JP4135474B2 - Laminated secondary battery, assembled battery module comprising a plurality of laminated secondary batteries, assembled battery comprising a plurality of assembled battery modules, and an electric vehicle equipped with any of these batteries - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a laminated secondary battery in which stacked electrodes are prevented from being displaced, an assembled battery module comprising a plurality of laminated secondary batteries, an assembled battery comprising a plurality of assembled battery modules, and any of these. The present invention relates to an electric vehicle equipped with a battery.
[0002]
[Prior art]
Due to the growing awareness of global environmental problems, the automobile industry is urgently developing electric vehicles (EV), hybrid electric vehicles (HEV), and fuel cell vehicles (FCV). As a power battery for EV or HEV, a secondary battery having a voltage higher than that of a 12V or 24V battery generally used at present is used. In order to obtain a high voltage, it is necessary to laminate a large number of electrodes. The battery described in Patent Document 1 below is a non-aqueous electrolyte secondary battery in which electrodes are wound. In this battery, electrodes constituting a plurality of layers are fixed in a cross shape with a winding tape. Yes. The battery described in Patent Document 2 below is a laminated polymer electrolyte battery in which a large number of flat electrodes are laminated. In this battery, a plurality of laminated electrodes are restrained by an outer package or a seal portion. is doing.
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 2001-185224 (FIG. 1)
[Patent Document 2]
JP 2000-235850 A (FIG. 3)
[0004]
[Problems to be solved by the invention]
In the case of a wound battery as shown in Patent Document 1, the electrode can be fixed in a cross shape as described above, but a flat battery as described in Patent Document 2 In this case, the laminated electrodes are not particularly positively fixed. In the case of a flat battery, the electrode is only temporarily fixed temporarily by the compressive force of the exterior body and locally by the seal portion.
[0005]
If the voltage required for the battery is not so high, the number of electrodes to be stacked is small, so that the displacement of the electrodes can be prevented to some extent even by compressive force from the exterior body or local fixation at the seal portion. However, when the required voltage increases and the number of stacked electrodes increases, it is impossible to prevent the displacement of the electrodes unless the stacked electrodes are positively fixed. The misalignment of the electrodes may induce various problems that cannot be predicted at the beginning of manufacture, such as a decrease in battery capacity and deterioration in battery characteristics.
[0006]
Since an EV or HEV power battery is always mounted on a vehicle body in which vibrations are generated, how to prevent the displacement of the electrodes over a long period of time is a particularly important issue.
[0007]
The present invention has been made in order to solve the conventional problems as described above, and a laminated secondary battery having a structure in which the stacked electrodes do not cause displacement, and a plurality of the laminated secondary batteries. It is an object of the present invention to provide an assembled battery module comprising: an assembled battery comprising a plurality of assembled battery modules; and an electric vehicle including any one of these batteries.
[0008]
[Means for Solving the Problems]
  In order to solve the above-described problems and achieve the object, a laminated secondary battery according to the invention forms a battery element having a square shape when viewed from the stacking direction by alternately stacking current collectors and separators serving as positive electrodes or negative electrodes. Then, two electrode terminals are taken out from the battery element in the opposite direction, and the battery element is packaged with a laminate film in which a polymer and a metal are combined. At least one of the positive electrodes, the negative electrodes, or the separators at the four corners of the battery element.LocallyIt is characterized by fixing in the stacking direction.
  If the positive electrodes or the negative electrodes are fixed to each other, even if vibration or thermal stress is applied for a long period of time, it is possible to prevent misalignment of the stacked electrodes.
[0009]
  The positive electrodes or the negative electrodes are preferably fixed by welding, welding, or adhesion. It can also be fixed by riveting.it can. Positive electrodeAlternatively, it is desirable to use thermal welding for welding for fixing the negative electrodes. Moreover, it is desirable to use ultrasonic welding for welding for fixing the positive electrodes or the negative electrodes.
[0010]
  It is desirable that the laminated secondary battery is vacuum-packed by extracting the air inside the laminate film while heat-sealing the laminated film so that the battery element is vacuum-packed. In addition, the separator has an area larger than the area of the negative electrode layer so that the entire negative electrode layer formed on the current collector serving as the negative electrode can be covered. It is desirable to have an area smaller than the area of the separator so that the whole is covered. In order to improve the electrical conductivity, it is preferable that the current collector as the positive electrode is bound together with a conductive material.
[0011]
An assembled battery that can maintain stable battery performance even if vibration or thermal stress is applied over a long period of time if a laminated battery module is configured by connecting a plurality of laminated secondary batteries according to the present invention in parallel, serial connection, or series-parallel connection. Modules can be provided.
