JP2009117255A - Secondary battery, battery pack, and vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a secondary battery capable of partially deforming or cleaving an exterior material, thereby releasing internal pressure, when the internal pressure increases. <P>SOLUTION: A member 60 for partitioning the surface of the exterior material 40 into a plurality of zones is arranged by firmly sticking on the surface of the exterior material 40 existed on at least one of both front and back surfaces of the secondary battery 1. The secondary battery 1 includes a charging and discharging element having an electrode plate laminated via a separator, the exterior material 40 for sealing by covering the charging and discharging element, and electrode terminals 21, 22 connected to the electrode plate and leading from the exterior material 40. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a secondary battery having an improved exterior material structure, an assembled battery in which a plurality of secondary batteries are connected, and a vehicle equipped with the secondary battery or the assembled battery.

  The secondary battery contains, for example, a power generation element having a positive electrode plate and a negative electrode plate laminated via a separator in an exterior material made of a resin-metal thin film laminate film (laminate film). The positive electrode plate and the negative electrode plate are connected to the positive electrode terminal and the negative electrode terminal, respectively. The positive electrode terminal and the negative electrode terminal are led out from the outer peripheral edge of the exterior material, and the outer peripheral edge of the exterior material is sealed by heat fusion or the like.

  In this type of secondary battery, gas may be generated inside the battery due to decomposition or vaporization of the electrolyte. If the generated gas cannot be discharged outside the battery, the battery internal pressure will increase.

Various techniques have been proposed for allowing gas to escape even when the battery internal pressure increases. For example, Patent Document 1 discloses a safety valve that uses a moisture-proof multilayer film including a resin layer and a metal foil layer as an exterior material and is cleaved when the internal pressure rises in the exterior material in a thin battery sealed with heat fusion or adhesive resin. A thin battery provided with a mechanism has been proposed. In this thin battery, a linear cut reaching the middle part of the thickness is made in the resin layer arranged on the innermost side of the exterior material, and this cut portion serves as a safety valve mechanism. By making the cut, even if the pressure rises in the thin battery, the cut portion is quickly cleaved to release the gas.
Japanese Patent Laid-Open No. 11-312505

  By the way, when the safety valve mechanism as in Patent Document 1 is applied to, for example, a large-sized secondary battery having a side of about 0.2 m, even if the internal pressure rises, the laminate exterior material is difficult to be cleaved, and the safety valve mechanism is effective. It becomes difficult to work (see the comparative example described later).

  The present invention provides a secondary battery capable of releasing the internal pressure by partially deforming or cleaving the exterior material, an assembled battery combining the secondary batteries, and a vehicle equipped with the secondary battery or the assembled battery. With the goal.

  In order to achieve the above object, a secondary battery according to the present invention is provided with a member that closely adheres to the surface of an exterior material on at least one of the front and back surfaces of the secondary battery and partitions the exterior material surface into a plurality of regions. ing. The secondary battery includes a charge / discharge element having an electrode plate laminated via a separator, an exterior material that covers and seals the charge / discharge element, and an electrode that is connected to the electrode plate and is derived from an outer peripheral edge of the exterior material And a terminal.

  According to the secondary battery according to the present invention configured as described above, since the member that partitions the exterior material surface into a plurality of regions is disposed, the strength of the exterior material partitioned by the member is disposed. It can be made relatively weaker than the strength of the portion. Therefore, when the internal pressure of the secondary battery increases, the internal pressure can be released by deforming or cleaving the external packaging material in the region partitioned by the member that partitions the exterior material surface.

  Further, the mechanical strength of the exterior material is increased by arranging a member that divides the exterior material surface into a plurality of regions on the exterior material surface. Therefore, durability against trauma is improved, expansion and contraction due to battery temperature change are suppressed, and deterioration of internal resistance is suppressed.

  Embodiments of the present invention will be described below with reference to the drawings. In the following drawings, each component is exaggerated for clarity of explanation.

[First Embodiment]
FIG. 1 is a perspective view showing a first embodiment of a secondary battery according to the present invention. FIG. 2 is a partially broken sectional view of the secondary battery. FIG. 3 is a partially broken cross-sectional view of a state in which a member for partitioning the exterior material surface is arranged on the exterior material surface of the secondary battery of FIG.

