JP2011049065A - Nonaqueous electrolyte battery and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte battery having reduced failures in ultrasonic joining, and high energy density. <P>SOLUTION: The nonaqueous electrolyte battery includes a container 1, an electrode group 2 stored in the container, and including a positive electrode and a negative electrode, a plurality of positive electrode current collecting tabs 3 and a plurality of negative electrode current collecting tabs 4 extending from the positive electrode and the negative electrode of the electrode group, respectively, a positive electrode lead 7 and a negative electrode lead 8 electrically connected to the plurality of positive electrode current collecting tabs and the plurality of negative electrode current collecting tabs, respectively, a cover 9 covering an opening portion of the container, and output terminals 12, 13 provided on the cover and electrically connected to the positive electrode lead and the negative electrode lead, respectively. At least one current collecting tabs out of the plurality of positive electrode current collecting tabs and the plurality of negative electrode current collecting tabs are held between holding plates 5, 6. The holding plates are caulked and fixed to each other at one or more places across at least one current collecting tabs. The leads, the holding plates and at least one current collecting tabs are ultrasonic-joined to one another at one or more places. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a nonaqueous electrolyte battery and a method for producing the same.

  In recent years, with the development of electronic devices, lithium secondary batteries have been developed as non-aqueous electrolyte secondary batteries that are small, lightweight, have high energy density, and can be repeatedly charged and discharged. Recently, it is suitable for in-vehicle secondary batteries mounted on hybrid cars and electric cars, and secondary batteries for power storage used for power leveling. Development of non-aqueous electrolyte secondary batteries is also desired. As such a secondary battery, rapid charging and high power discharge are possible using lithium titanium oxide (lithium titanium composite oxide) having a small particle size (average particle size of primary particles is 1 μm or less) as a negative electrode active material. In addition, non-aqueous electrolyte secondary batteries having excellent cycle performance have been developed.

  Due to the demand for secondary batteries with high energy density, it is necessary to combine a plurality of current collecting tabs. For example, Patent Document 1 describes using a current collecting plate having a substantially V-shaped cross section. . In this case, welding is performed by sandwiching a plurality of laminated metal foils with current collector plates and irradiating the ridges of the positive electrode current collector with laser light. In laser welding, it is generally known that adhesion between materials is important, and when the fixation is insufficient and there is a gap between the materials, a sufficient welding state cannot be obtained. In Patent Document 1, since the adhesiveness between the current collecting plate having a substantially V-shaped cross section and the tip of the metal foil is unstable, a sufficient welded state may not be obtained. For this reason, it is necessary to take measures such as collecting power by providing a plurality of welding points, but it is inevitable that the number of parts increases.

  Patent Document 2 has a structure in which an electrode connecting portion (lead) is sandwiched between metal foils (current collecting tabs) of an electrode protruding from the end face of the power generation element, and the metal foil is sandwiched between the electrode connecting portions and a sandwiching plate. It is disclosed.

Japanese Patent No. 4134521 Patent No. 4420258

  As a method of connecting a plurality of current collecting tabs, sandwiching plates and leads together, ultrasonic welding as well as laser welding can be mentioned. When ultrasonic bonding is used, the position of the holding plate may be shifted due to vibration, and the electrode group may not be accommodated in a container designed with a predetermined size. If there is a margin in the dimensions of the container, the energy density will be reduced.

  An object of the present invention is to provide a non-aqueous electrolyte battery having a high energy density with reduced defects during ultrasonic bonding and a method for manufacturing the same.

The nonaqueous electrolyte battery of the present invention includes a container,
An electrode group housed in the container and including a positive electrode and a negative electrode;
A plurality of positive current collecting tabs and a plurality of negative current collecting tabs extending from the positive electrode and the negative electrode of the electrode group, and
A positive electrode lead and a negative electrode lead electrically connected to the plurality of positive electrode current collecting tabs and negative electrode current collecting tabs, respectively;
A lid that closes the opening of the container;
A non-aqueous electrolyte battery comprising an output terminal provided on the lid and electrically connected to the positive electrode lead or the negative electrode lead,
At least one current collecting tab of the plurality of positive electrode current collecting tabs and the plurality of negative electrode current collecting tabs is sandwiched between sandwiching plates,
The clamping plate is fixed with one or more crimps across the at least one current collecting tab,
The lead, the clamping plate, and the at least one current collecting tab are bonded to each other by one or more ultrasonic waves.

  Further, the nonaqueous electrolyte battery manufacturing method of the present invention is the above-described nonaqueous electrolyte battery manufacturing method, wherein after fixing the clamping plate sandwiching the at least one current collecting tab by caulking, the lead and the lead and performing ultrasonic bonding with at least one of the current collector tab.