[0012]
Furthermore, when a plurality of assembled battery modules according to the present invention are connected in parallel, connected in series or connected in series and parallel to form an assembled battery, an assembled battery capable of maintaining stable battery performance even when vibration or thermal stress is applied over a long period of time. Can be provided.
[0013]
If any of the laminated secondary battery, the assembled battery module, and the assembled battery according to the present invention is mounted on an electric vehicle, even if vibration or thermal stress is applied over a long period of time, an electric device having a stable power source is provided. It can be a car.
[0014]
【The invention's effect】
According to the laminated secondary battery of the present invention, since at least the positive electrode or the negative electrode is fixed in the stacking direction, it is possible to prevent the displacement of the electrode, and various vibrations are applied over a long period of time, and thermal stress is generated. Even if added, stable battery performance can be obtained.
[0015]
Further, according to the assembled battery module or the assembled battery of the present invention, stable battery performance can be maintained even when vibration or thermal stress is applied for a long period of time.
[0016]
Furthermore, when any one of the laminated secondary battery, the assembled battery module, and the assembled battery according to the present invention is used as a power source for an electric vehicle, stable power performance can be maintained over a long period of time.
[0017]
  Referring to the accompanying drawings, a laminated secondary battery according to the present invention, an assembled battery module comprising a plurality of laminated secondary batteries, an assembled battery comprising a plurality of assembled battery modules, and an electric vehicle equipped with any one of these batteries The preferred embodiment will be described in detail. In addition, this invention is not limited to embodiment described below, It can implement by changing suitably within the range included in the technical idea of this invention. Hereinafter, the present invention will be described in detail based on [Embodiment 1] to [Embodiment 5].
[Embodiment 1]
  The laminated secondary battery according to the present invention has a current collector and a separator, which are positive or negative electrodes, alternately stacked to form a rectangular battery element when viewed from the stacking direction, and two electrode terminals are relative to the battery element. The battery element is a laminated secondary battery that is packaged with a laminate film in which a polymer and a metal are combined, and includes at least one of positive electrodes, negative electrodes, or separators that constitute the battery element. Either one of the four corners of the battery elementLocallyIt is characterized by being fixed in the stacking direction.
[0018]
FIG. 1 is an external view of a laminated secondary battery according to the present invention, and FIG. 2 is a front view showing the inside of the laminated secondary battery shown in FIG.
[0019]
As shown in FIG. 1, a laminated secondary battery 10 according to the present invention wraps a battery element with a battery exterior material made of a polymer-metal composite laminate film 12, and laminates positive and negative electrode terminals 14 connected to the battery element. The battery 12 is exposed to the outside from the opposite direction of the film 12, and the battery element is vacuum-packed by extracting the air inside the laminate film 12 while thermally fusing the periphery of the laminate film 12 and reducing the pressure.
[0020]
When the laminated secondary battery 10 shown in FIG. 1 is formed, a battery element as shown in FIG. 2 is placed on the laminated film 12 positioned on the lower side. The configuration of this battery element is as shown in FIG. The battery element 20 is obtained by alternately stacking current collectors and separators serving as positive electrodes or negative electrodes.
[0021]
In FIG. 2, when the inside of the battery is viewed from the stacking direction, first, the sheet-like negative electrode layer 22 is first visible. The negative electrode layer 22 is formed on both surfaces of a sheet-like negative electrode current collector 24 formed of a copper material. A separator 26 is positioned below the negative electrode current collector 24, and a sheet-like positive electrode current collector formed of an aluminum material having a positive electrode layer on both sides is positioned below the separator 26. Thus, in FIG. 2, the battery element 20 includes a plurality of negative electrode current collectors and positive electrode current collectors via a separator, such as a negative electrode current collector, a separator, a positive electrode current collector, a separator,. It has a multilayer structure in which electric bodies are alternately arranged.
[0022]
All the negative electrode current collectors 24 of the battery element 20 are bundled and the electrode terminals 14 are attached. On the other hand, electrode terminals 14 are attached to all positive electrode current collectors via lead wires. The negative electrode current collector 24 and the electrode terminal 14, and the positive electrode current collector and the electrode terminal 14 are welded at the joint portion 28 by, for example, ultrasonic welding. By this welding, the negative electrode current collector 24 and the electrode terminal 14 and the positive electrode current collector and the electrode terminal 14 are mechanically and electrically connected. The reason why the welding is performed by ultrasonic welding is that this welding generates less burrs than other welding, and there is almost no risk of an internal short circuit with the laminate film 12.
