JP2019067667A - Electrochemical cell - Google Patents

Abstract

To provide a highly reliable electrochemical cell.SOLUTION: A battery 1 includes: an electrode body 10 wound around a winding axis P while a positive electrode body 11 and a negative electrode body 12 are stacked therein; an outer package body 20 for housing the electrode body 10 and an electrolyte therein; a positive electrode lead 13 and a negative electrode lead 14 connected to the electrode body 10 and extending from a first end 10a of the electrode body 10 in an axial direction of the winding axis P; and an insulation member 40 interposed between the first end 10a of the electrode body 10 and the positive and negative electrode leads 13, 14.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an electrochemical cell.

  Electrochemical cells such as non-aqueous electrolyte secondary batteries and electric double layer capacitors are used as power supplies for various devices. As one form of the electrochemical cell, for example, a battery as described in Patent Document 1 below has been proposed. The battery described in Patent Document 1 includes a power generation element, a battery container for containing the power generation element, a non-aqueous electrolyte filled in the battery container, and a lead terminal for electrically connecting the power generation element to an external circuit. Is formed by superposing the positive electrode plate, the negative electrode plate, and the separator in this order and winding them in an oval vortex shape.

Unexamined-Japanese-Patent No. 2000-182574

  By the way, in the conventional electrochemical cell, the lead terminal may come in contact with the end of the power generating element inside the battery container. In this case, the lead connected to the positive electrode plate may be in contact with the negative electrode plate, or the lead connected to the negative electrode plate may be in contact with the positive electrode plate, which may cause a short circuit inside the battery container. As a result, there is a problem that the reliability of the electrochemical cell is reduced.

  Therefore, the present invention provides a highly reliable electrochemical cell.

  The electrochemical cell of the present invention is connected to an electrode body wound around a predetermined axis in a state in which a positive electrode body and a negative electrode body are stacked, an exterior body for containing the electrode body and an electrolyte, and the electrode body The electrode assembly may include a lead extending from an end of the electrode body in the axial direction of the predetermined axis, and an insulating member interposed between the end of the electrode assembly and the lead.

  According to the present invention, the insulating member can suppress conduction of the lead in contact with the end of the electrode body. Therefore, it is possible to prevent the positive electrode body from coming into contact with the opposite polarity lead at the end of the electrode body and shorting, and the negative electrode body from coming into contact with the opposite polarity lead at the end part of the electrode body. Therefore, a highly reliable electrochemical cell can be provided.

  In the above electrochemical cell, it is desirable that the insulating member has a liquid retention property.

  In the present invention, since the electrode body is wound around a predetermined axis, the interlayer between the positive electrode body and the negative electrode body is opened in the axial direction at the end portion in the axial direction. The insulating member is disposed between the end of the electrode body and the lead and has a liquid retaining property, so that the electrolysis can be performed in a state where the electrolytic solution can be supplied from the end of the electrode body to the interlayer of the positive electrode body and the negative electrode body It can hold liquid. Therefore, it can suppress that the lack of electrolyte solution arises inside an electrode body, and can stabilize the characteristic of an electrochemical cell.

  In the above electrochemical cell, the insulating member preferably has a cushioning property.

  According to the present invention, since the insulating member has a cushioning property, even if the unevenness due to the laminated structure of the positive electrode body and the negative electrode body is formed at the end portion of the electrode body, Can be filled in between. Thereby, when the exterior body is formed of a flexible member, after the degassing at the time of manufacture of the electrochemical cell, it can be suppressed that the exterior body is deformed by internal negative pressure. Moreover, it can suppress that the member (for example, positive electrode body, a negative electrode body, a lead, etc.) which contacts an insulation member is damaged.

  In the electrochemical cell described above, it is preferable that an insertion portion through which the lead is inserted is formed in the insulating member.

  According to the present invention, the insulating member is formed with the through hole through which the lead is inserted. Thereby, since the movement of the insulating member with respect to the lead can be restricted, positional deviation of the insulating member with respect to the lead and the electrode body can be suppressed. Therefore, contact of the lead with the end of the electrode body can be suppressed more reliably.

  In the electrochemical cell described above, it is preferable that the insulating member is formed such that an outer edge thereof is provided outside the positive electrode body and the negative electrode body with respect to the predetermined axis when viewed from the axial direction.

