JP2004158344A - Laminate secondary battery, battery pack modules composed of two or more laminate secondary batteries, battery pack composed of two or more battery pack modules as well as electric automobile equipped with either of these batteries - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the ocurring of position shift of a laminated electrode. <P>SOLUTION: This is a laminated secondary battery (10) in which a battery element (20) is formed by alternately laminating positive electrode current collectors and negative electrode current collectors (24) via separators (26) and the battery element is packed by a laminated film (12), and the negative electrode current collectors constituting the battery element are mutually fixed to the fixing parts (30A to 30D) at four corners of the electrode element in its laminating direction. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a laminated secondary battery in which the laminated electrodes do not cause displacement, an assembled battery module including a plurality of the laminated secondary batteries, an assembled battery including a plurality of the assembled battery modules, and any one of these. The present invention relates to an electric vehicle equipped with a battery.
[0002]
[Prior art]
Due to increasing awareness of global environmental issues, the automotive industry hastened the development of 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 higher voltage than a 12 V or 24 V battery generally used at present is used. In order to obtain a high voltage, it is necessary to stack a large number of electrodes. The battery described in Patent Literature 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. I have. The battery described in Patent Literature 2 below is a stacked polymer electrolyte battery in which a large number of flat electrodes are stacked. In this battery, a plurality of stacked electrodes are restrained by an outer package or a sealing portion. are doing.
[0003]
[Patent Document 1]
JP 2001-185224 A (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 disclosed in Patent Document 1, the electrodes can be fixed in a cross shape as described above, but a flat battery as described in Patent Document 2 In this case, the electrodes are not positively fixed. In the case of a flat battery, the electrodes are only temporarily fixed by the compressive force of the outer package and locally only by the sealing portion.
[0005]
If the voltage required for the battery is not too high, the number of electrodes to be stacked is small, so that the displacement of the electrodes can be prevented to some extent even with a compressive force from the outer package or a local fixation at the sealing portion. However, as the required voltage increases and the number of stacked electrodes increases, it becomes impossible to prevent electrode displacement unless the stacked electrodes are positively fixed. Displacement of the electrodes may cause various problems that cannot be expected at the beginning of manufacturing, such as a decrease in battery capacity and deterioration of battery characteristics.
[0006]
Since the power battery of the EV or the HEV is always mounted on the vehicle body where vibration is generated, it is particularly important how to prevent the electrode from being displaced for a long time in this battery.
[0007]
The present invention has been made in order to solve the conventional problems as described above, and has a structure in which laminated electrodes do not cause displacement of a laminated secondary battery, and a plurality of the laminated secondary batteries. , An assembled battery including a plurality of the assembled battery modules, and an electric vehicle equipped with 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 by alternately stacking a current collector and a separator serving as a positive electrode or a negative electrode, and forming the battery element. A laminated secondary battery packaged with a laminated film of a polymer and a metal, wherein at least one of the positive electrodes or the negative electrodes or the separators constituting the battery element is fixed in the laminating direction. It is characterized by. If the positive electrodes are fixed to each other 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 displacement of the stacked electrodes.
[0009]
It is desirable to fix the positive electrodes or the negative electrodes by welding, welding or bonding. The fixing can also be performed by riveting. If the battery element is rectangular when viewed from the stacking direction, it is preferable that the fixing is performed at four corners of the battery element. It is preferable to use heat welding for fixing the positive electrode or the negative electrode to each other. Further, it is desirable to use ultrasonic welding for welding for fixing the positive electrode or the negative electrode.
[0010]
Furthermore, if the separators are fixed in the laminating direction, the displacement of the electrodes can be prevented more reliably. The fixing of the separators is desirably performed by welding, welding or bonding linearly inside the two opposing sides of the separator along the respective sides. It is desirable to use heat welding for fixing the separators.
[0011]
If the assembled battery module is configured by connecting a plurality of the laminated secondary batteries according to the present invention in parallel, in series or in series / parallel, the assembled battery can maintain stable battery performance even when vibration or thermal stress is applied for a long period of time. Module can be provided.
[0012]
Furthermore, if a plurality of assembled battery modules according to the present invention are connected in parallel, in series or in series / parallel to form an assembled battery, an assembled battery capable of maintaining stable battery performance even when subjected to vibration or thermal stress for a long period of time. Can be provided.
[0013]
Then, when any one 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 for a long period, an electric power having a stable power source is provided. 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 laminating direction, displacement of the electrodes can be prevented, various vibrations are applied over a long period of time, and thermal stress is reduced. Even if added, stable battery performance can be obtained.
