JP2007018917A - Stacked battery, and battery pack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stacked battery improved in heat radiation performance. <P>SOLUTION: In the stacked battery 10, an electrode lamination body 20 is constituted by alternately laminating a positive electrode plate and a negative electrode plate through a separator, and a battery sheath 30 seals and houses an electrolyte together with this electrode lamination body 20. The electrode lamination body 20 is provided with a penetrating part 23 penetrating through the upper face side and the lower face side in lamination direction, and the battery sheath 30 is provided with a recessed part 33 dented toward the penetrating direction of this penetrating part 23 at a position corresponding to the penetrating part 23 of the electrode lamination body 20 to be housed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a stacked battery having a power generation element configured by alternately stacking positive and negative electrode plates with separators interposed therebetween, and an assembled battery including the stacked battery.

In recent years, electric vehicles powered by electricity and hybrid cars that run in combination with an engine and motor have attracted attention, and the development of high-power batteries with high energy density and high output density has been developed. It has been broken. As such a high output type battery, for example, there is a lithium ion battery, and in particular, a power generation element in which a flat plate-like positive electrode plate and a negative electrode plate are laminated with a separator interposed therebetween together with an electrolyte between a pair of exterior members. There is a stacked battery that is housed and sealed by joining the peripheral edge of an exterior member (see, for example, Patent Document 1).
JP 2004-087260 A

  By the way, since this laminated battery is required to have a high output, there is a possibility that the temperature rises during operation and there is a problem that the life of the battery is reduced. Therefore, in this type of stacked battery, it is one of important issues to improve the heat dissipation performance.

  This invention is made | formed in view of such a situation, The objective is to aim at the improvement of the thermal radiation performance of a laminated battery.

  In order to solve such a problem, the present invention includes a power generation element configured by alternately stacking positive and negative electrode plates with a separator interposed therebetween, a first exterior member that covers the upper surface side of the power generation element, A stacked battery having a battery exterior that seals and stores an electrolyte together with a power generation element by welding a second exterior member that covers the lower surface side of the power generation element to each other is provided. In such a stacked battery, the power generation element includes a penetrating portion that penetrates the upper surface side and the lower surface side in the stacking direction. In addition, the battery exterior includes at least a concave portion that is recessed in the penetration direction of the penetration portion at a position corresponding to the penetration portion of the power generation element to be housed.

  According to the present invention, the heat accumulated in the stacked battery is released by the concave portion of the battery exterior, and the heat dissipation performance can be improved. As a result, the life of the stacked battery can be extended.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is an exploded perspective view illustrating the configuration of a stacked battery 10 according to the first embodiment of the present invention. The stacked battery 10 is mainly composed of an electrode stack 20 as a power generation element and a battery outer package 30 that houses the electrode stack 20, and the electrode stack 20 is a pair constituting the battery outer cover 30. The metal composite films (exterior members) 31 and 32 are arranged in the center. The electrode laminate 20 is housed so as to be sandwiched between the individual metal composite films 31 and 32 in the thickness direction, and is sealed together with the electrolyte by welding these metal composite films 31 and 32.

  The electrode laminate 20 is configured by sequentially laminating a plurality of positive and negative electrode plates with a separator interposed therebetween, and the planar shape thereof is substantially rectangular. The positive electrode plate is obtained by applying a positive electrode active material to both surfaces (or one surface) of a sheet-like positive electrode current collector, and the negative electrode plate is formed by applying a negative electrode active material to both surfaces (or one surface) of a sheet-like negative electrode current collector. It has been applied. Each positive electrode plate is connected to a positive electrode tab 21 as one electrode terminal via a positive electrode lead (not shown). Each negative electrode plate is connected to a negative electrode tab 22 as the other electrode terminal via a negative electrode lead (not shown).

  The positive electrode lead and the negative electrode lead are each formed of a metal foil. Specifically, the positive electrode lead is formed from, for example, an aluminum foil, and the negative electrode lead is formed from, for example, a copper foil. And each positive electrode lead withdraw | derived from each positive electrode plate is piled up mutually in layers, and is joined to the positive electrode tab 21 by methods, such as welding. In addition, the respective negative electrode leads drawn out from the respective negative electrode plates are stacked in layers and joined to the negative electrode tab 22 by a technique such as welding. The positive electrode tab 21 and the negative electrode tab 22 are each formed of a metal plate. Specifically, the positive electrode tab 21 is made of, for example, an aluminum plate, and the negative electrode tab 22 is made of, for example, a nickel plate.

  As one of the features of the present embodiment, the electrode laminate 20 includes a through portion 23 that penetrates the upper surface side and the lower surface side in the stacking direction (z-axis direction). This penetration part 23 is comprised by the aggregate | assembly of the opening provided in each element (a positive electrode plate, a negative electrode plate, and a separator) which comprises the electrode laminated body 20, The opening formed in each element is an electrode. When laminated as the laminated body 20, the position is appropriately set so that the opening is in a series of penetrating states.

  The through portion 23 is provided in the vicinity of the center of the electrode laminate 20 having a low heat diffusing efficiency from the viewpoint of improving the heat dissipation performance of the electrode laminate 20. In the example shown in the figure, the electrode laminate 20 is approximately centered in the short direction (y-axis direction) and at a position about 1/4 of both ends in the longitudinal direction (x-axis direction). A total of two through portions 23 are provided. The electrode laminate 20 can include an arbitrary number of the through portions 23, and the size (opening diameter and shape) of the through portions 23 can be freely set. However, the size of the penetration part 23 is increased or the penetration part is satisfied so as to satisfy both conflicting requirements such as improvement of heat dissipation performance obtained by increasing the number of penetration parts 23 and reduction of the storage capacity associated therewith. It is desirable to set 23.