  According to the present invention, the positive electrode body and the negative electrode body can be covered with the insulating member at the outermost peripheral portion of the electrode body in which the positive electrode body and the negative electrode body are easily displaced in the axial direction. Therefore, contact of the lead with the end of the electrode body can be suppressed more reliably.

  In the above electrochemical cell, the exterior body is formed by overlapping a first member and a second member, and the exterior body sandwiches the electrode body between the first member and the second member, and the electrode is formed. A housing portion for housing the body, and a peripheral portion formed by overlapping the first member and the second member around the housing portion and sealing the inside of the housing portion, the peripheral portion Is preferably bent along the outer surface of the housing.

  In the configuration in which the peripheral edge portion is bent along the outer surface of the housing portion as in the present invention, when the peripheral edge portion is bent, a force may be applied to the housing portion and the housing portion may be deformed to be squeezed. As a result, the electrode body housed in the housing portion is pressed, and the positive electrode body and the negative electrode body are easily displaced from each other in the axial direction. According to the present invention, since the insulating member is interposed between the end of the electrode body and the lead, as described above, the positive electrode body contacts the lead of the reverse polarity at the end of the electrode body to short-circuit it. And it can suppress that a negative electrode body contacts the lead of reverse polarity in the edge part of an electrode body, and short-circuits. Therefore, by folding the peripheral portion, it is possible to provide an electrochemical cell which is miniaturized and reliable.

  According to the present invention, a highly reliable electrochemical cell can be provided.

It is a perspective view of the battery concerning an embodiment. It is an exploded perspective view of a battery concerning an embodiment. It is a longitudinal cross-sectional view of the battery concerning an embodiment. It is a perspective view of the battery concerning a 1st modification of an embodiment. It is a longitudinal cross-sectional view of the battery concerning the 2nd modification of an embodiment.

  Hereinafter, embodiments of the present invention will be described based on the drawings. In the following description, components having the same or similar functions are denoted by the same reference numerals. And duplicate explanation of those composition may be omitted. In the following description, as an electrochemical cell, a lithium ion secondary battery (hereinafter, simply referred to as "battery"), which is a type of non-aqueous electrolyte secondary battery, will be described as an example.

FIG. 1 is a perspective view of a battery according to the embodiment. FIG. 2 is an exploded perspective view of the battery according to the embodiment.
As shown in FIGS. 1 and 2, the battery 1 is a so-called small cylindrical battery. The battery 1 includes an electrode assembly 10 including a positive electrode assembly 11 and a negative electrode assembly 12, an outer package 20 containing the electrode assembly 10 and an electrolytic solution (electrolyte), and leads 13 and 14 (positive electrode leads) extending from the electrode assembly 10. 13 and the negative electrode lead 14), and an insulating member 40 disposed between the electrode body 10 and the leads 13 and 14.

  As shown in FIG. 2, the electrode body 10 is formed in a cylindrical shape. The electrode body 10 has a structure in which a strip-like positive electrode body 11 and a negative electrode body 12 are wound around a winding axis P (predetermined axis) in a state where the positive electrode body 11 and the negative electrode body 12 are stacked with a separator 15 interposed therebetween. That is, the separator 15 is disposed between the layers of the positive electrode body 11 and the negative electrode body 12 and insulates the positive electrode body 11 from the negative electrode body 12. At the outermost periphery of the electrode body 10, a separator 15 is disposed. In the example shown in FIG. 2, the positive electrode body 11 and the negative electrode body 12 are exposed on the outer peripheral surface of the electrode body 10 in order to explain the laminated structure of the electrode body 10. It is desirable that the separator 15 be disposed over the entire circumference. The electrode assembly 10 has a first end 10a located on one side in the axial direction of the winding axis P and a second end 10b located on the opposite side of the first end 10a in the axial direction of the winding axis P And. In the following description, the axial direction of the winding axis P is simply referred to as the axial direction, the direction around the winding axis P is referred to as the circumferential direction, and the direction orthogonal to the axial direction is referred to as the radial direction.

  The positive electrode body 11 includes a positive electrode current collector foil made of a metal material and a positive electrode active material coated on the positive electrode current collector foil. The positive electrode current collector foil is formed of, for example, a metal foil such as aluminum or stainless steel. The positive electrode active material is, for example, a composite oxide containing lithium and a transition metal such as lithium cobaltate, lithium titanate, lithium manganate and the like.

