JP4182858B2 - Secondary battery and assembled battery - Google Patents

Description

  The present invention relates to a secondary battery in which electrode plates are stacked via a separator, accommodated in an exterior member and sealed, and electrode terminals are led out from an outer peripheral edge of the exterior member.

  Conventionally, an electrode plate laminated via a separator is housed and sealed in a three-layer exterior member in which a metal layer is sandwiched between two resin layers, and an electrode terminal connected to the electrode plate is exteriorly provided. A secondary battery derived from the outer peripheral edge of a member is known (see, for example, Patent Document 1).

In such a secondary battery, heat radiation of the secondary battery is performed by laminating a metal flat heat sink on the exterior member, but the end of the exterior member is simply cut and the end surface of the metal layer Is exposed to the outside, and the end face of the metal layer of the exterior member and the metal heat sink come into contact with each other, and there is a possibility that the secondary battery having a potential and the heat sink may conduct, and the electrical insulation of the secondary battery There is a risk that the sex cannot be maintained.
JP 2003-187857 A

An object of this invention is to provide the secondary battery excellent in the electrical insulation with the exterior.
In order to achieve the above object, according to the present invention, an electrode laminate having an electrode plate laminated via a separator, an exterior member that accommodates and seals the electrode laminate, and the electrode laminate A secondary battery comprising: an electrode terminal that is connected and partly led out from an outer peripheral edge of the exterior member; and a heat radiating means having conductivity laminated on the exterior member, wherein the electrode terminal is the A secondary battery in which the heat dissipation means is shorter than the exterior member in a direction perpendicular to the direction derived from the exterior member is provided.

In order to achieve the above object, according to the present invention, an electrode laminate having electrode plates laminated via separators, an exterior member that accommodates and seals the electrode laminate, and the electrode laminate Two or more secondary batteries connected to the body and having electrode terminals partially derived from the outer peripheral edge of the exterior member, and at least one conductive heat dissipation layered on the exterior member of each secondary battery Provided that the heat dissipation means is shorter than the exterior member of each secondary battery in a direction orthogonal to the direction in which the electrode terminal is led out from the exterior member. Is done.

In the present invention , the heat radiating means is made shorter than the exterior member in the direction orthogonal to the direction in which the electrode terminal is led out from the exterior member. As a result, the end surface of the metal layer of the exterior member does not reach the heat dissipation means, and contact between the end surface of the metal layer and the heat dissipation means having conductivity is prevented, so that the end surface of the metal layer of the exterior member is exposed to the outside. Even in this case, it is possible to maintain the insulation of the secondary battery with respect to the heat radiating means, and it is possible to provide a secondary battery excellent in electrical insulation from the outside.

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

  FIG. 1 is a plan view of an entire secondary battery according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of the secondary battery taken along line II-II in FIG. 1 and 2 show one secondary battery 10 (unit battery), and a plurality of the secondary batteries 10 are stacked and connected to form an assembled battery having a desired voltage and capacity.

  First, a secondary battery 10 according to an embodiment of the present invention will be described. The secondary battery 10 is a lithium-based thin secondary battery, and includes three positive electrode plates as shown in FIGS. 1 and 2. 102, electrode separator 101 having seven separators 103 and three negative electrodes 104, positive electrode terminal 105 and negative electrode terminal 106 respectively connected to electrode laminate 101, and electrode power generator 101 and electrodes It comprises an upper exterior member 107 and a lower exterior member 108 that house and seal the terminals 105 and 106, and an electrolyte (not shown).

  The positive electrode plate 102 constituting the electrode laminate 101 includes a positive electrode current collector 102a extending to the positive electrode terminal 105 and a positive electrode layer (not shown) formed on a part of the main surface of the positive electrode current collector 102a. ). The positive electrode layer of the positive electrode plate 102 is not formed over the entire positive electrode side current collector 102a. When the electrode laminate 101 is configured as shown in FIG. Are formed only in the overlapping part.

  The positive electrode side current collector 102 a of the positive electrode plate 102 is an electrochemically stable metal foil such as an aluminum foil, an aluminum alloy foil, a copper foil, or a nickel foil having a thickness of about 20 μm.