[0023]
In the laminated secondary battery 10 according to the present invention, either the negative electrode current collectors or the positive electrode current collectors are arranged so as not to cause misalignment among the negative electrode current collector, the separator, and the positive electrode current collector. It is mechanically fixed in the stacking direction. If the positive electrode current collectors or the negative electrode current collectors are fixed, even if vibration or thermal stress is applied over a long period of time, the positional deviation of the stacked electrodes can be prevented, and the expansion of the battery element 20 can be suppressed to some extent. it can.
[0024]
The positive electrode current collectors or the negative electrode current collectors can be fixed by welding, welding, or adhesion. Specifically, it is desirable to use thermal welding for welding. Specifically, it is desirable to use ultrasonic welding for welding. When fixing by adhesion, an electrically conductive adhesive is used.
[0025]
In the present embodiment, since the shape of the battery element 20 is a quadrangle when viewed from the stacking direction, as shown in FIG. 2, in the fixing portions 30A, 30B, 30C, and 30D at the four corners of the negative electrode current collector 24, The stacked negative electrode current collectors 24 are fixed to each other. This fixing is performed by ultrasonic welding or heat welding.
[0026]
The battery element 20 placed on the lower laminate film 12 is covered with the laminate film 12, and the pressure is reduced by extracting air while thermally fusing the periphery of the laminate film 12, and the battery element in the laminate film 12 is removed. 20 is sealed.
[0027]
The fixed state of the negative electrode current collectors 24 will be described in more detail with reference to the cross-sectional views of FIGS. 3 is an AA cross-sectional view of the laminated secondary battery shown in FIG. 2, FIG. 4 is a BB cross-sectional view of the laminated secondary battery shown in FIG. 2, and FIG. 5 is a laminate shown in FIG. It is CC sectional drawing of a secondary battery.
[0028]
As shown in these cross-sectional views, the battery element 20 includes a negative electrode current collector 24, a separator 26, a positive electrode current collector 27, a separator 26, a negative electrode current collector 24, a separator 26, a positive electrode current collector 27, and a separator from above. 26 and the negative electrode current collector 24 are laminated in this order. As shown in FIG. 2, the length of the negative electrode current collector 24 in the vertical direction (direction between the electrode terminals 14) is the fixed portion 30 </ b> A except for the notch portion for connecting the positive electrode current collector 27 to the electrode terminal 14. , 30B, 30C, and 30D are longer than the vertical length of the separator 25 so that sufficient areas can be taken. A negative electrode layer 22 is formed on both surfaces of the negative electrode current collector 24 over the entire width direction, leaving areas as the fixing portions 30A, 30B, 30C, and 30D.
[0029]
The separator 26 is formed slightly larger than the area of the negative electrode layer 22 so as to cover the entire negative electrode layer 22 formed on the negative electrode current collector 24. On the other hand, as shown in FIG. 3, the positive electrode current collector 27 is formed smaller than the area of the separator 26 so that the whole is covered with the separator 26.
[0030]
As shown in FIGS. 3 and 5, each of the negative electrode current collectors 24 is bundled in a region where the electrode terminals 14 are connected, and in the fixing portions 30 </ b> A, 30 </ b> B, 30 </ b> C, 30 </ b> D at the four corners of the negative electrode current collector 24. The bundled negative electrode current collectors 24 are fixed. This fixing is performed by ultrasonic welding or heat welding. After fixing the negative electrode current collector 24, as shown in FIG. 4, the negative electrode current collector 24 and the electrode terminal 14 are welded at the joint portion 28 by, for example, ultrasonic welding. On the other hand, a lead wire 25 is connected to the positive electrode current collector 24, and the lead wire 25 is connected together at a joint portion 29 of the electrode terminal 14.
[0031]
As described above, the negative electrode current collectors 24 are firmly fixed to each other, and the displacement of each layer of the negative electrode current collector 24, the separator 26, and the positive electrode current collector 27 is prevented by the binding force due to the fixation.
[0032]
In the first embodiment, the negative electrode current collector 24 is fixed at the four corners by ultrasonic welding or heat welding. However, the positive electrode current collector 27 may be fixed instead of the negative electrode current collector 24. good. Further, both the negative electrode current collector 24 and the positive electrode current collector 27 may be fixed. When both the negative electrode current collector 24 and the positive electrode current collector 27 are fixed, the size and shape of the current collectors and the fixing thereof are prevented so that the negative electrode current collector 24 and the positive electrode current collector 27 do not contact each other. However, it is easy for those skilled in the art to determine how to fix them.