[0015]
Further, according to the battery module or battery module of the present invention, stable battery performance can be maintained even when vibration or thermal stress is applied over 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 of an electric vehicle, stable power performance can be maintained for a long time.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
With reference to the accompanying drawings, a laminated secondary battery according to the present invention, an assembled battery module including a plurality of laminated secondary batteries, an assembled battery including a plurality of assembled battery modules, and an electric vehicle equipped with any one of these batteries A preferred embodiment will be described in detail. It should be noted that the present invention is not limited to the embodiments described below, and can be implemented with appropriate modifications within a range included in the technical idea of the present 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 is formed by alternately laminating a current collector serving as a positive electrode or a negative electrode and a separator to form a battery element, and packaging the battery element with a laminate film in which a polymer and a metal are combined. A laminate secondary battery according to any one of claims 1 to 3, characterized in that either the positive electrodes or the negative electrodes constituting the battery element are fixed in the laminating 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 composed of a polymer-metal composite laminated film 12 and laminates positive and negative electrode terminals 14 connected to the battery element. The battery element is exposed to the outside from the opposite direction of the film 12, and the inside of the laminate film 12 is heat-sealed while removing the air therein to reduce the pressure. The battery element is vacuum-packaged.
[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 located on the lower side. The configuration of this battery element is as shown in FIG. The battery element 20 is formed by alternately stacking a current collector serving as a positive electrode or a negative electrode and a separator.
[0021]
In FIG. 2, when the inside of the battery is viewed from the stacking direction, first, a sheet-shaped negative electrode layer 22 can be seen at the top. The negative electrode layer 22 is formed on both surfaces of a sheet-shaped negative electrode current collector 24 formed of a copper material. A separator 26 is located 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 surfaces thereof is located below the separator 26. In this way, in FIG. 2, the battery element 20 includes a plurality of negative electrode current collectors and a positive electrode current collector 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, all the positive electrode current collectors have electrode terminals 14 attached 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 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 the ultrasonic welding is that this welding has less burrs than other welding, and there is almost no possibility of an internal short circuit with the laminated film 12.
[0023]
Laminated secondary battery 10 according to the present invention, the negative electrode current collector, the separator, the positive electrode current collector, so that no displacement between each other, between the negative electrode current collectors or between the positive electrode current collectors 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 for a long period of time, displacement of the stacked electrodes is prevented, and expansion of the battery element 20 can be suppressed to some extent. it can.
[0024]
Fixing between the positive electrode current collectors or between the negative electrode current collectors can be performed by welding, welding, or adhesion. Specifically, it is desirable to use heat welding. Specifically, it is desirable to use ultrasonic 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 lamination 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 thermal welding.
[0026]
The battery element 20 placed on the lower laminate film 12 is covered with the laminate film 12 from above, and the periphery of the laminate film 12 is depressurized by removing air while heat-sealing the periphery of the laminate film 12. Seal 20.
[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 a sectional view taken along line AA of the laminated secondary battery shown in FIG. 2, FIG. 4 is a sectional view taken along line BB 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 sectional views, the battery element 20 includes, from the top, 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. 26, and the negative electrode current collector 24 are stacked in this order. As shown in FIG. 2, the length of the negative electrode current collector 24 in the vertical direction (the direction between the electrode terminals 14) is the same as that of the fixing portion 30 </ b> A except for a cutout portion for connecting the positive electrode current collector 27 to the electrode terminal 14. , 30 </ b> B, 30 </ b> C, and 30 </ b> D are longer than the vertical length of the separator 25 so that sufficient areas can be obtained. On both surfaces of the negative electrode current collector 24, the negative electrode layer 22 is formed over the entire width direction except for regions 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 by the separator 26.
[0030]
Each of the negative electrode current collectors 24 is bundled in a region where the electrode terminal 14 is connected, as shown in FIGS. 3 and 5, and fixed at four corners of the negative electrode current collector 24 at the fixing portions 30A, 30B, 30C, and 30D. The bundled negative electrode current collectors 24 are fixed to each other. This fixing is performed by ultrasonic welding or thermal 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 28 thereof 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 collectively connected at a joint 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 fixing.
[0032]
In the first embodiment, the negative electrode current collector 24 is fixed at the four corners by ultrasonic welding or thermal 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. In the case where 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 of the current collectors are so set that the negative electrode current collector 24 and the positive electrode current collector 27 do not contact each other. And the like must be different from those in the present embodiment, but how to fix them can be easily considered by those skilled in the art.