The positive electrode layer of the positive electrode plate 102 is a mixture of a positive electrode active material such as a metal oxide, a conductive agent such as carbon black, and an adhesive such as an aqueous dispersion of polytetrafluoroethylene. It is formed by applying to a part of the main surface of the side current collector 102a, drying and rolling. Examples of the positive electrode active material include lithium composite oxides such as lithium nickelate (LiNiO ₂ ), lithium manganate (LiMnO ₂ ), and lithium cobaltate (LiCoO ₂ ), and chalcogen (S, Se, Te) compounds. Etc. can be mentioned. These materials are relatively easy to dissipate the heat generated in the secondary battery, and can suppress the stress accompanying expansion due to the heat generated in the secondary battery. It is particularly effective.

  The negative electrode plate 104 constituting the electrode laminate 101 includes a negative electrode side current collector 104a extending to the negative electrode terminal 106 and a negative electrode layer (non-deposited) formed on both main surfaces of a part of the negative electrode side current collector 104a. (Shown). The negative electrode layer of the negative electrode plate 104 is not formed over the entire negative electrode side current collector 104a, but when the electrode laminate 101 is configured as shown in FIG. In addition, the separator 103 is formed only in the portion where the separator 103 substantially overlaps in the negative electrode plate 104.

  The negative electrode side current collector 104a of the negative electrode plate 104 is an electrochemically stable metal foil such as a nickel foil, a copper foil, a stainless steel foil, or an iron foil having a thickness of about 10 μm.

  Further, the negative electrode layer of the negative electrode plate 104 includes, for example, a negative electrode active material that occludes and releases lithium ions of the positive electrode active material such as amorphous carbon, non-graphitizable carbon, graphitizable carbon, or graphite. Mainly a substance in which an aqueous dispersion of a styrene butadiene rubber resin powder as a precursor material of an organic fired body is mixed with a substance, dried, and pulverized to carry carbonized styrene butadiene rubber on the surface of carbon particles. The material is formed by further mixing a binder such as an acrylic resin emulsion with the mixture, applying the mixture to both main surfaces of a part of the negative electrode current collector 104a, and drying and rolling.

  In particular, if amorphous carbon or non-graphitizable carbon is used as the negative electrode active material, the flatness of the potential during charge / discharge is poor, and the output voltage decreases with the amount of discharge. Is not suitable, but it is advantageous when used as a power source for an electric vehicle because there is no sudden drop in output.

  The separator 103 of the electrode laminate 101 prevents the short circuit between the positive electrode plate 102 and the negative electrode plate 104 described above, and may have a function of holding an electrolyte. The separator 103 is a microporous film made of, for example, a polyolefin such as polyethylene (PE) or polypropylene (PP) having a thickness of about 25 μm. Has a function of blocking the current.

  The separator of the present invention is not limited to a single-layer film such as polyolefin, but a three-layer structure in which a polypropylene film is sandwiched with a polyethylene film, or a laminate of a polyolefin microporous film and an organic nonwoven fabric can also be used. By forming the separator in multiple layers, various functions such as an overcurrent prevention function, an electrolyte holding function, and a separator shape maintenance (rigidity improvement) function can be provided.

As shown in FIG. 2, the electrode laminate 101 has the positive plates 102 and the negative plates 104 alternately laminated via the separators 103, and the separators 103 are laminated on the uppermost layer and the lowermost layer, respectively. and has a width W ₁ as a whole. The three positive plates 102 are respectively connected to the positive terminal 105 made of metal foil via the positive current collector 102a, while the three negative plates 104 are connected to the negative current collector 104a. To the negative electrode terminal 106 made of metal foil.

The positive electrode plate 102, the separator 103, and the negative electrode plate 104 of the electrode laminate 101 are not limited to the above number in the present invention. For example, one positive electrode plate 102, three separators 103, and The electrode laminate 101 can also be configured with a single negative electrode plate 104, and the number of positive electrode plates, separators, and negative electrode plates can be selected as necessary. The width W ₁ of the electrode stack 101, the capacity and the positive electrode plate is required to the secondary battery, is set according to the number of sheets of separators and the negative electrode plate.

  The positive electrode terminal 105 and the negative electrode terminal 106 are not particularly limited as long as they are electrochemically stable metal foils. Examples of the positive electrode terminal 105 include an aluminum foil having a thickness of about 0.2 mm, an aluminum alloy foil, a copper foil, or And nickel foil. Examples of the negative electrode terminal 106 include a nickel foil, a copper foil, a stainless steel foil, or an iron foil having a thickness of about 0.2 mm. These metals are suitable as a constituent element of a secondary battery in terms of the resistance value, linear expansion coefficient, and resistivity of the metal, and particularly can suppress the stress accompanying expansion due to heat generation in the secondary battery. This is particularly effective for a thin secondary battery as in this embodiment.