  The pair of metal composite films 31 and 32 constituting the battery exterior 30 are sheet-like members formed in a rectangular shape slightly larger than the electrode laminate 20 in correspondence with the shape of the electrode laminate 20. Of the pair of metal composite films 31 and 32, one metal composite film 31 that covers the upper surface side of the electrode laminate 20 has a cup shape in which a concave portion that houses the electrode laminate 20 is provided at the center. The other metal composite film 32 that covers the lower surface side of the electrode laminate 20 has a flat shape that covers the recess.

  As one of the features of the present embodiment, the battery exterior 30 includes a recess 33 that is recessed in the penetration direction of the penetration portion 23 at a position corresponding to the penetration portion 23 of the electrode stack 20 to be housed. In the example shown in FIG. 1, the recess 33 is formed by sinking a part of the metal composite film 31 having a cup shape in the storage direction of the electrode laminate 20. Corresponding to the number, two recesses 33 are provided. The recess 33 has a shape that does not interfere with the through-hole 23 because the recess 33 itself is inserted into the through-hole 23 of the electrode stack 20.

  The pair of metal composite films 31 and 32 has, for example, a metal layer made of aluminum or the like as a base material, and a polymer resin layer made of PE (polyethylene) or PP (polypropylene) or the like is coated inside the metal layer. . Further, a protective layer made of nylon or the like is bonded to these metal composite films 31 and 32 via an adhesive layer on the outside of the metal layer. Furthermore, at the position where the positive electrode tab 21 and the negative electrode tab 22 are pulled out, a resin film such as polypropylene is interposed on both surfaces of each of the tabs 21 and 22 from the viewpoint of improving the sealing performance.

  FIG. 2 is a diagram for explaining a manufacturing process of the multilayer battery 10 according to the first embodiment, in which a cross-sectional state of the line segment AA of the multilayer battery 10 shown in FIG. 1 is depicted. When the laminated battery 10 is manufactured, first, as shown in FIG. 3A, the electrode laminate 20 is placed between the metal composite film 31 having a cup shape and the metal composite film 32 having a flat shape. Arrange. Next, in a state where the cup-shaped portion of the metal composite film 31 is filled with an electrolyte, the pair of metals is inserted so that the recesses 33 formed in the metal composite film 31 are respectively inserted into the through portions 23 of the electrode laminate 20. The electrode laminate 20 is sandwiched between the composite films 31 and 32. And while welding the outer edge part of a pair of metal composite films 31 and 32, the bottom face of the recessed part 33 of the metal composite film 31 and the site | part corresponding to the metal composite film 32 which makes a pair are heat-welded. As a result, as shown in FIG. 5B, the outer edge portion and the bottom surface of the recess 33 are sealed by the welded portion 34, and the electrode laminate 20 is sealed by the battery exterior 30 together with the electrolyte.

  The laminated battery 10 having such a configuration can be applied as, for example, a lithium ion battery. In this case, the positive electrode plate of the electrode laminate 20 has a lithium nickel composite oxide as a positive electrode active material, specifically, a general formula LiNi1-xMxO2 (where 0.01 ≦ x ≦ 0.5, and M is Fe , Co, Mn, Cu, Zn, Al, Sn, B, Ga, Cr, V, Ti, Mg, Ca, and Sr.).

  The positive electrode active material may be, for example, a general formula LiyMn2-zM′zO4 (where 0.9 ≦ y ≦ 1.2, 0.01 ≦ z ≦ 0.5, and M ′ Is at least one of Fe, Co, Ni, Cu, Zn, Al, Sn, B, Ga, Cr, V, Ti, Mg, Ca, and Sr.) Or general formula LiCo1-xMxO2 (where 0.01≤x≤0.5, where M is Fe, Ni, Mn, Cu, Zn, Al, Sn, B, Ga, Cr, V, Ti, Mg, It is also possible to contain a lithium cobalt composite oxide which is a compound represented by at least one of Ca and Sr.

  Here, the lithium nickel composite oxide, the lithium manganese composite oxide, the lithium cobalt composite oxide, etc., for example, are mixed with carbonates such as lithium, nickel, manganese, cobalt, etc. according to the composition, and 600 in an oxygen presence atmosphere. It is obtained by firing in a temperature range of [° C.] to 1000 [° C.]. The starting material is not limited to carbonates, and can be synthesized in the same manner from hydroxides, oxides, nitrates, organic acid salts, and the like. Moreover, it is preferable that the average particle diameter of positive electrode active materials, such as lithium nickel complex oxide and lithium manganese complex oxide, is 30 micrometers or less.

On the other hand, the negative electrode active material forming the negative electrode plate of the electrode laminate 20 is one having a specific surface area of 0.05 [m ² / g] or more and 2 [m ² / g] or less. . When the specific surface area of the negative electrode active material is in the range of 0.05 [m ² / g] to 2 [m ² / g], formation of the SEI layer on the negative electrode surface can be sufficiently suppressed.

When the specific surface area of the negative electrode active material is less than 0.05 [m 2 / g], the place where lithium can enter and exit is too small, so that the lithium doped in the negative electrode active material during charging is negative electrode active material during discharge Not fully dedoped from the inside, the charge / discharge efficiency decreases. On the other hand, when the specific surface area of the negative electrode active material exceeds 2 [m ² / g], it is difficult to control the formation of the SEI layer on the negative electrode surface.

  As a specific negative electrode active material, any material can be used as long as it can dope and dedope lithium in the range of the lithium potential to 2.0 V or less. Specifically, non-graphitizable carbon materials, artificial graphite, natural graphite, pyrolytic graphite, coke such as pitch coke, needle coke, petroleum coke, graphite, glassy carbon, phenol resin, furan resin, etc. It is possible to use a carbonaceous material such as a fired organic polymer compound fired at an appropriate temperature and carbonized, carbon fiber, activated carbon, carbon black and the like.