  The negative electrode body 12 includes a negative electrode current collector foil made of a metal material, and a negative electrode active material coated on the negative electrode current collector foil. The negative electrode current collector foil is formed of, for example, a metal foil such as copper or stainless steel. The negative electrode active material is, for example, silicon oxide, graphite, hard carbon, lithium titanate, LiAl or the like. In the axial direction, the dimension of the negative electrode body 12 is larger than the dimension of the positive electrode body 11. For example, the negative electrode body 12 is disposed such that the side edges on both sides in the axial direction are located on the outer side in the axial direction than the positive electrode body 11.

  The separator 15 is formed of, for example, a resin porous film made of polyolefin, a glass non-woven fabric, a resin non-woven fabric, a laminate of cellulose fibers, or the like, which has the property of transmitting lithium ions. In the axial direction, the dimension of the separator 15 is larger than the dimension of the negative electrode body 12. For example, the separators 15 are disposed such that the side edges on both sides in the axial direction are located axially outside the positive electrode body 11 and the negative electrode body 12. Thereby, the separator 15 suppresses the contact between the positive electrode body 11 and the negative electrode body 12 in the entire axial direction.

  As shown in FIGS. 1 and 2, the exterior body 20 is formed by overlapping a first sheet 21 (first member) and a second sheet 22 (second member). The exterior body 20 includes a housing portion 23 for housing the electrode body 10 and a peripheral portion 24 provided around the housing portion 23. The housing portion 23 sandwiches the electrode body 10 by the first sheet 21 and the second sheet 22 and covers the entire electrode body 10. The peripheral portion 24 is formed by overlapping the first sheet 21 and the second sheet 22 around the accommodation portion 23. The peripheral portion 24 seals the inside of the housing portion 23. The first sheet 21 and the second sheet 22 are joined at the peripheral portion 24 by, for example, heat fusion or the like.

  The first sheet 21 and the second sheet 22 are each formed of a flexible laminate film. The laminate film includes a metal layer (metal foil), a resin-made fusion layer provided on the laminated surface (inner side surface) and covering the metal foil, and a resin protection layer provided on the outer side and covering the metal foil. And. The metal layer is formed using, for example, a metal material such as stainless steel or aluminum that blocks outside air or water vapor. The fusion layer on the overlapping surface is formed using, for example, a thermoplastic resin such as polyolefin polyethylene or polypropylene. The protective layer on the outer side is formed of, for example, the above-mentioned polyolefin, polyester such as polyethylene terephthalate, nylon or the like.

  As shown in FIG. 2, the first sheet 25 has a first case 25 formed in a cylindrical shape with a bottom, and a projection extending outward in the radial direction of the first case 25 from the opening edge of the first case 25. A flange portion 26 is formed. The first sheet 21 is formed such that the fusion layer of the laminate film is located on the inner surface of the first case 25. The inner diameter of the first case 25 is larger than the outer diameter of the electrode body 10.

  The second sheet 27 is formed in a cylindrical shape with a bottom and has a second case 27 that opens toward the first case 25, and protrudes outward in the radial direction of the second case 27 from the opening edge of the second case 27. A second flange portion 28 is formed. The second sheet 22 is formed such that the fusion layer of the laminate film is located on the inner surface of the second case 27. The second case 27 is disposed coaxially with the first case 25 of the first sheet 21. For example, the second case 27 is formed deeper than the first case 25. The inner diameter of the second case 27 is equal to the inner diameter of the first case 25. The shape of the second flange portion 28 substantially matches the shape of the first flange portion 26. The second sheet 22 is joined to the first sheet 21 by, for example, thermal fusion so that the second flange portion 28 is superposed on the first flange portion 26.

  As shown in FIGS. 1 and 2, the housing portion 23 is formed in a cylindrical shape in which both ends in the axial direction are closed by the first case 25 and the second case 27. For example, the outer diameter of the housing portion 23 is set to about 10 mm, and the dimension of the housing portion 23 in the axial direction is set to about 6 mm. Inside the housing portion 23, the electrode body 10 is disposed in a state in which the winding axis P is substantially aligned with the central axis of the housing portion 23.