[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. Among these, a lithium ion secondary battery excellent in output and energy density is preferable in consideration of use as a power source for an electric vehicle. When a laminated secondary battery, which is a lithium ion secondary battery, is connected in series to provide a power supply for an electric vehicle, it is possible to obtain an assembled battery having an overall output voltage of about 400 V.
[0034]
In the laminated secondary battery of the present invention, the materials constituting the laminated film 12, the electrode terminals 14, the positive electrode current collector 27, the separator 26, and the negative electrode current collector 24 may be known materials, and are particularly limited. is not. For reference, the case where the laminated secondary battery of the present invention is a lithium ion secondary battery will be briefly described below. However, the laminated secondary battery of the present invention is not limited to a lithium ion secondary battery.
[0035]
[Positive electrode layer]
The sheet-shaped positive electrode layer constituting the positive electrode of the battery element 20 has a width substantially equal to the width of the battery element 20, and has a structure in which a positive electrode material is bound to both surfaces of a positive electrode current collector 27 made of aluminum or the like. Having. As the cathode material, various oxides (LiMn ₂ O ₄ Lithium manganese oxide; manganese dioxide; LiNiO ₂ Such as lithium nickel oxide; LiCoO ₂ Lithium cobalt oxide; lithium-containing nickel cobalt oxide; amorphous vanadium pentoxide containing lithium and the like; and chalcogen compounds (titanium disulfide, molybdenum disulfide and the like). Among these, lithium manganese oxide or lithium nickel oxide is preferable in consideration of the output characteristics of the obtained lithium ion secondary battery.
[0036]
A conductive material may be bound to the positive electrode current collector 27 in order to improve conductivity. Examples of the conductive material include artificial graphite, carbon black (eg, acetylene black), nickel powder, and the like.
[0037]
As the positive electrode current collector 27, for example, aluminum expanded metal, aluminum mesh, aluminum punched metal, or the like can be used. Note that 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-shaped 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 has substantially the same width as the width of the battery element 20, and is formed of a negative electrode current collector 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 stores and releases lithium ions can be used. As such a carbon material, natural graphite, artificial graphite, carbon black, activated carbon, carbon fiber, coke, and an organic precursor (for example, phenol resin, polyacrylonitrile, cellulose, etc.) were synthesized by heat treatment in an inert atmosphere. Carbon and the like. Preferably, the negative electrode is made of an amorphous carbon-based material. An amorphous carbon-based material is obtained by carbonizing a thermosetting resin. Incidentally, when an amorphous carbon-based 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. Note that the negative electrode may have a structure in which a negative electrode material is bonded to one surface of the negative electrode current collector 24.
[0040]
[Separator layer]
The sheet-shaped separator layer constituting the separator 26 of the battery element 20 has a width substantially equal to the width of the battery element 20, and a polyolefin-based microporous separator, for example, polyethylene or polypropylene can be used. A non-aqueous electrolyte is impregnated in the separator. The non-aqueous electrolyte is prepared by dissolving the electrolyte in a non-aqueous solvent. Examples of the non-aqueous solvent include ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), and γ-butyrolactone (γ-BL). ), Sulfolane, acetonitrile, 1,2-dimethoxyethane, 1,3-dimethoxypropane, dimethyl ether, tetrahydrofuran (THF), 2-methyltetrahydrofuran and the like. The non-aqueous solvents may be used alone or as a mixture of two or more. As the electrolyte, for example, lithium perchlorate (LiClO ₄ ), Lithium hexafluorophosphate (LiPF) ₆ ), Lithium boron tetrafluoride (LiBF ₄ ), Lithium arsenic hexafluoride (LiAsF) ₆ ), Lithium trifluoromethanesulfonate (LiCF ₃ SO ₃ ), Lithium bistrifluoromethylsulfonylimide [LiN (CF ₃ SO ₃ ) ₂ ] And the like. The amount of the electrolyte dissolved in the nonaqueous solvent is usually about 0.2 mol / L to 2 mol / L.
[0041]
Examples of the polymer that holds the non-aqueous electrolyte 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. Generally, a polymer-metal composite film in which a heat-fusible resin film, a metal foil, and a rigid resin film are laminated in this order is used.
