JP2021089851A

JP2021089851A - Alkaline storage battery

Info

Publication number: JP2021089851A
Application number: JP2019219707A
Authority: JP
Inventors: 丈博有馬; Takehiro Arima
Original assignee: FDK Corp
Current assignee: FDK Corp
Priority date: 2019-12-04
Filing date: 2019-12-04
Publication date: 2021-06-10

Abstract

To provide an alkaline storage battery capable of achieving both high capacity and improved charge/discharge efficiency.SOLUTION: An alkaline storage battery of the present invention includes: a spiral electrode group (22) spirally formed such that a negative electrode plate (26) is located closer on an outer peripheral side than a positive electrode plate (24); and a cylindrical outer can (10) where the spiral electrode group is stored. The negative electrode plate has an outermost negative electrode plate part (26e) electrically connected to the inner peripheral wall of the outer can and an adjacent negative electrode plate part (26f) located adjacent to the inner peripheral side of the outermost negative electrode plate part. The outermost negative electrode plate part has an inner peripheral side junction in at least part on the inner peripheral surface, and is in contact with the inner peripheral wall of the outer can in at least part on the outer peripheral surface. The adjacent negative electrode plate part has an outer peripheral side junction facing the inner peripheral side junction, on the outer peripheral surface. The negative electrode plate is joined at the inner peripheral side junction and the outer peripheral side junction.SELECTED DRAWING: Figure 1

Description

本発明はアルカリ蓄電池、特に円筒形状のアルカリ蓄電池に関する。 The present invention relates to an alkaline storage battery, particularly a cylindrical alkaline storage battery.

アルカリ蓄電池は、正極板と負極板とセパレータとを積層した電極群を備えている。電極群において、セパレータは正極板と負極版との間に配置されている。当該アルカリ蓄電池において、例えば電極群は渦巻き状に巻回されて、導電性を有する円筒形状の外装缶にアルカリ電解液と共に収容されている。当該アルカリ蓄電池では、セパレータを介して対向する正極板と負極版との間で所定の電気化学反応が生じ、これにより充電及び放電が行われている。 The alkaline storage battery includes a group of electrodes in which a positive electrode plate, a negative electrode plate, and a separator are laminated. In the electrode group, the separator is arranged between the positive electrode plate and the negative electrode plate. In the alkaline storage battery, for example, the electrode group is spirally wound and housed together with the alkaline electrolyte in a cylindrical outer can having conductivity. In the alkaline storage battery, a predetermined electrochemical reaction occurs between the positive electrode plate and the negative electrode plate facing each other via the separator, whereby charging and discharging are performed.

電極群を渦巻き状に形成した電池として、例えば特許文献１には、セパレータを介して正極板と負極板とを重ね合わせた巻回群を電池容器の内部に収容した円筒形リチウムイオン電池について記載されている。具体的には、特許文献１に記載の発明では、セパレータの先端部分を粘着テープ等で軸芯に接合した後、正極板及び負極板を挿入した状態で巻回して巻回群が作製される。そして、巻回群の外周部分が絶縁被覆（片面に粘着剤を塗布した粘着テープ）で覆われ、ステンレス製の電池容器の内径よりも僅かに小さくなるように粘着テープの巻き数を調整した後、巻回群が電池容器内に挿入される。 As a battery in which an electrode group is formed in a spiral shape, for example, Patent Document 1 describes a cylindrical lithium ion battery in which a winding group in which a positive electrode plate and a negative electrode plate are overlapped with each other via a separator is housed inside a battery container. Has been done. Specifically, in the invention described in Patent Document 1, after joining the tip portion of the separator to the shaft core with an adhesive tape or the like, the winding group is produced by winding with the positive electrode plate and the negative electrode plate inserted. .. Then, after adjusting the number of windings of the adhesive tape so that the outer peripheral portion of the winding group is covered with an insulating coating (adhesive tape coated with an adhesive on one side) and slightly smaller than the inner diameter of the stainless steel battery container. , The winding group is inserted into the battery container.

特開２００１−２２９９７０号公報Japanese Unexamined Patent Publication No. 2001-229970

ところで、電池の高容量化を図るためには、例えば巻回群の巻き数を増やすことにより、正極板と負極板との間の対向面積を増加させることが求められる。しかしながら、特許文献１に記載のリチウムイオン電池では、巻回群の外周部分が粘着テープで覆われており、且つ電池容器の内径よりも小さくなるように粘着テープの巻き数が調整されており、巻回群の巻き数を増やすことが難しく、当該電池の更なる高容量化を図ることが困難であった。 By the way, in order to increase the capacity of the battery, it is required to increase the facing area between the positive electrode plate and the negative electrode plate, for example, by increasing the number of turns of the winding group. However, in the lithium ion battery described in Patent Document 1, the outer peripheral portion of the winding group is covered with the adhesive tape, and the number of windings of the adhesive tape is adjusted so as to be smaller than the inner diameter of the battery container. It was difficult to increase the number of turns in the winding group, and it was difficult to further increase the capacity of the battery.

他方、仮に巻回群の巻き数を増やした場合、巻回群の外径も増加するため、巻回群を電池容器内へ挿入する際に巻回群の外周部分を覆う粘着テープが電池容器の内周壁と接触する恐れがある。この場合、巻回群の最外周に位置する負極板の、正極板に対する巻きずれが発生することがある。このような巻きずれが生じた場合、負極板と正極板との間の対向面積が減少するため、当該電池における充電及び放電の効率が低下するという問題があった。 On the other hand, if the number of turns of the winding group is increased, the outer diameter of the winding group also increases. Therefore, when the winding group is inserted into the battery container, the adhesive tape covering the outer peripheral portion of the winding group is applied to the battery container. There is a risk of contact with the inner peripheral wall of the. In this case, the negative electrode plate located on the outermost circumference of the winding group may be miswound with respect to the positive electrode plate. When such a winding shift occurs, the facing area between the negative electrode plate and the positive electrode plate is reduced, so that there is a problem that the charging and discharging efficiency of the battery is lowered.

本発明はこのような課題に鑑みてなされたものであり、その目的とするところは、高容量化と充放電効率の向上との両立を図ることのできるアルカリ蓄電池を提供することにある。 The present invention has been made in view of such a problem, and an object of the present invention is to provide an alkaline storage battery capable of achieving both high capacity and improvement of charge / discharge efficiency.