  As shown in FIGS. 1 to 3, the secondary battery 1 of the first embodiment is a thin (flat) lithium ion secondary battery having a flat plate shape, and a plurality of the secondary batteries 1 are stacked. By combining them, an assembled battery (stack) having a desired voltage and capacity is formed. The secondary battery 1 includes a charge / discharge element 10 composed of, for example, a stackable positive electrode plate, a separator 14, a negative electrode plate, and an electrolyte. The charge / discharge element 10 is laminated on a hard plate 30 having electrical insulation, covered with an exterior material 40 and bonded and sealed to the hard plate 30 with an adhesive or the like. The positive electrode plate or the negative electrode plate is connected to the positive electrode terminal electrode 21 or the negative electrode terminal electrode 22, and the terminal electrodes 21 and 22 are led out from the exterior material 40.

  A positive or negative electrode plate constituting the charge / discharge element 10 includes a current collector 11 and an active material layer 13 formed on both surfaces of the stacked portion of the current collector 11. The current collector 11 positioned at both ends (upper and lower ends) in the stacking direction has an active material layer 13 stacked on only one side. Each current collector 11 is formed of an electrochemically stable metal foil such as an aluminum foil, an aluminum alloy foil, a copper foil, or a nickel foil.

The active material layer on the positive electrode side is, for example, a lithium composite oxide such as lithium nickelate (LiNiO ₂ ), lithium manganate (LiMnO ₂ ), or lithium cobaltate (LiCoO ₂ ), or chalcogen (S, Se, Te). A positive electrode active material such as a compound, a conductive agent such as carbon black, and a binder such as an aqueous dispersion of polytetrafluoroethylene are mixed, and the mixed agent is mixed on both surfaces of the laminated portion of the positive electrode side current collector. It is formed by applying to, drying and compressing.

  Further, the active material layer on the negative electrode side is formed of, for example, a negative electrode active material that occludes and releases lithium ions of a positive electrode active material such as amorphous carbon, non-graphitizable carbon, graphitizable carbon, or graphite. An aqueous dispersion of styrene butadiene rubber resin powder as a precursor material of the fired body is mixed, dried, and then pulverized, so that the carbon material surface carries carbonized styrene butadiene rubber as the main material. Further, a binder such as an acrylic resin emulsion is further mixed, and this mixed material is applied to both surfaces of a part of the negative electrode side current collector, followed by drying and compression.

  In the charge / discharge element 10, positive plates and negative plates are alternately stacked via separators 14. The separator 14 is interposed to prevent a short circuit between the positive electrode plate and the negative electrode plate, and may have a function of holding the electrolyte. The separator 14 is a microporous film made of polyolefin such as polyethylene (PE) or polypropylene (PP).

  The separator 14 is not limited to a single-layer film such as polyolefin, but may be a three-layer film in which a polypropylene film is sandwiched between polyethylene films, or a laminate of a polyolefin microporous film and an organic nonwoven fabric.

  The electrolyte is a liquid electrolyte made up of 100% electrolyte solution that is usually used in lithium ion batteries, an all solid polymer electrolyte made up of 100% polymer, an all solid polymer electrolyte such as PEO (polyethylene oxide), etc. There is a polymer gel electrolyte in which an electrolytic solution is held in a polymer skeleton having no lithium ion conductivity, such as a molecular gel electrolyte, PVDF, PAN, and PMMA. By using a solid electrolyte as the electrolyte, it is possible to prevent leakage.

  In addition, the number of each of the positive electrode plate, the separator 14, and the negative electrode plate of the charge / discharge element 10 can be appropriately selected and configured according to a desired voltage, capacity, and the like.

  The positive electrode side terminal electrode 21 and the negative electrode side terminal electrode 22 are built in and integrally formed at both ends in the longitudinal direction of the hard plate member 30, and each terminal electrode 21, 22 is connected to its base end side connection portion 21 a, 22 a and an extension The side terminal portions 21 b and 22 b are exposed on the front and back surfaces of the hard plate 30. The connection portions 21a and 22a of the terminal electrodes 21 and 22 are connected to the current collector 11 of a positive electrode plate or a negative electrode plate. Each electrode terminal 21 and 22 is not particularly limited as long as it is an electrochemically stable metal material. Examples of the electrode terminals 21 and 22 include a nickel plate, a copper plate, a stainless steel plate, and an iron plate.

  In the present embodiment, the positive electrode plate or the negative electrode plate current collector 11 constituting the charge / discharge element 10 is connected to the positive electrode terminal 21 or the negative electrode terminal 22 integrally molded at both longitudinal ends of the hard plate material 30. However, the present invention is not limited to this, and the metal foil itself constituting the current collector 11 of the positive electrode plate or the negative electrode plate is extended to both end portions in the longitudinal direction of the hard plate material 30 to extend each current collector 11. The ends may be electrode terminals 21 and 22.

