the end EN1 of the arrangement range RN of the negative electrode active material layer 175 to the end EP1 of the arrangement range RP of the positive electrode active material layer 172 in the first direction DXP.

Further, in the second structural example of the laminated battery 13 shown in FIG. 5, the negative electrode active material layer 175 and the negative electrode coating 144 are extended in the second direction DXN as compared with the laminated battery 93 shown in FIG. .. As a result, in the direction DX, the center CN of the arrangement range RN of the negative electrode active material layer 175 is deviated from the center CP of the arrangement range RP of the positive electrode active material layer 172 to the second direction DXN. That is, also in the second structural example of the laminated battery 13, the distance from the end EN2 of the arrangement range RN of the negative electrode active material layer 175 in the second direction DXN to the end EP2 of the arrangement range RP of the positive electrode active material layer 172. Is longer than the distance from the end EN1 of the arrangement range RN of the negative electrode active material layer 175 to the end EP1 of the arrangement range RP of the positive electrode active material layer 172 in the first direction DXP.

3 Details of each element FIG. 7 is a cross-sectional view schematically showing a main part of a laminated battery 13 provided in the zinc secondary battery 1.

As shown in FIG. 7, the laminated battery 13 includes a positive electrode current collector 171, a positive electrode active material layer 172, a positive electrode side liquid retention member 191 and a negative electrode current collector 174, a negative electrode active material layer 175, a negative electrode side liquid retention member 192, and the negative electrode side liquid retention member 192. A separator 193 is provided. Further, the laminated battery 13 includes an electrolytic solution in a manner of being held by the positive electrode side liquid retaining member 191 and the negative electrode side liquid retaining member 192. The positive electrode side liquid retention member 191 constitutes the positive electrode coating 142 described above. The negative electrode side liquid retaining member 192 and the separator 193 form the negative electrode coating 144 described above.

The positive electrode current collector 171 has a plate-like or foil-like shape. The positive electrode current collector 171 is made of a conductor. The conductor is preferably made of nickel or a nickel alloy. The positive electrode current collector 171 is preferably made of a porous body, and more preferably made of a foam. In such a case, the area of the interface where the positive electrode current collector 171 and the positive electrode active material layer 172 come into contact with each other can be widened, and the efficiency of current collection can be increased.

In FIG. 7, the positive electrode current collector 171 is drawn by a broken line, which means that when the positive electrode current collector 171 is made of a porous body, the positive electrode current collector 171 has holes in the positive electrode active material layer 172. It is based on the fact that the contained positive electrode active material and the like will invade, and in such a case, it will be difficult to grasp the positive electrode current collector 171 and the positive electrode active material layer 172 as separate components. be.

The positive electrode active material layer 172 contains a positive electrode active material. The positive electrode active material preferably contains at least one selected from the group consisting of nickel hydroxide and nickel oxyhydroxide. The positive electrode active material layer 172 is formed by, for example, uniformly coating a paste containing the positive electrode active material and the dispersion medium on the positive electrode current collector 171 to form a coating film, and evaporating the dispersion medium from the formed coating film. ,It is formed. The positive electrode active material layer 172 or the paste may contain a binder. The press treatment may be performed on the composite including the positive electrode current collector 171 and the positive electrode active material layer 172. In such a case, the positive electrode active material layer 172 is suppressed from falling off, and the electrode density of the positive electrode 141 is improved.

The zinc secondary battery 1 includes a positive electrode side liquid retention member 191. The positive electrode side liquid retaining member 191 has a sheet-like shape. The positive electrode side liquid retaining member 191 covers the entire positive electrode active material layer 172. The positive electrode side liquid retaining member 191 may wrap the entire positive electrode active material layer 172. The positive electrode side liquid retention member 191 holds the electrolytic solution. As a result, the electrolytic solution is distributed throughout the positive electrode active material layer 172. The positive electrode side liquid retaining member 191 is preferably made of a non-woven fabric, a water-absorbent resin, a liquid-retaining resin, a porous sheet or a spacer, and more preferably made of a non-woven fabric. When the positive electrode side liquid retaining member 191 is provided with a non-woven fabric, the electrode reaction at the positive electrode 141 can be promoted, and the coated positive electrode 131 can be manufactured at low cost. The positive electrode side liquid retaining member 191 preferably has a thickness of 0.01 mm or more and 0.20 mm or less. In such a case, the positive electrode side liquid retaining member 191 can hold a sufficient amount of the electrolytic solution while suppressing the size of the coated positive electrode 131 from increasing.