上記目的を達成するため、本発明に係るアルカリ蓄電池は、帯状の正極板と、帯状の負極板と、前記正極板及び前記負極板の間に配置された帯状のセパレータとが互いに重ね合わされ、前記負極板が前記正極板より外周側に位置するように渦巻き状に形成された渦状電極群と、該渦状電極群がアルカリ電解液とともに収容された、導電性を有する円筒形状の外装缶と、前記正極板と電気的に接続されている正極端子と、を備え、前記負極板は、最外周に位置して前記外装缶の内周壁と電気的に接続されている最外周負極板部と、前記最外周負極板部の内周側に隣接して位置している隣接負極板部とを有し、前記最外周負極板部は、該最外周負極板部の内周面の少なくとも一部に内周側接合部を有し、外周面の少なくとも一部において前記外装缶の内周壁に接触しており、前記隣接負極板部は、該隣接負極板部の外周面に、前記内周側接合部と対向する外周側接合部を有し、前記負極板は、前記内周側接合部及び前記外周側接合部において接合されていることを特徴とする。 In order to achieve the above object, in the alkaline storage battery according to the present invention, a band-shaped positive electrode plate, a band-shaped negative electrode plate, and a band-shaped separator arranged between the positive electrode plate and the negative electrode plate are superposed on each other, and the negative electrode plate is used. A spiral electrode group formed in a spiral shape so as to be located on the outer peripheral side of the positive electrode plate, a conductive cylindrical outer can in which the spiral electrode group is housed together with an alkaline electrolytic solution, and the positive electrode plate. The negative electrode plate is provided with a positive electrode terminal electrically connected to the outer peripheral can, and the negative electrode plate is located on the outermost periphery and is electrically connected to the inner peripheral wall of the outer can. It has an adjacent negative electrode plate portion located adjacent to the inner peripheral side of the negative electrode plate portion, and the outermost negative electrode plate portion is on the inner peripheral side at least a part of the inner peripheral surface of the outermost outer peripheral negative electrode plate portion. It has a joint and is in contact with the inner peripheral wall of the outer can at least a part of the outer peripheral surface, and the adjacent negative electrode plate portion faces the outer peripheral surface of the adjacent negative electrode plate portion and faces the inner peripheral side joint portion. It is characterized in that it has an outer peripheral side joint portion to be formed, and the negative electrode plate is joined at the inner peripheral side joint portion and the outer peripheral side joint portion.

本発明の一態様に係るアルカリ蓄電池において、前記負極板は、金属製の負極芯体と、該負極芯体に坦持された、負極活物質を含む負極合剤層とを有し、前記内周側接合部及び前記外周側接合部は、前記負極芯体の一部が露出されて形成された部分であり、前記負極板は、前記内周側接合部及び前記外周側接合部において溶接されている。 In the alkaline storage battery according to one aspect of the present invention, the negative electrode plate has a negative electrode core made of metal and a negative electrode mixture layer containing a negative electrode active material carried on the negative electrode core. The peripheral side joint portion and the outer peripheral side joint portion are portions formed by exposing a part of the negative electrode core body, and the negative electrode plate is welded at the inner peripheral side joint portion and the outer peripheral side joint portion. ing.

本発明の一態様に係るアルカリ蓄電池において、前記内周側接合部は、前記渦状電極群の周方向における端部の側に設けられている。 In the alkaline storage battery according to one aspect of the present invention, the inner peripheral side bonding portion is provided on the side of the end portion in the circumferential direction of the spiral electrode group.

本発明の一態様に係るアルカリ蓄電池において、前記内周側接合部及び前記外周側接合部は、それぞれ、前記外装缶の軸線方向において前記負極板の全体に亘って設けられている。 In the alkaline storage battery according to one aspect of the present invention, the inner peripheral side joint portion and the outer peripheral side joint portion are provided over the entire negative electrode plate in the axial direction of the outer can, respectively.

本発明の一態様に係るアルカリ蓄電池において、前記内周側接合部及び前記外周側接合部は、それぞれ、前記外装缶の軸線方向において前記負極板の一方の端部分と他方の端部分とに部分的に設けられている。 In the alkaline storage battery according to one aspect of the present invention, the inner peripheral side joint portion and the outer peripheral side joint portion are partially formed at one end portion and the other end portion of the negative electrode plate in the axial direction of the outer can, respectively. Is provided for the purpose.

本発明に係るアルカリ蓄電池によれば、負極板の最外周負極板部は、内周面の少なくとも一部に内周側接合部を有し、外周面の少なくとも一部において外装缶の内周壁に接触している。又、負極板の隣接負極板部は、外周面に内周側接合部と対向する外周側接合部を有している。そして、負極板は、内周側接合部及び外周側接合部において接合されている。このように、本発明に係るアルカリ蓄電池においては、外装缶の内周壁に接触する最外周負極板部それ自体が隣接負極板部に接合されている。従って、巻き数を増加させることにより渦状電極群の外径が増加し、渦状電極群を外装缶に挿入する際に最外周負極板部が外装缶に接触する場合でも、正極板に対する負極板の巻きずれの発生を抑制することができる。このため、負極板と正極板と間の対向面積の減少が抑制され、アルカリ蓄電池における充放電効率の低下を抑制することができる。よって、高容量化と充放電効率の向上との両立を実現するアルカリ蓄電池を提供することができる。 According to the alkaline storage battery according to the present invention, the outermost peripheral negative electrode plate portion of the negative electrode plate has an inner peripheral side joint portion at least a part of the inner peripheral surface, and the inner peripheral wall of the outer can is formed at least a part of the outer peripheral surface. Are in contact. Further, the adjacent negative electrode plate portion of the negative electrode plate has an outer peripheral side joint portion facing the inner peripheral side joint portion on the outer peripheral surface. The negative electrode plate is joined at the inner peripheral side joint portion and the outer peripheral side joint portion. As described above, in the alkaline storage battery according to the present invention, the outermost negative electrode plate portion itself in contact with the inner peripheral wall of the outer can is joined to the adjacent negative electrode plate portion. Therefore, by increasing the number of turns, the outer diameter of the spiral electrode group increases, and even when the outermost peripheral negative electrode plate portion comes into contact with the outer can when the spiral electrode group is inserted into the outer can, the negative electrode plate with respect to the positive electrode plate The occurrence of unwinding can be suppressed. Therefore, the decrease in the facing area between the negative electrode plate and the positive electrode plate can be suppressed, and the decrease in charge / discharge efficiency in the alkaline storage battery can be suppressed. Therefore, it is possible to provide an alkaline storage battery that achieves both high capacity and improved charge / discharge efficiency.

本発明の一実施形態に係るアルカリ蓄電池を部分的に破断して示した斜視図である。It is a perspective view which showed by partially breaking the alkaline storage battery which concerns on one Embodiment of this invention. 図１のアルカリ蓄電池における負極板を展開して示す側面図である。It is a side view which shows the negative electrode plate in the alkaline storage battery of FIG. 1 developed. 図２の負極板を矢視Ａ方向から見た状態を示す図である。It is a figure which shows the state which the negative electrode plate of FIG. 2 was seen from the arrow A direction. 本発明の一実施形態に係るアルカリ蓄電池の渦状電極群が外装缶に挿入された状態を示す図である。It is a figure which shows the state which the spiral electrode group of the alkaline storage battery which concerns on one Embodiment of this invention is inserted into the outer can.