[0043]
As the heat-fusible resin, for example, polyethylene (PE), ionomer, ethylene vinyl acetate (EVA) and the like can be used. As the metal foil, for example, an Al foil or a Ni foil can be used. As the resin having rigidity, for example, polyethylene terephthalate (PET), nylon or the like can be used. Specifically, a laminated film of PE / Al foil / PET laminated from the sealing surface side to the outer surface; a laminated film of PE / Al foil / Nylon; a laminated film of ionomer / Ni foil / PET; EVA / Al foil / A PET laminated film; an ionomer / Al foil / PET laminated film or the like can be used. The heat-fusible resin film functions as a seal layer when the battery element is housed inside. A metal foil or a rigid resin film imparts moisture, air resistance, and chemical resistance to the exterior material. The laminate film can be easily and reliably joined by 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 also be used. Nickel is most preferably used for the surface coating layer, but metal materials such as silver and gold can also be used. 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 with the improvement of the sealing property. Specifically, the width of the electrode terminal 14 can be set within a range of 20% to 100% of the width of the current collector. If the width of the electrode terminal 14 can be widened, 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]
FIG. 6 is a front view showing the inside of the laminated secondary battery according to the second embodiment, and FIG. 7 is a sectional view of the laminated secondary battery taken along line AA of FIG. The sectional view taken along the line BB 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 the material of the rivet, a material that is well compatible with the material of the negative electrode current collector 24, has chemical stability to the battery element 20, and is easily deformed plastically is used.
[0046]
Holes for penetrating the rivets 32 are formed at four corners of the negative electrode current collector 24. In this embodiment, except that the negative electrode current collectors 24 are fixed to each other with rivets 32, and holes are formed at four corners of the negative electrode current collector 24 to allow the rivets 32 to pass therethrough. Since it is exactly the same as 1, the detailed description is omitted. In the case where the negative electrode current collectors 24 are fixed with the rivets 32, the work efficiency is improved as compared with the case where the negative electrode current collectors 24 are fixed by welding, welding and bonding as in Embodiment 1, and an expensive device is not required. It is.
[0047]
In the present embodiment, the respective negative electrode current collectors 24 are bundled in a region where the electrode terminals 14 are connected as shown in FIG. 24 are caulked and fixed with rivets 32 from both sides thereof. After fixing the negative electrode current collector 24, as shown in FIGS. 4 and 6, the negative electrode current collector 24 and the electrode terminal 14 are welded at their joints 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 collectively connected at a joint 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 fixing.
[0049]
In the second embodiment, the negative electrode current collector 24 is fixed at the four corners with 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. In the case where 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 their fixing are so set that the negative electrode current collector 24 and the positive electrode current collector 27 do not come into contact with each other. Must be different from that in the present embodiment, but how to fix it can be easily considered by those skilled in the art.
[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 linearly welded, welded, or bonded at both ends 34 in the width direction.
[0050]
As described above, when the fixing is performed at the both ends 34 of the negative electrode current collector 24 along the edge of the negative electrode current collector 24, the fixing is locally (four points) as in the first and second embodiments. In comparison, the negative electrode current collectors 24 can be fixed more firmly.
[0051]
In the case of this embodiment, the width of the negative electrode current collector 24 needs to be wider than the width of the negative electrode current collector 24 of the first and second embodiments. The size of the negative electrode layer 22 formed on both surfaces of the negative electrode current collector 24 is the size of the area excluding the width of the fixing of the negative electrode current collector 24 in the width direction and the bonding margin of the electrode terminals 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 in the related art, and the positive electrode current collector 27 and the electrode terminal 14 are similarly connected.
[0053]
In the third embodiment, the form in which the negative electrode current collector 24 is fixed has been illustrated, but a 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 the fourth embodiment, and FIG. 10 is a cross-sectional view of the laminated secondary battery shown in FIG. The sectional view taken along the line BB of the laminated secondary battery shown in FIG. 9 is the same as FIG. In this embodiment, the negative electrode current collectors 24 are fixed together, and the separators 26 are also fixed together. The fixing of the negative electrode current collectors 24 is exactly the same as that of the first embodiment, and the 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, the stacked separators 26 are linearly welded, welded, or bonded at both ends 36 in the width direction thereof. It is fixed.
[0055]
As described above, when the both ends 36 of the separator 26 are fixed along the edge of the separator 26, the negative electrode dielectric 24 is fixed linearly at the four corners and 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. The structure is the strongest compared to the first to third embodiments.
[0056]
In the present embodiment, since the separators 26 are fixed to each other in the width direction, the width of the separator 26 needs to be wider than the width of the separator 26 of the first to third embodiments.