  Metals capable of forming alloys with lithium and alloys thereof can also be used. Specifically, iron is doped with lithium at a relatively low potential such as iron oxide, ruthenium oxide, molybdenum oxide, tungsten oxide, and tin oxide. In addition to oxides to be dedoped, nitrides thereof, group 3B typical elements, elements such as Si and Sn, or, for example, MxSi, MxSn (wherein M represents one or more metal elements excluding Si or Sn. An alloy of Si or Sn represented by Among these, it is particularly preferable to use Si or Si alloy.

  Further, the electrolyte may be a so-called liquid electrolyte prepared by dissolving an electrolyte salt in a nonaqueous solvent, or a solution in which the electrolyte salt is dissolved in a nonaqueous solvent is held in a polymer matrix. It may be a polymer gel electrolyte or a polymer electrolyte in which an electrolyte salt is dissolved in a polymer.

  When a polymer gel electrolyte is used as the non-aqueous electrolyte, examples of the polymer material to be used include polyvinylidene fluoride and polyacrylonitrile. Moreover, when using a polymer electrolyte, a polyethylene oxide (PEO) type | system | group polymer etc. are mentioned.

  As the non-aqueous solvent, any non-aqueous solvent used so far in this type of non-aqueous electrolyte laminated battery can be used. For example, propylene carbonate, ethylene carbonate, 1,2-dimethoxyethane, diethyl carbonate Dimethyl carbonate, γ-butyrolactone, tetrahydrofuran, 1,3-dioxolane, 4-methyl-1,3-dioxolane, diethyl ether, sulfolane, methyl sulfolane, acetonitrile, propionitrile and the like. In addition, these non-aqueous solvents may be used individually by 1 type, and may mix and use 2 or more types.

  In particular, the non-aqueous solvent preferably contains an unsaturated carbonate, and specifically, preferably contains vinylene carbonate, ethylene ethylidene carbonate, ethylene isopropylidene carbonate, propylidene carbonate, and the like. Among these, it is most preferable to contain vinylene carbonate. By containing unsaturated carbonate as the non-aqueous solvent, it is considered that the effect due to the properties of the SEI layer generated in the negative electrode active material is obtained, and the overdischarge resistance is further improved.

  The unsaturated carbonate is preferably contained in the electrolyte in a proportion of 0.05% by weight or more and 5% by weight or less, and may be contained in a proportion of 0.5% by weight or more and 3% by weight or less. Most preferred. By setting the content of the unsaturated carbonate within the above range, a non-aqueous laminated battery having a high initial discharge capacity and a high energy density is obtained.

  The electrolyte salt is not particularly limited as long as it is a lithium salt exhibiting ion conductivity. For example, LiClO4, LiAsF6, LiPF6, LiBF4, LiB (C6H5) 4, LiCl, LiBr, CH3SO3Li, CF3SO3Li, and the like can be used. is there. These electrolyte salts may be used alone or in a combination of two or more.

  Thus, according to the present embodiment, the electrode laminate 20 includes the through portion 23 that penetrates the upper surface side and the lower surface side in the stacking direction. And the battery exterior 30 (in this embodiment, the metal composite film 31 having a cup shape) is a recess recessed in the penetration direction of the penetration part 23 at a position corresponding to the penetration part 23 of the electrode laminate 20 to be accommodated. 33 is provided. Thereby, the heat | fever accumulate | stored in the inside of the laminated battery 10 is performed by the recessed part 33 of the battery exterior 30, and the improvement of the thermal radiation performance can be aimed at. As a result, the life of the stacked battery 10 can be extended.

  Further, according to the present embodiment, the penetrating portion 23 of the electrode laminate 20 (and the corresponding concave portion 33 of the battery exterior 30) is provided near the center of the electrode laminate 20. Therefore, it is possible to dissipate heat inside the center of the electrode laminate 20 having relatively poor heat dissipation efficiency. Thereby, the lifetime of the laminated battery 10 can be further extended. In addition, according to this method, heat can be radiated inside the center of the electrode stack 20, so that the number of electrode stacks 20 constituting the stacked battery 10 can be increased. Therefore, there is also a new effect that the energy density of the single stacked battery 10 can be improved.

  In addition, in this embodiment, although the recessed part 33 of the battery exterior 30 is formed in the metal composite film 31 side which has a cup shape, this invention is not limited to this. For example, you may provide the recessed part 33 in the metal composite film 32 side which has the flat shape which makes this metal composite film 31 and a pair. Further, a recess may be provided in each of the pair of metal composite films 31 and 32, and the recess 33 may be configured by a recess formed in both. Even with this configuration, the heat dissipation performance of the stacked battery 10 can be improved as in the above-described embodiment. In other words, the recess 33 of the battery exterior 30 is sufficient if at least one of the pair of metal composite films 31 and 32 is depressed in the thickness direction in the penetrating portion 23 of the electrode stack 20 to be accommodated and welded together. .

  FIG. 3 is an explanatory diagram illustrating a modification of the stacked battery 10 according to the first embodiment. The stacked battery 10 shown in the figure further includes a heat conducting member 40 in addition to the configuration shown in FIG. The heat conducting member 40 has an outer surface shape corresponding to the inner surface shape of the recess 33 provided in the battery exterior 30, and is inserted into the recess 33. The heat conduction member 40 has a heat conductivity higher than the heat conductivity of the electrode laminate 20 housed in the battery exterior 30, and for example, a material such as copper or aluminum can be used. According to such a configuration, the heat conduction member 40 inserted into the recess 33 of the battery exterior 30 promotes the release of heat accumulated in the stacked battery 10, so that the heat dissipation of the stacked battery 10 can be more effectively performed. The performance can be improved.