  ADVANTAGE OF THE INVENTION According to this invention, the defect at the time of ultrasonic joining can be reduced, and the nonaqueous electrolyte battery which is high energy density, and its manufacturing method can be provided.

The disassembled perspective view which shows the nonaqueous electrolyte battery which concerns on one Embodiment. The top view which shows an example of a connection with a current collection tab and a clamping board. Schematic view showing a caulking process and a collector tab and the clamping plate. Electrode tabs, the holding plate, and a plan view showing an example of a lead connection. Electrode tabs, the holding plate, and a schematic view showing a process of ultrasonic bonding leads. Electrode tabs, the holding plate, and a plan view showing another example of the lead connection. Electrode tabs, the holding plate, and a plan view showing another example of the lead connection. Electrode tabs, the holding plate, and a plan view showing another example of the lead connection. The disassembled perspective view which shows the nonaqueous electrolyte battery which concerns on other embodiment. Schematic view showing a caulking process and a collector tab and the clamping plate. Electrode tabs, the holding plate, and a schematic view showing a process of ultrasonic bonding leads. The disassembled perspective view which shows the nonaqueous electrolyte battery which concerns on other embodiment. The disassembled perspective view which shows the nonaqueous electrolyte battery which concerns on other embodiment. Plan view showing another example of the connection between the current collector tabs and the holding plate. The top view which shows the other example of the connection of a current collection tab, a clamping board, and a lead. The disassembled perspective view which shows the nonaqueous electrolyte battery which concerns on other embodiment.

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

  As shown in FIG. 1, the nonaqueous electrolyte battery according to one embodiment includes a container 1 having a bottomed rectangular tube shape. The container 1 is formed by, for example, performing deep drawing on an aluminum plate or an aluminum alloy plate. For example, the electrode group 2 is formed by winding a sheet-like positive electrode and a sheet-like negative electrode in a spiral shape with a separator interposed therebetween, and then crushing and deforming the whole into a quadrangular cross-sectional shape that matches the cross-sectional shape of the container. It is produced by this.

  The positive electrode is produced, for example, by applying a slurry containing a positive electrode active material to a current collector made of an aluminum foil or an aluminum alloy foil. As the positive electrode active material, oxides, sulfides, polymers, and the like that can occlude and release lithium can be used. Preferable active materials include lithium manganese composite oxide, lithium nickel composite oxide, lithium cobalt composite oxide, lithium iron phosphate, and the like that can obtain a high positive electrode potential.

  The negative electrode is produced by applying a slurry containing a negative electrode active material to a current collector made of an aluminum foil or an aluminum alloy foil. As the negative electrode active material, metal oxides, metal sulfides, metal nitrides, alloys, and the like that can occlude and release lithium can be used. Preferably, the occlusion and release potential of lithium ions is 0.4 V or higher relative to the metal lithium potential. It is a substance. Since the negative electrode active material having such a lithium ion storage / release potential can suppress the alloy reaction between aluminum or an aluminum alloy and lithium, it is possible to use aluminum or an aluminum alloy for a negative electrode current collector and a negative electrode related component. And For example, there are titanium oxide, lithium titanium oxide, tungsten oxide, amorphous tin oxide, tin silicon oxide, and silicon oxide. Among these, lithium titanium composite oxide is preferable. As the separator, a microporous film, a woven fabric, a non-woven fabric, a laminate of the same material or different materials among these can be used. Examples of the material for forming the separator include polyethylene, polypropylene, ethylene-propylene copolymer, and ethylene-butene copolymer.

A non-aqueous electrolyte (not shown) is accommodated in the container 1 and impregnated in the electrode group 2. The non-aqueous electrolyte is prepared by dissolving an electrolyte (for example, a lithium salt) 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), 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 ₄ ), lithium hexafluorophosphate (LiPF ₆ ), lithium tetrafluoroborate (LiBF ₄ ), lithium hexafluoroarsenide (LiAsF ₆ ), and trifluoromethanesulfone. Examples thereof include lithium salts such as lithium acid lithium (LiCF ₃ SO ₃ ). The electrolyte may be used alone or in combination of two or more. The amount of electrolyte dissolved in the non-aqueous solvent is desirably 0.2 mol / L to 3 mol / L.

  On one end face of the electrode group 2, a positive electrode current collector not coated with slurry is exposed. The exposed positive electrode current collector is laminated in the thickness direction of the electrode group 2, and this functions as a plurality of positive electrode current collection tabs 3. On the other hand, the negative electrode current collector to which the slurry is not applied is exposed on the other end face of the electrode group 2. The exposed negative electrode current collector is laminated in the thickness direction of the electrode group 2, and this functions as a plurality of negative electrode current collection tabs 4.