The negative electrode current collector 174 has a plate-like, foil-like or net-like shape. The negative electrode current collector 174 is made of a conductor. The conductor is preferably made of copper. The negative electrode current collector 174 is preferably made of foil, expanded metal or punching metal, and more preferably made of expanded metal. When the negative electrode current collector 174 is provided with expanded metal, the negative electrode current collector 174 can hold the negative electrode active material layer 175 having a sufficient amount.

The negative electrode active material layer 175 contains a negative electrode active material. The negative electrode active material preferably contains at least one selected from the group consisting of zinc, zinc oxide, zinc alloys and zinc compounds, and more preferably at least one selected from the group consisting of zinc, zinc oxide and calcium zincate. Includes seeds, particularly preferably zinc and zinc oxide. The negative electrode active material preferably has powdery properties. In such a case, the area of the surface on which the negative electrode active material is exposed can be increased, whereby the current that can be passed through the negative electrode 143 can be increased. The negative electrode active material layer 175 is formed, for example, by applying an object to be coated containing a powder of the negative electrode active material onto the negative electrode current collector 174. The negative electrode active material layer 175 or the object to be coated may contain a binder. The binder includes, for example, polytetrafluoroethylene particles. The press treatment may be performed on the composite including the negative electrode current collector 174 and the negative electrode active material layer 175. In such a case, the negative electrode active material layer 175 is suppressed from falling off, and the electrode density of the negative electrode 143 is improved. The negative electrode active material layer 175 may have a gel-like property. When the negative electrode active material layer 175 has a gel-like property, the negative electrode active material layer 175 contains an electrolytic solution and a thickener in addition to the negative electrode active material. Thickeners preferably include polyvinyl alcohol, polyacrylate, carboxymethyl cellulose (CMC) or alginic acid, and more preferably polyacrylate. When the thickener contains polyacrylate, the chemical resistance of the thickener to a strongly alkaline electrolytic solution is enhanced.

When the negative electrode active material contains a zinc alloy, the autolysis rate of zinc in a strongly alkaline electrolytic solution can be delayed. In such a case, the generation of hydrogen gas in the negative electrode 143 is suppressed. As a result, the safety of the zinc secondary battery 1 is enhanced. The zinc alloy is preferably a mercury- and lead-free zinc alloy. The zinc alloy is preferably 0.01% by mass or more and 0.1% by mass or less of indium, 0.005% by mass or more and 0.02% by mass or less of bismuth, and 0.0035% by mass or more and 0.015% by mass or less. Contains aluminum. When the zinc alloy contains indium and bismuth, the discharge performance of the negative electrode 143 is enhanced.

When the negative electrode active material contains a zinc alloy and has powdery properties, the negative electrode active material preferably has a short diameter of 3 μm or more and an average particle size of 100 μm or less. In such a case, the area of the surface on which the negative electrode active material is exposed can be widened, and the negative electrode active material, the electrolytic solution, and the gelling agent can be easily mixed uniformly, so that when the zinc secondary battery 1 is manufactured. The handling of the negative electrode active material of the above becomes easy.

The zinc secondary battery 1 includes a negative electrode side liquid retention member 192. The negative electrode side liquid retaining member 192 has a sheet-like shape. The negative electrode side liquid retaining member 192 covers the entire negative electrode active material layer 175. The negative electrode side liquid retaining member 192 may wrap the entire negative electrode active material layer 175. The negative electrode side liquid retention member 192 holds the electrolytic solution. As a result, the electrolytic solution is distributed throughout the negative electrode active material layer 175.

The negative electrode side liquid retaining member 192 is preferably made of a non-woven fabric, a water-absorbent resin, a liquid-retaining resin, a porous sheet or a spacer, and more preferably made of a non-woven fabric. When the negative electrode side liquid retaining member 192 is provided with a non-woven fabric, the electrode reaction at the negative electrode 143 can be promoted, and the coated negative electrode 132 can be manufactured at low cost.

The negative electrode side liquid retaining member 192 preferably has a thickness of 0.01 mm or more and 0.20 mm or less, more preferably 0.02 mm or more and 0.20 mm or less, and particularly preferably 0.02 mm or more. It has a thickness of 0.15 mm or less, more preferably 0.02 mm or more and 0.10 mm or less, and most preferably 0.02 mm or more and 0.06 mm or less. When the negative electrode side liquid retaining member 192 has a thickness in these ranges, the negative electrode side liquid retaining member 192 is allowed to hold a sufficient amount of electrolytic solution while suppressing the overall size of the coated negative electrode 132 in a compact manner without waste. Can be done.