  The peripheral portion 24 is formed by overlapping the first flange portion 26 and the second flange portion 28. The peripheral portion 24 surrounds the opening edge of the first case 25 and the opening edge of the second case 27 in the accommodation portion 23 from the outer side in the radial direction to the entire periphery. The peripheral portion 24 protrudes along the radial direction from the accommodation portion 23 and extends along the circumferential direction. The peripheral portion 24 has a pair of lead holding portions 31A, 31B for holding the positive electrode lead 13 and the negative electrode lead 14 separately between the first sheet 21 and the second sheet 22, and a pair of lead holding portions 31A, 31 in the circumferential direction. And a narrow portion 32 which is provided between 31B and which is narrower in the radial direction than the lead holding portions 31A, 31B. The lead holding portions 31A and 31B are provided at positions facing each other in the radial direction across the housing portion 23.

  As shown in FIG. 2, the positive electrode lead 13 is formed in a strip shape from a metal material such as aluminum and drawn from the inside to the outside of the exterior body 20. The positive electrode lead 13 is attached to the positive electrode current collector foil of the positive electrode body 11 at one end by welding or the like, and is electrically connected to the positive electrode body 11. The positive electrode lead 13 is connected to the end of the positive electrode body 11 near the winding center of the electrode body 10. In the following description, one end side of the positive electrode lead 13 attached to the positive electrode body 11 is a base end side, and a side drawn out of the exterior body 20 is a tip end side. The positive electrode lead 13 extends from the portion near the winding axis P at the first end 10 a of the electrode body 10 to the side where the first end 10 a in the axial direction faces.

FIG. 3 is a longitudinal sectional view of the battery according to the embodiment.
As shown in FIG. 3, the positive electrode lead 13 extends from the first end 10 a of the electrode assembly 10 toward the bottom wall of the first case 25 of the exterior body 20 in order from the proximal end toward the distal end. A second portion 13b extending along a direction (radial direction in the present embodiment) axially crossing between the portion 13a, the bottom wall of the first case 25 and the first end 10a of the electrode body 10; The third portion 13c extending along the axial direction between the peripheral wall of the first case 25 and the outer peripheral surface of the electrode body 10 and the first sheet 21 and the second sheet 22 at the peripheral portion 24 of the exterior body 20 And an extending fourth portion 13d.

  The second portion 13 b is bent relative to the first portion 13 a so that one main surface is directed to the bottom wall of the first case 25. The second portion 13 b is curved in the radial direction and in a direction away from the winding axis P with respect to the first portion 13 a.

  The third portion 13 c is bent with respect to the second portion 13 b so that the pair of main surfaces faces the peripheral wall of the first case 25 and the outer peripheral surface of the electrode body 10. The third portion 13c is curved with respect to the second portion 13b in a direction away from the bottom wall of the first case 25 in the axial direction.

  The fourth portion 13d is bent relative to the third portion 13c so that both main surfaces are directed in the axial direction. The fourth portion 13 d extends in the radial direction in the direction away from the electrode body 10. The fourth portion 13 d passes between the first sheet 21 and the second sheet 22 in the lead holding portion 31 A of the exterior body 20 and extends to the outside of the exterior body 20.

  Thus, the positive electrode lead 13 extends from the first end 10 a of the electrode body 10 to the side facing the first end 10 a in the axial direction, and at the same time, the exterior body 20 and the first end 10 a of the electrode body 10. And extends in a direction intersecting the axial direction.

  As shown in FIG. 2, the negative electrode lead 14 is formed in a strip shape from a metal material such as stainless steel, nickel, copper or the like, and is drawn from the inside of the exterior body 20 to the outside. The negative electrode lead 14 is attached to the negative electrode current collector foil of the negative electrode body 12 at one end by welding or the like, and is electrically connected to the negative electrode body 12. The negative electrode lead 14 is connected to the end of the negative electrode body 12 on the side close to the winding center of the electrode body 10. In the following description, one end side of the negative electrode lead 14 attached to the negative electrode body 12 is taken as a base end side, and the side drawn out of the exterior body 20 is taken as a tip end side. The negative electrode lead 14 extends from the side opposite to the positive electrode lead 13 across the winding axis P at the first end 10 a of the electrode body 10 to the side facing the first end 10 a in the axial direction.

  As shown in FIG. 3, the negative electrode lead 14 extends from the first end 10 a of the electrode assembly 10 toward the bottom wall of the first case 25 of the exterior body 20 in order from the proximal end toward the distal end. A second portion 14b extending along a direction (radial direction in the present embodiment) axially crossing between the portion 14a, the bottom wall of the first case 25 and the first end 10a of the electrode body 10; The third portion 14c extending along the axial direction between the peripheral wall of the first case 25 and the outer peripheral surface of the electrode body 10 and the first sheet 21 and the second sheet 22 at the peripheral portion 24 of the exterior body 20 And an extending fourth portion 14d.