  As the positive electrode current collecting tab 3, for example, as shown in FIG. 1, a positive electrode current collector extended can be used, but it may be separate from the positive electrode. Further, as the negative electrode current collecting tab 4, for example, as shown in FIG. 1, a negative electrode current collector extended can be used, but it may be separate from the negative electrode.

  The positive electrode current collecting tab 3 and the negative electrode current collecting tab 4 are sandwiched between the sandwiching plate 5 and the sandwiching plate 6, respectively. Since the electrode group is formed by winding the sheet-like positive electrode and the sheet-like negative electrode, the sandwiching plate is disposed with only the straight portions except for the curved ends of the current collecting tab. As shown in FIG. 2, the clamping plate 6 sandwiching the negative electrode current collecting tab 4 is fixed by caulking. Connection according to caulking is shown in the figure as reference numeral 17.

  Here, caulking refers to connecting the current collecting tab 4 and the clamping plate 6 by pressure bonding. The connecting portion 17 by caulking has a shape in which a concave portion is formed on one surface of the sandwiching plate 6 sandwiching the current collecting tab 4, and a convex portion is formed at a position corresponding to the concave portion on the other surface of the sandwiching plate. Have

  For example, as shown in FIG. 3, the clamping plate 6 and the current collecting tab 4 can be fixed by placing the clamping plate 6 sandwiching the current collecting tab 4 on a base 18 and using a caulking punch 19. It is done by squeezing. Similarly, the sandwiching plate 5 sandwiching the positive electrode current collecting tab 3 is preferably fixed by caulking.

  The clamping plate 6 is temporarily fixed to the current collecting tab 4 by caulking. As a result, the position shift can be reduced when the leads are joined to the sandwiching plate by ultrasonic waves in a later step.

  By the way, the opening part of the container 1 is sealed by the sealing member. As shown in FIG. 1, the sealing member includes a lid 9 that closes the opening of the container 1, and a positive output terminal 12 and a negative output terminal that are caulked and fixed to the outer surface (upper surface) of the lid 9 via gaskets 10 and 11, respectively. 13 is provided. The lid 9 is made of a press-formed product made of a metal such as aluminum or an aluminum alloy plate. Although not shown, the lid 9 is provided with an electrolyte injection hole and a safety valve. After the electrolyte injection, the electrolyte injection hole is closed with a sealing plug (not shown), and this sealing plug is welded to the lid 9.

On the inner surface (lower surface) of the lid 9, the negative electrode lead 8 is disposed via the insulator 15, and the positive electrode lead 7 is disposed via the insulator 14. Anode lead 8 includes a connecting plate _81, and the connecting plate 8 through hole ₈₂ which is open to _1, and a collector portion 8 ₃ extending downward from the connecting plate _81. Insulator 15 is made of a rectangular plate having a through-hole 15 ₁ is opened. The negative electrode output terminal 13 is a rivet and has a head portion 13 a disposed on the lid 9 and a shaft portion (not shown) extending downward from the head portion 13 a. Shaft portion of the negative output terminal 13 is inserted into the through hole ₈₂ of the through-hole 15 ₁ and the negative electrode lead 8 of the insulator 15 is caulked and fixed, that is, the negative output terminal 13 is caulked to the cover 9, further It is also caulked and fixed to the negative electrode lead 8. Thus, the negative electrode lead 8 is electrically connected to the negative electrode output terminal 13.

The positive electrode lead 7 has a connecting plate _71, the through hole 7 ₂ opened in connecting plate _71, and a collector portion 7 ₃ extending downward from the connecting plate _71. Insulator 14 is made of a rectangular plate having a through-hole 14 ₁ is opened. The positive electrode output terminal 12 is a rivet, and has a head portion 12a disposed on the lid 9, and a shaft portion (not shown) extending downward from the head portion 12a. The shaft portion of the positive electrode output terminal 12 is inserted into the through hole 14 ₁ of the insulator 14 and the through hole 7 ₂ of the positive electrode lead 7 and fixed by caulking, that is, the positive electrode output terminal 12 is caulked and fixed to the lid 9. It is also caulked and fixed to the positive electrode lead 7. Thus, the positive electrode lead 7 is electrically connected to the positive electrode output terminal 12.

  The material of the negative electrode output terminal 13 and the negative electrode lead 8 can be changed according to the material of the active material. For example, when lithium titanate is used as the negative electrode active material, aluminum or an aluminum alloy can be used. On the other hand, for example, aluminum or an aluminum alloy can be used for the positive electrode output terminal 12 and the positive electrode lead 7.