以下、本発明を具体化したアルカリ蓄電池の一例としてニッケル水素二次電池２（以下、単に「電池２」ともいう）の実施形態を説明する。なお、本実施形態として、ＡＡサイズの円筒形の電池２に本発明が適用された場合を説明するが、電池２のサイズはこれに限るものではなく、例えばＡＡＡサイズ等他のサイズでもよい。また、アルカリ蓄電池としては、電解液にアルカリ溶液を用いるものであればよく、例えばニッケルカドミウム蓄電池等でもよい。 Hereinafter, embodiments of a nickel-metal hydride secondary battery 2 (hereinafter, also simply referred to as “battery 2”) will be described as an example of an alkaline storage battery that embodies the present invention. As the present embodiment, the case where the present invention is applied to the AAA size cylindrical battery 2 will be described, but the size of the battery 2 is not limited to this, and other sizes such as AAA size may be used. Further, the alkaline storage battery may be any one that uses an alkaline solution as the electrolytic solution, and may be, for example, a nickel cadmium storage battery or the like.

図１は、本発明の一実施形態に係るニッケル水素二次電池２（アルカリ蓄電池）を部分的に破断して示した斜視図である。図２は、図１のニッケル水素二次電池２における負極板２６を展開して示す側面図である。図３は、図２の負極板２６を矢視Ａ方向から見た状態を示す図である。図４は、本発明の一実施形態に係るニッケル水素二次電池２の渦状電極群２２が外装缶１０に挿入された状態を示す図である。なお、説明の便宜上、円筒形状の外装缶１０の軸線ｘにおいて、矢印ａ方向を上側、矢印ｂ方向を下側とする。ここで、上側とは、電池２における正極端子２０が設けられている側を意味し、下側とは、電池２における底壁３５が設けられている側であり、上側の反対側を意味する。また、軸線ｘに垂直な方向（以下、「径方向」ともいう。）において、軸線ｘから遠ざかる方向を外周側とし（矢印ｃ方向）、軸線ｘに向かう方向を内周側とする（矢印ｄ方向）。 FIG. 1 is a perspective view showing a partially broken nickel-metal hydride secondary battery 2 (alkaline storage battery) according to an embodiment of the present invention. FIG. 2 is a side view showing the negative electrode plate 26 of the nickel-metal hydride secondary battery 2 of FIG. 1 in an unfolded manner. FIG. 3 is a diagram showing a state in which the negative electrode plate 26 of FIG. 2 is viewed from the direction of arrow A. FIG. 4 is a diagram showing a state in which the spiral electrode group 22 of the nickel-metal hydride secondary battery 2 according to the embodiment of the present invention is inserted into the outer can 10. For convenience of explanation, the direction of the arrow a is the upper side and the direction of the arrow b is the lower side of the axis x of the cylindrical outer can 10. Here, the upper side means the side of the battery 2 where the positive electrode terminal 20 is provided, and the lower side means the side of the battery 2 where the bottom wall 35 is provided, and means the opposite side of the upper side. .. Further, in the direction perpendicular to the axis x (hereinafter, also referred to as “diameter direction”), the direction away from the axis x is the outer peripheral side (arrow c direction), and the direction toward the axis x is the inner peripheral side (arrow d). direction).

図１に示すように、電池２は、上側（矢印ａ方向）が開口した有底円筒形状をなす外装缶１０を備えている。外装缶１０は導電性を有し、下側（矢印ｂ方向）に設けられた底壁３５は負極端子として機能する。外装缶１０の開口には、封口体１１が固定されている。この封口体１１は、蓋板１４及び正極端子２０を含み、外装缶１０を封口する。蓋板１４は、導電性を有する円板形状の部材である。外装缶１０の開口内には、蓋板１４及びこの蓋板１４を囲むリング形状の絶縁パッキン１２が配置され、絶縁パッキン１２は外装缶１０の開口縁３７をかしめ加工することにより外装缶１０の開口縁３７に固定されている。すなわち、蓋板１４及び絶縁パッキン１２は互いに協働して外装缶１０の開口を気密に閉塞している。 As shown in FIG. 1, the battery 2 includes an outer can 10 having a bottomed cylindrical shape with an opening on the upper side (direction of arrow a). The outer can 10 has conductivity, and the bottom wall 35 provided on the lower side (direction of arrow b) functions as a negative electrode terminal. A sealing body 11 is fixed to the opening of the outer can 10. The sealing body 11 includes a lid plate 14 and a positive electrode terminal 20, and seals the outer can 10. The lid plate 14 is a disk-shaped member having conductivity. A lid plate 14 and a ring-shaped insulating packing 12 surrounding the lid plate 14 are arranged in the opening of the outer can 10, and the insulating packing 12 is formed by caulking the opening edge 37 of the outer can 10 to form the outer can 10. It is fixed to the opening edge 37. That is, the lid plate 14 and the insulating packing 12 cooperate with each other to airtightly close the opening of the outer can 10.

ここで、蓋板１４は中央に中央貫通孔１６を有し、そして、蓋板１４の上側の面である外面上には中央貫通孔１６を塞ぐゴム製の弁体１８が配置されている。更に、蓋板１４の外面上には、弁体１８を覆うようにしてフランジ付き円筒形状をなす金属製の正極端子２０が電気的に接続されている。この正極端子２０は弁体１８を蓋板１４に向けて押圧している。なお、正極端子２０には、図示しないガス抜き孔が開口されている。 Here, the lid plate 14 has a central through hole 16 in the center, and a rubber valve body 18 that closes the central through hole 16 is arranged on the outer surface which is the upper surface of the lid plate 14. Further, a metal positive electrode terminal 20 having a flanged cylinder shape is electrically connected on the outer surface of the lid plate 14 so as to cover the valve body 18. The positive electrode terminal 20 presses the valve body 18 toward the lid plate 14. The positive electrode terminal 20 is provided with a gas vent hole (not shown).

通常時、中央貫通孔１６は弁体１８によって気密に閉じられている。一方、外装缶１０内にガスが発生し、そのガスの圧力が高まれば、弁体１８はガスの圧力によって圧縮され、中央貫通孔１６を開き、その結果、外装缶１０内から中央貫通孔１６及び正極端子２０のガス抜き孔（図示せず）を介して外部にガスが放出される。つまり、中央貫通孔１６、弁体１８及び正極端子２０は電池２のための安全弁を形成している。 Normally, the central through hole 16 is airtightly closed by the valve body 18. On the other hand, when gas is generated in the outer can 10, and the pressure of the gas increases, the valve body 18 is compressed by the pressure of the gas and opens the central through hole 16, and as a result, the central through hole 16 is opened from the inside of the outer can 10. And the gas is discharged to the outside through the gas vent hole (not shown) of the positive electrode terminal 20. That is, the central through hole 16, the valve body 18, and the positive electrode terminal 20 form a safety valve for the battery 2.