The electrolytic solution held by the positive electrode side liquid retaining member 191 and the negative electrode side liquid retaining member 192 preferably consists of an aqueous solution of hydroxide. The hydroxide is preferably an alkali metal hydroxide or ammonium hydroxide, more preferably an alkali metal hydroxide, and particularly preferably potassium hydroxide, sodium hydroxide or lithium hydroxide, most preferably. Desirably, potassium hydroxide.

The zinc compound may be dissolved in the electrolytic solution. The zinc compound is preferably zinc oxide or zinc hydroxide. When the zinc compound is dissolved in the electrolytic solution, the zinc and / or zinc oxide constituting the negative electrode active material layer 175 is suppressed from being self-dissolved in the electrolytic solution.

A gelling agent may be added to the electrolytic solution. The gelling agent preferably consists of a polymer that absorbs and swells the solvent contained in the electrolytic solution, and more preferably consists of polyethylene oxide, polyvinyl alcohol, polyacrylamide or starch. When the gelling agent is added to the electrolytic solution, it is possible to prevent the electrolytic solution from gelling and leaking from the case 11.

The electrolytic solution and the positive electrode active material may be mixed to form a positive electrode mixture. The electrolytic solution and the negative electrode active material may be mixed to form a negative electrode mixture.

Separator 193 has a sheet-like shape. The separator 193 preferably covers or wraps the negative electrode active material layer 175 with the negative electrode side liquid retaining member 192 interposed therebetween. One or two sides of the outer edge of the separator 193 are open to project the negative electrode current collecting tab 103.

Separator 193 contains a porous base material and a hydroxide ion conductive layered compound that closes the pores of the porous base material. The hydroxide ion conductive layered compound is a layered double hydroxide (LDH) and / or a layered double hydroxide (LDH) -like compound. In the present specification, the separator 193 is a separator containing LDH and / or LDH-like compound, and selectively passes hydroxide ions by utilizing the hydroxide ion conductivity of LDH and / or LDH-like compound. Defined as a thing. In the present specification, the "LDH-like compound" is a hydroxide and / or oxide having a layered crystal structure similar to LDH, although it may not be called LDH, and can be said to be an equivalent of LDH. However, as a broad definition, "LDH" can be interpreted as including LDH-like compounds as well as LDH.

In the separator 193, the hydroxide ion conductive layered compound closes the pores of the porous base material, and the hydroxide ion conductive layered compound is connected between the upper surface and the lower surface of the separator 193 sandwiching the porous base material. .. As a result, the separator 193 exhibits hydroxide ion conductivity while exhibiting gas impermeableness. In other words, it functions as a separator exhibiting hydroxide ion conductivity. However, the pores of the porous substrate do not have to be completely closed, and a small amount of residual pores may be present.

It is particularly preferable that the hydroxide ion conductive layered compound is incorporated over the entire area of the porous substrate in the thickness direction. The thickness of the separator 193 is preferably 3 μm to 80 μm, more preferably 3 μm to 60 μm, and even more preferably 3 μm to 40 μm.

Generally, the separator separates the positive electrode plate and the negative electrode plate so that hydroxide ions can be conducted when they are incorporated in a zinc secondary battery. Preferred separators have gas impermeable and / or water impermeable. In other words, the separator is preferably densified to have gas impermeable and / or water impermeable. In addition, as described in International Publication No. 2016/076047 and International Publication No. 2016/067884, "having gas impermeable" in the present specification means helium gas on one side of the object to be measured in water. This means that no bubbles are generated due to helium gas from the other surface side even if they are brought into contact with each other with a differential pressure of 0.5 atm. Further, in the present specification, "having water impermeable" means that water in contact with one side of an object to be measured is defined as described in International Publication No. 2016/076047 and International Publication No. 2016/067884. It means that it does not penetrate to the other side. That is, in the present specification, the fact that the separator has gas impermeableness and / or water impermeability means that the separator has a high degree of denseness that does not allow gas or water to pass through, and is water permeable or gas. It means that it is not a permeable porous film or other porous material. In such a case, the separator selectively passes only hydroxide ions due to its hydroxide ion conductivity, and can exhibit a function as a battery separator. By incorporating such a separator into a zinc secondary battery, an extremely effective configuration is realized in which the penetration of the separator by the zinc dendrite generated during charging is physically prevented to prevent a short circuit between the positive and negative electrodes. Further, since the separator has hydroxide ion conductivity, it is possible to efficiently move the required hydroxide ion between the positive electrode plate and the negative electrode plate, so that the charge / discharge reaction in the positive electrode plate and the negative electrode plate can be performed. Is realized.