The negative electrode lead 8 is connected to the negative electrode current collecting tab 4. Specifically, the collector portions 8 ₃ of the negative electrode lead 8, as shown in FIG. 4, a holding plate 6 which is fixed to the negative electrode current collector tab 4 by crimping, it is joined by ultrasonic. An ultrasonic joint is shown in the figure as reference numeral 20. The collector portions 8 ₃ of the negative electrode current collector holding plate 6 and the negative electrode lead across the tabs 4, for example, can be bonded by ultrasonic using the anvil 21 and the horn 22 as shown in FIG. As a result, the negative electrode current collecting tab 4 is electrically connected to the negative electrode output terminal 13 via the negative electrode holding plate 6 and the negative electrode lead 8. In addition, what is necessary is just to select an anvil and a horn suitably according to the dimension, position, etc. of the junction part 20 by an ultrasonic wave.

  As already described, since the current collecting tab 4 and the sandwiching plate 6 are fixed by caulking, even if the lead 8 is subjected to vibration when it is joined by ultrasonic waves, it is possible to avoid positional deviation.

Similarly clamping plate 5 of the positive electrode are preferably joined by ultrasonic waves to the collector portion 7 ₃ of the positive electrode lead 7. Thereby, the positive electrode current collecting tab 3 is electrically connected to the positive electrode output terminal 12 through the positive electrode holding plate 5 and the positive electrode lead 7.

  Further, in the above-described drawings, both the positive output terminal and the negative output terminal are rivets, but only the negative output terminal is a rivet, and the positive output terminal may be constituted by a portion protruding in a convex shape on the outer surface of the lid 9. Good. Alternatively, only the positive electrode output terminal can be used as a rivet, and the portion protruding from the outer surface of the lid 9 can be used as a negative electrode output terminal.

Various changes can be made to the form of connection between the holding plate and the lead. For example, as shown in FIG. 6 may be provided a current collecting portion 8 ₃ and the joint portion 20 by ultrasonic and holding plate 6 of the lead 8 in two places. In this case, the joint portions 20 by two ultrasonic waves are arranged along the longitudinal direction of the sandwiching plate 6 with the connection portion 17 by caulking in between. Compared with the example of FIG. 4, the width of the sandwiching plate, that is, the width of the current collecting tab can be reduced, so that there is an advantage that a wider width of the electrode group can be secured.

  Moreover, when the connection part 17 which fixes a clamping board and a current collection tab by caulking is provided in two or more places, these fixation will become more reliable. The position of the connecting portion 17 by caulking may be either the both ends of the long side of the sandwiching plate 6 as shown in FIG. 7 or the both ends of the short side of the sandwiching plate 6 as shown in FIG. Although not shown, the connecting portions 17 by caulking can be provided at two locations on the diagonal line of the sandwiching plate 6, and various modifications can be made in combination with the ultrasonic bonded portions 20.

  In addition, both the connection part by caulking and the junction part by ultrasonic waves are counted for each of a plurality of current collecting tabs bundled together. The plurality of current collecting tabs and the sandwiching plate that are bundled together are fixed by caulking at at least one location, and the sandwiching plate and the lead are joined by at least one ultrasound.

  Hereinafter, non-aqueous electrolyte batteries having various configurations according to other embodiments will be described. In any case, the above-described change in the connection form of the sandwiching plate can be applied.

The nonaqueous electrolyte battery shown in FIG. 9 has the same configuration as that shown in FIG. 1 except that the structure of the current collecting tab, the sandwiching plate, and the leads connected thereto is different. Specifically, the positive electrode current collecting tab 3a and the negative electrode current collecting tab 4a are divided into two parts and sandwiched between the sandwiching plate 5a and the sandwiching plate 6a. The clamping plates 5a and 6a used here each have two U-shaped portions. In each current collecting tab, the places bundled by the sandwiching plate are two places. Correspondingly, the current collecting part 7 ₃ of the positive electrode lead 7a and the current collecting part 8 ₃ of the negative electrode lead 8a are also bifurcated. Composed.

  When the clamping plate and the current collecting tab are fixed, for example, as shown in FIG. 10, the thickness of the current collecting tab 4 a is divided into two and the pedestal 24 is arranged between the clamping plates 6 a, and the caulking punch 25 is used. Caulking.

Holding plate 6a fixed to the negative electrode current collector tab 4a by caulking is joined to the current collecting portion 8 _third lead 8a ultrasonically. Ultrasonic bonding can be performed using an anvil 26 and a horn 27 as shown in FIG.

  Since the current collecting tabs are divided into two parts and sandwiched between the holding plates, the number of stacked current collecting tabs is reduced. By caulking in such a state, the clamping plate and the current collecting tab can be more securely fixed.