外装缶１０には、渦状電極群２２が収容されている。この渦状電極群２２は、それぞれ帯状の正極板２４、負極板２６及びセパレータ２８が互いに重ね合わされて形成されている。渦状電極群２２は、正極板２４と負極板２６との間にセパレータ２８が挟み込まれた状態で、負極板２６が正極板２４より外周側（矢印ｃ方向）に位置するように渦巻き状に形成されている。すなわち、セパレータ２８を介して正極板２４及び負極板２６が互いに重ね合わされている。 The outer can 10 contains a spiral electrode group 22. The spiral electrode group 22 is formed by superimposing a strip-shaped positive electrode plate 24, a negative electrode plate 26, and a separator 28 on each other. The spiral electrode group 22 is formed in a spiral shape so that the negative electrode plate 26 is located on the outer peripheral side (arrow c direction) of the positive electrode plate 24 with the separator 28 sandwiched between the positive electrode plate 24 and the negative electrode plate 26. Has been done. That is, the positive electrode plate 24 and the negative electrode plate 26 are superposed on each other via the separator 28.

そして、外装缶１０内には、渦状電極群２２の上側の端部と蓋板１４との間に正極リード３０が配置されている。詳しくは、正極リード３０は、その一端が正極板２４に接続され、その他端が蓋板１４に接続されている。従って、正極端子２０と正極板２４とは、正極リード３０及び蓋板１４を介して互いに電気的に接続されている。なお、蓋板１４と渦状電極群２２との間には円形の上部絶縁部材３２が配置され、正極リード３０は上部絶縁部材３２に設けられたスリット３９の中を通されて延びている。また、渦状電極群２２と外装缶１０の底壁３５との間にも円形の下部絶縁部材３４が配置されている。 Then, in the outer can 10, the positive electrode lead 30 is arranged between the upper end portion of the spiral electrode group 22 and the lid plate 14. Specifically, one end of the positive electrode lead 30 is connected to the positive electrode plate 24, and the other end is connected to the lid plate 14. Therefore, the positive electrode terminal 20 and the positive electrode plate 24 are electrically connected to each other via the positive electrode lead 30 and the lid plate 14. A circular upper insulating member 32 is arranged between the lid plate 14 and the spiral electrode group 22, and the positive electrode lead 30 extends through a slit 39 provided in the upper insulating member 32. Further, a circular lower insulating member 34 is also arranged between the spiral electrode group 22 and the bottom wall 35 of the outer can 10.

更に、外装缶１０内には、所定量のアルカリ電解液（図示せず）が注入されている。このアルカリ電解液は、渦状電極群２２に含浸され、正極板２４と負極板２６との間での充放電の際の電気化学反応（充放電反応）を進行させる。このアルカリ電解液としては、ＫＯＨ、ＮａＯＨ及びＬｉＯＨのうちの少なくとも一種を溶質として含む水溶液を用いることが好ましい。 Further, a predetermined amount of alkaline electrolytic solution (not shown) is injected into the outer can 10. This alkaline electrolytic solution is impregnated in the spiral electrode group 22, and causes an electrochemical reaction (charge / discharge reaction) during charging / discharging between the positive electrode plate 24 and the negative electrode plate 26. As the alkaline electrolytic solution, it is preferable to use an aqueous solution containing at least one of KOH, NaOH and LiOH as a solute.

セパレータ２８の材料としては、例えば、ポリアミド繊維製不織布に親水性官能基を付与したもの、ポリエチレンやポリプロピレンなどのポリオレフィン繊維製不織布に親水性官能基を付与したもの等を用いることができる。 As the material of the separator 28, for example, a polyamide fiber non-woven fabric provided with a hydrophilic functional group, a polyolefin fiber non-woven fabric such as polyethylene or polypropylene provided with a hydrophilic functional group, or the like can be used.

正極板２４は、多孔質構造を有する導電性の正極基材と、この正極基材の空孔内に保持された正極合剤とを含んでいる。このような正極基材としては、例えば、発泡ニッケルのシートを用いることができる。正極合剤は、正極活物質粒子と、結着剤とを含む。また、正極合剤には、必要に応じて正極添加剤が添加される。 The positive electrode plate 24 contains a conductive positive electrode base material having a porous structure and a positive electrode mixture held in the pores of the positive electrode base material. As such a positive electrode base material, for example, a foamed nickel sheet can be used. The positive electrode mixture contains positive electrode active material particles and a binder. Further, a positive electrode additive is added to the positive electrode mixture as needed.

上記した結着剤は、正極活物質粒子を互いに結着させるとともに、正極活物質粒子を正極基材に結着させる働きをする。ここで、結着剤としては、例えば、カルボキシメチルセルロース、メチルセルロース、ＰＴＦＥ（ポリテトラフルオロエチレン）ディスパージョン、ＨＰＣ（ヒドロキシプロピルセルロース）ディスパージョンなどを用いることができる。また、正極添加剤としては、酸化亜鉛、水酸化コバルト等が挙げられる。 The above-mentioned binder has a function of binding the positive electrode active material particles to each other and also binding the positive electrode active material particles to the positive electrode base material. Here, as the binder, for example, carboxymethyl cellulose, methyl cellulose, PTFE (polytetrafluoroethylene) dispersion, HPC (hydroxypropyl cellulose) dispersion and the like can be used. Moreover, as a positive electrode additive, zinc oxide, cobalt hydroxide and the like can be mentioned.

正極活物質粒子としては、ニッケル水素二次電池用として一般的に用いられている水酸化ニッケル粒子が用いられる。この水酸化ニッケル粒子は、高次化されている水酸化ニッケル粒子を採用することが好ましい。上記したような正極活物質粒子は、ニッケル水素二次電池用として一般的に用いられている製造方法により製造される。 As the positive electrode active material particles, nickel hydroxide particles generally used for a nickel hydrogen secondary battery are used. As the nickel hydroxide particles, it is preferable to use higher-order nickel hydroxide particles. The positive electrode active material particles as described above are produced by a production method generally used for nickel-metal hydride secondary batteries.

ついで、正極板２４は、例えば、以下のようにして製造することができる。まず、正極活物質粒子、水及び結着剤を含む正極合剤スラリーを調製する。調製された正極合剤スラリーは、例えば、発泡ニッケルのシートに充填され、乾燥させられる。乾燥後、水酸化ニッケル粒子等が充填された発泡ニッケルのシートは、圧延されてから裁断され、正極板２４が製造される。 Then, the positive electrode plate 24 can be manufactured as follows, for example. First, a positive electrode mixture slurry containing positive electrode active material particles, water and a binder is prepared. The prepared positive electrode mixture slurry is filled in, for example, a sheet of expanded nickel and dried. After drying, the foamed nickel sheet filled with nickel hydroxide particles and the like is rolled and then cut to produce a positive electrode plate 24.

次に、負極板２６について説明する。図２及び図３に示すように、負極板２６は、金属製の負極芯体２６ａと、この負極芯体２６ａに担持された、負極活性物質を含む負極合剤層２６ｂとを備え、全体として帯状をなしている。負極芯体２６ａは、導電性を有している。 Next, the negative electrode plate 26 will be described. As shown in FIGS. 2 and 3, the negative electrode plate 26 includes a metal negative electrode core body 26a and a negative electrode mixture layer 26b containing a negative electrode active substance supported on the negative electrode core body 26a as a whole. It has a band shape. The negative electrode core body 26a has conductivity.