(Second Embodiment)
FIG. 4 is an exploded perspective view for explaining the configuration of the stacked battery 10a according to the second embodiment of the present invention, and corresponds to FIG. 1 shown in the first embodiment. The laminated battery 10a according to the second embodiment is mainly configured by an electrode laminate 20 as a power generation element and a battery exterior 30 that houses the electrode laminate 20, and the electrode laminate 20 is a battery. Arranged in the center of a pair of metal composite films (exterior members) 31 and 32 constituting the exterior 30. The electrode laminate 20 is housed so as to be sandwiched between the pair of metal composite films 31 and 32 in the thickness direction, and is sealed together with the electrolyte by welding the pair of metal composite films 31 and 32.

  The difference between the laminated battery 10a and the laminated battery 10 of the first embodiment is that the battery exterior 30 is provided with a surface side of the metal composite film 31 covering the upper surface side of the electrode laminate 20 and a lower surface side thereof. The communication portion 36 is provided to communicate with the surface side of the metal composite film 32 to be covered. In the present embodiment, the same reference numerals are given to the components corresponding to those in the first embodiment, and detailed description thereof is omitted.

  Specifically, from the viewpoint of improving the heat dissipation performance, the electrode laminate 20 includes a through portion 23a that penetrates the upper surface side and the lower surface side in the stacking direction, as in the first embodiment. This penetration part 23a is comprised by the aggregate | assembly of the opening provided in each element (a positive electrode plate, a negative electrode plate, and a separator) which comprises the electrode laminated body 20, and the opening formed in each element is an electrode. When laminated as the laminated body 20, the position is appropriately set so that the opening is in a series of penetrating states. In the example shown in FIG. 4, the electrode stack 20 has a total of approximately the center in the short direction (y direction) and the center side by about 1/4 from both ends in the longitudinal direction (x direction). Two through portions 23a are provided.

  Further, as one of the features of the present embodiment, the battery exterior 30 is recessed in the penetrating direction of the penetrating portion 23a at a position corresponding to the penetrating portion 23a of the electrode stack 20 to be stored, as in the first embodiment. A recess 33a is provided. In the example shown in FIG. 4, the recess 33 a is formed by depression of a part of the metal composite film 31 having a cup shape in the storage direction of the electrode laminate 20, and the number of the through portions 23 a of the electrode laminate 20. Corresponding to the above, two recesses 33a are provided. Further, the battery exterior 30 has a bottom surface of a recess 33a formed in one metal composite film 31, and a corresponding portion of the other metal composite film 32 that forms a pair with the metal composite film 31 formed with the recess 33a. An opening 35 is provided in each.

  FIG. 5 is a diagram for explaining a manufacturing process of the stacked battery 10a according to the second embodiment, and corresponds to FIG. 2 shown in the first embodiment. When producing the laminated battery 10a, first, as shown in FIG. 5A, the electrode laminate 20 is placed between a metal composite film 31 having a cup shape and a metal composite film 32 having a flat shape. Arrange. In the pair of metal composite films 31 and 32, only the recess 33a is formed in one metal composite film 31, and the opening 35 is not formed at this stage. Next, in a state where the cup-shaped portion of the metal composite film 31 is filled with an electrolyte, the pair of metals is inserted such that the recesses 33a formed in the metal composite film 31 are respectively inserted into the through portions 23a of the electrode laminate 20. The electrode laminate 20 is sandwiched between the composite films 31 and 32. And while welding the outer edge part of these pair of metal composite films 31 and 32, the bottom face of the recessed part 33 of the metal composite film 31 and the site | part corresponding to the metal composite film 32 used as a pair are heat-welded. Finally, an opening 35 is formed so as to penetrate the pair of metal composite films 31 and 32 on the bottom surface of the recess 33a at the welded portion of the recess 33a. As a result, as shown in FIG. 5B, the periphery of the opening 35 on the outer edge and the bottom surface of the recess 33 is sealed by the welded portion 34, and the electrode stack 20 is sealed by the battery exterior 30 together with the electrolyte. . In addition, the recess 33 a formed in the metal composite film 31 and the opening 35 formed in the bottom surface of the recess 33 a constitute a communication portion 36 that connects the upper surface side and the lower surface side of the battery exterior 30.

  As described above, according to the present embodiment, the electrode laminate 20 includes the through portion 23a penetrating the upper surface side and the lower surface side in the lamination direction. Moreover, the battery exterior 30 communicates the surface side of the metal composite film 31 having a cup shape and the surface side of the metal composite film 32 having a flat shape at a position corresponding to the through portion 23a of the electrode stack 20 to be accommodated. A communication unit 36 is provided. Thereby, the heat | fever accumulate | stored in the inside of the laminated battery 10a is performed by the communication part 36 of the battery exterior 30, and the improvement of the thermal radiation performance can be aimed at. As a result, the life of the stacked battery 10a can be extended. Further, according to the present embodiment, the penetrating portion 23 a of the electrode stack 20 (and the corresponding communication portion 36 of the battery exterior 30) is provided near the center of the electrode stack 20. Therefore, as in the first embodiment, heat can be dissipated inside the center of the electrode laminate 20 having relatively poor heat dissipation efficiency. As a result, the lifetime of the multilayer battery 10a can be further increased, and the new energy density of the single multilayer battery 10a can be improved.