  The second portion 14 b is bent relative to the first portion 14 a so that one major surface is directed to the bottom wall of the first case 25. The second portion 14b is curved in the radial direction and in a direction away from the winding axis P with respect to the first portion 14a. The second portion 14 b is disposed on the opposite side to the second portion 13 b of the positive electrode lead 13 across the winding axis P.

  The third portion 14 c is curved with respect to the second portion 14 b so that the pair of main surfaces faces the peripheral wall of the first case 25 and the outer peripheral surface of the electrode body 10. The third portion 14c bends in a direction away from the bottom wall of the first case 25 in the axial direction with respect to the second portion 14b.

  The fourth portion 14d is bent relative to the third portion 14c so that both main surfaces are axially oriented. The fourth portion 14 d extends in the radial direction in the direction away from the electrode body 10. The fourth portion 14 d extends between the first sheet 21 and the second sheet 22 in the lead holding portion 31 B of the exterior body 20 and extends to the outside of the exterior body 20.

  Thus, the negative electrode lead 14 extends from the first end 10 a of the electrode body 10 to the side facing the first end 10 a in the axial direction, and at the same time, the exterior body 20 and the first end 10 a of the electrode body 10 And extends in a direction intersecting the axial direction.

  A sealant film 17 is interposed between the first and second flanges 26 and 28 and the leads 13 and 14, respectively. The sealant film 17 is a film material made of a thermoplastic resin such as, for example, polyolefin, polyethylene, or polypropylene. The sealant film 17 sandwiches the leads 13 and 14 from both sides in the thickness direction by the pair of film materials. The sealant film 17 is welded and fixed to the first sheet 21 and the second sheet 22.

  The insulating member 40 is interposed between the first end 10 a of the electrode body 10 and the positive electrode lead 13 and the negative electrode lead 14. The insulating member 40 is, for example, a member formed in a plate shape or a sheet shape. The insulating member 40 is formed of a material having electrical insulation and insolubility to the electrolytic solution. For example, the insulating member 40 is formed of a material that can be used as the separator 15. The insulating member 40 has a liquid retaining property and a cushioning property. The cushioning property is a property that can be deformed following the shape of another object in contact. The insulating member 40 is formed of, for example, a resin non-woven fabric such as polyolefin, a glass non-woven fabric, or the like.

  As shown in FIG. 2, the insulating member 40 overlaps the first end 10 a of the electrode body 10 and the second portion 13 b of the positive electrode lead 13 and the second portion 14 b of the negative electrode lead 14 when viewed in the axial direction. It is provided as. In the present embodiment, the insulating member 40 is formed in a disk shape in which the through hole 41 (insertion portion) is formed at the center. The insulating member 40 is disposed coaxially with the electrode body 10. The first portion 13 a of the positive electrode lead 13 and the first portion 14 a of the negative electrode lead 14 are inserted into the through hole 41. The outer peripheral edge (outer edge) of the insulating member 40 is provided radially outward of the positive electrode body 11 and the negative electrode body 12 with respect to the winding axis P when viewed from the axial direction. That is, the outer peripheral edge of insulating member 40 is provided at the same position or at a position farther from winding axis P than the outermost peripheral portions of positive electrode body 11 and negative electrode body 12. The insulating member 40 covers substantially the entire first end 10 a of the electrode body 10. The outer diameter of the insulating member 40 substantially matches the outer diameter of the electrode body 10.

As described above, in the present embodiment, the insulating member 40 is interposed between the first end 10 a of the electrode body 10 and the positive electrode lead 13 and the negative electrode lead 14.
When the electrode assembly 10 is formed by winding the positive electrode assembly 11, the negative electrode assembly 12, and the separator 15 in a stacked state, the positive electrode assembly 11 and the negative electrode assembly 12 move from the winding center to the outer periphery of the electrode assembly 10. And the separators 15 are easily offset from each other in the axial direction. Thereby, at the end of the electrode body 10 in the axial direction (for example, the first end 10a), at least one of the positive electrode body 11 and the negative electrode body 12 may protrude in the axial direction more than the separator 15.
According to the present embodiment, the insulating member 40 can suppress conduction between the first end 10 a of the electrode body 10 and at least one of the positive electrode lead 13 and the negative electrode lead 14. Therefore, the positive electrode body 11 contacts the negative electrode lead 14 at the first end 10 a of the electrode body 10 and shorts, and the negative electrode body 12 contacts the positive electrode lead 13 at the first end 10 a of the electrode body 10 and shorts Can be suppressed. Therefore, highly reliable battery 1 can be provided.