[0033]
Examples of the laminated secondary battery of the present invention include a lithium ion secondary battery, a polymer lithium battery, a nickel-hydrogen battery, and a nickel-cadmium battery. Of these, lithium ion secondary batteries excellent in output and energy density are preferable in consideration of applications as power sources for electric vehicles. When laminated secondary batteries, which are lithium ion secondary batteries, are connected in series to provide a power source for an electric vehicle, it is possible to obtain an assembled battery having an overall output voltage of about 400V.
[0034]
In the laminated secondary battery of the present invention, a material constituting the laminate film 12, the electrode terminal 14, the positive electrode current collector 27, the separator 26, and the negative electrode current collector 24 may be a known material and is particularly limited. is not. For reference, the case where the laminate secondary battery of the present invention is a lithium ion secondary battery will be briefly described below. However, the laminate secondary battery of the present invention is not limited to the lithium ion secondary battery.
[0035]
[Positive electrode layer]
The sheet-like positive electrode layer constituting the positive electrode of the battery element 20 has a width substantially the same as the width of the battery element 20, and a structure in which the positive electrode material is bound on both surfaces of the positive electrode current collector 27 made of aluminum or the like. Have As the positive electrode material, various oxides (LiMn₂O_FourLithium manganese oxide such as manganese dioxide; LiNiO₂Lithium nickel oxide such as LiCoO₂And lithium-containing nickel cobalt oxide; lithium-containing amorphous vanadium pentoxide, etc.) and chalcogen compounds (titanium disulfide, molybdenum disulfide, etc.). Among these, lithium manganese oxide or lithium nickel oxide is preferable in consideration of output characteristics of the obtained lithium ion secondary battery.
[0036]
In order to improve conductivity, the positive electrode current collector 27 may be bound together with a conductive material. Examples of the conductive material include artificial graphite, carbon black (for example, acetylene black), nickel powder, and the like.
[0037]
As the positive electrode current collector 27, for example, an aluminum expanded metal, an aluminum mesh, an aluminum punched metal, or the like can be used. The positive electrode may have a structure in which a positive electrode material is bound to one surface of the positive electrode current collector 27.
[0038]
[Negative electrode layer]
The sheet-like negative electrode layer 22 constituting the negative electrode of the battery element 20 has a length longer than that of the battery element 20 but substantially the same width as the battery element 20 and is made of copper or the like. 24 has a structure in which a negative electrode material is bound to both surfaces. As the negative electrode material, a carbon material that occludes and releases lithium ions can be used. As such carbon materials, natural graphite, artificial graphite, carbon black, activated carbon, carbon fiber, coke, organic precursors (for example, phenol resin, polyacrylonitrile, cellulose, etc.) were synthesized by heat treatment in an inert atmosphere. Examples include carbon. Preferably, the negative electrode is made of an amorphous carbon-based material. The amorphous carbon-based material can be obtained by carbonizing a thermosetting resin. Incidentally, when an amorphous carbon material having a large voltage dependency due to discharge is used, the cycle characteristics of the lithium ion secondary battery when two or more lithium ion secondary batteries are connected in parallel can be improved.
[0039]
As the negative electrode current collector 24, for example, a copper expanded metal, a copper mesh, a copper punched metal, or the like can be used. The negative electrode may have a structure in which a negative electrode material is bound to one surface of the negative electrode current collector 24.
[0040]
[Separator layer]
The sheet-like separator layer constituting the separator 26 of the battery element 20 has a width substantially the same as the width of the battery element 20, and a polyolefin microporous separator such as polyethylene or polypropylene can be used. The separator is impregnated with a non-aqueous electrolyte. The nonaqueous electrolytic solution is prepared by dissolving an electrolyte in a nonaqueous solvent. Nonaqueous solvents include ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), γ-butyrolactone (γ-BL ), Sulfolane, acetonitrile, 1,2-dimethoxyethane, 1,3-dimethoxypropane, dimethyl ether, tetrahydrofuran (THF), 2-methyltetrahydrofuran and the like. Nonaqueous solvents may be used alone or in combination of two or more. Examples of the electrolyte include lithium perchlorate (LiClO)._Four), Lithium hexafluorophosphate (LiPF)₆), Lithium boron tetrafluoride (LiBF)_Four), Lithium hexafluoroarsenide (LiAsF)₆), Lithium trifluoromethanesulfonate (LiCF)_ThreeSO_Three), Bistrifluoromethylsulfonylimide lithium [LiN (CF_ThreeSO_Three)₂And the like. The amount of the electrolyte dissolved in the non-aqueous solvent is usually about 0.2 mol / L to 2 mol / L.