The porous base material is preferably composed of a polymer material. The polymer porous substrate has 1) flexibility (hence, it is hard to break even if it is thinned), 2) easy to increase the porosity, and 3) easy to increase the conductivity (while increasing the porosity). It has the advantages of being easy to manufacture and handle) (because the thickness can be reduced). Further, taking advantage of the flexibility of 1) above, 5) a hydroxide ion conductive separator containing a porous base material made of a polymer material can be easily bent or sealed and bonded. There is also the advantage of.

Preferred examples of the polymer material include polystyrene, polyether sulfone, polypropylene, epoxy resin, polyphenylene sulfide, fluororesin (tetrafluororesin: PTFE, etc.), cellulose, nylon, polyethylene and any combination thereof. .. More preferably, from the viewpoint of a thermoplastic resin suitable for heat pressing, polystyrene, polyether sulfone, polypropylene, epoxy resin, polyphenylene sulfide, fluororesin (tetrafluororesin: PTFE, etc.), nylon, polyethylene and any of them. Examples include the combination of. All of the various preferable materials described above have alkali resistance as resistance to the electrolytic solution of the battery. Particularly preferable polymer materials are polyolefins such as polypropylene and polyethylene, and most preferably polypropylene or polyethylene, because they are excellent in heat resistance, acid resistance and alkali resistance, and are low in cost.

The hydroxide ion conductive layered compound is incorporated over the entire thickness direction of the polymer porous substrate (for example, most or almost all the pores inside the polymer porous substrate are hydroxide ion conductive layered compounds). It is particularly preferable that it is buried). As such a polymer porous substrate, a commercially available polymer microporous membrane can be preferably used.

LDH is composed of a plurality of hydroxide basic layers and an intermediate layer interposed between the plurality of hydroxide basic layers. The basic hydroxide layer is mainly composed of metal elements (typically metal ions) and OH groups. Intermediate layer of LDH is composed of anionic and _{H 2} O. The anion is a monovalent or higher anion, preferably a monovalent or divalent ion. Preferably, the anions in LDH contain OH ⁻ and / or CO ₃ ^2- . LDH also has excellent ionic conductivity due to its unique properties.

In general, LDH is M ²⁺ _1-x M ³⁺ _x (OH) ₂ A ^n- _{x / n} · mH ₂ O (in the formula, M ²⁺ is a divalent cation and M ³⁺ is a trivalent cation. It is a cation, ^An- is an n-valent anion, n is an integer of 1 or more, x is 0.1 to 0.4, and m is 0 or more). It is known as a representative. In the above basic composition formula, M ²⁺ can be any divalent cation, but preferred examples include Mg ²⁺ , Ca ²⁺ and Zn ²⁺ , and more preferably Mg ²⁺ . M ³⁺ can be any trivalent cation, with preferred examples being Al ³⁺ or Cr ³⁺ , more preferably Al ³⁺ . A ^n- may be any anion, preferred examples OH ^- and _CO ^{3 2-} and the like. Accordingly, in the above basic ^{formula, M 2+} comprises ^{Mg 2+, M 3+} comprises ^{Al 3+, A n-is} OH ^- and / or _CO preferably contains ^{3 2-.} n is an integer greater than or equal to 1, but is preferably 1 or 2. x is 0.1 to 0.4, preferably 0.2 to 0.35. m is an arbitrary number meaning the number of moles of water, and is a real number greater than or equal to 0, typically greater than or equal to 0 or greater than or equal to 1.

However, the above basic composition formula is merely a formula of the "basic composition" generally exemplified with respect to LDH, and the constituent ions can be appropriately replaced. For example, it may be replaced with some or all of the M ³⁺ in the basic formula tetravalent or higher valency cations (e.g. Ti ^4+), that case, the anion A ⁿ in the basic composition formula The coefficient x / n of ^{− may be changed as appropriate.}

For example, it is particularly preferable that the hydroxide basic layer of LDH contains Mg, Al, Ti and OH groups in terms of exhibiting excellent alkali resistance. In this case, the hydroxide basic layer may contain other elements or ions as long as it contains Mg, Al, Ti and OH groups. For example, the LDH or hydroxide basic layer may contain Y and / or Zn. Further, when Y and / or Zn is contained in the LDH or hydroxide basic layer, Al or Ti may not be contained in the LDH or hydroxide basic layer. However, the hydroxide basic layer preferably contains Mg, Al, Ti and OH groups as main components. That is, the hydroxide basic layer is preferably mainly composed of Mg, Al, Ti and OH groups. Therefore, the hydroxide basic layer is typically composed of Mg, Al, Ti, OH groups and, in some cases, unavoidable impurities.

