JP2013055020A - Battery and battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery in which a terminal shape can be easily changed, and a battery pack.SOLUTION: According to an embodiment of the present invention, there is provided a battery including: an enclosure can 1; an electrode group 5; a lid 2; first terminals 21, 23; and second terminals 22, 24. The battery group 5 is housed in the enclosure can 1, and includes a positive electrode 6 and a negative electrode 7. The lid 2 is attached to an opening of the enclosure can 1. The first terminals 21, 23 are electrically connected to the positive electrode or the negative electrode, and arranged on the top face of the lid 2. The second terminals 22, 24 are fixed on the first terminals 21, 23.

Description

  Embodiments described herein relate generally to a battery and an assembled battery.

  With the advancement of electronic devices such as mobile phones and personal computers, secondary batteries used in these devices have been required to be smaller and lighter. Lithium ion secondary batteries can be cited as secondary batteries with high energy density that meet these requirements. On the other hand, secondary batteries such as lead-acid batteries and nickel-metal hydride batteries are used as large-scale, large-capacity power sources such as electric vehicles, hybrid vehicles, electric motorcycles, and forklifts. Recently, lithium ions with high energy density are used. Development toward the adoption of secondary batteries is thriving. Lithium-ion secondary batteries that respond to this trend are being developed in larger sizes and larger capacities while taking into consideration long life and safety.

  As a power source for these applications, since the driving power is large, a battery pack containing a large number of batteries connected in series or in parallel is used. In the battery pack, electrical connection between a large number of batteries is performed by connecting terminals of the batteries with a bus bar. In connection between the terminal and the bus bar, in order to minimize the electrical resistance, a connection method in which the bus bar is directly laser welded to the terminal is performed. However, since this connection method requires expensive equipment and advanced technology, a method of easily connecting the terminal and the bus bar is desired.

  In order to easily connect the terminal and the bus bar, it is necessary to change the terminal shape according to the connection method. However, in order to produce batteries having different terminal shapes, dedicated equipment or complicated equipment is required for each terminal shape, and a large capital investment is required.

JP 2002-251990 A JP 2003-346778 A JP 2008-98012 A

  The problem to be solved by the present invention is to provide a battery and an assembled battery that can easily change the terminal shape.

  According to the first embodiment, a battery including an outer can, an electrode group, a lid, a first terminal, and a second terminal is provided. The electrode group is housed in an outer can and includes a positive electrode and a negative electrode. The lid is attached to the opening of the outer can. The first terminal is electrically connected to the positive electrode or the negative electrode and is disposed on the upper surface of the lid. The second terminal is fixed on the first terminal.

  According to the second embodiment, an assembled battery is provided that includes a plurality of the batteries of the first embodiment and a bus bar that electrically connects the second terminals of the batteries.

The partial exploded perspective view of the nonaqueous electrolyte battery concerning a 1st embodiment. The partial expansion perspective view which shows the electrode group used for the nonaqueous electrolyte battery of FIG. The perspective view which shows the part in which the positive / negative electrode terminal of the nonaqueous electrolyte battery of FIG. 1 was provided. The partial exploded perspective view of the part in which the positive / negative electrode terminal of the nonaqueous electrolyte battery of FIG. 1 was provided. The side view which looked at the battery from the long side direction about the part in which the positive / negative electrode terminal of the nonaqueous electrolyte battery of FIG. 1 was provided. The side view for demonstrating the relationship between the height of a 1st terminal and the height of a convex part. The side view which shows the initial charging process performed after laser welding. The side view which shows the initial charging process performed before laser welding. The perspective view which shows the state before welding a bus bar to the nonaqueous electrolyte battery of FIG. The side view near the positive / negative electrode terminal which looked at the nonaqueous electrolyte battery with which the bus-bar was welded from the long side direction. The perspective view which shows the part in which the positive / negative electrode terminal of the nonaqueous electrolyte battery which concerns on 2nd Embodiment was provided. The side view which looked at the battery from the long side direction about the part in which the positive / negative electrode terminal of the nonaqueous electrolyte battery which concerns on 2nd Embodiment was provided. The perspective view which shows the part in which the positive / negative electrode terminal of the nonaqueous electrolyte battery which concerns on 3rd Embodiment was provided. The perspective view which shows the part in which the positive / negative electrode terminal of the nonaqueous electrolyte battery which concerns on 4th Embodiment was provided. The perspective view of the assembled battery of the nonaqueous electrolyte battery which is not provided with the 2nd positive / negative electrode terminal.