  In this embodiment, the electrode plates 102 and 104 are directly connected to the electrode terminals 105 and 106 by extending the metal foil itself constituting the current collectors 102a and 104a of the electrode bodies 102 and 104 to the electrode terminals 105 and 106. Although connected, the current collectors 102a and 104a of the electrode plates 102 and 104 and the electrode terminals 105 and 106 are connected by a material or a part different from the metal foil constituting the current collectors 102a and 104a. Also good.

  The electrode laminate 101 configured as described above is housed and sealed in the upper exterior member 107 and the lower exterior member 108. As shown in FIG. 2, the upper exterior member 107 and the lower exterior member 108 in this embodiment both have a cup shape with a convex portion that accommodates the electrode stack 101, and are not particularly illustrated. And toward the outside of the secondary battery 10, for example, an inner layer composed of a resin film excellent in electrolytic solution resistance and heat fusion properties such as polyethylene, modified polyethylene, polypropylene, modified polypropylene, or ionomer For example, a three-layer structure of an intermediate layer made of a metal foil such as an aluminum foil and an outer layer made of a resin film having an excellent electrical insulation property such as a polyamide resin or a polyester resin It has become. Therefore, in both the upper exterior member 107 and the lower exterior member 108, one surface of the metal foil (the inner surface of the secondary battery 10) is laminated with a material excellent in electrolytic solution resistance and heat fusion property, The surface (the outer surface of the secondary battery 10) is made of a resin-metal thin film laminate material having a thickness of about 125 μm, for example, laminated with a material having excellent electrical insulation.

  As described above, when the exterior member includes the metal layer in addition to the resin layer, it is possible to improve the strength of the exterior member itself. Further, the inner layer of the exterior member is made of, for example, a synthetic resin material such as polyethylene, modified polyethylene, polypropylene, modified polypropylene, or ionomer, thereby ensuring good fusion property with a metal electrode terminal. It becomes possible.

  As shown in FIGS. 1 and 2, the positive terminal 105 is led out from one end of the sealed exterior members 107 and 108, and the negative terminal 106 is led out from the other end. Since a gap is generated between the upper exterior member 107 and the lower exterior member 108 by the thickness of 105, 106, the electrode terminals 105, 106 and the exterior member are maintained in order to maintain the sealing performance inside the secondary battery 10. For example, a seal film made of polyethylene, polypropylene, or the like may be interposed between the portions 107 and 108 in contact with each other. It is preferable from the viewpoint of heat-sealing property that this seal film is made of a synthetic resin material of the same system as the inner layers of the exterior members 107 and 108 on either side of the positive electrode terminal 105 and the negative electrode terminal 106.

These exterior members 107 and 108 enclose the electrode laminate 101 described above and a part of the electrode terminals 105 and 106, and in a space formed by the exterior members 107 and 108, perchloric acid is added to the organic liquid solvent. While injecting a liquid electrolyte having a lithium salt such as lithium or lithium borofluoride as a solute and sucking the space to form a vacuum, the exterior members 107 and 108 were thermally fused as shown in FIG. sealed Te, the secondary battery 10 is configured to have a width W ₂ as a whole as shown in FIG. Note that the width W ₂ of the secondary battery 10 is set according to the width W ₁ of the electrode laminate 101 and the thermal fusion width of the exterior members 107 and 108.

  Examples of the organic liquid solvent include ester solvents such as propylene carbonate (PC), ethylene carbonate (EC), and dimethyl carbonate (DMC), but the organic liquid solvent of the present invention is not particularly limited thereto, An organic liquid solvent prepared by mixing and preparing an ether solvent such as γ-butylactone (γ-BL) and dietoshikitane (DEE) in the ester solvent can also be used.

  Hereinafter, an assembled battery configured by combining a plurality of secondary batteries according to the above-described embodiments will be described.