  As described above, the charge / discharge element 10 is laminated on the hard plate 30 having electrical insulation, and the upper portion thereof is covered with the exterior material 40 and bonded and sealed with an adhesive or the like. A protrusion 31 having a height equal to or greater than the thickness of the charge / discharge element 10 is formed on a portion of the hard plate 30 around the charge / discharge element 10. That is, the protrusion 31 has a rectangular frame shape, and the charge / discharge element 10 is accommodated in the protrusion 31. Therefore, the positive or negative current collectors 11 located at both ends (upper and lower ends) of the charge / discharge element 10 in the stacking direction of the positive terminal electrode 21 or the negative terminal electrode 22 so as to straddle the projection 31. Connected to the connecting portions 21a and 22a. In addition, in the secondary battery 1 of this embodiment, although the charging / discharging element 10 is arrange | positioned only on the single side | surface of the hard board | plate material 30, it is not limited to this, The charging / discharging element 10 is arrange | positioned on both surfaces of the hard board | plate material 30. Also good.

  Examples of the hard plate member 30 include engineering plastics such as polyamide, polyphenylene sulfide, polyester, polyacetal, and modified polyphenylene ether, and the above engineering plastic (FRP) mixed with filler. The hard plate member 30 has a protruding portion 31 formed by, for example, injection molding or machining, and is integrally formed as a thin rectangular parallelepiped flat plate incorporating the terminal electrodes 21 and 22. By incorporating the terminal electrodes 21 and 22 into the hard plate member 30 and integrally molding them, it is possible to improve the battery assembling property, improve the strength of the terminal electrodes, and improve the assembling property of the assembled battery.

  The packaging material 40 includes, for example, a film-like core material and electrical insulating layers laminated on both surfaces thereof. That is, the exterior material 40 is composed of an inner layer composed of an electrically insulating resin film excellent in electrolytic resistance and heat-fusibility, a film core material, and a resin film excellent in electrical insulation. It has a three-layer structure with an outer layer.

  Examples of the film core material of the exterior material 40 include single metals such as aluminum, iron, copper, nickel, titanium, and molybdenum, and alloys such as aluminum alloy, copper alloy, titanium alloy, stainless steel, and hastelloy. These metal materials are formed into a metal foil, a metal vapor-deposited film, a metal sputtered film or the like to form a film, and the exterior material 40 is formed.

  The inner layer of the exterior material 40 is disposed facing the charge / discharge element 10, and examples of the inner layer include a resin film such as polyethylene, polypropylene, modified polyolefin, ionomer, or ethylene-vinyl acetate copolymer. On the other hand, the outer layer of the outer packaging material 40 is disposed facing the outside of the battery, and examples of the outer layer include resin films such as polyethylene, polypropylene, modified polyolefin, ionomer, amorphous polyolefin, polyethylene terephthalate, and polyamide. .

  A member (hereinafter also referred to as “partition member”) 60 that partitions the surface of the exterior material 40 into a plurality of regions is disposed on the surface of the exterior material 40 having such a three-layer structure. In the present embodiment, the partition member 60 is constituted by, for example, a linear or strip-shaped wire 61. Examples of the material of the wire 61 include, for example, simple metals such as aluminum, iron, copper, nickel, titanium, and molybdenum, and alloys such as aluminum alloy, copper alloy, titanium alloy, stainless steel, and Hastelloy, carbon fiber, and kevlar, Examples include high-strength fibers such as glass fibers. Examples of the method for producing the wire 61 include stretching.

  In the present embodiment, the wires 61 are arranged in a lattice shape with a predetermined interval r on the surface of the exterior material 40. That is, the wire 61 is wound obliquely with respect to the longitudinal direction of the secondary battery 1, and is wound in a lattice shape so that the wires 61 cross each other on the surface of the exterior material 40. The winding shape of the wire 61 is not limited to this, and the wire 61 may be arranged in a plurality of strips along the same direction on the surface of the exterior member 40, but is wound in a lattice shape (mesh shape). It is preferable. That is, the wire 61 may be arranged in a plurality of strips along the same direction so as to be in close contact with the outer layer of the exterior member 40, or may be in a lattice shape (mesh shape), but is applied to the battery. In order to make the load uniform, it is preferable to arrange the wires 61 so that the wires 61 are equidistant and parallel to each other. The winding shape of the wire rod 61 is not limited to this embodiment, and various winding shapes such as a triangular mesh shape, a square mesh shape, a polygonal mesh shape, and a honeycomb shape can be devised.