The atomic ratio of Ti / Al in LDH, as determined by Energy Dispersive X-ray Analysis (EDS), is preferably 0.5-12, more preferably 1.0-12. When the LDH satisfies the above range, the effect of suppressing a short circuit caused by zinc dendrite in the separator 193 (that is, dendrite resistance) can be better obtained without impairing the ionic conductivity.

For the same reason, the atomic ratio of Ti / (Mg + Ti + Al) in LDH, as determined by Energy Dispersive X-ray Analysis (EDS), is preferably 0.1 to 0.7, more preferably 0.2. It is ~ 0.7. The atomic ratio of Al / (Mg + Ti + Al) in LDH is preferably 0.05 to 0.4, more preferably 0.05 to 0.25. Further, the atomic ratio of Mg / (Mg + Ti + Al) in LDH is preferably 0.2 to 0.7, more preferably 0.2 to 0.6.

For EDS analysis, an EDS analyzer (for example, X-act, manufactured by Oxford Instruments) is used to 1) capture an image at an acceleration voltage of 20 kV and a magnification of 5,000 times, and 2) 5 μm in the point analysis mode. It is preferable to perform a three-point analysis at appropriate intervals, repeat the above 1) and 2) once more, and 4) calculate the average value of a total of 6 points.

Alternatively, the hydroxide basic layer of LDH may contain Ni, Al, Ti and OH groups. In this case, the hydroxide basic layer may contain other elements or ions as long as it contains Ni, Al, Ti and OH groups. However, the hydroxide basic layer preferably contains Ni, Al, Ti and OH groups as main components. That is, the hydroxide basic layer is preferably mainly composed of Ni, Al, Ti and OH groups. Therefore, the hydroxide basic layer is typically composed of Ni, Al, Ti, OH groups and, in some cases, unavoidable impurities.

The atomic ratio of Ti / (Ni + Ti + Al) in LDH, as determined by Energy Dispersive X-ray Analysis (EDS), is preferably 0.10 to 0.90, more preferably 0.20 to 0.80. It is more preferably 0.25 to 0.70, and particularly preferably 0.30 to 0.61. When the LDH satisfies the range, both the alkali resistance and the ionic conductivity of the separator 193 are improved. Therefore, the hydroxide ion conductive layered compound may contain not only LDH but also Ti so much that titania is by-produced. That is, the hydroxide ion conductive layered compound may further contain titania. It can be expected that the content of titania increases the hydrophilicity and the wettability with the electrolytic solution (that is, the conductivity is improved).

The LDH-like compound preferably contains Mg and one or more elements containing at least Ti selected from the group consisting of Ti, Y and Al. As described above, by using an LDH-like compound which is a hydroxide and / or an oxide having a layered crystal structure containing at least Mg and Ti as the hydroxide ion conductive substance instead of the conventional LDH, the alkali resistance is improved. It is possible to provide a hydroxide ion conductive separator which is excellent and can suppress a short circuit caused by zinc dendrite more effectively. Therefore, a preferred LDH-like compound is a hydroxide and / or oxide having a layered crystal structure containing Mg and at least one element containing at least Ti selected from the group consisting of Ti, Y and Al. Typical LDH-like compounds are composite hydroxides and / or composite oxides of Mg, Ti, optionally Y and optionally Al, particularly preferably composite hydroxides and / of Mg, Ti, Y and Al. Or it is a composite oxide. The element may be replaced with another element or ion to the extent that the basic properties of the LDH-like compound are not impaired, but the LDH-like compound preferably does not contain Ni.

LDH-like compounds can be identified by X-ray diffraction. Specifically, when X-ray diffraction is performed on the surface of a separator containing an LDH-like compound, it is typically in the range of 5 ° ≤ 2θ ≤ 10 °, and more typically 7 ° ≤ 2θ ≤ 10. Peaks derived from LDH-like compounds are detected in the ° range.

Meanwhile, LDH, as described above, exchangeable anions and H _{2 O} as an intermediate layer between the stacked hydroxide base layer is present, a substance having alternating lamination structure. When the LDH is measured by an X-ray diffraction method, a peak due to the crystal structure of LDH (that is, the (003) peak of LDH) is originally detected at a position of 2θ = 11 ° to 12 °.