  Hereinafter, a battery according to an embodiment of the present invention will be described with reference to the drawings. Note that the present invention is not limited to these embodiments.

(First embodiment)
1 is a partially exploded perspective view of the nonaqueous electrolyte battery according to the first embodiment, FIG. 2 is a partially developed perspective view showing an electrode group used in the nonaqueous electrolyte battery of FIG. 1, and FIG. FIG. 4 is a perspective view showing a portion of the nonaqueous electrolyte battery of FIG. 1 provided with positive and negative electrode terminals, and FIG. 4 is a partially exploded perspective view of a portion of the nonaqueous electrolyte battery of FIG. FIG. 5 is a cross-sectional view obtained by cutting the battery in the long side direction for the portion provided with the positive and negative terminals of the nonaqueous electrolyte battery of FIG. 1, and FIG. 6 shows the height of the first terminal and the height of the convex portion. FIG. 7 is a sectional view showing an initial charging process performed after laser welding, and FIG. 8 is a sectional view showing an initial charging process performed before laser welding.

  The battery shown in FIG. 1 is a sealed square nonaqueous electrolyte secondary battery. As shown in FIGS. 1 and 2, the nonaqueous electrolyte secondary battery includes an outer can 1, a lid 2, a positive electrode terminal 3, a negative electrode terminal 4, and an electrode group 5. As shown in FIG. 1, the outer can 1 has a bottomed rectangular tube shape, and is formed of a metal such as aluminum, an aluminum alloy, iron, or stainless steel, for example.

  As shown in FIG. 2, the flat electrode group 5 has a positive electrode 6 and a negative electrode 7 wound in a flat shape with a separator 8 therebetween. The positive electrode 6 is a positive electrode except for, for example, a strip-shaped positive electrode current collector made of a metal foil, a positive electrode current collector tab 6a having one end parallel to the long side of the positive electrode current collector, and at least the positive electrode current collector tab 6a. And a positive electrode active material layer 6b formed on the current collector. On the other hand, the negative electrode 7 excludes, for example, a strip-shaped negative electrode current collector made of a metal foil, a negative electrode current collector tab 7a having one end parallel to the long side of the negative electrode current collector, and at least a portion of the negative electrode current collector tab 7a. And a negative electrode active material layer 7b formed on the negative electrode current collector.

  In the positive electrode 6, the separator 8, and the negative electrode 7, the positive electrode current collecting tab 6 a protrudes from the separator 8 in the winding axis direction of the electrode group, and the negative electrode current collecting tab 7 a protrudes from the separator 8 in the opposite direction. Thus, the positive electrode 6 and the negative electrode 7 are wound while being shifted in position. As a result of such winding, as shown in FIG. 2, the electrode group 5 has the positive electrode current collecting tab 6a wound in a spiral shape from one end face and is wound in a spiral form from the other end face. The negative electrode current collection tab 7a protrudes. An electrolytic solution (not shown) is impregnated in the electrode group 5.

  As shown in FIG. 3, the rectangular plate-like lid 2 is seam welded to the opening of the outer can 1 by, for example, a laser. The lid 2 is made of a metal such as aluminum, aluminum alloy, iron or stainless steel, for example. The lid 2 and the outer can 1 are preferably formed from the same type of metal. The electrolyte injection hole 18 is opened in the lid 2 and sealed with a sealing lid (not shown) after the electrolyte injection.

  As shown in FIG. 1, a safety valve 9 is provided near the center of the outer surface of the lid 2. The safety valve 9 has a rectangular recess 9a provided on the outer surface of the lid 2 and an X-shaped groove 9b provided in the recess 9a. The groove 9b is formed, for example, by press-molding the lid 2 in the plate thickness direction. When the battery internal pressure rises, the groove 9b is broken, so that the battery internal pressure is released and the battery can be prevented from being ruptured.