負極芯体２６ａは、貫通孔（図示せず）が分布された帯状の金属材であり、例えば、パンチングメタルシートを用いることができる。負極合剤層２６ｂは、負極活性物質を含む負極合剤により形成されている。負極合剤は、負極芯体２６ａの貫通孔内に充填されるばかりでなく、負極芯体２６ａの表面２６ｃ及び裏面２６ｄにも層状に担持されて負極合剤層２６ｂを形成している。負極合剤は、負極活物質としての水素を吸蔵及び放出可能な水素吸蔵合金粒子、導電剤、結着剤及び負極補助剤を含む。 The negative electrode core body 26a is a strip-shaped metal material in which through holes (not shown) are distributed, and for example, a punching metal sheet can be used. The negative electrode mixture layer 26b is formed of a negative electrode mixture containing a negative electrode active substance. The negative electrode mixture is not only filled in the through holes of the negative electrode core body 26a, but is also supported in layers on the front surface 26c and the back surface 26d of the negative electrode core body 26a to form the negative electrode mixture layer 26b. The negative electrode mixture includes hydrogen storage alloy particles capable of storing and releasing hydrogen as a negative electrode active material, a conductive agent, a binder, and a negative electrode auxiliary agent.

上記した結着剤は水素吸蔵合金粒子、導電剤等を互いに結着させると同時に水素吸蔵合金粒子、導電剤等を負極芯体２６ａに結着させる働きをする。ここで、結着剤としては、特に限定されるものではなく、例えば、親水性若しくは疎水性のポリマー、カルボキシメチルセルロースなどの、ニッケル水素二次電池用として一般的に用いられている結着剤を用いることができる。また、負極補助剤としては、スチレンブタジエンゴム、ポリアクリル酸ナトリウム等を用いることができる。水素吸蔵合金粒子における水素吸蔵合金としては、特に限定されるものではなく、一般的なニッケル水素二次電池に用いられているものを用いるのが好ましい。導電剤としては、ニッケル水素二次電池の負極に一般的に用いられている導電剤が用いられる。例えば、カーボンブラック等が用いられる。 The above-mentioned binder has a function of binding the hydrogen storage alloy particles, the conductive agent and the like to each other, and at the same time, binding the hydrogen storage alloy particles, the conductive agent and the like to the negative electrode core body 26a. Here, the binder is not particularly limited, and for example, a binder generally used for a nickel hydrogen secondary battery such as a hydrophilic or hydrophobic polymer or carboxymethyl cellulose is used. Can be used. Further, as the negative electrode auxiliary agent, styrene-butadiene rubber, sodium polyacrylate and the like can be used. The hydrogen storage alloy in the hydrogen storage alloy particles is not particularly limited, and it is preferable to use one used in a general nickel-metal hydride secondary battery. As the conductive agent, a conductive agent generally used for the negative electrode of a nickel-metal hydride secondary battery is used. For example, carbon black or the like is used.

図１から図４に示すように、渦状電極群２２の負極板２６は、最外周に位置して外装缶１０の内周壁１０ａと電気的に接続されている最外周負極板部２６ｅと、最外周負極板部２６ｅの内周側（矢印ｄ方向）に隣接して位置している隣接負極板部２６ｆとを有している。すなわち、負極板２６と外装缶１０とは互いに電気的に接続されている。最外周負極板部２６ｅは、最外周負極板部２６ｅの内周面２６ｇの少なくとも一部に内周側接合部２６ｈを有し、外周面２６ｉの少なくとも一部において外装缶１０の内周壁１０ａに接触している。又、隣接負極板部２６ｆは、隣接負極板部２６ｆの外周面２６ｊに、内周側接合部２６ｈと対向する外周側接合部２６ｋを有している。 As shown in FIGS. 1 to 4, the negative electrode plate 26 of the spiral electrode group 22 has the outermost negative electrode plate portion 26e located at the outermost periphery and electrically connected to the inner peripheral wall 10a of the outer can 10. It has an adjacent negative electrode plate portion 26f located adjacent to the inner peripheral side (arrow d direction) of the outer peripheral negative electrode plate portion 26e. That is, the negative electrode plate 26 and the outer can 10 are electrically connected to each other. The outermost peripheral negative electrode plate portion 26e has an inner peripheral side joint portion 26h on at least a part of the inner peripheral surface 26g of the outermost peripheral negative electrode plate portion 26e, and is formed on the inner peripheral wall 10a of the outer can 10 at least a part of the outer peripheral surface 26i. Are in contact. Further, the adjacent negative electrode plate portion 26f has an outer peripheral side joint portion 26k facing the inner peripheral side joint portion 26h on the outer peripheral surface 26j of the adjacent negative electrode plate portion 26f.

図４に示すように、負極板２６は、内周側接合部２６ｈ及び外周側接合部２６ｋにおいて接合されている。より具体的には、図２から図４に示すように、内周側接合部２６ｈ及び外周側接合部２６ｋは、負極芯体２６ａの一部が露出されて形成された部分であり、負極板２６は、内周側接合部２６ｈ及び外周側接合部２６ｋにおいて溶接されている。例えば、負極板２６は、内周側接合部２６ｈ及び外周側接合部２６ｋにおいて抵抗溶接により固定されている。なお、内周側接合部２６ｈ及び外周側接合部２６ｋにおける接合の態様としては、溶接に限るものではなく、例えば接着剤により固定するものでもよい。 As shown in FIG. 4, the negative electrode plate 26 is joined at the inner peripheral side joint portion 26h and the outer peripheral side joint portion 26k. More specifically, as shown in FIGS. 2 to 4, the inner peripheral side joint portion 26h and the outer peripheral side joint portion 26k are portions formed by exposing a part of the negative electrode core body 26a, and are negative electrode plates. 26 is welded at the inner peripheral side joint portion 26h and the outer peripheral side joint portion 26k. For example, the negative electrode plate 26 is fixed by resistance welding at the inner peripheral side joint portion 26h and the outer peripheral side joint portion 26k. The mode of joining at the inner peripheral side joint portion 26h and the outer peripheral side joint portion 26k is not limited to welding, and may be fixed by, for example, an adhesive.