That is, when the LDH-like compound is measured by the X-ray diffraction method, the peak is typically detected in the above-mentioned range shifted to the lower angle side than the above-mentioned peak position of LDH. Further, the interlayer distance of the layered crystal structure constituting the LDH-like compound, which is determined by applying the value of 2θ corresponding to the peak derived from the LDH-like compound detected by X-ray diffraction to the Bragg equation, is 0. It is typically .883 nm to 1.8 nm, and more typically 0.883 nm to 1.3 nm.

The atomic ratio of Mg / (Mg + Ti + Y + Al) in the LDH-like compound, as determined by energy dispersive X-ray analysis (EDS), is preferably 0.03 to 0.25, more preferably 0.05 to 0. It is 2. The atomic ratio of Ti / (Mg + Ti + Y + Al) in the LDH-like compound is preferably 0.40 to 0.97, more preferably 0.47 to 0.94. Further, the atomic ratio of Y / (Mg + Ti + Y + Al) in the LDH-like compound is preferably 0 to 0.45, more preferably 0 to 0.37. The atomic ratio of Al / (Mg + Ti + Y + Al) in the LDH-like compound is preferably 0 to 0.05, more preferably 0 to 0.03. When the LDH-like compound satisfies the above range, the alkali resistance of the separator 193 can be further improved, and the effect of suppressing a short circuit caused by zinc dendrite in the separator 193 (that is, dendrite resistance) can be obtained. , Can be obtained better.

By the way, as described above, LDH is M ²⁺ _1-x M ³⁺ _x (OH) ₂ ^Ann- _{x / n} · mH ₂ O (in the formula, M ²⁺ is a divalent cation and M ³⁺ is a trivalent cation. It is a cation, and An ^- is an n-valent anion, n is an integer of 1 or more, x is 0.1 to 0.4, and m is 0 or more). On the other hand, the atomic ratio of LDH-like compounds generally deviates from the basic composition formula of LDH. Therefore, it can be said that the LDH-like compound generally has a composition ratio (atomic ratio) different from that of the conventional LDH.

For EDS analysis, an EDS analyzer (for example, X-act, manufactured by Oxford Instruments) is used to 1) capture an image at an acceleration voltage of 20 kV and a magnification of 5,000 times, and 2) 5 μm in the point analysis mode. It is preferable to perform a three-point analysis at appropriate intervals, repeat the above 1) and 2) once more, and 4) calculate the average value of a total of 6 points.

The method for producing the separator 193 is not particularly limited, and the method for producing the already known LDH separator (or LDH-containing functional layer and composite material) (for example, International Publication No. 2013/118561, International Publication No. 2016/076047, International Publication No. It can be prepared by changing the conditions (particularly LDH raw material composition) of 2016/067884, International Publication No. 2019/124270 and International Publication No. 2019/124212) as they are or by appropriately changing them.

For example, (1) a porous base material is prepared, and (2) a mixed sol of alumina and titania (when forming LDH) or ii) titania sol (or further yttrium sol and / or) is prepared on the porous base material. A solution containing (alumina sol) (when forming an LDH-like compound) is applied and dried to form a titania-containing layer, and (3) magnesium ion (Mg ²⁺ ) and urea (or further yttrium ion (Y ³⁺ )). (4) The porous base material is hydrothermally heat-treated in the raw material aqueous solution containing (4) the hydroxide ion conductive layered compound on the porous base material and / or the porous base material. By forming the separator 193 inside, the separator 193 can be manufactured.

Further, in the presence of urea in the above step (3), the pH value rises due to the generation of ammonia in the solution by utilizing the hydrolysis of urea, and the coexisting metal ions are hydroxide and / or oxidized. It is considered that a hydroxide ion conductive layered compound (that is, LDH and / or LDH-like compound) can be obtained by forming an object. In addition, since hydrolysis involves the generation of carbon dioxide, when LDH is formed, anions can be obtained as carbonate ion type LDH.

In particular, when producing a separator in which the hydroxide ion conductive layered compound is incorporated over the entire area of the polymer porous substrate in the thickness direction, the application of the mixed sol solution in the above step (2) to the substrate is performed. It is preferable to carry out the method so that the mixed sol solution permeates the whole or most of the inside of the base material. By doing so, most or almost all the pores inside the porous substrate can be finally filled with the hydroxide ion conductive layered compound. Examples of a preferable coating method include a dip coating, a filtration coating and the like, and a dip coating is particularly preferable. By adjusting the number of times of application of the dip coat or the like, the amount of adhesion of the mixed sol solution can be adjusted. The base material coated with the mixed sol solution by dip coating or the like may be dried and then the above steps (3) and (4) may be carried out.