[0057]
In the fourth embodiment, the negative electrode current collector 24 is fixed at the four corners, but 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. In the case where 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 their fixing are so set that the negative electrode current collector 24 and the positive electrode current collector 27 do not come into contact with each other. Devise the position of
[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 linearly welded, welded or bonded at both ends 38 in the width direction.
[0058]
As described above, when the fixing is performed along the edge of the separator 26 at the both end portions 38 of the separator 26, compared with the case where only the current collectors 24 and 27 are fixed as in the first to third embodiments, the separator A more rigid structure can be achieved by increasing the number of layers of 26.
[0059]
In the case of this embodiment, similarly to the fourth embodiment, the width of the separator 26 needs to be wider than the width of the separator 26 of the first to third embodiments. When the separator 26 is fixed, a negative electrode layer or a positive electrode layer can be formed over the entire current collectors 24 and 27 in the width direction.
[0060]
In the first to fifth embodiments, the two electrode terminals 14 as shown in FIG. 1 are taken out from the opposite end faces of the laminated secondary battery 10 and the entire peripheral portion of the laminated film 12 is heat-sealed. Although a laminated type secondary battery of a joining type is illustrated, the present invention further takes out two electrode terminals 14 from the opposite end faces of the laminated secondary battery 10 as shown in FIG. The present invention is also applicable to a laminated secondary battery of a type that is housed in a laminate film and the opening is thermally fused. Also, as shown in FIG. 13, a laminated secondary battery of a type in which two electrode terminals 14 are taken out from the same side end surface of the laminated secondary battery 10 and the entire peripheral portion of the laminated film 12 is joined by heat fusion. As shown in FIG. 14, two electrode terminals 14 are taken out from the same side end surface of the laminated secondary battery 10 and stored in a bag-shaped laminated film, and the opening thereof is heat-sealed to form a laminated secondary battery. It is also applicable.
[0061]
In the present invention, at least two or more of the above laminated secondary batteries 10 are connected in series or in parallel to form a battery module. Specifically, for example, as shown in FIG. 15, four laminated secondary batteries 10 are connected in parallel (see FIG. 15B), and the four laminated secondary batteries 10 are further connected. The assembled battery module 40 can be stored in a metal assembled battery case 35 in series (see FIGS. 15A and 15C). As described above, by connecting the laminated secondary batteries 10 in an arbitrary number in series and parallel, it is possible to provide the assembled battery module 40 capable of coping with a desired current, voltage and capacity.
[0062]
Note that the positive terminal 42 and the negative terminal 44 of the battery module 40 provided on the lid body above the battery case 35 and the electrode terminals 14 of each laminated secondary battery 10 are the positive electrode and the negative electrode of the battery 40. They are electrically connected using terminal lead wires 46 and 48. 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. 4). 15 (b)). Similarly, when connecting four laminated secondary batteries 10 in parallel to each other, six more are connected in series using an appropriate connecting member such as a bus bar 50. May be sequentially electrically connected (see FIG. 15C).
[0063]
However, the assembled battery module 40 of the present invention is not limited to the one described here, and a conventionally known one can be appropriately used. The assembled battery module 40 may be provided with various measuring devices and control devices according to the intended use. For example, the lid on the upper part of the assembled battery case 35 measures the voltage to monitor the battery voltage. There is no particular limitation, for example, a connector 55 may be provided. 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, or by using a rivet, or by using a caulking method. Good.
[0064]
Next, at least two or more of the above assembled battery modules are connected in series, parallel or series-parallel to form an assembled battery, and a new assembled battery module is produced according to the demand for battery capacity and output for each purpose of use. It is possible to respond relatively inexpensively. As shown in FIG. 16, for example, as shown in FIG. 16, in order to connect the above six assembled battery modules 40 in parallel to form an assembled battery 60, the assembled battery modules 40 are provided on a lid above each assembled battery case 35. The positive terminal 42 and the negative terminal 44 of the battery module 40 are electrically connected using a battery positive terminal connecting plate 62 and a battery negative terminal connecting plate 64 having an external positive terminal and an external negative terminal, respectively. A connection plate 66 having an opening corresponding to the fixing screw hole is fixed to each screw hole (not shown) provided on both side surfaces of each battery pack case 35 with fixing screws 67. The battery modules 40 are connected to each other. In addition, the positive electrode terminal 42 and the negative electrode terminal 44 of each battery module 40 are protected by positive and negative electrode insulating covers 68 and 69, respectively, and are identified by being classified into appropriate colors, for example, red and blue.