  3 (A) to 3 (C) are views showing an assembled battery including a plurality of secondary batteries according to the embodiment of the present invention, FIG. 3 (A) is a front view thereof, and FIG. 3C is a sectional view taken along line IIIC-IIIC in FIG. 3A, FIG. 4 is an exploded perspective view of the assembled battery shown in FIGS. 3A to 3C, and FIG. (A)-(D) is a figure which shows the heat sink used for the assembled battery of FIG. 3 (A)-(C), FIG.5 (A) is the perspective view, FIG.5 (B) is the top view, figure 5C is a cross-sectional view taken along the line VC-VC in FIG. 5B, FIG. 5D is a cross-sectional view taken along the line VD-VD in FIG. 5B, and FIGS. FIG. 6D is a view showing a first spacer used in the assembled battery of FIGS. 3A to 3C, FIG. 6A is a perspective view thereof, FIG. 6B is a plan view thereof, and FIG. 6C is a cross-sectional view taken along the line VIC-VIC in FIG. 6B, and FIG. ) Is a cross-sectional view taken along the line VID-VID, and FIGS. 7A to 7D are views showing a second spacer used in the assembled battery of FIGS. 3A to 3C. 7A is a perspective view, FIG. 7B is a plan view thereof, FIG. 7C is a cross-sectional view taken along line VIIC-VIIC in FIG. 7B, and FIG. 7D is FIG. 7B. 8A to 8C are cross-sectional views taken along the line VIID-VIID of FIGS. 8A to 8C, showing the insulating sleeve used in the assembled battery of FIGS. 3A to 3C. FIG. FIG. 8B is a side view thereof, FIG. 8C is a front view thereof, FIG. 9 is an enlarged cross-sectional view of a portion IX in FIG. 3A, and FIG. 10 is an X portion in FIG. It is an expanded sectional view of a part.

The assembled battery 20 according to this embodiment is formed by arranging three secondary batteries 10a to 10c, 10d to 10f, and 10g to 10i in a line, as shown in FIGS. 3 (A) to 3 (C) and FIG. The first to third layers 21 to 23, the four heat sinks 24 that perform heat radiation and application of surface pressure to the secondary batteries 10a to 10i constituting the layers 21 to 23, and the secondary batteries 10a. 10 spacers 25 and 26 provided between the electrode terminals 105 and 106 of 10 to 10i and the heat sink 24, and four sets of bolts for fixing the secondary batteries 10a to 10i, the heat sink 24 and the spacers 25 and 26. 27, the nut 28, four insulating sleeves 29 for preventing the secondary batteries 10a to 10i from being short-circuited by the bolts 27, a housing 30 for housing these components, and a lead-out from the housing 30. And a battery pack terminal 31 and 32 for connecting the secondary battery 10a~10i housed inside of the casing 30 to the outside. In addition, in order to clarify the internal structure of the assembled battery 20, the housing 30 and the assembled battery electrode terminals 31 and 32 are illustrated by broken lines in FIGS. 3A and 3B, and in FIG. Not shown.

First, each component of the assembled battery 20 will be described. As shown in FIG. 1 and FIG. 2, the first positive terminal 105 of each of the nine first to ninth secondary batteries 10 a to 10 i has a first Through-holes 105a are respectively formed. Similarly, the first through holes 106a are also formed in the negative terminals 106 of the secondary batteries 10a to 10i. The inner diameters of the first through holes 105 a and 106 a are large enough to insert the insulating sleeve 29. Further, in each of the secondary batteries 10a-10i, the first through-hole 105a formed in the positive terminal 105, the distance between the first through-hole 106a of the negative terminal 106 has a pitch _{P 1} .

As shown in FIGS. 5A to 5D, the heat sink 24 (heat dissipating means) of the assembled battery 20 is a flat plate member made of a conductive material such as a metal material, and each secondary battery 10a. wider than the width _{W 1} of the electrode stack 101 of ～10I, and has a width _{W 3} than the entire width _{W 2} of each of the secondary batteries _{10a~10i (W 1 <W 3 <} W 2). Further, this heat sink 24, as shown in the figure, four second through-hole 241 is formed at intervals of a pitch P _2. The pitch _{P 2,} the first through-hole 105a formed in the electrode terminal 105 of each of the secondary batteries 10a-10i, and has a 106a substantially the same as the pitch _{P 1} of the _(P 1 = _{P 2} ).

Thus, by making the width W ₃ of the heat sink 24 narrower than the width W ₂ of the exterior members 107 and 108 of the secondary batteries 10 a to 10 i (W ₃ <W ₂ ), for example, the secondary battery 10 a with respect to the heat sink 24. 10i of the exterior members 107 and 108 are relatively thin, and even if the exterior members 107 and 108 are curved with respect to the heat sink 24, the end surfaces of the metal layers of the exterior members 107 and 108 are Since it does not reach the heat sink and contact between the end face of the metal layer and the conductive heat sink 24 is prevented, even if the end face of the metal layer of the exterior members 107 and 108 is exposed to the outside, the secondary battery for the heat sink 24 The electric insulation of 10a to 10i can be maintained.