  The nonaqueous electrolyte battery shown in FIG. 12 has an electrode group 2b produced by alternately laminating a sheet-like positive electrode and a sheet-like negative electrode with a separator in between. The plurality of positive electrode current collecting tabs 3b are electrically connected to a plurality of positions of the positive electrode, and each is led out from one side surface of the stacked electrode surface in a lateral direction. The plurality of negative electrode electrostatic tabs 4b are electrically connected to a plurality of locations of the negative electrode, and each is led out laterally from the other side surface of the stacked electrode.

  As the positive electrode current collecting tab 3b, for example, a positive electrode current collector partially extended can be used, but may be separate from the positive electrode. Moreover, as the negative electrode current collection tab 4b, for example, a negative electrode current collector partially extended can be used, but may be separate from the negative electrode.

  Since it is the laminated electrode group 2b, the sandwiching plate 6b can sandwich the entire width of the negative electrode current collecting tab 4b. The entire width of the positive electrode current collecting tab 3b is also sandwiched between the clamping plates 5b.

  Except for these differences, the illustrated battery has the same configuration as the nonaqueous electrolyte battery shown in FIG. 1, and the current collecting tab and the sandwiching plate are caulked in the same manner. Further, the current collecting tab, the sandwiching plate, and the lead are joined by ultrasonic waves as described above.

  In the above, an example of a double-sided nonaqueous electrolyte battery in which a plurality of current collecting tabs are drawn from both sides of the electrode group has been shown. The battery having such a configuration is particularly affected by a positional shift when accommodated in a container. In the present invention, since at least one of the plurality of current collecting tabs is sandwiched and fixed by caulking and the sandwiching plate and the lead are joined by ultrasonic waves, it is possible to greatly reduce the positional deviation. It was. As a result, a high energy density non-aqueous electrolyte battery can be provided.

  The present invention is effective not only for the double-sided type but also for a single-sided nonaqueous electrolyte battery in which a plurality of current collecting tabs are drawn from one side of the electrode group.

  FIG. 13 is an example of a wound piece-out nonaqueous electrolyte battery, and an electrode group 32 is accommodated in a container 31. The electrode group 32 is formed by winding a sheet-like positive electrode and a sheet-like negative electrode in a spiral shape with a separator in between, and then crushing and deforming the whole into a quadrangular cross-sectional shape that matches the cross-sectional shape of the container. Produced.

  The plurality of positive electrode current collecting tabs 34 are electrically connected to a plurality of positions of the positive electrode, and are respectively led upward from the upper end surface 32 a of the electrode group 32. On the other hand, the plurality of negative electrode current collecting tabs 35 are electrically connected to a plurality of portions of the negative electrode, and each is led upward from the upper end surface 32 a of the electrode group 32.

  As the positive electrode current collecting tab 34, for example, a positive electrode current collector partially extended can be used, but it may be separate from the positive electrode. Moreover, as the negative electrode current collection tab 35, for example, a negative electrode current collector partially extended can be used, but may be separate from the negative electrode.

  The positive electrode current collecting tab 34 and the negative electrode current collecting tab 35 are sandwiched between the sandwiching plate 36 and the sandwiching plate 37, respectively, and are caulked as described above. For example, as shown in FIG. 14, the sandwiching plate 37 sandwiching the negative electrode current collecting tab 35 is fixed by caulking. The connection by caulking is shown as reference numeral 58.

  The opening of the container 31 is sealed with a sealing member. The sealing member includes a lid 38 that closes the opening of the container 31, a negative output terminal (rivet) 40 that is attached to the outer surface (upper surface) of the lid 38 via a gasket 39, and a convex surface on the outer surface (upper surface) side of the lid 38. And a positive electrode output terminal 43 protruding in a shape. Although not shown, the lid 38 is provided with an electrolyte solution inlet and a safety valve. The negative electrode lead 41 is L-shaped having an upper surface and a side surface, and is disposed on the inner surface (lower surface) of the lid 38 via an insulating member (not shown). The upper surface of the negative electrode lead 41 is electrically connected to the negative electrode output terminal 40 by being caulked and fixed to the negative electrode output terminal 40. On the other hand, the positive electrode lead 42 is electrically connected to the positive electrode output terminal 43 by being disposed directly on the inner surface (lower surface) of the lid 38. The electrolyte solution (not shown) is injected from the electrolyte solution injection hole (not shown) and then closed with a sealing plug (not shown). This sealing plug is welded to the lid 38.

  A negative electrode lead 41 of the L-shape, is connected to the negative electrode current collector tab 35. Specifically, as shown in FIG. 15, the side surface of the negative electrode lead 41 is joined by ultrasonic waves to a holding plate 37 fixed to the negative electrode current collecting tab 35 by a connecting portion 58 by caulking. The ultrasonic joint is shown as reference numeral 59.