[0041]
Examples of the polymer that holds the nonaqueous electrolytic solution include a polyethylene oxide derivative, a polypropylene oxide derivative, a polymer containing the derivative, a copolymer of vinylidene fluoride (VdF) and hexafluoropropylene (HFP), and the like.
[0042]
[Laminate film]
The laminate film 12 is used as a battery exterior material. In general, a polymer metal composite film in which a heat-fusible resin film, a metal foil, and a resin film having rigidity are laminated in this order is used.
[0043]
As the heat-fusible resin, for example, polyethylene (PE), ionomer, ethylene vinyl acetate (EVA), or the like can be used. As the metal foil, for example, Al foil or Ni foil can be used. As the resin having rigidity, for example, polyethylene terephthalate (PET), nylon or the like can be used. Specifically, PE / Al foil / PET laminated film laminated from the sealing surface side to the outer surface; PE / Al foil / nylon laminated film; Ionomer / Ni foil / PET laminated film; EVA / Al foil / A laminated film of PET; an ionomer / Al foil / PET laminated film or the like can be used. The heat-fusible resin film acts as a seal layer when the battery element is housed inside. A metal foil or a rigid resin film imparts moisture, breathability, and chemical resistance to the exterior material. The laminate film can be easily and reliably bonded using ultrasonic fusion or the like.
[0044]
[Electrode terminal]
A metal selected from copper and iron can be used for the electrode terminal 14, but a metal such as aluminum or stainless steel or an alloy material containing these can be used as well. In addition, nickel is most preferably used for the surface coating layer, but metal materials such as silver and gold can be used as well. In order to improve the sealing property of the sealing portion of the laminate film 12 from which the electrode terminal 14 is drawn out, the width of the electrode terminal 14 can be increased along with the improvement of the sealing property. Specifically, the width of the electrode terminal 14 can be set to a size within a range of 20% to 100% of the width of the current collector. If the electrode terminal 14 has a wide width, a large current can be taken out, so that it can be easily adapted to increase the capacity of the laminated secondary battery. [Embodiment 2]
6 is a front view showing the inside of the laminated secondary battery according to the second embodiment, and FIG. 7 is an AA cross-sectional view of the laminated secondary battery shown in FIG. In addition, the BB sectional view of the laminated secondary battery shown in FIG. 6 is the same as FIG.
[0045]
In this embodiment, the stacked negative electrode current collectors 24 are fixed at their four corners using rivets. As a material for the rivet, a material that is well suited to the material of the negative electrode current collector 24, has chemical stability with respect to the battery element 20, and is easily plastically deformed is used.
[0046]
At the four corners of the negative electrode current collector 24, holes for allowing the rivets 32 to pass therethrough are formed. In this embodiment, the negative electrode current collectors 24 are fixed to each other by rivets 32, and holes for penetrating the rivets 32 are formed at the four corners of the negative electrode current collector 24. Since it is exactly the same as 1, the detailed description is omitted. When the negative electrode current collectors 24 are fixed to each other with the rivets 32, the working efficiency is improved as compared with the case where the negative electrode current collectors 24 are fixed by welding, welding, and adhesion as in the first embodiment, and an expensive device is not required. It is.
[0047]
In the present embodiment, each negative electrode current collector 24 is bundled in a region to which the electrode terminal 14 is connected, as shown in FIG. 7, and bundled at four corners of the negative electrode current collector 24. 24 are fixed with rivets 32 from both sides. After fixing the negative electrode current collector 24, the negative electrode current collector 24 and the electrode terminal 14 are welded to each other at the joint portion 28 by, for example, ultrasonic welding as shown in FIGS. 4 and 6. On the other hand, a lead wire 25 is connected to the positive electrode current collector 24, and the lead wire 25 is connected together at a joint portion 29 of the electrode terminal 14.
[0048]
As described above, the negative electrode current collectors 24 are firmly fixed to each other, and the displacement of each layer of the negative electrode current collector 24, the separator 26, and the positive electrode current collector 27 is prevented by the binding force due to the fixation.
[0049]
In the second embodiment, the negative electrode current collector 24 is fixed at the four corners with the rivets 32. However, the positive electrode current collector 27 may be fixed instead of the negative electrode current collector 24. Further, both the negative electrode current collector 24 and the positive electrode current collector 27 may be fixed. When both the negative electrode current collector 24 and the positive electrode current collector 27 are fixed, the size and shape of the current collectors and the fixing thereof are fixed so that the negative electrode current collector 24 and the positive electrode current collector 27 do not contact each other. However, it is easy for a person skilled in the art to determine how to fix the position.