Further, by making the width W _{3 of the} heat sink 24 wider than the width W ₁ of the electrode stack 101 of the secondary batteries 10 a to 10 i (W ₃ > W ₁ ), the exterior member of the secondary batteries 10 a to 10 i is formed by the heat sink 24. It becomes possible to apply a substantially uniform surface pressure to 107 and 108.

  Each of the first spacer 25 and the second spacer 26 of the assembled battery 20 is a spacer that fixes the electrode terminals 105 and 106 of the secondary batteries 10a to 10i to the heat sink 24. FIG. (D) and as shown in FIGS. 7 (A) to (D), it has a convex outer shape in which convex portions 251 and 261 protrude at substantially the center thereof, and further has a third penetration inside thereof. Holes 252 and 262 are provided. The outer diameters of the convex portions 251 and 261 can be inserted into the second through holes 241 of the heat sink 24 and are larger than the inner diameters of the first through holes 105a and 106a of the secondary batteries 10a to 10i. Yes. The inner diameters of the third through holes 252 and 262 are large enough to insert the insulating sleeve 29.

  Further, the first spacer 25 and the second spacer 26 are made of a material having excellent electrical insulation, such as ceramic, but as shown in FIGS. A conductive sleeve 263 made of a material having excellent conductivity, such as a metal material, is embedded in the inner periphery of the spacer 26.

  As shown in FIGS. 8A to 8C, the insulating sleeve 29 is a tubular member made of a material having excellent electrical insulation such as a synthetic resin material such as polypropylene (PP). The outer diameter of the insulating sleeve 29 is a size that can be inserted into the first through holes 105a and 106a of the secondary batteries 10a to 10i and the third through holes 252 and 262 of the spacers 25 and 26, The inner diameter of the fourth through-hole 291 formed therein is a size that allows the bolt 27 to be inserted.

  The first to ninth secondary batteries 10a to 10i, the heat sink 24, the spacers 25 and 26, and the insulating sleeve 29 are assembled as follows.

  First, as shown in FIG. 4, the first to third secondary batteries 10a to 10i are arranged in a row so that the different polarity terminals 105 and 106 of the secondary batteries 10a to 10c are overlapped with each other. A first layer 21 is formed. Similarly, the fourth to sixth secondary batteries 10d to 10f are arranged in a line so that the different polarity terminals 105 and 106 of the secondary batteries 10d to 10f overlap with each other, and the second layer 2 In addition, the seventh to ninth secondary batteries 10g to 10i are arranged in a line so that the different polarity terminals 105 and 106 of the secondary batteries 10g to 10i overlap each other, and the third Layer 23 is formed.

  More specifically, the negative terminal 106 of the first secondary battery 10a and the positive terminal 105 of the second secondary battery 10b are overlapped, and the negative terminal 106 of the second secondary battery 10b, The first layer 21 is formed by arranging the first to third secondary batteries 10a in a row so as to overlap the positive electrode terminal 105 of the third secondary battery 10c. Further, the negative electrode terminal 106 of the fourth secondary battery 10d and the positive electrode terminal 105 of the fifth secondary battery 10e are overlapped, and the negative electrode terminal 106 of the fifth secondary battery 10e and the sixth secondary battery 10f. The second layer 22 is formed by arranging the fourth to sixth secondary batteries 10d to 10f in a line so as to overlap the positive electrode terminal 105. Further, the negative terminal 106 of the seventh secondary battery 10g and the positive terminal 105 of the eighth secondary battery 10h are overlapped, and the negative terminal 106 of the eighth secondary battery 10h and the ninth secondary battery 10i. The third layer 23 is formed by arranging the seventh to ninth secondary batteries 10g to 10i in a line so as to overlap the positive electrode terminal 105. Note that in any of the electrode terminals 105 and 106 superimposed on each other, the center lines of the first through holes 105a and 106a formed in the electrode terminals 105 and 106 are overlapped with each other. It has been.