  Furthermore, spacers 51a and 51b are arranged so as to surround a space provided between the inner surface (lower surface) of the lid 38 and the upper end surface 32a from which the positive electrode current collecting tab 34 and the negative electrode current collecting tab 35 of the electrode group 32 protrude. Is done. The spacer 51a is provided with partition plates 52a to 52c at both short sides of the rectangular plate and an intermediate point in the long side direction. Projections 53 are provided on the end surfaces of the partition plates 52a to 52c.

  On the other hand, the spacer 51b is provided with partition plates 54a to 54c at both short sides of the rectangular plate and an intermediate point in the long side direction. Concave portions 55 for fitting the protrusions 53 of the spacers 51a are provided on the end surfaces of the partition plates 54a to 54c. When the projections 53 of the partition plates 52a to 52c of the spacer 51a are fitted into the recesses 55 of the partition plates 54a to 54c of the spacer 51b, they are surrounded by the partition plates 52a and 52b of the spacer 51a and the partition plates 54a and 54b of the spacer 51b. The positive electrode current collecting tab 34, the clamping plate 36, and the positive electrode lead 42 are located in the space, and the negative electrode current collector is in a space surrounded by the partition plates 52b and 52c of the spacer 51a and the partition plates 54b and 54c of the spacer 51b. The tab 35, the clamping plate 37, and the negative electrode lead 41 are located. Thereby, the insulation between the positive electrode current collecting tab 34 and the negative electrode current collecting tab 35, the insulation between the holding plate 36 and the holding plate 37, the insulation between the positive electrode lead 42 and the negative electrode lead 41, and the insulation between these members and the container 31 are achieved. Is done.

  Further, the spacers 51a and 51b can prevent the electrode group 2 from moving when a vibration or impact is applied to the battery. Furthermore, since the electrolyte injected from the electrolyte injection hole accumulates in the upper part of the electrode group 32, the electrolyte easily penetrates from the upper end surface of the electrode group 32, and the electrode group 32 can be uniformly impregnated with the electrolyte. it can. Holes 56 are provided in the four corners of the spacers 51a and 51b to allow the electrolyte to penetrate into the gap between the container 31 and the electrode group 32. Examples of the material of the spacers 51a and 51b include PP and PFA.

  The nonaqueous electrolyte battery having the above-described configuration can also be applied to a laminated piece-out configuration as shown in FIG. The nonaqueous electrolyte battery shown in the figure has an electrode group 33 produced by alternately laminating a sheet-like positive electrode and a sheet-like negative electrode with a separator interposed therebetween.

  Except for these differences, the illustrated battery has the same configuration as the nonaqueous electrolyte battery shown in FIG. 13, and the current collecting tab and the sandwiching plate are caulked in the same manner. Further, the current collecting tab, the sandwiching plate, and the lead are joined by ultrasonic waves as described above.

  Even in a non-aqueous electrolyte battery in which a plurality of current collecting tabs are drawn out from one side of the electrode group, it is desirable to avoid positional deviation when housed in a container. In the present invention, at least one of the plurality of current collecting tabs is sandwiched and fixed by caulking, and the sandwiching plate and the lead are joined by ultrasonic waves, so that the positional deviation can be greatly reduced. became. As a result, a high energy density non-aqueous electrolyte battery can be provided.

[Example]
Hereinafter, the present invention will be described in detail with reference to examples.

Example 1
The positive electrode has a current collector in which an active material-containing layer containing lithium cobalt oxide (LiCoO ₂ ), graphite powder as a conductive agent, and polyvinylidene fluoride (PVdF) as a binder is made of aluminum or an aluminum alloy foil The sheet-like thing formed in both surfaces was used. On the other hand, the negative electrode includes a negative electrode active material powder having a lithium occlusion potential of 0.4 V or more with respect to the open circuit potential of lithium metal, carbon powder as a conductive agent, and polyvinylidene fluoride (PVdF) as a binder. The sheet-like thing in which the active material content layer containing this was formed on both surfaces of the electrical power collector which consists of aluminum or aluminum alloy foil was used.

  The electrode group 2 is obtained by winding the separator between a positive electrode and a negative electrode in a spiral shape and then crushing and deforming the whole into a quadrangular cross section that matches the cross sectional shape of the metal container 1. A manufactured product having the structure shown in FIG. 1 was used.

  As the positive electrode current collecting tab 3, a positive electrode current collector extended in a spiral shape was used. Moreover, the negative electrode current collection tab 4 used what the negative electrode current collector extended in the spiral shape. As shown in FIG. 1, for each of the positive electrode current collecting tab 3 and the negative electrode current collecting tab 4, a predetermined number of sheets are stacked, the leading ends of the current collecting tabs are overlapped, and the sandwiching plates 5 and 6 are sandwiched between the current collecting tabs. Arranged.