It is preferable to press the separator 193 obtained by the above method or the like. By doing so, it is possible to obtain a separator 193 that is even more excellent in compactness. The pressing method may be, for example, a roll press, a uniaxial pressure press, a CIP (cold isotropic pressure press), or the like, and is not particularly limited, but is preferably a roll press. This press is preferably performed while heating because the pores of the polymer porous substrate can be sufficiently closed with the hydroxide ion conductive layered compound by softening the polymer porous substrate. For sufficient softening, for example, when the polymer porous base material is polypropylene or polyethylene, it is preferable to heat at 60 ° C. to 200 ° C. By performing a press such as a roll press in such a temperature range, the residual pores of the separator 193 can be significantly reduced. As a result, the separator 193 can be made extremely dense, and therefore short circuits caused by zinc dendrites can be suppressed even more effectively. When the roll press is performed, the morphology of the residual pores can be controlled by appropriately adjusting the roll gap and the roll temperature, whereby the separator 193 with the desired density can be obtained.

The denseness of the above-mentioned separator can be evaluated by the He transparency. The separator has a He transmittance of 10 cm / min · atm or less, more preferably 5.0 cm / min · atm or less, and further preferably 1.0 cm / min · atm or less per unit area. It can be said that a separator having a He transmittance within such a range has extremely high density. That is, a separator having a He permeability of 10 cm / min · atm or less can block the passage of substances other than hydroxide ions at a high level. For example, in the case of a zinc secondary battery incorporating this, Zn permeation (typically zinc ion or zinc acid ion permeation) can be suppressed extremely effectively in the electrolytic solution.

The He permeability is determined through a step of supplying He gas to one surface of the separator and allowing the He gas to permeate through the separator, and a step of calculating the He permeability and evaluating the denseness of the hydroxide ion conduction separator. Be measured. The He permeability is determined by the formula of F / (P × S) using the permeation amount F of the He gas per unit time, the differential pressure P applied to the separator when the He gas permeates, and the membrane area S through which the He gas permeates. calculate. By evaluating the gas permeability using He gas in this way, it is possible to evaluate the presence or absence of denseness at an extremely high level, and as a result, substances other than hydroxide ions (particularly zinc dendrite growth) can be evaluated. It is possible to effectively evaluate a high degree of denseness such that the causing Zn) is not transmitted as much as possible (only a very small amount is transmitted). This is because He gas has the smallest structural unit among a wide variety of atoms or molecules that can constitute gas, and has extremely low reactivity. That is, He constitutes He gas by a single He atom without forming a molecule. In this respect, since hydrogen gas is _{composed of H 2} molecules, the He atom alone is smaller as a gas constituent unit. In the first place, H ₂ gas is dangerous because it is a flammable gas.

By adopting the index of He gas permeability defined by the above formula, it is possible to easily objectively evaluate the density regardless of the difference in various sample sizes and measurement conditions. Thereby, it is possible to easily, safely and effectively evaluate whether or not the separator has sufficiently high density suitable for the separator for zinc secondary batteries.

4 Comparison between Reference Example and Embodiment 4.1 Before the charge / discharge cycle is repeated in the shape change zinc secondary battery 1, the negative electrode active material layer 175 is above substantially the entire main surface of the negative electrode current collector 174. It exists almost uniformly in. However, after the charge / discharge cycle is repeated, the negative electrode active material layer 175 is unevenly present on the central portion of the main surface of the negative electrode current collector 174. This phenomenon is called shape change. The shape change is considered to occur due to the self-dissolution of zinc constituting the negative electrode active material layer 175 in the electrolytic solution. Along with such a shape change, a region is formed in the peripheral portion of the negative electrode plate 153 after the charge / discharge cycle is repeated so that the negative electrode current collector 174 is exposed without being covered by the negative electrode active material layer 175. Therefore, after the charge / discharge cycle is repeated, the peripheral portion of the negative electrode current collector 174 is likely to be electrically short-circuited with the positive electrode current collector 171. In particular, when the negative electrode current collector 174 is made of an expanded metal, burrs, sasakure, etc. that are likely to occur at the ends of the expanded metal break through the negative electrode side liquid retention member 192 and the separator 193, and the expanded metal and the positive electrode current collector 171 Is likely to be electrically short-circuited.