図１及び図４に示すように、内周側接合部２６ｈは、渦状電極群２２の周方向における端部の側に設けられている。具体的には、内周側接合部２６ｈは、渦状電極群２２の巻終側（図２の右側）の端部分において、当該巻終側の端縁から所定の幅Ｄ５を有して形成されている。なお、内周側接合部２６ｈの位置はこれに限るものではなく、電池反応に影響を及ぼさない部分即ち正極板２４と対向しない部分であれば、例えば巻終側の端縁を含まない部分に設けられていてもよい。 As shown in FIGS. 1 and 4, the inner peripheral side joint portion 26h is provided on the side of the end portion in the circumferential direction of the spiral electrode group 22. Specifically, the inner peripheral side joint portion 26h is formed at the end portion of the spiral electrode group 22 on the winding end side (right side in FIG. 2) with a predetermined width D5 from the end edge on the winding end side. ing. The position of the inner peripheral side joint portion 26h is not limited to this, and if it is a portion that does not affect the battery reaction, that is, a portion that does not face the positive electrode plate 24, for example, a portion that does not include the end edge on the winding end side. It may be provided.

図２に示すように、内周側接合部２６ｈ及び外周側接合部２６ｋは、それぞれ、外装缶１０の軸線ｘ方向（図２の矢印ａｂ方向）において、負極板２６の全体に亘って設けられている。なお、内周側接合部２６ｈ及び外周側接合部２６ｋの範囲はこれに限るものではなく、内周側接合部２６ｈ及び外周側接合部２６ｋは、外装缶１０の軸線ｘ方向において、負極板２６の一方（上側）の端部分と他方（下側）の端部分とに部分的に設けられていてもよい。更に、内周側接合部２６ｈ及び外周側接合部２６ｋは、外装缶１０の軸線ｘ方向において、負極板２６の一方（上側）の端部分と他方（下側）の端部分との間に部分的に設けられてもよい。 As shown in FIG. 2, the inner peripheral side joint portion 26h and the outer peripheral side joint portion 26k are provided over the entire negative electrode plate 26 in the axial x direction (arrow ab direction in FIG. 2) of the outer can 10, respectively. ing. The range of the inner peripheral side joint 26h and the outer peripheral side joint 26k is not limited to this, and the inner peripheral side joint 26h and the outer peripheral side joint 26k are the negative electrode plate 26 in the axis x direction of the outer can 10. It may be partially provided at one (upper) end portion and the other (lower) end portion. Further, the inner peripheral side joint portion 26h and the outer peripheral side joint portion 26k are portions between one (upper) end portion and the other (lower side) end portion of the negative electrode plate 26 in the axial x direction of the outer can 10. It may be provided as a target.

負極板２６は、例えば、以下のようにして製造することができる。まず、上記のような水素吸蔵合金粒子の集合体である水素吸蔵合金粉末と、導電剤と、結着剤と、水とを準備し、これらを混練して負極合剤のペーストを調製する。得られたペーストは負極芯体２６ａに塗着され、乾燥させられる。乾燥後、負極板２６から、負極合剤層２６ｂの一部が切削され、負極芯体２６ａの一部が露出される。例えば、切削は、タガネやバイト等の一般的な切削用工具の歯を用いて行われる。なお、負極芯体２６ａの一部を露出させるためには、負極芯体２６ａの一部をマスキングした状態で負極合剤のペーストを負極芯体２６ａに塗着させてもよいし、負極芯体２６ａの露出させた部分だけ負極合剤のペーストの塗着を止めるいわゆる間欠塗工を行ってもよい。これにより、例えば図２に示すような内周側接合部２６ｈ（幅Ｄ５）及び外周側接合部２６ｋ（幅Ｄ４）が形成される。その後、負極芯体２６ａの一部が露出した状態の負極板２６に対し、全体的に圧延が施される圧延工程により負極合剤層２６ｂの密度が所定の値になるように調整が行われる。このようにして、負極板２６が製造される。なお、図３において、負極合剤層２６ｂの一部分だけ厚さが薄く形成されているが、負極合剤層２６ｂの厚さはこれに限るものではなく、例えば同じ厚さに形成されていてもよい。 The negative electrode plate 26 can be manufactured, for example, as follows. First, a hydrogen storage alloy powder, which is an aggregate of hydrogen storage alloy particles as described above, a conductive agent, a binder, and water are prepared, and these are kneaded to prepare a paste of a negative electrode mixture. The obtained paste is applied to the negative electrode core body 26a and dried. After drying, a part of the negative electrode mixture layer 26b is cut from the negative electrode plate 26 to expose a part of the negative electrode core body 26a. For example, cutting is performed using the teeth of a general cutting tool such as a chisel or a cutting tool. In order to expose a part of the negative electrode core body 26a, a paste of the negative electrode mixture may be applied to the negative electrode core body 26a with a part of the negative electrode core body 26a masked, or the negative electrode core body 26a may be coated. A so-called intermittent coating may be performed to stop the application of the negative electrode mixture paste only to the exposed portion of 26a. As a result, for example, the inner peripheral side joint portion 26h (width D5) and the outer peripheral side joint portion 26k (width D4) as shown in FIG. 2 are formed. After that, the negative electrode plate 26 in a state where a part of the negative electrode core body 26a is exposed is adjusted so that the density of the negative electrode mixture layer 26b becomes a predetermined value by a rolling process in which the negative electrode plate 26 is entirely rolled. .. In this way, the negative electrode plate 26 is manufactured. In FIG. 3, only a part of the negative electrode mixture layer 26b is formed to be thin, but the thickness of the negative electrode mixture layer 26b is not limited to this, and even if the negative electrode mixture layer 26b is formed to have the same thickness, for example. Good.

以上のようにして製造された正極板２４及び負極板２６は、セパレータ２８を介在させた状態で、渦巻き状に巻回される。その後、内周側接合部２６ｈ及び外周側接合部２６ｋを接合（例えば溶接）することで、負極板２６を固定し、渦状電極群２２が形成される。このようにして得られた渦状電極群２２は、外装缶１０内に収容される。引き続き、当該外装缶１０内には所定量のアルカリ電解液が注入される。その後、渦状電極群２２及びアルカリ電解液を収容した外装缶１０は、正極端子２０を備えた封口体１１により封口され、本発明に係る電池２が得られる。電池２は、初期活性化処理が施され、使用可能状態とされる。 The positive electrode plate 24 and the negative electrode plate 26 manufactured as described above are spirally wound with the separator 28 interposed therebetween. After that, the negative electrode plate 26 is fixed and the spiral electrode group 22 is formed by joining (for example, welding) the inner peripheral side joint portion 26h and the outer peripheral side joint portion 26k. The spiral electrode group 22 thus obtained is housed in the outer can 10. Subsequently, a predetermined amount of alkaline electrolytic solution is injected into the outer can 10. After that, the outer can 10 containing the spiral electrode group 22 and the alkaline electrolytic solution is sealed by the sealing body 11 provided with the positive electrode terminal 20, and the battery 2 according to the present invention is obtained. The battery 2 is subjected to an initial activation treatment and is ready for use.