  As shown in FIG. 3, caulking was performed from above the sandwiching plate using a punch in a state where a block-like pedestal was disposed below the sandwiching plate. The current collecting tab and the clamping plate after crimping and the lead were joined by ultrasonic waves.

  For ultrasonic bonding, an ultrasonic welding machine manufactured by Nippon Emerson Co., Ltd. was used. The tip angle of the horn of the ultrasonic welder was 90 °, and the pattern depth of the horn was equal to the thickness of the current collecting tab group and the sandwiching plate. The battery thus obtained was referred to as Example 1. The connection state of the current collecting tab, the sandwiching plate, and the lead in the battery of Example 1 was as shown in FIG.

  In addition, the batteries of Examples 2 and 3 were manufactured by changing the number of crimps to fix the sandwiching plates or the number of stacked current collecting tabs sandwiched by the sandwiching plates. The battery of Example 2 is the same as Example 1 except that the current collecting tab and the holding plate are fixed by caulking in two places, and the current collecting tab, the holding plate, and the lead are connected as shown in FIG. It was prepared. The battery of Example 3 was produced in the same manner as Example 1 except that the number of stacked current collecting tabs was increased.

  Furthermore, the batteries of Comparative Examples 1 and 2 were produced without caulking the current collecting tab and the sandwiching plate. In the comparative example, since the positional displacement of the clamping plate occurred during joining by ultrasonic waves and the electrode group could not be inserted into the container, the dimensions of the electrode group were estimated in advance with the amount of displacement. Therefore, although the container used for the Example and the comparative example is the same size, the dimension of an electrode group differs.

The energy density of Comparative Example 1 was set to 100%, and the energy densities of the batteries of Examples 1 to 3 and Comparative Example 2 were determined as relative values. The volume energy density of each battery is summarized in Table 1 below together with the number of stacked current collecting tabs sandwiched between the sandwiching plates and the number of caulkings that secure the sandwiching plates.

  Compared with the battery of Comparative Example 1, the batteries of Examples 1 and 2 have a volume energy density improved by 5%. Even when the number of stacked current collecting tabs sandwiched between the sandwiching plates is increased, if the current collecting tabs and the sandwiching plates are caulked, an equivalent volume energy density can be obtained as shown in the third embodiment. it can.

  On the other hand, when caulking is not performed, the positional deviation during ultrasonic bonding increases as the number of stacked current collecting tabs increases. In order to be accommodated in a container having an equivalent size, the size of the electrode group must be reduced. Therefore, it is shown in the result of Comparative Example 2 that the volume energy density decreases.

  That is, by fixing the current collecting tab and the sandwiching plate by caulking, these are temporarily fixed, so that the positional deviation at the time of ultrasonic bonding is reduced and the yield is not reduced. In addition, the electrode group can be produced with appropriate dimensions without waste with respect to the container, and a lithium ion secondary battery with high energy density can be obtained.

  Next, a stacked battery was produced. Specifically, the same positive electrode, negative electrode, and separator as in Example 1 were used, and the positive electrode and the negative electrode were alternately laminated with a separator interposed therebetween, to produce a laminated electrode group.

  As the positive electrode current collector tab, a positive electrode current collector extended in a strip shape was used. Moreover, what extended the negative electrode collector to the strip | belt shape was used for the negative electrode current collection tab. As shown in FIG. 12, for each of the positive electrode current collecting tab 3b and the negative electrode current collecting tab 4b, sandwiching plates 5b and 6b are stacked so that a predetermined number of sheets are stacked and the tips of the current collecting tabs are overlapped to sandwich the current collecting tabs. Arranged.

  In the same manner as described above, the current collecting tab and the sandwiching plate were fixed by caulking, and then the current collecting tab and the sandwiching plate and the lead were joined by ultrasonic waves. The battery thus obtained was referred to as Example 4.

  In addition, batteries of Examples 5 and 6 were fabricated by the same method as described above, except that the number of crimps to fix the sandwiching plates or the number of stacked current collecting tabs sandwiched by the sandwiching plates was changed. The battery of Example 5 was caulked at two locations to fix the current collecting tab and the sandwiching plate, and the current collecting tab, the sandwiching plate, and the lead were connected as shown in FIG. In Examples 4 and 6, the connecting portion 58 by caulking in FIG.

  Further, the batteries of Comparative Examples 3 and 4 were produced without caulking the current collecting tab and the sandwiching plate. In the comparative example, since the positional displacement of the clamping plate occurred during joining by ultrasonic waves and the electrode group could not be inserted into the container, the dimensions of the electrode group were estimated in advance with the amount of displacement. Therefore, although the container used for the Example and the comparative example is the same size, the dimension of an electrode group differs.