  Assuming the secondary battery 1 with a side of 0.2 m, assuming that the thickness of the exterior material 40 is t and the distance between the wire materials 61 is r, the thickness t of the exterior material 40 and the distance r between the wire materials 61 are: It is preferable to set in the range of 1 μm <t <1 mm and 1 mm <r <30 mm, respectively. More preferably, it is set in the range of 5 μm <t <200 μm, 5 mm <r <20 mm. In addition, the space | interval r between the wire rods 61 is a space | interval between the center lines of a band width, when the wire rod 61 is strip | belt shape.

  As described above, the charge / discharge element 10 is housed in the rectangular frame-shaped protrusion 31 in the hard plate member 30, and the protrusion 31 has a height equal to or higher than the thickness of the charge / discharge element 10. . Therefore, the wire 61 can be wound around the secondary battery 1 without crushing the corners of the charge / discharge element 10. Note that the number of windings of the wire 61 at the same location on the surface of the exterior member 40 is not limited to a single time but may be a plurality of times. Further, the height of the protrusion 31 is preferably slightly higher than the thickness of the charge / discharge element 10. This is because if the height of the protrusion 31 is too high with respect to the thickness of the charge / discharge element 10, the problem of the present invention cannot be solved.

  On the other hand, the safety valve mechanism as described in Patent Document 1 is applied to a large secondary battery having a side of 0.2 m, and examination is attempted. The specifications of the aluminum core material of the laminate exterior material are as shown in Table 1 below, and a large secondary battery having a side of 0.2 m is assumed.

  When the pressure inside the battery rises due to gas generation due to an internal short circuit, etc., the laminate exterior material is the same as the lid of the pressure vessel that is freely supported around the periphery, as in the displacement model (r = 0.1 m) in FIG. It is considered to be deformed.

  Using this model, the battery center stress with respect to the battery center displacement δ is calculated as shown in FIG. From this result, it can be seen that the aluminum core material is cleaved only when the displacement reaches about 146 mm.

  That is, when the safety valve mechanism as in Patent Document 1 is applied to a large secondary battery having a side of 0.2 m, the safety valve mechanism will not work effectively until the internal pressure in the secondary battery becomes considerably high. It is done.

  In addition, by forming a thin portion by pressing or the like in a small region portion of the exterior member 40 partitioned by the wire 61, it is possible to adjust the amount of deformation leading to the tearing and the internal pressure, even if the internal pressure is low. The part can be reliably cleaved.

  4 is a perspective view of a state in which a longitudinal groove is formed on the side surface of the hard plate as a modification of the first embodiment, and FIG. 5 is a perspective view of a state in which a wire is wound around the secondary battery of FIG. is there.

  As shown in FIG. 4, a plurality of longitudinal groove portions 32 are formed on both side surfaces in the longitudinal direction of the hard plate member 30 of the secondary battery 1. These longitudinal groove portions 32 are used for preventing the displacement of the wire material 61 on both side surfaces of the hard plate 30 by hooking the wire material 61 on the longitudinal groove portion 32 when the wire material 61 is wound around the secondary battery 1. It is. In particular, in the present embodiment, the wire 61 is wound obliquely with respect to both side surfaces in the longitudinal direction of the secondary battery 1, and the wire 61 is wound in a lattice shape so as to intersect each other on the surface of the exterior material 40. If the both sides of the hard plate 30 are not caught, the wire 61 is easily displaced.

  Therefore, as shown in FIG. 5, if the wire rod 61 is wound around the secondary battery 1 using a plurality of longitudinal groove portions 32 formed on both side surfaces in the longitudinal direction of the hard plate material 30, both side surfaces of the hard plate material 30. It is possible to prevent the wire 61 from being displaced. In addition, it is possible to prevent the deterioration of the shape of the small region partitioned by the wire 61 in a lattice shape, and to maintain stable cleavage characteristics.

  Further, the wire 61 can be prevented from being displaced by attaching a curable resin such as an epoxy resin to the wire 61 and winding the resin before the resin is cured, followed by drying and hardening after the winding. In particular, when an organic material such as Kevlar is used as the wire 61, a curable resin such as an epoxy resin is used, and by winding a plurality of times, there is no need to devise special treatment for the winding start and winding end terminals. The loosening of the wire 61 can be prevented with the hardening of the resin.