次いで、本発明の一実施形態のニッケル水素二次電池２の作用、効果について説明する。上述したように、本発明の実施形態に係るニッケル水素二次電池２によれば、負極板２６の最外周負極板部２６ｅは、内周面２６ｇの少なくとも一部に内周側接合部２６ｈを有し、外周面２６ｉの少なくとも一部において外装缶１０の内周壁１０ａに接触している。又、負極板２６の隣接負極板部２６ｆは、外周面２６ｊに内周側接合部２６ｈと対向する外周側接合部２６ｋを有している。そして、負極板２６は、内周側接合部２６ｈ及び外周側接合部２６ｋにおいて接合されている。このように、本発明に係るニッケル水素二次電池２においては、外装缶１０の内周壁１０ａに接触する最外周負極板部２６ｅそれ自体が隣接負極板部２６ｆに接合されている。従って、巻き数を増加させることにより渦状電極群２２の外径が増加し、渦状電極群２２を外装缶１０に挿入する際に最外周負極板部２６ｅが外装缶１０に接触する場合でも、正極板２４に対する負極板２６の巻きずれの発生を抑制することができる。特に、最外周負極板部２６ｅが隣接負極板部２６ｆに溶接されている場合、最外周負極板部２６ｅを隣接負極板部２６ｆに強固に固定することができる。このため、負極板２６と正極板２４との間の対向面積の減少が抑制され、アルカリ蓄電池における充放電効率の低下を抑制することができる。よって、高容量化と充放電効率の向上との両立を実現するアルカリ蓄電池を提供することができる。更に、正極板２４に対する負極板２６の巻きずれの発生を抑制することができるため、負極板２６と正極板２４とが直接接触するいわゆるショートを回避することができ、高品質のアルカリ蓄電池を提供することができる。 Next, the operation and effect of the nickel-metal hydride secondary battery 2 according to the embodiment of the present invention will be described. As described above, according to the nickel-metal hydride secondary battery 2 according to the embodiment of the present invention, the outermost peripheral negative electrode plate portion 26e of the negative electrode plate 26 has an inner peripheral side joint portion 26h on at least a part of the inner peripheral surface 26g. It has and is in contact with the inner peripheral wall 10a of the outer can 10 at least a part of the outer peripheral surface 26i. Further, the adjacent negative electrode plate portion 26f of the negative electrode plate 26 has an outer peripheral side joint portion 26k facing the inner peripheral side joint portion 26h on the outer peripheral surface 26j. The negative electrode plate 26 is joined at the inner peripheral side joint portion 26h and the outer peripheral side joint portion 26k. As described above, in the nickel-metal hydride secondary battery 2 according to the present invention, the outermost peripheral negative electrode plate portion 26e itself in contact with the inner peripheral wall 10a of the outer can 10 is bonded to the adjacent negative electrode plate portion 26f. Therefore, the outer diameter of the spiral electrode group 22 is increased by increasing the number of turns, and even when the outermost peripheral negative electrode plate portion 26e comes into contact with the outer can 10 when the spiral electrode group 22 is inserted into the outer can 10, the positive electrode is positive. It is possible to suppress the occurrence of unwinding of the negative electrode plate 26 with respect to the plate 24. In particular, when the outermost peripheral negative electrode plate portion 26e is welded to the adjacent negative electrode plate portion 26f, the outermost peripheral negative electrode plate portion 26e can be firmly fixed to the adjacent negative electrode plate portion 26f. Therefore, the decrease in the facing area between the negative electrode plate 26 and the positive electrode plate 24 can be suppressed, and the decrease in charge / discharge efficiency in the alkaline storage battery can be suppressed. Therefore, it is possible to provide an alkaline storage battery that achieves both high capacity and improved charge / discharge efficiency. Further, since it is possible to suppress the occurrence of unwinding of the negative electrode plate 26 with respect to the positive electrode plate 24, it is possible to avoid a so-called short circuit in which the negative electrode plate 26 and the positive electrode plate 24 come into direct contact with each other, providing a high quality alkaline storage battery. can do.

［実施例］
図２に示すように、負極板２６の全体長さをＤ１＝１５５ｍｍとし、負極板２６の巻始側（図２の左側）から外周側接合部２６ｋまでの長さをＤ２＝１１０ｍｍとし、外周側接合部２６ｋの幅をＤ３＝２ｍｍとし、内周側接合部２６ｈを除く最外周負極板部２６ｅの長さをＤ４＝４１ｍｍとし、内周側接合部２６ｈの幅をＤ５＝２ｍｍと設定した。つまり、負極板２６の製造において、まず、水素吸蔵合金粒子の集合体である水素吸蔵合金粉末と、導電剤と、結着剤と、水とを混練して調製された負極合剤のペーストを負極芯体２６ａに塗着し、乾燥させる。乾燥後、負極板２６から、負極合剤層２６ｂの一部を切削し、負極芯体２６ａの一部を露出させる。この際、内周側接合部２６ｈの幅がＤ５＝２ｍｍ、外周側接合部２６ｋの幅がＤ４＝２ｍｍとなるように負極合剤層２６ｂを切削する。その後、負極芯体２６ａの一部が露出した状態の負極板２６に対し、全体的に圧延を施し、負極合剤層２６ｂの密度が所定の値になるように調整を行う。このようにして製造された負極板２６と上記方法で製造した正極板２４を、セパレータ２８を介在させた状態で、渦巻き状に巻回して渦状電極群２２を製造する。当該渦状電極群２２において、内周側接合部２６ｈ及び外周側接合部２６ｋを接合（例えば溶接）することで、負極板２６を固定した。このような渦状電極群２２を３０セル製造した。当該渦状電極群２２を外装缶１０に挿入する試験を行った結果、本実施例に係る渦状電極群２２では３０セル中巻きずれ発生がゼロであった。これに対し、比較例としての渦状電極群、即ち負極板を固定しない渦状電極群では３０セル中４個において、正極板２４に対する負極板２６の巻きずれが発生した。このように、本実施例のように負極板２６の接合を行った場合、外装缶１０への挿入時に、渦状電極群２２において巻きずれが発生しないことが確認できた。 [Example]
As shown in FIG. 2, the overall length of the negative electrode plate 26 is D1 = 155 mm, the length from the winding start side (left side of FIG. 2) of the negative electrode plate 26 to the outer peripheral side joint portion 26k is D2 = 110 mm, and the outer circumference. The width of the side joint 26k was set to D3 = 2 mm, the length of the outermost negative electrode plate portion 26e excluding the inner peripheral side joint 26h was set to D4 = 41 mm, and the width of the inner peripheral side joint 26h was set to D5 = 2 mm. .. That is, in the production of the negative electrode plate 26, first, a paste of a negative electrode mixture prepared by kneading hydrogen storage alloy powder, which is an aggregate of hydrogen storage alloy particles, a conductive agent, a binder, and water, is prepared. It is applied to the negative electrode core body 26a and dried. After drying, a part of the negative electrode mixture layer 26b is cut from the negative electrode plate 26 to expose a part of the negative electrode core body 26a. At this time, the negative electrode mixture layer 26b is cut so that the width of the inner peripheral side joint 26h is D5 = 2 mm and the width of the outer peripheral side joint 26k is D4 = 2 mm. After that, the negative electrode plate 26 in a state where a part of the negative electrode core body 26a is exposed is rolled as a whole, and the density of the negative electrode mixture layer 26b is adjusted to a predetermined value. The negative electrode plate 26 manufactured in this manner and the positive electrode plate 24 manufactured by the above method are spirally wound with the separator 28 interposed therebetween to manufacture the spiral electrode group 22. In the spiral electrode group 22, the negative electrode plate 26 was fixed by joining (for example, welding) the inner peripheral side joint portion 26h and the outer peripheral side joint portion 26k. 30 cells of such a spiral electrode group 22 were manufactured. As a result of conducting a test of inserting the spiral electrode group 22 into the outer can 10, the spiral electrode group 22 according to the present embodiment had no winding misalignment in 30 cells. On the other hand, in the spiral electrode group as a comparative example, that is, the spiral electrode group in which the negative electrode plate is not fixed, the negative electrode plate 26 was unwound with respect to the positive electrode plate 24 in 4 out of 30 cells. In this way, when the negative electrode plate 26 was joined as in this embodiment, it was confirmed that winding misalignment did not occur in the spiral electrode group 22 when the negative electrode plate 26 was inserted into the outer can 10.