  On the outer surface of the lid 2, rectangular recesses 10 are provided on both sides of the safety valve 9. The positive electrode terminal 3 is accommodated in one recess 10, and the negative electrode terminal 4 is accommodated in the other recess 10. Each recess 10 is provided with a through hole 11. The positive electrode terminal 3 includes a first positive electrode terminal 21 and a second positive electrode terminal 22. On the other hand, the negative electrode terminal 4 includes a first negative electrode terminal 23 and a second negative electrode terminal 24.

  As shown in FIGS. 1, 3, 4 and 5, the first positive electrode terminal 21 and the first negative electrode terminal 23 are respectively a rectangular pedestal portion 25a and a rectangular convex portion 25b protruding from the upper surface of the pedestal portion 25a. And a shaft portion 26 extending downward from the pedestal portion 25a. As shown in FIG. 6, it is desirable that the height H of the convex portion 25b be in the range of 10% to 50% of the height A of the first positive terminal 21 (or the first negative terminal 23). This is because the contact resistance between the first terminal and the second terminal is lowered within this range. Here, the height H of the convex portion 25b is a height from the upper surface of the pedestal portion 25a to the upper surface of the convex portion 25b. The height A of the first positive electrode terminal 21 (or the first negative electrode terminal 23) is the height from the upper surface of the lid 2 to the upper surface of the convex portion 25b.

  As shown in FIGS. 3 to 5, the second positive electrode terminal 22 and the second negative electrode terminal 24 are disposed on the upper surface of the substantially rhombus pedestal portion 27 having the convex portion 27 a and the convex portion 27 a of the pedestal portion 27, respectively. And a cylindrical projection 28. As shown in FIGS. 4 and 5, in the second positive electrode terminal 22, the peripheral edge portion 27 b of the pedestal portion 27 is disposed on the pedestal portion 25 a of the first positive electrode terminal 21. Further, the convex portion 25 b of the first positive electrode terminal 21 is disposed in the convex portion 27 a of the pedestal portion 27. On the other hand, in the second negative electrode terminal 24, the peripheral edge portion 27 b of the pedestal portion 27 is disposed on the pedestal portion 25 a of the first negative electrode terminal 23. Further, the convex portion 25 b of the first negative electrode terminal 23 is disposed in the convex portion 27 a of the pedestal portion 27. About each of the 2nd positive electrode terminal 22 and the 2nd negative electrode terminal 24, the peripheral part 27b of the base part 27 is fixed on the base part 25a by laser welding. In FIG. 5, the laser welding location is indicated by 29.

  Thus, by fixing the second positive and negative terminals 22 and 24 to the first positive and negative terminals 21 and 23 by laser welding, the contact resistance between the first positive and negative terminals 21 and 23 and the second positive and negative terminals 22 and 24 is achieved. Therefore, the voltage drop of the battery and the assembled battery can be further reduced.

  Laser welding can be performed before or after the initial charge of the battery. Among these, it is desirable to carry out after the first charge. As illustrated in FIG. 7, after the second positive and negative terminals 22 and 24 are fixed to the first positive and negative terminals 21 and 23 by laser welding, the upper surface of the protruding portion 28 of the second positive and negative terminals 22 and 24 is charged. When initial charging is performed by applying the probe 40, hydrolysis of an electrolyte (for example, lithium salt) proceeds due to welding heat during laser welding, hydrofluoric acid is generated, and resistance increases due to the hydrofluoric acid. On the other hand, as illustrated in FIG. 8, when the charge probe 40 is applied to the upper surfaces of the convex portions 25 b of the first positive and negative electrode terminals 21 and 23 and the initial charge is performed, the water that is an inevitable impurity in the electrolyte solution by the initial charge. Is electrolyzed. After the initial charging, when the second positive and negative terminals 22 and 24 are fixed to the first positive and negative terminals 21 and 23 by laser welding, hydrolysis of the electrolyte (for example, lithium salt) due to welding heat at that time is suppressed, Increase can be suppressed. In addition, you may perform required processes, such as aging, after an initial charge and before laser welding.