  As described above, according to the secondary battery 1 of the present embodiment, the wire 61 is wound around the secondary battery 1 so as to be in close contact with the surface of the exterior material 40, and the surface of the exterior material 40 is partitioned into a plurality of regions. is doing. Therefore, the strength of the partitioned exterior member 40 can be made relatively weaker than the strength of the portion around which the wire 61 is wound. Therefore, when the internal pressure in the secondary battery 1 rises, the internal pressure can be released by deforming or cleaving the exterior material portion of the region partitioned by the wire 61. Therefore, even if it is a large sized battery, release | release of an internal pressure becomes easy by partitioning the surface of the exterior material 40 into a some area | region. Further, by winding the wire 61 around the secondary battery 1, the mechanical strength of the exterior material 40 is increased, so that the durability against damage is improved and the expansion and contraction due to the temperature change of the battery are suppressed. Deterioration of internal resistance is suppressed.

  Further, the protrusion 31 has a height equal to or greater than the thickness of the charge / discharge element 10. Therefore, the wire 61 can be wound around the secondary battery 1 without crushing the corners of the charge / discharge element 10.

[Second Embodiment]
Next, with reference to FIG. 6 and FIG. 7, the secondary battery of 2nd Embodiment is demonstrated. FIG. 6 is a perspective view showing the secondary battery of the second embodiment, and FIG. 7 is a perspective view showing a modification of the secondary battery of the second embodiment. In addition, about the member of the same structure as 1st Embodiment, the same code | symbol is attached | subjected and demonstrated.

  In the secondary battery 1 of the first embodiment, the wire 61 is wound as the partition member 60 around the secondary battery 1, the wire 61 is brought into close contact with the surface of the exterior material 40, and the surface of the exterior material 40 is It is partitioned into multiple areas.

  In contrast, as shown in FIG. 6, in the secondary battery 100 of the second embodiment, a net member 160 described later is employed as a member 60 that partitions the surface of the exterior material 40 into a plurality of regions. That is, in the secondary battery 100 of the second embodiment, a battery main body (hereinafter simply referred to as “battery”) 110 is placed on a rectangular mesh member 160, and along the both longitudinal sides of the battery 110. A pair of connecting members 150 and 150 are arranged so as to sandwich this. Then, another net member 160 is placed on the connecting members 150 and 150 so as to straddle the exterior material 40 of the battery 110.

  In the secondary battery 100 shown in FIG. 6, both the front and back surfaces of the charge / discharge element 10 are covered with the outer packaging material 40, and the positive terminal electrode 21 and the negative terminal electrode 22 are outside in the longitudinal direction from the outer peripheral edge of the outer packaging material 40. It is extended to each.

  The mesh member 160 is fixed to the surface of the exterior material 40 of the secondary battery 100 and the connection members 150 and 150 with an epoxy resin adhesive or the like. The width W1 of the net member 160 is set to be a total width of the width S1 of the secondary battery 100 and the width 2D1 of the two connecting members 150 and 150. The length of the net member 160 is set to be at least approximately equal to the length of the charge / discharge element 10 of the battery 110.

  Examples of the material of the net member 160 include, for example, simple metals such as aluminum, iron, copper, nickel, titanium, and molybdenum, alloys such as aluminum alloy, copper alloy, titanium alloy, stainless steel, and Hastelloy, and engineering plastics. Is mentioned. Examples of a method for producing the net member 160 include weaving, etching, injection molding, and machining.

  The connecting member 150 is formed as a rod-shaped member (square member) having a rectangular cross section having a length at least equal to that of the charge / discharge element 10 of the battery 110. The height T1 of these connecting members 150 is set to be equal to or greater than the thickness of the battery 110, but is preferably substantially equal to the thickness of the battery 110. By setting the height T of the connecting member 150 to be equal to or greater than the thickness of the battery, the surface of the exterior member 40 can be partitioned into small regions without crushing the corners of the charge / discharge element 10.

  Examples of the connecting member 150 include engineering plastics such as polyamide, polyphenylene sulfide, polyester, polyacetal, and modified polyphenylene ether. Moreover, the said engineering plastic (FRP) etc. which mixed the filler are mentioned.

  Further, as shown in FIG. 7, in the modification of the secondary battery 100 of the second embodiment, on the flat plate portion 131 of the rectangular flat plate-like hard plate material 30 having a pair of protrusions 130, 130 at both ends in the longitudinal direction. In FIG. A net member 160 is placed on the protrusions 130 and 130 so as to straddle the exterior material 40 of the battery 110. The net member 160 is fixed on the surface of the exterior material 40 and the protrusions 130 and 130 by an epoxy resin adhesive or the like.

  In the secondary battery 100 shown in FIG. 7, the charge / discharge element 10 is disposed on the flat plate portion 131 of the hard plate material 30, and the charge / discharge element 10 is covered with the exterior material 40. The side terminal electrode 21 and the negative side terminal electrode 22 are extended outward in the longitudinal direction.