  A single heat sink 24 is laminated on the upper surface of the third layer 23 thus formed. The convex portions 251 of the first spacers 25 are inserted into the respective second through holes 241 formed in the heat sink 24, and the convex portions 251 of the heat sink 24 protrude downward in FIG. Are stacked. In addition, the third layer 23 and the second layer are disposed via the heat sink 24 so that the positive electrode terminal 105 of the seventh secondary battery 10g and the negative electrode terminal 106 of the sixth secondary battery 10f are directed in the same direction. Layer 22 is laminated. Similarly, the positive electrode terminal 105 of the fourth secondary battery 10d and the negative electrode terminal 106 of the third secondary battery 10c are oriented in the same direction via the heat sink 24 and the second layer 22 and the first Layer 21 is laminated. Further, a heat sink 24 is laminated on the lower surface of the first layer 21. The convex portions 251 and 261 of the first spacer 25 or the second spacer 26 are also inserted into the second through holes 211 of these heat sinks 24, respectively. In the figure, they are stacked so as to protrude upward. In addition, the second layer 22 includes the electrode terminals 105 and 106 of the secondary batteries 10d to 10f of the second layer 22 and the secondary batteries 10a to 10c and 10g of the first layer 21 and the third layer 23. 10i of different polarity terminals 106 and 105 are stacked in the direction leading out in the same direction, that is, in the direction opposite to the first layer 21 and the third layer 23.

  As shown in FIGS. 4, 9, and 10, the first to third layers 21 to 23, the heat sinks 24, and the spacers 25 and 26 assembled as described above are on the same center line. Insulating sleeves 29 are inserted into the respective third through holes 252 and 262 of the respective spacers 25 and 26, and bolts 27 are inserted into the fourth through holes 291 of the respective insulating sleeves 29. 27 and the nut 28 are fixed by being fastened.

  By fixing the bolts 27 and the nuts 28, the spacers 25 and 26 provided between the electrode terminals 105 and 106 of the secondary batteries 10a to 10i and the heat sinks 24 cause the electrode terminals 105 and 106 to be heat sinks. 24 is fixed.

  At this time, since the different polarity terminals 105 and 106 of the secondary batteries 10a to 10i in a state of being overlapped with each other are fixed by the single spacers 25 and 26, the electrode terminals 105 and 106 are fixed to the heat sink 24. The electrode terminals 105 and 106 can be electrically connected to each other with the same parts, and the number of parts of the assembled battery 20 can be reduced and the assembly process of the assembled battery 20 can be shortened. Become.

  Further, by interposing the spacers 25 and 26 between the electrode terminals 105 and 106 of the secondary batteries 10a to 10i and the heat sink 24, the electrode terminals 105 and 106 can be fixed on a relatively wide surface. It becomes possible to prevent deformation of the electrode terminals 105 and 106 due to the fixing.

  Here, in the heat sink 24 laminated between the first layer 21 and the second layer 22, as shown in FIGS. 4 and 9, the negative electrode terminal 106 of the third secondary battery 10c and the fourth layer A second spacer 26 is inserted into the second through hole 241 located between the positive electrode terminal 105 of the secondary battery 10d, and the third spacer 26 is inserted into the third through hole 241 by the conductive spacer 263 inserted into the second spacer 26. The first layer 21 and the second layer 22 are electrically connected through the negative electrode terminal 106 of the secondary battery 10c and the positive electrode terminal 105 of the fourth secondary battery 10d.

  Similarly, in the heat sink 24 laminated between the second layer 22 and the third layer 23, as shown in FIG. 4, the negative terminal 106 of the sixth secondary battery 10f and the seventh secondary battery. The second spacer 26 is inserted into the second through hole 241 located between the positive electrode terminal 105 of 10 g, and the sixth secondary electrode is formed by the conductive spacer 263 inserted into the second spacer 26. The second layer 22 and the third layer 23 are electrically connected via the negative electrode terminal 106 of the battery 10f and the positive electrode terminal 105 of the seventh secondary battery 10g.

  In addition, as shown in FIG. 4, FIG. 9, and FIG. 10, the first spacer 25 is inserted into the other second through hole 241 of each heat sink 24, and this first spacer 25 is inserted. In the part which is done, between each layer 21-23 is electrically insulated. For example, as shown in FIG. 10, when all the spacers fixed by the same bolt 27 are the first spacers 25, the first to third layers 21 to 23 are electrically connected in this portion. Is insulated.