  In the case of a lithium ion secondary battery using a carbon-based material as the negative electrode active material, for example, aluminum or an aluminum alloy is used for the positive electrode terminal 3, and for example, copper, nickel, or nickel is plated on the negative electrode terminal 4. Metals such as iron are used. When lithium titanate is used as the negative electrode active material, aluminum or an aluminum alloy may be used for the negative electrode terminal 4 in addition to the above.

  The external insulator 15 is used for caulking and fixing the positive electrode terminal 3 and the negative electrode terminal 4, respectively. As shown in FIG. 1, each of the external insulators 15 includes a cylindrical tube portion 15a and a flange portion 15b formed in a bowl shape at one opening end of the tube portion 15a. The cylindrical portion 15 a of the external insulator 15 is inserted into the through hole 11 in the recess 10 of the lid 2, and the lower opening end of the cylindrical portion 15 a is inserted into the through hole 12 c of the internal insulator 12. The flange portion 15 b of the external insulator 15 covers the periphery of the through hole 11 in the concave portion 10 of the lid 2. The pedestal portion 25a and the convex portion 25b of the first positive electrode terminal 21 and the first negative electrode terminal 23 are accommodated in spaces surrounded by the flange portion 15b of the external insulator 15, respectively.

  As shown in FIG. 1, the positive and negative internal insulators 12 are respectively disposed on the back surface of the lid 2. One internal insulator 12 is disposed at a location corresponding to the recess 10 in which the positive electrode terminal 3 is accommodated, and the other internal insulator 12 is disposed at a location corresponding to the recess 10 in which the negative electrode terminal 4 is accommodated. Yes. There is a gap between the two internal insulators 12, and the safety valve 9 faces this space. The internal insulator 12 includes a rectangular top plate 12a, a side plate 12b extending downward from the periphery of the top plate 12a, and a through hole 12c opened in the insulating plate 12a.

  The positive electrode lead 13 is electrically connected to the positive electrode 6. The positive electrode lead 13 includes a rectangular support plate 13a, a strip-shaped current collector 13b extending downward from the short side of the support plate 13a, and a through hole 13c opened in the support plate 13a. The current collector 13b is welded to the positive electrode current collecting tab 6a.

  The negative electrode lead 14 is electrically connected to the negative electrode 7. The negative electrode lead 14 includes a rectangular support plate 14a, a strip-shaped current collecting portion 14b extending downward from the short side of the support plate 14a, and a through hole 14c opened in the support plate 14a. The current collector 14b is welded to the negative electrode current collector tab 7a.

  The material of the positive and negative electrode leads 13 and 14 is not particularly specified, but is preferably the same material as that of the positive and negative electrode terminals 3 and 4. For example, when the terminal material is aluminum or an aluminum alloy, the lead material is preferably aluminum or an aluminum alloy. In addition, when the terminal is copper, it is desirable that the material of the lead is copper.

  The method for welding the current collecting portions 13b and 14b of the positive and negative electrode leads 13 and 14 to the positive and negative electrode current collecting tabs 6a and 7a is not particularly limited, and examples thereof include ultrasonic welding and laser welding.

  The shaft portion 26 of the first positive electrode terminal 21 is inserted into the external insulator 15, the through hole 11 of the lid 2, the through hole 12 c of the internal insulator 12, and the through hole 13 c of the support plate 13 a of the positive electrode lead 13. . The shaft portion 26 is expanded in diameter by caulking and is caulked and fixed to the lid 2, the internal insulator 12, and the positive electrode lead 13. On the other hand, the shaft portion 26 of the first negative electrode terminal 23 is inserted into the external insulator 15, the through hole 11 of the lid 2, the through hole 12 c of the internal insulator 12, and the through hole 14 c of the support plate 14 a of the negative electrode lead 14. ing. The shaft portion 26 is enlarged and deformed by caulking, and is caulked and fixed to the lid 2, the internal insulator 12, and the negative electrode lead 14. As a result, the positive and negative terminals 3 and 4 and the lid 2 are fixed in a state where insulation and airtightness are ensured, and the first positive and negative terminals 21 and 23 and the positive and negative leads 13 and 14 are electrically connected. Fixed in a secured state.