  The width W2 of the net member 160 is set to be the total width of the width S2 of the battery 110 and the width 2D2 of the pair of protrusions 130 and 130. The length of the net member 160 is set to be at least approximately equal to the length of the charge / discharge element 10 of the battery 110.

  A height T <b> 2 from the flat plate portion 131 of the hard plate member 30 to the upper end of the protruding portion 130 is set to be equal to or greater than the thickness of the battery 110. By setting the height T <b> 2 of the protrusion 130 to be equal to or greater than the thickness of the battery 110, the surface of the exterior material 40 can be partitioned into small regions without crushing the corners of the charge / discharge element 10.

  In the second embodiment, the mesh shape of the mesh member 160 is formed vertically and horizontally so as to be parallel and perpendicular to the longitudinal direction of the connecting member 150 or the protrusion 130. However, the present invention is not limited to this, and the mesh shape of the mesh member 160 may be formed or arranged so as to cross obliquely with respect to the longitudinal direction of the connecting member 150 or the protrusion 130.

  Therefore, according to the second embodiment, when the internal pressure of the secondary battery rises, the internal pressure can be released by deforming or cleaving the exterior material portion of the region partitioned by the mesh member 160. Therefore, even if it is a large sized battery, an internal pressure can be easily open | released by partitioning the surface of the exterior material 40 into a some area | region. Further, by arranging the mesh member 160 on the surface of the exterior material 40, the mechanical strength of the exterior material 40 is increased, so that the durability against damage is improved, and the expansion and contraction due to the temperature change of the battery are suppressed, so Resistance degradation can be suppressed.

  Moreover, by setting the height T of the connecting member 150 to be equal to or greater than the thickness of the battery, the surface of the exterior member 40 can be partitioned into small regions without crushing the corners of the charge / discharge element 10.

[Third Embodiment]
Next, with reference to FIG. 8 and FIG. 11, the secondary battery of 3rd Embodiment is demonstrated. FIG. 8 is a perspective view showing the secondary battery of the third embodiment. FIG. 9 is a perspective view showing a first example of a honeycomb member in the secondary battery of the third embodiment. FIG. 10 is a perspective view showing a second example of the honeycomb member in the secondary battery of the third embodiment. FIG. 11 is a perspective view showing a third example of the honeycomb member in the secondary battery of the third embodiment. In addition, about the member of the same structure as 1st Embodiment, the same code | symbol is attached | subjected and demonstrated.

  As shown in FIG. 8, in the third embodiment, a honeycomb-shaped net member (hereinafter simply referred to as “honeycomb member”) 260 described later is used as the member 60 that partitions the surface of the exterior material 40 into a plurality of regions. Adopted. That is, in the third embodiment, a plurality of secondary batteries 200 are stacked via the honeycomb member 260, and the plurality of secondary batteries 200 are connected in parallel or in series to form an assembled battery (stack) 300. It is composed.

  In each secondary battery 200, both the front and back surfaces of the charge / discharge element 10 are covered with the exterior material 40, and the positive terminal electrode 21 and the negative terminal electrode 22 are outward in the longitudinal direction from the outer peripheral edge of the exterior material 40. Each is extended. Therefore, in the assembled battery 300 of the third embodiment, the honeycomb members 260 and 260 are disposed on the front and back surfaces of the secondary batteries 200 so as to sandwich the secondary batteries 200, and the honeycomb members 260 and the secondary batteries 200 are alternately arranged. positioned.

  Although each section of the honeycomb member 260 of the present embodiment has a quadrangular shape, it is not limited thereto, and may be another polygon such as a triangle, a pentagon, and a hexagon. The material of the honeycomb member 260 is, for example, a single metal such as aluminum, iron, copper, nickel, titanium, molybdenum, an alloy such as aluminum alloy, copper alloy, titanium alloy, stainless steel, hastelloy, or engineering plastic. And ceramics. As a manufacturing method of the honeycomb material 260, for example, in addition to bleaching, injection molding, or machining, firing after molding by injection molding or press working can be cited.

  When a plurality of secondary batteries 200 are connected in parallel, the plurality of secondary batteries 200 are alternately stacked via the honeycomb member 260. Then, the positive terminals 21 and the negative terminals 22 of one adjacent secondary battery 200 and another secondary battery 200 are connected to each other by a metal foil or a component of a conductor (not shown). In other words, the secondary batteries 200 are arranged so that the arrangement order of the secondary batteries 200 matches, that is, the positive electrode terminal 21 and the negative electrode terminal 23 at both ends in the longitudinal direction of the battery are located on the same side. In this way, by simply stacking a plurality of secondary batteries 200 and connecting the electrode terminals 21 and 23 of the upper and lower secondary batteries 200, it is possible to obtain a long-life battery pack 300 in which the secondary batteries are connected in parallel. it can.