  Furthermore, according to the present embodiment, even if the temperature of the stacked battery 10a rises and the internal pressure rises abnormally, the stress generated with the expansion of the battery exterior 30 is around the opening 35 constituting the communication portion 36. Concentrate on. Therefore, when the internal pressure of the laminated battery 10a rises, the welded portion 34 at the periphery of the opening 35 is selectively broken, so that the situation of the laminated battery 10a does not occur without causing the battery exterior 30 to rupture. There is a new effect that the internal pressure can be released.

(Third embodiment)
FIG. 6 is an explanatory view illustrating a cross-sectional state of the assembled battery 1 according to the third embodiment of the present invention. The assembled battery 1 is obtained by electrically connecting a plurality of unit cells, and each unit cell is stacked in the thickness direction. For example, the individual cells are stacked and connected in series so that the cells on the positive electrode side and the terminal on the negative electrode side are alternated between the cells adjacent in the stacking direction (thickness direction). An assembly of these single cells is housed in a battery case (not shown) and modularized as a single assembled battery 1.

  Each unit cell constituting the assembled battery 1 is configured by the stacked battery 10 shown in the first embodiment described above, and an electrode stack 20 as a power generation element and a battery that houses the electrode stack 20. The exterior 30 is mainly configured. As described with reference to FIG. 1, the electrode laminate 20 is disposed at the center of a pair of metal composite films (exterior members) 31 and 32 that constitute the battery exterior 30. The electrode laminate 20 includes a penetration portion 23 that penetrates the upper surface side and the lower surface side in the lamination direction, and the battery exterior 30 is located at a position corresponding to the penetration portion 23 of the electrode laminate 20 to be accommodated. 23 is provided with a recess 33 that is recessed in the through direction. The recesses 33 provided in the individual stacked batteries 10 are provided corresponding to each other in the stacking direction. Furthermore, as described with reference to FIG. 3, in each stacked battery 10, the heat conducting member 40 having an outer surface shape corresponding to the inner surface shape of the recess 33 is inserted into the recess 33 provided in the battery exterior 30. Has been.

  According to the assembled battery 1 of the present embodiment having such a configuration, as in the first embodiment, the heat conductive member 40 inserted into the recess 33 of the battery exterior 30 accumulates inside the stacked battery 10. Therefore, the heat dissipation performance of each stacked battery 10 can be improved. Moreover, in the assembled battery 1 which is an assembly of a plurality of single cells (in the present embodiment, the laminated battery 10), there is a problem that the heat dissipation efficiency decreases as the laminated battery 10 located at the center portion. According to the embodiment, the heat accumulated inside is transmitted to the heat conducting member 40 inserted in each stacked battery 10 and released to the upper surface side or the lower surface side. Thereby, the heat flow which has lost the escape space due to the stacked batteries 10 being in close contact with each other can be guided in the stacking direction. As a result, it is possible to extend the life of the assembled battery 1 that is an aggregate of the individual stacked batteries 10.

  Further, conventionally, from the viewpoint of extending the life of the assembled battery, a device such as providing a clearance for cooling between individual unit cells has been provided, but according to the present embodiment, The life of the assembled battery 1 can be extended without providing a gap. Furthermore, since it is not necessary to provide a cooling gap between the individual cells, there is a new effect that the volume energy density of the assembled battery 1 can be improved.

(Fourth embodiment)
FIG. 7 is an explanatory view illustrating a cross-sectional state of the assembled battery 1 according to the fourth embodiment of the present invention. The assembled battery 1a is obtained by electrically connecting a plurality of unit cells, and each unit cell is stacked in the thickness direction. For example, the individual cells are stacked and connected in series so that the cells on the positive electrode side and the terminal on the negative electrode side are alternated between the cells adjacent in the stacking direction (thickness direction). These cell assemblies are housed in a battery case (not shown) and modularized as a single assembled battery 1a.

  Each unit cell constituting the assembled battery 1a is configured by the stacked battery 10a shown in the second embodiment described above, and an electrode stack 20 as a power generation element and a battery that houses the electrode stack 20. The exterior 30 is mainly configured. As described with reference to FIG. 4, the electrode laminate 20 is disposed in the center of a pair of metal films (exterior members) 31 and 32 constituting the battery exterior 30. The electrode laminate 20 includes a through portion 23a penetrating the upper surface side and the lower surface side in the laminating direction, and the battery exterior 30 is located at a position corresponding to the through portion 23a of the electrode laminate 20 to be accommodated. The communication part 36 which connects the surface side of the metal composite films 31 and 32 is provided in the penetration direction of 23a. In the state where the individual stacked batteries 10a are stacked, each of the communication portions 36 of the battery exterior 30 constitutes a communication path that communicates in the stacking direction. This communication path can function as a path for a refrigerant such as air or water that cools each stacked battery 10a.

  According to the assembled battery 1 of the present embodiment having such a configuration, the heat accumulated in the stacked battery 10a is released as in the second embodiment, and the heat dissipation performance is improved. Can do. Further, in the assembled battery 1 that is an aggregate of a plurality of single cells (in the present embodiment, the laminated battery 10a), there is a problem that the heat dissipation efficiency decreases as the laminated battery 10a located in the center portion. According to the form, the heat trapped inside is released from the communication passage formed by the individual communication portions 36 to the upper surface side or the lower surface side. Thereby, the heat flow which has lost the escape space due to close contact between the stacked batteries 10a can be guided in the stacking direction. Furthermore, the heat radiation performance can be further improved by circulating a refrigerant such as air or water in the communication path constituted by the respective communication portions 36. As a result, it is possible to extend the life of the assembled battery 1a, which is an assembly of the individual stacked batteries 10a, and to improve the volume energy density of the assembled battery 1a.