  Accordingly, the nine secondary batteries 10a to 10i are connected in series by the two second spacers 26, and the secondary batteries 10a to 10i in the layers 21 to 23 are connected to the electrode terminals 105 and 106, respectively. The layers 21 to 23 are connected to each other through two second spacers 26 by being directly overlapped. In the present embodiment, the orientations of the electrode terminals 105 and 106 of the secondary batteries 10a to 10i are set so that the nine secondary batteries 10a to 10i are connected in series, and the first and second spacers are set. 25 and 26 are arranged, but the present invention is not particularly limited to this arrangement, and the electrodes of the secondary battery are obtained so that a desired parallel connection or series connection according to the capacity or voltage required for the assembled battery can be obtained. The direction of the terminal can be arbitrarily set, and the first and second spacers can be arbitrarily arranged.

  Thus, in the assembled battery 20 according to the present embodiment, the spacers provided between the secondary batteries 10a to 10i and the heat sink 24 are electrically insulated from the secondary batteries 10a to 10i of the different layers 21 to 23. By selecting from the first spacer 25 to be connected and the second spacer 26 to electrically connect the secondary batteries 10a to 10i of the different layers 21 to 23, the second spacer 26 can be selected according to the required capacity, voltage, etc. It becomes possible to arbitrarily set the electrical connection between the secondary batteries.

  As shown in FIG. 3, the structures 21 to 29 assembled as described above are accommodated in a casing 30 made of, for example, a synthetic resin material or the like, and are positive terminals of the first secondary battery 10a. The assembled battery positive electrode terminal 31 is connected to 105, and the assembled battery negative electrode terminal 32 is connected to the negative electrode terminal 106 of the ninth secondary battery 10i so that it can be electrically connected to the outside. In addition, the assembled battery electrode terminals 31 and 32 are led out from the housing 27.

  As described above, in this embodiment, by setting the width of the heat sink to be narrower than the width of the exterior member of the secondary battery, the end surface of the metal layer of the exterior member does not reach the heat sink, and the end surface of the metal layer is electrically conductive. Because it prevents contact with the heat sink, it can maintain the insulation of the secondary battery against the heat sink even if the end surface of the metal layer of the exterior member is exposed to the outside, and it has excellent electrical insulation from the outside A secondary battery can be provided.

Further, in the present embodiment, by greater than the width of the electrode stack of a secondary battery the width of the heat sink, it is possible to apply a substantially uniform surface pressure against the exterior member of the rechargeable battery by the heat sink It becomes.

  Furthermore, in this embodiment, the electrode terminals in a state where they are overlapped with each other are fixed by a single spacer, so that the fixing of the electrode terminals to the heat sink and the electrical contact between the electrode terminals are the same. This can be done with parts, and the number of parts of the assembled battery can be reduced and the assembly process of the assembled battery can be shortened.

  In addition, by interposing a spacer between the electrode terminal of the secondary battery and the heat sink, it becomes possible to fix the electrode terminal on a relatively wide surface, thus preventing deformation of the electrode terminal due to fixation. It becomes.

  Furthermore, in this embodiment, the spacer provided between the secondary battery and the heat sink is electrically connected to the first spacer that insulates the secondary batteries of different layers from each other. By selecting from the second spacer, it is possible to arbitrarily set the electrical connection between the secondary batteries according to the capacity, voltage, etc. required for the assembled battery.

The embodiment described above is described for facilitating the understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