  Moreover, when connecting each secondary battery 200 in series, it arrange | positions so that the positive electrode terminal 21 and the negative electrode terminal 23 in the longitudinal direction both ends of the adjacent secondary battery 200 may be located alternately. Then, by connecting the positive electrode terminal 21 and the negative electrode terminal 23 of the upper and lower secondary batteries 200, it is possible to create a high-power assembled battery 300 in which a plurality of secondary batteries 200 are connected in series.

  In the third embodiment, by forming the assembled battery (stack) 300 by alternately stacking the secondary batteries 200 and the honeycomb members 260, the surface of the exterior material 40 can be partitioned into small regions.

  Therefore, according to the third embodiment, when the internal pressure of the secondary battery 200 increases, the internal pressure can be released by deforming or cleaving the exterior material portion of the region partitioned by the honeycomb member 260. Therefore, even if it is a large sized battery, an internal pressure can be easily open | released by partitioning the surface of the exterior material 40 into a some area | region. In addition, by disposing the honeycomb member 260 between the adjacent secondary batteries 200 and 200, the mechanical strength of the exterior material 40 is increased, so that durability against damage is improved, and expansion and contraction due to battery temperature change. As a result, the reliability of the assembled battery can be improved.

  Next, the structure of the honeycomb member 260 will be described with reference to FIGS. 9 to 11. In the honeycomb member 260 of FIG. 9, through holes 262 through which the refrigerant passes are opened in the partition wall surfaces 261 that partition the small regions 41 of the exterior material 40. When the through holes 262 are opened in the partition wall surfaces 261 of the honeycomb member 260 as described above, when the assembled battery (stack) 300 is configured by stacking a plurality of secondary batteries 200, the cooling performance of the assembled battery 300 is improved. Can be improved. This is because the refrigerant can be passed between the secondary batteries 200 and 200 adjacent to each other by using the through holes 262 of the honeycomb member 260.

  Further, in the honeycomb member 260 of FIG. 10, a notch portion 270 through which the refrigerant passes is formed on the partition wall surface 261 that partitions the small region 41 of the exterior material 40. In this example, notches 271 and 272 are formed on each partition wall surface 261 in the row direction or the column direction so as to be alternately up and down from the center. However, the present invention is not limited to this, and notches 271 and 272 may be formed on each partition wall surface 261 in both the row direction and the column direction so as to be staggered vertically from the center. Further, the shape and arrangement of the notch 270 are not limited to the example of FIG.

  When the notch 270 is formed in the partition wall surface 261 of the honeycomb member 260 as described above, the cooling performance of the assembled battery 300 can be improved when the assembled battery (stack) 300 is configured. This is because the coolant can be passed between the adjacent secondary batteries 200 and 200 using the upper and lower cutout portions 271 and 272 of the honeycomb member 260.

  Further, in the honeycomb member 260 of FIG. 12, a deformed wall 280 having a sharp tip is formed on the partition wall surface 261 that partitions the small region 41 of the exterior material 40 so as to face the exterior material 40. In this example, a rhombus-shaped deformed wall 280 is formed on each partition wall surface 261 in the row direction or the column direction, and the notch portions are staggered upward and downward from the center portion on each partition wall surface 261 in the column direction or the row direction. 271 and 272 are formed. The shape and arrangement of the deformed wall 280 and the notch 270 are not limited to the example of FIG.

  In this way, the partition wall surface 261 of the honeycomb member 260 faces the exterior material 40 and is formed as a sharp-shaped wall 280 having a sharp tip, thereby facilitating the tearing of the exterior material 40 when the exterior material 40 is deformed. Can be easily released. The shape, arrangement, and the like of the deformed wall 280 are not limited to this example.

[Fourth Embodiment]
The fourth embodiment is a vehicle 500 on which the secondary batteries 1 and 100 of the first and second embodiments or the assembled battery 300 of the third embodiment is mounted as a driving power source.

  FIG. 13 is a schematic view showing a vehicle equipped with an assembled battery to which the secondary battery according to the present invention is applied.

  The secondary batteries 1 and 100 have various characteristics as described above, and are particularly compact batteries. For this reason, it is suitable as a power source for vehicles in which particularly severe demands are made regarding energy density and power density.