  Further, in the present embodiment, since the electrode body 10 is wound around the winding axis P, the layer between the positive electrode body 11 and the negative electrode body 12 is an axis at each of the first end 10a and the second end 10b. Opening in the direction. According to the present embodiment, since the insulating member 40 is disposed between the first end 10 a of the electrode body 10 and the positive electrode lead 13 and the negative electrode lead 14 and has a liquid retaining property, the first end of the electrode body 10 is The electrolytic solution can be held in a state in which the electrolytic solution can be supplied from the portion 10 a to the layer between the positive electrode body 11 and the negative electrode body 12. For this reason, it can suppress that the lack of electrolyte solution arises inside the exterior body 20, and the characteristic of the battery 1 can be stabilized.

  Further, in the present embodiment, since the insulating member 40 has a cushioning property, even if the first end portion 10a of the electrode body 10 has irregularities formed by the laminated structure of the positive electrode body 11, the negative electrode body 12 and the separator 15, insulation is provided. The space between the package 20 and the first end 10 a of the electrode assembly 10 can be filled with the member 40. Thereby, after the degassing at the time of manufacture of the battery 1, it can suppress that the exterior body 20 formed of the soft laminate film loses a shape by internal negative pressure. Moreover, it can suppress that the member (For example, the positive electrode body 11, the negative electrode body 12, the separator 15, the positive electrode lead 13, the negative electrode lead 14 etc.) which contacts the insulating member 40 is damaged.

  Further, in the present embodiment, the insulating member 40 is formed with the through holes 41 through which the positive electrode lead 13 and the negative electrode lead 14 are inserted. Thereby, the movement of the insulating member 40 with respect to the positive electrode lead 13 and the negative electrode lead 14 can be restricted, so that the positional deviation of the insulating member 40 with respect to the positive electrode lead 13, the negative electrode lead 14 and the electrode assembly 10 can be suppressed. Therefore, contact of at least one of the positive electrode lead 13 and the negative electrode lead 14 with the first end 10 a of the electrode body 10 can be more reliably suppressed.

  Further, in the present embodiment, the outer peripheral edge of the insulating member 40 is provided on the outer side with respect to the winding axis P than the positive electrode body 11 and the negative electrode body 12 when viewed from the axial direction. Thus, the positive electrode body 11 and the negative electrode body 12 can be covered with the insulating member 40 at the outermost peripheral portion of the electrode body 10 in which the positive electrode body 11, the negative electrode body 12 and the separator 15 easily shift in the axial direction. Therefore, contact of the positive electrode lead 13 and the negative electrode lead 14 with the first end 10 a of the electrode body 10 can be suppressed more reliably.

In addition, in the said embodiment, although the peripheral part 24 of the exterior body 20 protrudes along the radial direction from the accommodating part 23, it is not limited to this.
FIG. 4 is a perspective view of a battery according to a first modification of the embodiment.
As shown in FIG. 4, the peripheral edge portion 24 may be bent along the outer peripheral surface of the housing portion 23. In this case, the peripheral edge portion 24 is bent by draw forming, for example, after the first flange portion 26 of the first sheet 21 and the second flange portion 28 of the second sheet 22 are heat-sealed.

  As described above, in the configuration in which the peripheral edge portion 24 is bent along the outer surface of the housing portion 23, when the peripheral edge portion 24 is bent, a force is applied to the housing portion 23 and the housing portion 23 is deformed to be squeezed. As a result, the electrode assembly 10 accommodated in the accommodation portion 23 is deformed, and the positive electrode assembly 11, the negative electrode assembly 12 and the separator 15 are easily displaced from each other in the axial direction (see FIG. 2). For this reason, by interposing the insulating member 40 between the first end 10 a of the electrode body 10 and the positive electrode lead 13 and the negative electrode lead 14, the positive electrode body 11 is the first electrode body 10 as in the first embodiment. A short circuit in contact with the negative electrode lead 14 at the end 10 a and a short circuit in contact with the positive electrode lead 13 at the first end 10 a of the electrode assembly 10 can be suppressed. Therefore, the battery 1 can be provided with high reliability by reducing the size by bending the peripheral portion 24.