[Embodiment 3]
FIG. 8 is a front view showing the inside of the laminated secondary battery according to the third embodiment. In this embodiment, the stacked negative electrode current collectors 24 are fixed to each other at both end portions 34 in the width direction by linear welding, welding, or adhesion.
[0050]
As described above, when the two ends 34 of the negative electrode current collector 24 are fixed along the edge of the negative electrode current collector 24, when fixed locally (four points) as in the first and second embodiments described above. In comparison, the negative electrode current collectors 24 can be fixed more firmly.
[0051]
In the case of this embodiment, it is necessary to make the width of the negative electrode current collector 24 wider than the width of the negative electrode current collector 24 of the first and second embodiments. The negative electrode layer 22 formed on both surfaces of the negative electrode current collector 24 has a size excluding the fixing margin in the width direction of the negative electrode current collector 24 and the bonding margin of the electrode terminal 14.
[0052]
In the case of this embodiment, the negative electrode current collector 24 and the electrode terminal 14 are connected using a lead wire as usual, and the positive electrode current collector 27 and the electrode terminal 14 are similarly connected.
[0053]
In the third embodiment, the configuration in which the negative electrode current collector 24 is fixed is illustrated, but the positive electrode current collector 27 may be fixed instead of the negative electrode current collector 24.
[Embodiment 4]
FIG. 9 is a front view showing the inside of the laminated secondary battery according to Embodiment 4, and FIG. 10 is a DD cross-sectional view of the laminated secondary battery shown in FIG. In addition, the BB sectional view of the laminated secondary battery shown in FIG. 9 is the same as FIG. In this embodiment, the anode current collectors 24 are fixed together, and the separators 26 are also fixed. Fixing of the negative electrode current collectors 24 is exactly the same as in the first embodiment, and fixing of the separators 26 can be performed by applying the third embodiment.
[0054]
In the case of the fourth embodiment, in addition to fixing the negative electrode current collectors 24 to each other, the stacked separators 26 are linearly welded, welded or bonded at both end portions 36 in the width direction. It is fixed.
[0055]
As described above, when both ends 36 of the separator 26 are fixed along the edges of the separator 26, the negative dielectric 24 is fixed at the four corners, and the separator 26 is fixed at the both ends 36 in the width direction. Therefore, the displacement of each layer of the negative electrode current collector 24, the separator 26, and the positive electrode current collector 27 is effectively prevented by the binding force due to the fixing. Even when compared with the first to third embodiments, the most robust structure is obtained.
[0056]
In the present embodiment, since the separators 26 are fixed in the width direction, the width of the separators 26 needs to be wider than the width of the separators 26 of the first to third embodiments.
[0057]
In the fourth embodiment, the negative electrode current collector 24 is fixed at the four corners. However, the positive electrode current collector 27 may be fixed instead of the negative electrode current collector 24. Further, both the negative electrode current collector 24 and the positive electrode current collector 27 may be fixed. When both the negative electrode current collector 24 and the positive electrode current collector 27 are fixed, the size and shape of the current collectors and the fixing thereof are fixed so that the negative electrode current collector 24 and the positive electrode current collector 27 do not contact each other. Devise the position of the.
[Embodiment 5]
FIG. 11 is a front view showing the inside of the laminated secondary battery according to the fifth embodiment. In this embodiment, the stacked separators 26 are fixed by linear welding, welding or adhesion at both end portions 38 in the width direction.
[0058]
Thus, if it fixes along the edge of the separator 26 in the both ends 38 of the separator 26, compared with the case where only the electrical power collectors 24 and 27 are fixed like said Embodiment 1-3, the separator Since the number of layers of 26 is large, a more rigid structure can be obtained.
[0059]
In the case of this embodiment, as in the fourth embodiment, it is necessary to make the width of the separator 26 wider than the width of the separator 26 of the first to third embodiments. When the separator 26 is fixed, the negative electrode layer or the positive electrode layer can be formed over the entire width direction of the current collectors 24 and 27.
[0060]
In the above first to fifth embodiments, the two electrode terminals 14 as shown in FIG. 1 are taken out from the opposite end surfaces of the laminated secondary battery 10 and the entire periphery of the laminated film 12 is heat-sealed. The laminated secondary battery of the type to be joined was illustrated, but in the present invention, as shown in FIG. 12, two electrode terminals 14 are further taken out from the opposite end surfaces of the laminated secondary battery 10 and formed into a bag shape. The present invention can also be applied to a laminate secondary battery that is housed in a laminate film and heat-sealed at its opening. Further, as shown in FIG. 13, a laminate secondary battery of the type in which two electrode terminals 14 are taken out from the same side end face of the laminate secondary battery 10 and the entire peripheral portion of the laminate film 12 is joined by heat fusion. As shown in FIG. 14, the two electrode terminals 14 are taken out from the same side end surface of the laminated secondary battery 10 and stored in a bag-like laminated film, and the opening thereof is heat-sealed. It can also be applied to.