  Both the external insulator 15 and the internal insulator 12 are desirably resin molded products. In order to ensure airtightness by caulking, it is desirable to use a molded product using a resin material having a melting point higher than that of the internal insulator 12 for the external insulator 15. Thereby, the airtightness at a high temperature (for example, 100 ° C. or less) can be further improved.

  Both ends of the electrode group 5 electrically connected to the positive and negative leads 13 and 14 are covered with a spacer 16 made of a resin molded product and insulated from the outer can 1. That is, the first side plate 16 a of the spacer 16 covers the current collecting portions 13 b and 14 b of the positive and negative electrode leads 13 and 14 disposed on the end surface of the electrode group 5. The second side plate 16 b covers the outermost periphery of both ends of the electrode group 5 and is fixed to the outermost periphery of the electrode group 5 with an insulating tape (not shown). A bottom plate (not shown) of the spacer 16 covers a part of the bottom surface on the outermost periphery of the electrode group 5. By using the spacer 16, the electrode group 5 and the positive and negative electrode leads 13 and 14 can be insulated from the outer can 1.

  When a battery pack is manufactured using a plurality of the batteries described above, the second positive and negative electrode terminals 22 and 24 of each battery are electrically connected by the bus bar 30. An example is shown in FIGS. 9 is a perspective view showing a state before the bus bar is welded to the non-aqueous electrolyte battery of FIG. 1, and FIG. 10 is obtained by cutting the non-aqueous electrolyte battery with the bus bar welded in parallel in the long side direction. It is sectional drawing of the positive / negative terminal vicinity.

  The bus bar 30 functions as a wiring between the batteries, but can also be used to extract electric energy from the batteries to the outside. The bus bar 30 has a rectangular plate shape and has circular through holes 30a in the vicinity of both short sides. The bus bar 30 is made of a conductive material such as metal (for example, aluminum, aluminum alloy, copper, copper alloy). As shown in FIG. 9, after inserting the protrusions 28 of the second positive and negative terminals 22 and 24 into the circular through hole 30a of the bus bar 30, the vicinity of the boundary between the circular through hole 30a and the protrusion 28 is connected by, for example, welding. . Since the height of the protruding portion 28 is higher than the height A of the first positive and negative electrode terminals 21 and 23, the protruding portion 28 protrudes from the bus bar 30. For this reason, it is easy to insert a welding electrode into a welding location, and the vicinity of the boundary between the circular through hole 30a and the protruding portion 28 can be connected, for example, by arc welding that is inexpensive and technically easy. Thereby, since welding work becomes easy, manufacturing cost can be suppressed low.

The case where an assembled battery is comprised from the battery which is not provided with the 2nd positive / negative electrode terminal is demonstrated with reference to FIG. FIG. 15 is a perspective view of an assembled battery manufactured from a nonaqueous electrolyte battery that does not include the second positive and negative electrode terminals. The assembled battery 31 includes a plurality of nonaqueous electrolyte batteries 32 _{1 to} 32 ₃ . The positive and negative terminals 3 and 4 of the batteries 32 _{1 to} 32 ₃ are not provided with the second positive and negative terminals, and the first positive and negative terminals 21 and 21 have the same structure as that of FIG. 23. The bus bar 30 has a thin portion 30b for laser welding near both short sides. The pedestal 25a of the positive and negative terminals 3 and 4 and the thin part 30b for laser welding are connected by overlapping laser welding. The reason why laser welding is used is to perform fine and high-precision welding. However, the use of laser welding increases the manufacturing cost because it requires expensive equipment and advanced technology. Results of the laser welding, the bus bar 30 electrically connects the negative electrode terminal 4 and the positive electrode terminal 3 of the battery 32 _{and second} batteries 32 ₁ and the positive electrode terminal 3 of the battery 32 the negative terminal 4 _of the battery 32 ₃ Connect electrically. That is, the batteries 32 _{1 to} 32 ₃ are connected in series by the bus bar 30.