(Fifth embodiment)
FIG. 8 is an explanatory view illustrating a cross-sectional state of an assembled battery 1b according to the fifth embodiment of the present invention. The assembled battery 1b is obtained by electrically connecting a plurality of unit cells, and each unit cell is stacked in the thickness direction. For example, the individual cells are stacked and connected in series so that the cells on the positive electrode side and the terminal on the negative electrode side are alternated between the cells adjacent in the stacking direction (thickness direction). These battery groups are housed in a battery case (not shown) and configured as an integrated battery pack 1b.

  Each unit cell constituting the assembled battery 1b is configured by the stacked battery 10a shown in the second embodiment described above, and an electrode stack 20 as a power generation element and a battery that houses the electrode stack 20 The exterior 30 is mainly configured. As described with reference to FIG. 4, the electrode laminate 20 is disposed in the center of a pair of metal films (exterior members) 31 and 32 constituting the battery exterior 30. The electrode laminate 20 includes a through portion 23a penetrating the upper surface side and the lower surface side in the laminating direction, and the battery exterior 30 is located at a position corresponding to the through portion 23a of the electrode laminate 20 to be accommodated. The communication part 36 which connects the surface side of the metal composite films 31 and 32 is provided in the penetration direction of 23a. In a state where the individual stacked batteries 10a are stacked, each of the communication portions 36 of the battery exterior 30 communicates in the stacking direction. In the present embodiment, the heat conducting member 40a is inserted into the communication portion 36 provided in the battery exterior 30 of each stacked battery 10a. The heat conducting member 40a has a heat conductivity higher than the heat conductivity of the electrode laminate 20 housed in the battery exterior 30, and for example, a material such as copper or aluminum can be used.

  FIG. 9 is a perspective view showing a structure of a heat conducting member 40a according to the fifth embodiment. As shown in the figure, the heat conducting member 40 a has an outer surface shape corresponding to the inner surface shape of the communication portion 36, and a tapered portion 41 corresponding to the concave portion 33 of the communication portion 36 and an opening 35 of the communication portion 36. The corresponding straight part 42 is comprised. In the heat conducting member 40 a, the tapered portion 41 and the straight portion 42 are integrally formed. When the heat conducting member 40 a is inserted into the communicating portion 36, the end of the straight portion 42 is the communicating portion 36. It has a size that slightly protrudes from the opening 35. Further, a groove 43 having a part thereof depressed is formed on the upper surface of the tapered portion 41. The groove portion 43 has an inner surface shape corresponding to the outer surface shape of the straight portion 42, and has a depth enough to allow the portion where the straight portion 42 protrudes from the opening 35 of the communication portion 36. Further, the heat conducting member 40a has a hollow portion 44 formed in the axial direction (stacking direction of the stacked battery 10a) and has a hollow shape.

  Referring to FIG. 8 again, when the heat conducting member 40a is inserted into the communicating portion 36 of each stacked battery 10a, the heat conducting member 40a inserted into the communicating portion 36 of the adjacent stacked battery 10a They can be connected to each other. Specifically, as shown in FIG. 8, the heat conducting member 40a inserted into the uppermost stacked battery 10a has a straight portion 42 protruding from the lower surface side of the stacked battery 10a. This projecting portion is fitted into a groove 43 formed in the tapered portion 41 of the heat conducting member 40a inserted in the stacked battery 10a adjacent to the lower side thereof, and can be connected to each other. Similarly, with respect to the other heat conducting members 40a, the straight portions 42 are fitted into the groove portions 43 formed in the tapered portions 41 of the heat conducting members 40a inserted into the adjacent stacked battery 10a and are connected to each other. ing.

  In such a connected state of the heat conducting member 40a, the welded portion 34 around the opening 35 constituting the communicating portion 36 of each stacked battery 10a is adjacent to the heat conducting member 40a inserted therein and the adjacent laminated type. It is pressed by the heat conducting member 40a inserted in the communication part 36 of the battery 10a. Further, the hollow portion 44 of the heat conducting member 40a inserted in each stacked battery 10a constitutes a communication path that communicates in the stacking direction of the stacked battery 10a. The communication path functions as a refrigerant path for cooling each stacked battery 10a.

  FIG. 10 is an explanatory diagram for explaining a storage state of the assembled battery 1b according to the fifth embodiment. An assembled battery 1 b that is an assembly of the stacked batteries 10 a is housed in a battery case 2. The battery case 2 includes positioning portions (positioning means) 3 and 4 for restricting a change in position of the assembly of the stacked batteries 10a. One positioning portion 3 is formed on the inner wall surface on the upper surface side of the battery case 2. Specifically, the positioning portion 3 is a position corresponding to the heat conducting member 40a inserted into the stacked battery 10a located on the uppermost surface in a state where the assembly of the stacked batteries 10a is stored in the battery case 2. The shape is a convex shape that can be fitted to the groove 43 formed on the upper surface of the tapered portion 41 of the heat conducting member 40a. On the other hand, the other positioning portion 4 is formed on the inner wall surface on the lower surface side of the battery case 2. Specifically, the positioning portion 4 is a position corresponding to the heat conducting member 40a inserted into the stacked battery 10a located on the lowermost surface in a state where the assembly of the stacked batteries 10a is stored in the battery case 2. The shape thereof is a concave shape that can be fitted to the straight portion 42 protruding from the lower surface side of the laminated battery 10a. Therefore, when the assembly of the stacked batteries 10a is stored in the battery case 2, the positioning unit 3 and the heat conducting member 40a inserted into the stacked battery 10a located on the uppermost surface are connected, The positioning part 4 is connected to the heat conducting member 40a inserted into the stacked battery 10a located on the lowermost surface.