[0061]
In the present invention, at least two or more of the laminated secondary batteries 10 can be connected in series or in parallel to form an assembled battery module. Specifically, for example, as shown in FIG. 15, four laminated secondary batteries 10 are connected in parallel (see FIG. 15B), and four laminated secondary batteries 10 are arranged in parallel. The assembled battery module 40 can be made in series and housed in a metal assembled battery case 35 (see FIGS. 15A and 15C). Thus, the assembled battery module 40 which can respond | correspond to a desired electric current, voltage, and capacity | capacitance can be provided by connecting the arbitrary number of lamination | stacking secondary batteries 10 in series parallel.
[0062]
The positive terminal 42 and the negative terminal 44 of the assembled battery module 40 provided on the lid on the upper part of the assembled battery case 35 and the electrode terminals 14 and 14 of each laminated secondary battery 10 are the positive and negative electrodes of the assembled battery 40. Electrical connection is established using terminal lead wires 46 and 48. Further, when four laminated secondary batteries 10 are connected in parallel, the electrode terminals 14 of each laminated secondary battery 10 may be electrically connected using an appropriate connecting member such as a spacer 49 (see FIG. 15 (b)). Similarly, when the six laminated secondary batteries 10 arranged in parallel are further connected in series, the electrode terminals 14 and 14 of the laminated secondary batteries 10 using an appropriate connecting member such as the bus bar 50 are used. May be electrically connected sequentially (see FIG. 15C).
[0063]
However, the assembled battery module 40 of the present invention should not be limited to the one described here, and a conventionally known one can be appropriately employed. In addition, the assembled battery module 40 may be provided with various measuring devices and control devices depending on the intended use. For example, a voltage measurement is performed on the lid on the assembled battery case 35 in order to monitor the battery voltage. For example, a connector 55 may be provided, and the present invention is not particularly limited. Further, in order to connect the laminated secondary batteries 10 to each other, they may be connected by ultrasonic welding, heat welding, laser welding or electron beam welding, using a rivet, or using a caulking method. Good.
[0064]
Next, at least two or more of the above assembled battery modules are connected in series, in parallel, or in series and parallel to form an assembled battery, so that a new assembled battery module is produced to meet the battery capacity and output requirements for each purpose of use. Therefore, it becomes possible to cope with relatively low cost. As an assembled battery, for example, as shown in FIG. 16, in order to connect six assembled battery modules 40 in parallel to form an assembled battery 60, the assembled battery is provided on a lid at the top of each assembled battery case 35. The positive electrode terminal 42 and the negative electrode terminal 44 of the assembled battery module 40 are electrically connected using an external positive electrode terminal portion, an assembled battery positive electrode terminal connecting plate 62 having an external negative electrode terminal portion, and an assembled battery negative electrode terminal connecting plate 64, respectively. Further, a connecting plate 66 having an opening corresponding to the fixing screw hole portion is fixed to each screw hole portion (not shown) provided on both side surfaces of each assembled battery case 35 with a fixing screw 67, and The battery modules 40 are connected to each other. Further, the positive electrode terminal 42 and the negative electrode terminal 44 of each assembled battery module 40 are protected by positive and negative electrode insulating covers 68 and 69, respectively, and are identified by color-coding into appropriate colors, for example, red and blue.
[0065]
Thus, the assembled battery 60 in which a plurality of assembled battery modules 40 are connected in series and parallel can be repaired only by replacing the failed part even if some of the laminated secondary batteries 10 and the assembled battery module 40 fail. Is possible.
[0066]
In order to mount the assembled battery 60 on an electric vehicle, the battery pack 60 is mounted under the seat at the center of the vehicle body of the electric vehicle 70 as shown in FIG. This is because if it is installed under the seat, the interior space and the trunk room can be widened. The place where the battery is mounted is not limited to under the seat, but may be a lower part of the rear trunk room or an engine room in front of the vehicle.
[0067]
In the present invention, not only the assembled battery 60 but also an assembled battery module may be mounted depending on the usage, or the assembled battery 60 and the assembled battery module 40 may be mounted in combination. . In addition, as the vehicle on which the assembled battery 60 or the assembled battery module 40 of the present invention can be mounted, the above-described electric vehicle and hybrid car are preferable, but are not limited thereto.