Moreover, in the battery 1 of the said embodiment, although the positive electrode lead 13 and the negative electrode lead 14 are extended from the 1st end part 10a of the electrode body 10, it is not limited to this.
FIG. 5 is a longitudinal sectional view of a battery according to a second modification of the embodiment.
For example, as in the battery 101 shown in FIG. 5, the positive electrode lead 13 may extend from the first end 10 a of the electrode assembly 10 and the negative electrode lead 14 may extend from the second end 10 b of the electrode assembly 10. In this case, the first insulating member 40A is interposed between the first end 10a of the electrode body 10 and the second portion 13b of the positive electrode lead 13. The first insulating member 40A is provided so as to overlap the first end 10a of the electrode body 10 and the second portion 13b of the positive electrode lead 13 when viewed in the axial direction. The second insulating member 40 B is interposed between the second end 10 b of the electrode body 10 and the second portion 14 b of the negative electrode lead 14. The second insulating member 40B is provided so as to overlap the second end 10b of the electrode body 10 and the second portion 14b of the negative electrode lead 14 when viewed in the axial direction.

  Thus, even if the pair of leads 13 and 14 extend from the different ends 10 a and 10 b of the electrode assembly 10, the pair of leads 13 and 14 and the ends 10 a and 10 b of the electrode assembly 10 By interposing the insulating members 40A and 40B between them, the same function and effect as those of the embodiment described above can be obtained.

The present invention is not limited to the above-described embodiment described with reference to the drawings, and various modifications can be considered within the technical scope.
For example, in the said embodiment, although the insulation member 40 is formed in disk shape and covers the substantially whole 1st edge part 10a of the electrode body 10, it is not limited to this. The insulating member may be provided so as to overlap with the end portions 10 a and 10 b of the electrode body 10 and the positive electrode lead 13 and the negative electrode lead 14 at least viewed in the axial direction. Further, the insulating member is an outer peripheral surface of the electrode body 10 and a positive electrode lead from between the first end 10 a of the electrode body 10 and the second portion 13 b of the positive electrode lead 13 and the second portion 14 b of the negative electrode lead 14. It may be disposed between the third portion 13 c of 13 and the third portion 14 c of the negative electrode lead 14.

  Moreover, in the said embodiment, although the positive electrode lead 13 and the negative electrode lead 14 are penetrated by the through-hole 41 of the insulation member 40, it is not limited to this. For example, the insulating member may be formed with a slit through which the positive electrode lead 13 and the negative electrode lead 14 are inserted. Also, the insulating member may be divided into a plurality.

  Moreover, in the said embodiment, although the insulation member 40 has a liquid retaining property and cushioning property, it is not limited to this. The insulating member may be formed of, for example, a film-like member. Also, the insulating member may be formed of a hard material.

  Moreover, in the said embodiment, while the electrode body 10 is formed in cylindrical shape, and the accommodating part 23 of the exterior body 20 is formed in cylindrical shape, it is not limited to this. For example, the electrode body may be formed in an elliptic cylindrical shape, and the housing portion of the outer package may be formed in an elliptical cylindrical shape corresponding to the electrode body.

  In the above embodiment, the bottomed cylindrical cases 25 and 27 are formed on the sheets 21 and 22 forming the exterior body 20, but the present invention is not limited to this. That is, a cylindrical case with a bottom is formed in one of the pair of sheets forming the exterior body, and the other sheet is formed in a flat plate shape and arranged so as to close the case of one sheet. May be

  Moreover, in the said embodiment, although the non-aqueous electrolyte secondary battery was mentioned as an example and demonstrated as an example of an electrochemical cell, it is not limited in this case, The structure mentioned above to an electric double layer capacitor, a primary battery, etc. It can apply.

  In addition, without departing from the spirit of the present invention, it is possible to replace components in the above-described embodiment with known components as appropriate.