  As described above, according to the present embodiment, the heat conduction member 40a inserted into the communication portion 36 of the battery exterior 30 promotes the release of heat accumulated in the stacked battery 10a. It is possible to improve the heat dissipation performance of 10a. Further, in the assembled battery 1b that is an assembly of a plurality of single cells (in this embodiment, the stacked battery 10a), there is a problem that the heat dissipation performance is worse as the stacked battery 10a located in the center portion. According to the above, the heat accumulated inside is transmitted to the heat conducting member 40a inserted in each stacked battery 10a and released to the upper surface side or the lower surface side. Thereby, the heat flow which has lost the escape space due to the stacked batteries 10a being in close contact with each other can be guided in the stacking direction. As a result, it is possible to extend the life of the assembled battery 1b, which is an assembly of the individual stacked batteries 10a. Further, since it is not necessary to provide a cooling gap between the individual stacked batteries 10a, the volume energy density of the assembled battery 1b can be improved.

  Furthermore, according to this embodiment, since a refrigerant such as air or water can be circulated through the communication path constituted by the hollow portion 44 of the heat conducting member 40a inserted into each stacked battery 10a, the heat dissipation performance. Can be further improved. As a result, it is possible to extend the life of the assembled battery 1b, which is an assembly of the individual stacked batteries 10a, and to improve the volume energy density of the assembled battery 1b.

  Moreover, according to this embodiment, each heat conductive member 40a can be mutually connected with the heat conductive member 40a inserted in the communication part 36 provided in the adjacent laminated battery 10a. And the heat conduction member 40a inserted in the communication part 36 provided in the laminated battery 10a located on the uppermost surface and the heat conduction inserted in the communication part 36 provided in the laminated battery 10a located on the lowermost surface. The member 40a is connected by positioning portions 3 and 4 provided in the battery case 2 that houses the assembly of the stacked batteries 10a. As a result, the positioning accuracy of each stacked battery 10a can be improved, and even if an external force due to vibration or the like is input to the assembled battery 1b, There is a new effect that the generated positional deviation can be suppressed.

  For example, conventionally, the outer edge portion of each unit cell is held by a guide member formed on the inner surface of the battery case, but such a configuration is vulnerable to an input external force. For this reason, use over a long period of time has been a factor that reduces the mechanical strength of individual stacked batteries and the reliability of electrical joints. However, according to the present embodiment, since the central portion of the stacked battery 10a is supported by the heat conducting member 40a, the mechanical strength and the reliability of the electrical joint are more reliable than the configuration in which the outer edge is supported. There is a new effect that it is possible to improve the performance.

  Further, according to the present embodiment, the welded portion around the opening 35 constituting the communication portion 36 is inserted into the heat conduction member 40a inserted therein and the communication portion 36 provided in the adjacent stacked battery 10a. The heat conduction member 40a is pressed. Therefore, since the sealing performance of the opening 35 constituting the communication portion 36 can be improved, it is possible to suppress the occurrence of a situation in which the welded portion 34 around the opening 35 is unnecessarily broken. Moreover, the ease of fracture | rupture of the welding part 34 of the opening 35 periphery can be easily adjusted by adjusting the pressing force of the heat conductive member 40a.

  In the present embodiment, the heat conducting member 40a is formed in a hollow shape, but the present invention is not limited to this. For example, the heat conducting member 40 a may be in a form that does not include the hollow portion 44. Even in such a configuration, the heat flow that has lost its escape due to the contact between the stacked batteries 10a can be guided in the stacking direction by heat transfer of the heat conducting member 40a. As a result, it is possible to extend the life of the assembled battery 1b, which is an assembly of the individual stacked batteries 10a.

  Further, according to the present embodiment, the heat conducting member 40a is provided corresponding to each stacked battery 10a, but a needle or a hollow shape having a length corresponding to the stacked height of each stacked battery 10a. You may insert the pipe member provided with in each communication part 36. FIG. Even in such a configuration, since the heat flow can be guided in the stacking direction, it is possible to extend the life of the assembled battery 1b that is an aggregate of the individual stacked batteries 10a. In addition, the heat conducting member 40a may not be provided corresponding to each stacked battery 10a, and the heat conducting member 40a is configured by a single pipe member having a length equivalent to the height of the assembled battery 1b. Therefore, the life of the assembled battery 1b can be extended.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view illustrating a configuration of a stacked battery 10 according to a first embodiment of the present invention. It is a figure for demonstrating the preparation process of the laminated battery 10 concerning 1st Embodiment. It is explanatory drawing which shows the modification of the laminated battery concerning 1st Embodiment. It is an expansion | deployment perspective view explaining the structure of the laminated battery 10a concerning the 2nd Embodiment of this invention. It is a figure for demonstrating the preparation process of the laminated battery 10 concerning 2nd Embodiment. It is explanatory drawing explaining the cross-sectional state of the assembled battery 1 concerning the 3rd Embodiment of this invention. It is explanatory drawing explaining the cross-sectional state of the assembled battery 1 concerning the 4th Embodiment of this invention. It is explanatory drawing explaining the cross-sectional state of the assembled battery 1 concerning the 5th Embodiment of this invention. It is a perspective view which shows the structure of the heat conductive member 40 concerning 5th Embodiment. It is explanatory drawing explaining the accommodation state of the assembled battery 1b concerning 5th Embodiment.