FIG. 1 is a plan view of an entire secondary battery according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the secondary battery taken along line II-II in FIG. 3 (A) to 3 (C) are views showing an assembled battery including a plurality of secondary batteries according to the embodiment of the present invention, and FIG. 3 (A) is a front view thereof, and FIG. 3 (B). Is a side view thereof, and FIG. 3C is a sectional view taken along line IIIC-IIIC in FIG. FIG. 4 is an exploded perspective view of the assembled battery shown in FIGS. 5A to 5D are views showing a heat sink used in the assembled battery of FIGS. 3A to 3C, FIG. 5A is a perspective view thereof, and FIG. FIG. 5C is a cross-sectional view taken along the line VC-VC in FIG. 5B, and FIG. 5D is a cross-sectional view taken along the line VD-VD in FIG. 5B. FIGS. 6A to 6D are views showing a first spacer used in the assembled battery of FIGS. 3A to 3C. FIG. 6A is a perspective view thereof, and FIG. ) Is a plan view thereof, FIG. 6C is a cross-sectional view taken along line VIC-VIC in FIG. 6B, and FIG. 6D is a cross-sectional view taken along line VID-VID in FIG. is there. FIGS. 7A to 7D are views showing a second spacer used in the assembled battery of FIGS. 3A to 3C. FIG. 7A is a perspective view thereof, and FIG. ) Is a plan view thereof, FIG. 7C is a cross-sectional view taken along line VIIC-VIIC in FIG. 7B, and FIG. 7D is a cross-sectional view taken along line VIID-VIID in FIG. 7B. is there. 8A to 8C are diagrams showing an insulating sleeve used in the assembled battery of FIGS. 3A to 3C, FIG. 8A is a perspective view thereof, and FIG. The side view and FIG. 8C are front views thereof. FIG. 9 is an enlarged cross-sectional view of a part IX in FIG. FIG. 10 is an enlarged cross-sectional view of a portion X in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 10a-10i ... Secondary battery 101 ... Electrode laminated body 102 ... Positive electrode plate 102a ... Positive electrode side collector 103 ... Separator 104 ... Negative electrode plate 104a ... Negative electrode side collector 105 ... Positive electrode terminal 105a ... First through-hole DESCRIPTION OF SYMBOLS 106 ... Negative electrode terminal 106a ... 1st through-hole 107 ... Upper exterior member 108 ... Lower exterior member 20 ... Assembly battery 21-23 ... 1st-3rd layer 24 ... Heat sink 241 ... 2nd through-hole 25 ... 1st Spacer 251 ... convex portion 252 ... third through hole 26 ... second spacer 261 ... convex portion 262 ... third through hole 263 ... conductive sleeve 27 ... bolt 28 ... nut 29 ... insulating sleeve 291 ... fourth through hole Hole 30 ... Housing 31, 32 ... Battery pack terminal W ₁ ... Width of electrode stack W ₂ ... Width of secondary battery W ₃ ... Width of heat sink

Claims (12)

An electrode laminate having an electrode plate laminated via a separator;
An exterior member that houses and seals the electrode laminate;
An electrode terminal connected to the electrode laminate and partially derived from the outer periphery of the exterior member;
A heat radiating means having conductivity laminated on the exterior member, and a secondary battery comprising:
A secondary battery in which the heat dissipation means is shorter than the exterior member in a direction orthogonal to the direction in which the electrode terminal is led out from the exterior member.
The secondary battery according to claim 1 , wherein the heat dissipating means is longer than the electrode laminate in a direction orthogonal to a direction in which the electrode terminal is led out from the exterior member .
  The secondary battery according to claim 1, further comprising a fixing unit that is provided between the electrode terminal and the heat radiating unit and fixes the electrode terminal to the heat radiating unit.   The fixing means includes the electrode terminal of the one secondary battery and the electrode terminal of the other secondary battery in a state where the electrode terminal of the one secondary battery and the electrode terminal of the other secondary battery overlap each other. The secondary battery according to claim 3, wherein a terminal is fixed to the heat dissipation means.   The secondary battery according to claim 3 or 4, wherein the fixing means includes first fixing means made of an insulating material.   The secondary battery according to claim 3, wherein the fixing means includes second fixing means having a conductive member. An electrode laminate having an electrode plate laminated via a separator, an exterior member that accommodates and seals the electrode laminate, and a part from the outer periphery of the exterior member that is connected to the electrode laminate and Two or more secondary batteries having derived electrode terminals;
An assembled battery comprising at least one conductive heat dissipating means laminated on the exterior member of each secondary battery,
In the direction orthogonal to the direction in which the electrode terminal is led out from the exterior member, the heat dissipation means is a battery assembly shorter than the exterior member of each secondary battery.
The assembled battery according to claim 7 , wherein the heat dissipating means is longer than the electrode stack of each of the secondary batteries in a direction orthogonal to a direction in which the electrode terminal is led out from the exterior member .
  The assembled battery according to claim 7, further comprising a fixing unit that is provided between the electrode terminal of each secondary battery and the heat dissipation unit, and fixes the electrode terminal to the heat dissipation unit.   The fixing means includes the electrode terminal of the one secondary battery and the electrode terminal of the other secondary battery in a state where the electrode terminal of the one secondary battery and the electrode terminal of the other secondary battery overlap each other. The assembled battery according to claim 9, wherein a terminal is fixed to the heat dissipation means.   The assembled battery according to claim 9 or 10, wherein the fixing means includes first fixing means made of an insulating material.   The assembled battery according to any one of claims 9 to 11, wherein the fixing means includes second fixing means having a conductive member.

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