4.2 Effect of shape change FIGS. 8 and 9 are cross-sectional views schematically illustrating a first structural example and a second structural example of the main part of the laminated battery 13 provided in the zinc secondary battery 1, respectively. .. FIG. 10 is a cross-sectional view schematically showing a main part of a laminated battery 93 provided in a zinc secondary battery of a reference example. 8, 9 and 10 show the state after the charge / discharge cycle is repeated in the zinc secondary battery 1.

As described above, in the laminated battery shown in FIGS. 4, 5 and 6 before the charge / discharge cycle is repeated, the negative electrode active material layer 175 is substantially above the main surface of the negative electrode current collector 174. It exists almost uniformly in.

On the other hand, in the laminated battery shown in FIGS. 8, 9 and 10 after the charge / discharge cycle is repeated, the negative electrode active material layer 175 is above the central portion of the main surface of the negative electrode current collector 174. It exists in a biased manner.

Therefore, in the laminated battery 93 of the reference example shown in FIG. 6, after the charge / discharge cycle is repeated and the shape change occurs, the battery 93 is located near the root of the negative electrode current collector tab 103 and near the end of the positive electrode current collector 171. The peripheral portion of the negative electrode current collector 174 in the above is easily exposed. Therefore, an electrical short circuit S between the negative electrode current collector 174 and the positive electrode current collector 171 is likely to occur.

On the other hand, in the case of the first structural example and the second structural example of the laminated battery 13 shown in FIGS. 4 and 5, respectively, the negative electrode current collection is performed even after the charge / discharge cycle is repeated and the shape change occurs. The peripheral portion of the negative electrode current collector 174, which is near the base of the tab 103 and near the end of the positive electrode current collector 171, is not easily exposed. Therefore, an electrical short circuit S between the negative electrode current collector 174 and the positive electrode current collector 171 is unlikely to occur.

That is, in the zinc secondary battery 1 according to the present embodiment, the peripheral portion of the negative electrode current collector 174 located near the root of the negative electrode current collector tab 103 and near the end of the positive electrode current collector 171 is exposed. Is suppressed. As a result, it is possible to prevent the positive electrode current collector 171 and the negative electrode current collector 174 from being electrically short-circuited.

Although the present invention has been described in detail, the above description is an example in all aspects, and the present invention is not limited thereto. It is understood that innumerable variations not illustrated can be assumed without departing from the scope of the present invention.

Claims (4)

A positive electrode plate including a positive electrode current collector and a positive electrode active material layer arranged around the positive electrode current collector.
A negative electrode plate comprising a negative electrode current collector and a negative electrode active material layer arranged around the negative electrode current collector and superposed on the positive electrode plate.
With a laminate
A positive electrode current collector tab connected to the positive electrode current collector and protruding from the laminated body in the first direction,
A negative electrode current collector tab connected to the negative electrode current collector and protruding from the laminated body in a second direction opposite to the first direction.
With
With respect to the first direction and the direction parallel to the second direction, the center of the arrangement range of the negative electrode active material layer is deviated from the center of the arrangement range of the positive electrode active material layer in the second direction. ,
Zinc secondary battery. The zinc secondary battery according to claim 1.
With respect to the first direction and the direction parallel to the second direction, the entire arrangement range of the positive electrode active material layer is included in the arrangement range of the negative electrode active material layer.
With respect to the first direction and the direction parallel to the second direction, the range in which the positive electrode active material layer is arranged from the end of the second direction in the range in which the negative electrode active material layer is arranged. The distance to the end in the second direction is from the end in the first direction of the range in which the negative electrode active material layer is arranged to the end in the first direction in the range in which the positive electrode active material layer is arranged. Longer than the distance to the part,
Zinc secondary battery. The zinc secondary battery according to claim 1 or 2.
The laminate is
A plurality of the positive electrode plates each including the positive electrode current collector, and
A plurality of the negative electrode plates each including the negative electrode current collector,
With
The plurality of positive electrode plates and the plurality of negative electrode plates are alternately stacked, and the plurality of positive electrode plates are alternately stacked.
A plurality of the positive electrode current collector tabs, each of which is connected to the positive electrode current collector and projects from the laminated body in the first direction.
A plurality of the negative electrode current collector tabs, each of which is connected to the negative electrode current collector and projects from the laminated body in the second direction.
With
The tips of the plurality of positive electrode current collector tabs are aggregated.
The tips of the plurality of negative electrode current collector tabs are aggregated.
Zinc secondary battery. The zinc secondary battery according to any one of claims 1 to 3.
The negative electrode current collector is made of expanded metal.
A negative electrode side liquid retaining member that covers the entire negative electrode active material layer or holds the wrapping electrolytic solution is provided.
Zinc secondary battery.

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