  According to the present invention, a member that partitions the surface of the exterior material into a plurality of regions is disposed in close contact with the surface of the exterior material on at least one of the front and back surfaces of the battery. For this reason, the strength of the exterior material is improved, and when the internal pressure of the battery increases, the exterior material portion of the region partitioned by the partition member can be deformed and cleaved to release the internal pressure, and the battery function can be maintained.

1 is a perspective view showing a first embodiment of a secondary battery according to the present invention. It is a partially broken sectional view of a secondary battery. FIG. 3 is a partially broken cross-sectional view of a state in which a member for partitioning the exterior material surface is disposed on the exterior material surface of the secondary battery of FIG. 2. As a modification of the first embodiment, it is a perspective view of a state in which a longitudinal groove is formed on the side surface of a hard plate. It is a perspective view of the state which wound the wire around the secondary battery of FIG. It is a perspective view which shows the secondary battery of 2nd Embodiment. It is a perspective view which shows the modification of the secondary battery of 2nd Embodiment. It is a perspective view which shows the secondary battery of 3rd Embodiment. It is a perspective view which shows the 1st example of the honeycomb member in the secondary battery of 3rd Embodiment. It is a perspective view which shows the 2nd example of the honeycomb member in the secondary battery of 3rd Embodiment. It is a perspective view which shows the 3rd example of the honeycomb member in the secondary battery of 3rd Embodiment. It is the schematic which shows the vehicle carrying the assembled battery to which the secondary battery which concerns on this invention is applied. It is a schematic diagram which shows the displacement model of a comparison form. It is explanatory drawing which shows the relationship between the center part stress and center part displacement in a comparison form.

Explanation of symbols

1, 100, 200 secondary battery,
10 charge / discharge elements,
11 Current collector,
13 Active material layer,
14 separator,
21 positive electrode terminal,
22 negative electrode terminal,
30 hard plate,
31 protrusions,
40 exterior materials,
41 small area,
60 compartment members,
61 wire rod,
130 protrusions,
150 connecting member,
160 mesh member,
260 honeycomb member,
262 through hole,
270 Notch,
280 deformed wall,
300 battery packs,
500 vehicles.

Claims (12)

A charge / discharge element having an electrode plate laminated via a separator; an exterior material covering and sealing the charge / discharge element; and an electrode terminal connected to the electrode plate and led out from an outer peripheral edge of the exterior material. In the provided secondary battery,
A secondary battery comprising a member for partitioning the exterior material surface into a plurality of regions on the exterior material surface on at least one of the front and back surfaces of the battery.   2. The secondary battery according to claim 1, wherein a wire is wound and mounted on the surface of the exterior material at intervals, and the surface of the exterior material is partitioned into a plurality of regions.   The charging / discharging element is disposed in at least one of the front and back surfaces of the plate material having electrical insulation, or the frame body having electrical insulation, and sealed with an exterior material. The secondary battery according to claim 2, wherein the secondary battery is mounted and the surface of the exterior material is partitioned into a plurality of regions.   4. The secondary battery according to claim 3, wherein a protrusion having a height equal to or greater than the thickness of the battery is formed in the periphery of the charge / discharge element of the plate member or frame.   The secondary battery according to claim 1, wherein a net member is disposed in close contact with the surface of at least one of the outer and front surfaces of the battery.   The secondary battery according to claim 5, wherein the mesh members are arranged on the front and back surfaces of the battery so as to sandwich the battery, and these mesh members are connected to each other by a connecting member on a side surface of the battery.   The secondary material according to claim 5, wherein a plate material is arranged on the surface of the other exterior material of the front and back surfaces of the battery, and a protrusion having a height equal to or higher than the thickness of the battery is formed on the plate material. battery.   In the case of a secondary battery having a side of 0.2 m, the thickness of the exterior material is t, and the distance between the members defining the exterior material surface is r, and 1 μm <t <1 mm, 1 mm <r <30 mm. The secondary battery according to any one of claims 1 to 7, wherein:   A plurality of the secondary batteries according to any one of claims 1 to 8, wherein the secondary batteries are stacked via a net member, and the plurality of secondary batteries are connected in parallel or in series. A battery pack characterized by having   The assembled battery according to claim 9, wherein a through hole or a notch is formed in a partition wall portion of the mesh member.   11. The assembled battery according to claim 9, wherein a deformed wall having a sharp tip is formed on the partition wall portion of the mesh member so as to face the exterior material.   A secondary battery according to any one of claims 1 to 8, or an assembled battery according to any one of claims 9 to 11 is mounted as a driving power source. Vehicle.