  According to 1st Embodiment, since the 2nd terminal is being fixed on the 1st terminal, compared with the case where the resistance between a 1st terminal and a 2nd terminal is provided in the upper surface of a lid | cover. Can be lowered. When this second terminal is used as an external terminal for connecting a wiring such as a bus bar or lead, the voltage drop of the battery and the assembled battery can be reduced. Further, since the second terminal is a separate component from the first terminal, the shape and material can be freely changed to those suitable for wiring connection. For this reason, a degree of freedom can be given to the method of connecting the wiring to the second terminal, and the method of connecting the wiring to the second terminal can be facilitated. Furthermore, when it is necessary to change the wiring to be used and the connection method for each user, only the second terminal needs to be changed, so that the design can be easily changed according to the user's request.

(Second Embodiment)
In 1st Embodiment, although the 1st positive / negative terminal 21 and 23 which has the convex part 25b was used, it is not restricted to this, For example, using the 1st positive / negative terminal 21 and 23 which does not have the convex part 25b is used. it can. An example of this is shown in FIGS. 11 and 12, members similar to those in FIGS. 1 to 10 are denoted by the same reference numerals and description thereof is omitted. FIG. 11 is a perspective view of a portion provided with the positive and negative electrode terminals of the nonaqueous electrolyte battery according to the second embodiment, and FIG. 12 is provided with the positive and negative electrode terminals of the nonaqueous electrolyte battery according to the second embodiment. It is the side view which looked at the battery from the long side direction about the obtained part.

  As shown in FIG.11 and FIG.12, the 1st positive electrode terminal 21 and the 1st negative electrode terminal 23 have the base part 25a and the axial part 26 extended below from the base part 25a, respectively. On the other hand, the second positive electrode terminal 22 and the second negative electrode terminal 24 are respectively disposed on the upper surface of the substantially rhombus pedestal portion 27c, the fitting portions 27d provided at four positions on the side surface of the pedestal portion 27c, and the pedestal portion 27c. And a cylindrical projection 28. The pedestals 27 c of the second positive and negative terminals 22 and 24 are disposed on the pedestals 25 a of the first positive and negative terminals 21 and 23. Further, the fitting portions 27d of the second positive and negative terminals 22 and 24 are fitted into the periphery of the pedestal portion 25a of the first positive and negative terminals 21 and 23. The pedestal portion 27c and the fitting portion 27d are fixed by laser welding from the upper surface of the pedestal portion 25a. In FIG. 12, the weld location is indicated by 29.

  According to the second embodiment, since the second terminal is fixed on the first terminal, if the second terminal is used as an external terminal for connecting wiring such as a bus bar or a lead, the voltage drop of the battery and the assembled battery Can be reduced. Further, since the second terminal is a separate component from the first terminal, the shape and material can be freely changed to those suitable for wiring connection. For this reason, a degree of freedom can be given to the method of connecting the wiring to the second terminal, and the method of connecting the wiring to the second terminal can be facilitated. Furthermore, when it is necessary to change the wiring to be used and the connection method for each user, only the second terminal needs to be changed, so that the design can be easily changed according to the user's request. Further, since the first terminal does not have a convex portion, it is easy to apply a charging probe for initial charging, and the initial charging before laser welding the second terminal to the first terminal can be performed efficiently.

(Third embodiment)
In the first and second embodiments, the shape of the protrusions 28 of the second positive and negative terminals 22 and 24 is a cylindrical shape. However, the shape is not limited to this, and for example, a columnar shape, a rectangular tube shape, a prismatic shape, a side surface shape A part of the surface may be a flat surface, a screw shape, or the like. An example of this is shown in FIGS. FIG. 13 is a partially exploded perspective view of a portion provided with positive and negative terminals of a nonaqueous electrolyte battery according to the third embodiment, and FIG. 14 is a positive and negative sign of another nonaqueous electrolyte battery according to the third embodiment. It is a partial exploded perspective view about the part in which the pole terminal was provided. 13 and 14, members similar to those in FIGS. 1 to 12 are denoted by the same reference numerals and description thereof is omitted.

  In the protruding portions 28 of the second positive and negative terminals 22 and 24 shown in FIG. 13, a lower portion 28a has a substantially cylindrical shape, and an upper portion 28b is formed of a flat plate. Thus, by providing the flat surface 28b on a part of the side surface of the protruding portion 28, the rectangular plate-like bus bar 30 can be connected to the flat surface 28b.