[Brief description of the drawings]
FIG. 1 is an external view of a laminated secondary battery according to the present invention.
2 is a front view showing the inside of the laminated secondary battery shown in FIG. 1. FIG.
3 is a cross-sectional view taken along line AA of the laminated secondary battery shown in FIG.
4 is a cross-sectional view taken along line BB of the laminated secondary battery shown in FIG.
5 is a cross-sectional view taken along the line CC of the laminated secondary battery shown in FIG.
6 is a front view showing the inside of a laminated secondary battery according to a second embodiment; FIG.
7 is a cross-sectional view taken along line AA of the laminated secondary battery shown in FIG.
FIG. 8 is a front view showing the inside of the laminated secondary battery according to the third embodiment.
9 is a front view showing the inside of a laminated secondary battery according to Embodiment 4. FIG.
10 is a cross-sectional view taken along DD of the laminated secondary battery shown in FIG.
FIG. 11 is a front view showing the inside of a laminated secondary battery according to a fifth embodiment;
FIG. 12 is an external view of another type of laminated secondary battery according to the present invention.
FIG. 13 is an external view of another type of laminated secondary battery according to the present invention.
FIG. 14 is an external view of another type of laminated secondary battery according to the present invention.
FIG. 15 is a schematic view schematically showing a typical embodiment of the assembled battery module structure according to the present invention, (a) is a plan view thereof, (b) is a side view thereof, (C) is the front view.
FIG. 16 is a schematic view schematically showing a typical embodiment of an assembled battery structure according to the present invention.
FIG. 17 is a schematic view schematically showing a vehicle equipped with the assembled battery according to the present invention.
[Explanation of symbols]
10 ... laminated secondary battery,
12 ... Laminated film,
14 ... Electrode terminal,
20 ... Battery element,
22 ... negative electrode layer,
24 ... negative electrode current collector,
25. Lead wire,
26 ... separator,
27 ... Positive electrode current collector,
28, 29 ... junction,
30A-30D ... adhering part,
32 ... Rivets,
34, 36, 38 ... both ends,
35 ... assembled battery case,
40 ... assembled battery module,
42 ... positive terminal,
44 ... negative terminal,
46 ... Lead wire for positive terminal,
48 ... Lead wire for negative electrode terminal,
49 ... spacer,
50 ... Bus bar,
55 ... Connector for voltage measurement,
60 ... assembled battery,
62 ... assembled battery positive electrode terminal connecting plate,
64 ... assembled battery negative terminal connecting plate,
66 ... connecting plate,
67 ... Fixing screw,
68 ... positive electrode insulation cover,
69 ... negative electrode insulation cover,
70: Electric car.

Claims (12)

A current collector and a separator to be a positive electrode or a negative electrode are alternately stacked to form a rectangular battery element when viewed from the stacking direction, two electrode terminals are taken out from the battery element in a facing direction, A laminate secondary battery that is packaged with a laminate film in which a polymer and a metal are combined,
A laminated secondary battery, wherein at least one of positive electrodes, negative electrodes, or separators constituting the battery element is locally fixed in the stacking direction at four corners of the battery element.   The laminated secondary battery according to claim 1, wherein the fixing is performed by welding, welding, or adhesion.   The laminated secondary battery according to claim 1, wherein the fixing is performed by riveting.   The laminated secondary battery according to claim 2, wherein the welding is heat welding.   The laminated secondary battery according to claim 2, wherein the welding is ultrasonic welding.   The laminated secondary battery according to claim 1 is characterized in that while the laminate film is heat-sealed, the air inside the laminate film is extracted and decompressed, and the battery element is vacuum packaged. .   The said separator has an area larger than the area of the said negative electrode layer so that the whole negative electrode layer currently formed in the electrical power collector used as the said negative electrode can be covered. The laminated secondary battery as described.   The laminated secondary battery according to claim 1, wherein the current collector serving as the positive electrode has an area smaller than the area of the separator so as to be entirely covered by the separator.   The laminated secondary battery according to claim 1, wherein a conductive material is also bound to the current collector serving as the positive electrode in order to improve conductivity.   The assembled battery module in which the laminated secondary battery in any one of Claims 1-9 is connected in multiple parallel connection, series connection, or series-parallel connection.   An assembled battery comprising a plurality of the assembled battery modules according to claim 10 connected in parallel, connected in series or connected in series and parallel.   An electric vehicle comprising the laminated secondary battery according to any one of claims 1 to 9, the assembled battery module according to claim 10, and the assembled battery according to claim 11.

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