  DESCRIPTION OF SYMBOLS 1, 101 ... Battery (electrochemical cell) 10 ... Electrode body 10a ... 1st end part (end part) 10b ... 2nd end part (end part) 11 ... Positive electrode body 12 ... Negative electrode body 13 ... Positive electrode lead (lead) 14 Anode lead (lead) 20 Outer body 21 First sheet (first member) 22 Second sheet (second member) 23 Accommodating portion 24 Peripheral portion 40, 40A, 40B Insulating member 41 Through hole (Insertion portion) P: winding axis (predetermined axis)

The electrochemical cell of the present invention is connected to an electrode body wound around a predetermined axis in a state in which a positive electrode body and a negative electrode body are stacked, an exterior body for containing the electrode body and an electrolyte, and the electrode body The electrode body includes a lead extending from an end of the predetermined axis in the axial direction and an insulating member interposed between the end of the electrode and the lead ; The member and the second member are formed one on the other, and the case is formed by holding the electrode body by the first member and the second member, and a housing portion for housing the electrode body, and around the housing portion. A peripheral portion formed by overlapping the first member and the second member and sealing the inside of the storage portion, the peripheral portion being bent along the outer surface of the storage portion Are characterized.
The electrochemical cell of the present invention is formed of a laminated film including an electrode body wound around a predetermined axis in a state where a positive electrode body and a negative electrode body are laminated, and a metal layer and a resin layer covering the metal layer. An exterior body that accommodates the electrode body and the electrolyte; a lead connected to the electrode body and extending from an end of the electrode body in an axial direction of the predetermined axis; the end of the electrode body and the lead An insulating member interposed between the insulating members, and the insulating member has a liquid retaining property.
The electrochemical cell of the present invention is formed of a laminated film including an electrode body wound around a predetermined axis in a state where a positive electrode body and a negative electrode body are laminated, and a metal layer and a resin layer covering the metal layer. An exterior body that accommodates the electrode body and the electrolyte; a lead connected to the electrode body and extending from an end of the electrode body in an axial direction of the predetermined axis; the end of the electrode body and the lead An insulating member interposed between the first and second members, and the insulating member has a cushioning property.
In the above electrochemical cell, the exterior body is formed by overlapping a first member and a second member formed of the laminate film, and the exterior body is formed by the first member and the second member. It is preferable that a housing part that holds the electrode body and that accommodates the electrode body is provided, and the housing part is formed in a cylindrical shape in which both ends in the axial direction are closed.

According to the present invention, the insulating member can suppress conduction of the lead in contact with the end of the electrode body. Therefore, it is possible to prevent the positive electrode body from coming into contact with the opposite polarity lead at the end of the electrode body and shorting, and the negative electrode body from coming into contact with the opposite polarity lead at the end part of the electrode body. Therefore, a highly reliable electrochemical cell can be provided.
Furthermore, as in the present invention, in the configuration in which the peripheral portion is bent along the outer surface of the housing portion, a force may be applied to the housing portion when the peripheral portion is bent, and the housing portion may be deformed to be squeezed. . As a result, the electrode body housed in the housing portion is pressed, and the positive electrode body and the negative electrode body are easily displaced from each other in the axial direction. According to the present invention, since the insulating member is interposed between the end of the electrode body and the lead, as described above, the positive electrode body contacts the lead of the reverse polarity at the end of the electrode body to short-circuit it. And it can suppress that a negative electrode body contacts the lead of reverse polarity in the edge part of an electrode body, and short-circuits. Therefore, by folding the peripheral portion, it is possible to provide an electrochemical cell which is miniaturized and reliable.

Claims (6)

An electrode body wound around a predetermined axis in a state in which a positive electrode body and a negative electrode body are laminated;
An exterior body for containing the electrode body and the electrolyte;
A lead connected to the electrode body and extending from an end of the electrode body in the axial direction of the predetermined axis;
An insulating member interposed between the end of the electrode body and the lead;
An electrochemical cell comprising: The insulating member has a liquid retention property.
An electrochemical cell according to claim 1, characterized in that. The insulating member has a cushioning property,
The electrochemical cell according to claim 1 or 2, wherein The insulating member is formed with an insertion portion through which the lead is inserted.
The electrochemical cell according to any one of claims 1 to 3, characterized in that. The insulating member is formed such that an outer edge thereof is provided outside the positive electrode body and the negative electrode body with respect to the predetermined axis when viewed from the axial direction.
The electrochemical cell according to any one of claims 1 to 4, characterized in that. The exterior body is formed by overlapping a first member and a second member,
The exterior body is
A housing portion for holding the electrode body by the first member and the second member, and housing the electrode body;
A peripheral edge portion formed by overlapping the first member and the second member around the housing portion and sealing the inside of the housing portion;
Equipped with
The peripheral portion is bent along the outer surface of the housing portion.
The electrochemical cell according to any one of claims 1 to 5, characterized in that.

Images