Explanation of symbols

1-1b assembled battery 2 battery case 3, 4 positioning part 10, 10a laminated battery 20 electrode laminated body 21 positive electrode tab 22 negative electrode tab 23, 23a penetrating part 30 battery exterior 31, 32 metal composite film 33, 33a concave part 34 welded part 35 Opening 36 Communication part 40, 40a Thermal conduction member 41 Damper part 42 Straight part 43 Groove part 44 Hollow part

Claims (16)

A power generation element configured by alternately stacking positive plates and negative plates through separators;
A battery that seals and stores an electrolyte together with the power generation element by welding a first exterior member that covers the upper surface side of the power generation element and a second exterior member that covers the lower surface side of the power generation element. And having an exterior
The power generation element includes a penetrating portion that penetrates the upper surface side and the lower surface side in the stacking direction,
The stacked battery is characterized in that the battery exterior includes a recessed portion that is recessed in a penetrating direction of the penetrating portion at a position corresponding to the penetrating portion of the power generating element to be housed.   The concave portion of the battery exterior causes at least one of the first exterior member and the second exterior member to be depressed in the storage direction of the power generation element, and the first exterior member and the second exterior member are mutually connected. The stacked battery according to claim 1, wherein the stacked battery is formed by welding.   3. The stacked battery according to claim 1, further comprising a heat conductive member that has a thermal conductivity higher than a thermal conductivity of the power generation element and is inserted into a recess of the battery exterior. A power generation element configured by alternately stacking positive plates and negative plates through separators;
A battery that seals and stores an electrolyte together with the power generation element by welding a first exterior member that covers the upper surface side of the power generation element and a second exterior member that covers the lower surface side of the power generation element. And having an exterior
The power generation element includes a penetrating portion that penetrates the upper surface side and the lower surface side in the stacking direction,
The battery exterior communicates with the surface side of the first exterior member and the surface side of the second exterior member at a position corresponding to the penetration part of the power generation element to be accommodated in the penetration direction of the penetration part. A laminated battery comprising a portion.   The communication portion of the battery exterior causes the at least one of the first exterior member and the second exterior member to be depressed in the storage direction of the power generation element, and the first exterior member and the second exterior member are 5. The stacked battery according to claim 4, wherein the stacked battery is formed by welding each other and providing an opening in a welded portion between the first exterior member and the second exterior member. In an assembled battery composed of a plurality of single cells stacked in the thickness direction,
Each of the unit cells
A power generation element configured by alternately stacking positive plates and negative plates through separators;
A battery that seals and stores an electrolyte together with the power generation element by welding a first exterior member that covers the upper surface side of the power generation element and a second exterior member that covers the lower surface side of the power generation element. The exterior,
A heat conducting member having a thermal conductivity higher than the thermal conductivity of the power generating element,
The power generation element includes a penetrating portion that penetrates the upper surface side and the lower surface side in the stacking direction,
The battery exterior includes a recess that is recessed in the penetration direction of the penetration portion at a position corresponding to the penetration portion of the power generation element to be stored.
The heat conducting member is inserted into a recess in the battery exterior,
Each of the concave portions of the battery exterior corresponds to each other in a position in the stacking direction of the unit cells. In an assembled battery composed of a plurality of single cells stacked in the thickness direction,
Each of the unit cells
A power generation element configured by alternately stacking positive plates and negative plates through separators;
A battery that seals and stores an electrolyte together with the power generation element by welding a first exterior member that covers the upper surface side of the power generation element and a second exterior member that covers the lower surface side of the power generation element. And having an exterior
The power generating element includes a penetrating portion that penetrates the upper surface side and the lower surface side in the stacking direction,
The battery exterior communicates with the surface side of the first exterior member and the surface side of the second exterior member at a position corresponding to the penetration part of the power generation element to be accommodated in the penetration direction of the penetration part. Department,
Each of the communication parts of the battery exterior constitutes a communication path that communicates in the stacking direction of the unit cells.   The assembled battery according to claim 7, wherein the communication path is a path for a refrigerant that cools each of the unit cells.   The assembled battery according to claim 7, further comprising a heat conduction member that has a thermal conductivity higher than a thermal conductivity of the power generation element and is inserted into the communication path.   The said heat conductive member is provided with the outer surface shape corresponding to the inner surface shape of the communication part of the said battery exterior, and is inserted in each of the communication part of the said battery exterior separately, It is characterized by the above-mentioned. Assembled battery.   11. The assembled battery according to claim 10, wherein each of the heat conducting members is connectable to the heat conducting member inserted in a communication portion included in a battery exterior of the adjacent unit cell. An assembled battery case that houses the plurality of unit cells;
The assembled battery case is inserted into the communication part provided in the communication part provided in the battery exterior of the single cell located on the uppermost surface, and the communication part provided in the battery exterior of the single battery located in the lowermost surface. The assembled battery according to claim 11, further comprising positioning means for restricting a change in position of the plurality of single cells by being connected to the heat conducting member. Each of the communicating parts of the battery exterior causes the first exterior member and the second exterior member to be recessed in at least one of the first exterior member and the second exterior member in the storage direction of the power generation element. And by providing an opening in the welded portion between the first exterior member and the second exterior member,
The welded portion around the opening is pressed by the heat conducting member inserted therein and the heat conducting member inserted in a communication portion provided in the battery exterior of the adjacent unit cell. The assembled battery according to any one of claims 10 to 12.   The assembled battery according to any one of claims 9 to 13, wherein the heat conducting member has a hollow shape in a stacking direction of the unit cells. The hollow portion of the heat conducting member constitutes a communication passage that communicates in the stacking direction of the unit cells,
The assembled battery according to claim 14, wherein the communication path is a path for a refrigerant that cools each of the unit cells. A power generation element configured by alternately stacking positive plates and negative plates through separators;
A battery that seals and stores an electrolyte together with the power generation element by welding a first exterior member that covers the upper surface side of the power generation element and a second exterior member that covers the lower surface side of the power generation element. In a laminated battery having an exterior,
The battery exterior is depressed in the storage direction of the power generation element to be stored, or the surface side of the first exterior member and the surface side of the second exterior member are communicated in the storage direction of the power generation element to be stored. Thus, the stacked battery is characterized in that the heat accumulated therein is released.

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