[0065]
In this manner, the assembled battery 60 in which a plurality of assembled battery modules 40 are connected in series and parallel is repaired only by replacing the failed part even if some of the laminated secondary batteries 10 and the assembled battery module 40 fail. It is possible.
[0066]
In order to mount the battery pack 60 on an electric vehicle, as shown in FIG. This is because if installed below the seat, the interior space and the trunk room can be widened. The place where the battery is mounted is not limited to below the seat, but may be below the rear trunk room or in the 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 intended use, or the assembled battery 60 and the assembled battery module 40 may be mounted in combination. . Further, 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 or hybrid car is preferable, but is not limited thereto.
[Brief description of the drawings]
FIG. 1 is an external view of a laminated secondary battery according to the present invention.
FIG. 2 is a front view showing the inside of the laminated secondary battery shown in FIG.
FIG. 3 is a sectional view taken along line AA of the laminated secondary battery shown in FIG.
FIG. 4 is a cross-sectional view of the laminated secondary battery taken along line BB of FIG. 2;
FIG. 5 is a cross-sectional view of the laminated secondary battery taken along line CC of FIG. 2;
FIG. 6 is a front view showing the inside of the laminated secondary battery according to the second embodiment;
7 is a cross-sectional view of the laminated secondary battery shown in FIG. 6 taken along the line AA.
FIG. 8 is a front view showing the inside of the laminated secondary battery according to the third embodiment;
FIG. 9 is a front view showing the inside of the laminated secondary battery according to the fourth embodiment.
FIG. 10 is a sectional view taken along line DD of the laminated secondary battery shown in FIG.
FIG. 11 is a front view showing the inside of the laminated secondary battery according to the 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, wherein (a) is a plan view thereof, (b) is a side view thereof, (C) is the front view.
FIG. 16 is a schematic diagram schematically showing a typical embodiment of a battery pack structure according to the present invention.
FIG. 17 is a schematic diagram schematically showing a vehicle equipped with the battery pack according to the present invention.
[Explanation of symbols]
10. Laminated secondary battery,
12 ... Laminated film,
14 ... electrode terminals,
20 ... battery element,
22 ... negative electrode layer,
24 ... negative electrode current collector,
25 ... lead wire,
26 ... separator
27 ... positive electrode current collector,
28, 29 ... joint,
30A-30D: fixed part,
32 ... rivets,
34, 36, 38 ... both ends,
35 ... Battery case,
40 ... battery module,
42 ... positive terminal,
44 ... negative electrode terminal,
46 ... lead wire for positive terminal
48 lead wire for negative electrode terminal
49 ... spacer,
50 ... Bus bar,
55 ... voltage measurement connector
60 ... battery pack,
62 ... battery assembly positive terminal connecting plate,
64 ... battery negative electrode terminal connecting plate,
66 ... connecting plate,
67 ... fixing screw,
68 ... Positive insulating cover,
69 ... Negative electrode insulating cover,
70 ... Electric vehicle.

Claims (13)

A laminated secondary battery in which a battery element is formed by alternately laminating a current collector serving as a positive electrode or a negative electrode and a separator, and the battery element is packaged with a laminate film in which a polymer and a metal are combined. ,
A laminated secondary battery, wherein at least one of the positive electrodes, the negative electrodes, and the separators constituting the battery element is fixed in the laminating direction. The laminated secondary battery according to claim 1, wherein the fixing is performed by welding, welding, or bonding. The said secondary battery is fixed by riveting, The laminated secondary battery of Claim 1 characterized by the above-mentioned. The laminated secondary battery according to claim 1, wherein the fixing is performed at four corners of the battery element if the battery element is a quadrangle when viewed from the stacking direction. 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 any one of claims 1 to 6, wherein the separators are fixed in the laminating direction. The laminated secondary battery according to claim 7, wherein the fixing of the separators is performed by linearly welding, welding, or bonding the inside of two opposite sides of the separator along each side. . The laminated secondary battery according to claim 8, wherein the welding is heat welding. The laminated secondary battery according to claim 8, wherein the welding is ultrasonic welding. An assembled battery module comprising a plurality of the laminated secondary batteries according to claim 1 connected in parallel, in series, or in series / parallel. An assembled battery comprising a plurality of the assembled battery modules according to claim 11 connected in parallel, in series, or in series / parallel. An electric vehicle, comprising the laminated secondary battery according to any one of claims 1 to 10, the assembled battery module according to claim 11, and the assembled battery according to claim 12.

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