以上、本発明の好適な実施の形態について説明したが、本発明は上記の実施の形態に係るニッケル水素二次電池２に限定されるものではなく、本発明の概念及び特許請求の範囲に含まれるあらゆる態様を含み、各構成を適宜選択的に組み合わせても良い。また、上記実施の形態における各構成要素の形状、材料、配置、サイズ等は、本発明の具体的態様によって適宜変更され得る。 Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the nickel-metal hydride secondary battery 2 according to the above-described embodiment, and is included in the concept of the present invention and the scope of claims. Each configuration may be selectively combined as appropriate, including all aspects. In addition, the shape, material, arrangement, size, etc. of each component in the above embodiment can be appropriately changed depending on the specific embodiment of the present invention.

２ニッケル水素二次電池（アルカリ蓄電池）
１０外装缶
２０正極端子
２２渦状電極群
２４正極板
２６負極板
２６ａ負極芯体
２６ｂ負極合剤層
２６ｅ最外周負極板部
２６ｆ隣接負極板部
２６ｈ内周側接合部
２６ｋ外周側接合部
２８セパレータ 2 Nickel-metal hydride rechargeable battery (alkaline storage battery)
10 Exterior can 20 Positive electrode terminal 22 Swirl electrode group 24 Positive electrode plate 26 Negative electrode plate 26a Negative electrode core body 26b Negative electrode mixture layer 26e Outermost outer negative electrode plate part 26f Adjacent negative electrode plate part 26h Inner peripheral side joint part 26k Outer peripheral side joint part 28 Separator

Claims

帯状の正極板と、帯状の負極板と、前記正極板及び前記負極板の間に配置された帯状のセパレータとが互いに重ね合わされ、前記負極板が前記正極板より外周側に位置するように渦巻き状に形成された渦状電極群と、
該渦状電極群がアルカリ電解液とともに収容された、導電性を有する円筒形状の外装缶と、
前記正極板と電気的に接続されている正極端子と、を備え、
前記負極板は、最外周に位置して前記外装缶の内周壁と電気的に接続されている最外周負極板部と、前記最外周負極板部の内周側に隣接して位置している隣接負極板部とを有し、
前記最外周負極板部は、該最外周負極板部の内周面の少なくとも一部に内周側接合部を有し、外周面の少なくとも一部において前記外装缶の内周壁に接触しており、
前記隣接負極板部は、該隣接負極板部の外周面に、前記内周側接合部と対向する外周側接合部を有し、
前記負極板は、前記内周側接合部及び前記外周側接合部において接合されていることを特徴とするアルカリ蓄電池。 The band-shaped positive electrode plate, the band-shaped negative electrode plate, and the band-shaped separator arranged between the positive electrode plate and the negative electrode plate are superposed on each other, and the negative electrode plate is spirally formed so as to be located on the outer peripheral side of the positive electrode plate. The formed spiral electrode group and
A conductive cylindrical outer can in which the spiral electrode group is housed together with an alkaline electrolytic solution, and
A positive electrode terminal electrically connected to the positive electrode plate is provided.
The negative electrode plate is located adjacent to the outermost negative electrode plate portion which is located on the outermost circumference and is electrically connected to the inner peripheral wall of the outer can, and the inner peripheral side of the outermost negative electrode plate portion. It has an adjacent negative electrode plate and
The outermost peripheral negative electrode plate portion has an inner peripheral side joint portion at least a part of the inner peripheral surface of the outermost outer peripheral negative electrode plate portion, and is in contact with the inner peripheral wall of the outer can at at least a part of the outer peripheral surface. ,
The adjacent negative electrode plate portion has an outer peripheral side joint portion facing the inner peripheral side joint portion on the outer peripheral surface of the adjacent negative electrode plate portion.
An alkaline storage battery characterized in that the negative electrode plate is joined at the inner peripheral side joint portion and the outer peripheral side joint portion.

前記負極板は、金属製の負極芯体と、該負極芯体に坦持された、負極活物質を含む負極合剤層とを有し、
前記内周側接合部及び前記外周側接合部は、前記負極芯体の一部が露出されて形成された部分であり、
前記負極板は、前記内周側接合部及び前記外周側接合部において溶接されている、請求項１記載のアルカリ蓄電池。 The negative electrode plate has a negative electrode core made of metal and a negative electrode mixture layer containing a negative electrode active material carried on the negative electrode core.
The inner peripheral side joint portion and the outer peripheral side joint portion are portions formed by exposing a part of the negative electrode core body.
The alkaline storage battery according to claim 1, wherein the negative electrode plate is welded at the inner peripheral side joint portion and the outer peripheral side joint portion.

前記内周側接合部は、前記渦状電極群の周方向における端部の側に設けられている、請求項１又は２記載のアルカリ蓄電池。 The alkaline storage battery according to claim 1 or 2, wherein the inner peripheral side joint is provided on the end side in the circumferential direction of the spiral electrode group.

前記内周側接合部及び前記外周側接合部は、それぞれ、前記外装缶の軸線方向において前記負極板の全体に亘って設けられている、請求項１から３までのいずれか１項記載のアルカリ蓄電池。 The alkali according to any one of claims 1 to 3, wherein the inner peripheral side joint portion and the outer peripheral side joint portion are provided over the entire negative electrode plate in the axial direction of the outer can, respectively. Storage battery.

前記内周側接合部及び前記外周側接合部は、それぞれ、前記外装缶の軸線方向において前記負極板の一方の端部分と他方の端部分とに部分的に設けられている、請求項１から３までのいずれか１項記載のアルカリ蓄電池。 The inner peripheral side joint portion and the outer peripheral side joint portion are partially provided at one end portion and the other end portion of the negative electrode plate in the axial direction of the outer can, respectively, according to claim 1. The alkaline storage battery according to any one of up to 3.