The energy density of Comparative Example 3 was set to 100%, and the energy densities of the batteries of Examples 4 to 6 and Comparative Example 4 were determined as relative values. The volume energy density of each battery is summarized in Table 2 below together with the number of stacked current collecting tabs sandwiched between the sandwiching plates and the number of caulks that secure the sandwiching plates.

  Compared with the battery of Comparative Example 3, the batteries of Examples 4 and 5 have a volume energy density improved by 5%. Even when the number of stacked current collecting tabs sandwiched between the clamping plates is increased, an equivalent volume energy density can be obtained as shown in Example 6 if the current collecting tabs and the clamping plates are caulked. it can.

  On the other hand, when caulking is not performed, the positional deviation during ultrasonic bonding increases as the number of stacked current collecting tabs increases. In order to be accommodated in a container having an equivalent size, the size of the electrode group must be reduced. Therefore, it is shown in the result of Comparative Example 4 that the volume energy density decreases.

  That is, by fixing the current collecting tab and the sandwiching plate by caulking, these are temporarily fixed, so that the positional deviation at the time of ultrasonic bonding is reduced and the yield is not reduced. In addition, the electrode group can be produced with appropriate dimensions without waste with respect to the container, and a lithium ion secondary battery with high energy density can be obtained.

  In the above-described embodiments, a battery using a non-aqueous electrolyte is described as an example. However, a battery using a solid electrolyte, a polymer electrolyte, or an aqueous electrolyte instead of the non-aqueous electrolyte can be naturally applied. Furthermore, the positive and negative electrode active materials are not limited to this, and other active materials can be used.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

DESCRIPTION OF SYMBOLS 1 ... Container; 2, 2b ... Electrode group; 3, 3a, 3b ... Positive electrode current collection tab 4, 4a, 4b ... Negative electrode current collection tab; 5, 5a, 5b ... Nipping plate 6, 6a, 6b ... Nipping plate; , 7a ... positive electrode lead; 8, 8a ... negative electrode lead 7 ₁ , 8 ₁ ... connection plate; 7 ₂ , 8 ₂ ... through hole; 7 ₃ , 8 ₃ ... current collector; 9 ... lid 10 ... gasket; 12 ... Positive electrode output terminal 13 ... Negative electrode output terminal; 14, 15 ... Insulator; 14 ₁ , 15 ₁ ... Through hole 17 ... Connection part by caulking; 18, 24 ... Base; 19, 25 ... Punch for caulking 20 ... Over 21, 26 ... anvil; 22, 27 ... horn 31 ... container; 32, 33 ... electrode group; 32a, 33a ... upper end surface 34 ... positive current collecting tab; 35 ... negative current collecting tab; ... sandwiching plate; 38 ... lid 39 ... gasket; 40 ... negative 41 ... Negative electrode lead; 42 ... Positive electrode lead 43 ... Positive electrode output terminal; 51a, 51b ... Spacer; 52a-52c ... Partition plate 53 ... Projection; 54a-54c ... Partition plate; 55 ... Recessed portion; 56 ... Hole 58 ... Connection part by caulking; 59 ... Joint part by ultrasonic waves.

Claims (3)

A container,
An electrode group housed in the container and including a positive electrode and a negative electrode;
A plurality of positive current collecting tabs and a plurality of negative current collecting tabs extending from the positive electrode and the negative electrode of the electrode group, and
A positive electrode lead and a negative electrode lead electrically connected to the plurality of positive electrode current collecting tabs and negative electrode current collecting tabs, respectively;
A lid that closes the opening of the container;
A non-aqueous electrolyte battery comprising an output terminal provided on the lid and electrically connected to the positive electrode lead or the negative electrode lead,
At least one current collecting tab of the plurality of positive electrode current collecting tabs and the plurality of negative electrode current collecting tabs is sandwiched between sandwiching plates,
The clamping plate is fixed with one or more crimps across the at least one current collecting tab,
The non-aqueous electrolyte battery, wherein the lead, the sandwiching plate, and the at least one current collecting tab are formed by ultrasonic bonding at one or more locations.   2. The nonaqueous electrolyte battery according to claim 1, wherein each of the plurality of positive electrode current collecting tabs and the plurality of negative electrode current collecting tabs is sandwiched between sandwiching plates.   3. The method of manufacturing a non-aqueous electrolyte battery according to claim 1, wherein a clamping plate sandwiching the at least one current collecting tab is fixed by caulking, and then the lead and the at least one current collecting tab are sandwiched. A method characterized by ultrasonically joining a holding plate.

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