Examples of the connection method include resistance welding and ultrasonic welding. Although two planes 28b are provided in FIG. 13, one plane may be used.

  The protrusions 28 of the second positive and negative terminals 22 and 24 shown in FIG. 14 have a screw shape. The protrusion 28 is connected to the circular through hole 30 a of the bus bar 30 by fitting the screw-like protrusion 28 into the circular through hole 30 a of the bus bar 30.

  Thus, by changing the shape of the second positive and negative terminals 22 and 24, it is possible to cope with various connection methods such as fusion welding, pressure welding, brazing, and fastening.

  According to the third embodiment, since the second terminal is fixed on the first terminal, if the second terminal is used as an external terminal for connecting a wiring such as a bus bar or a lead, the voltage drop of the battery and the assembled battery Can be reduced. Further, since the second terminal is a separate component from the first terminal, the shape and material can be freely changed to those suitable for wiring connection. Specifically, arc welding is adopted when the shape of the projecting portion of the second terminal is cylindrical, resistance welding or ultrasonic welding is adopted when the projecting portion is shaped to have a flat side surface, and fitting is adopted when the projecting portion is made into a screw shape. be able to. Furthermore, when it is necessary to change the wiring to be used and the connection method for each user, only the second terminal needs to be changed, so that the design can be easily changed according to the user's request.

  Hereinafter, a positive electrode, a negative electrode, a separator, and an electrolytic solution that can be used in each embodiment will be described.

  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. Although it does not specifically limit as a positive electrode active material, The oxide, sulfide, polymer, etc. which can occlude / 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. The negative electrode active material is not particularly limited, and metal oxides, metal sulfides, metal nitrides, alloys, and the like that can occlude and release lithium can be used. Preferably, the lithium ion occlusion and release potential is metal lithium. It is a substance that becomes noble 0.4V or more with respect to the potential. 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, silicon oxide, etc. Among them, 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.

As the electrolytic solution, a nonaqueous electrolytic solution prepared by dissolving an electrolyte (for example, lithium salt) in a nonaqueous solvent is used. 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 arsenic hexafluoride (LiAsF ₆ ), and trifluorometa. A lithium salt such as lithium sulfonate (LiCF ₃ SO ₃ ) can be given. 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.

  According to the embodiment described above, since the second terminal is fixed on the first terminal, it is possible to provide a battery having a degree of freedom in the connection method between the external terminal and the wiring such as the bus bar at a low cost. it can. As a result, sales expansion can also be expected.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... Exterior can, 2 ... Cover, 3 ... Positive electrode terminal, 4 ... Negative electrode terminal, 5 ... Electrode group, 6 ... Positive electrode, 6a ... Positive electrode current collection tab, 7 ... Negative electrode, 7a ... Negative electrode current collection tab, 8 ... Separator, DESCRIPTION OF SYMBOLS 9 ... Safety valve, 9a ... Recessed part, 9b ... Groove part, 10 ... Recessed part, 11 ... Through-hole, 12 ... Internal insulator, 13 ... Positive electrode lead, 14 ... Negative electrode lead, 13a, 14a ... Support plate, 13b, 14b ... Current collection Part, 13c, 14c ... through-hole, 15 ... external insulator, 16 ... spacer, 18 ... liquid inlet, 21 ... first positive terminal, 22 ... second positive terminal, 23 ... first negative terminal, 24 ... second Negative electrode terminal, 25a ... pedestal part, 25b ... convex part, 26 ... shaft part, 27c ... pedestal part, 27d ... fitting part, 28 ... projecting part, 29 ... laser welding location, 30 ... bus bar, 31 ... assembled battery, 40 ... Charging probe.

Claims (7)

An outer can,
An electrode group housed in the outer can and including a positive electrode and a negative electrode;
A lid attached to the opening of the outer can;
A first terminal electrically connected to the positive electrode or the negative electrode and disposed on an upper surface of the lid;
And a second terminal fixed on the first terminal.   The battery according to claim 1, wherein the second terminal has a protrusion.   The battery according to claim 2, wherein the second terminal is fixed on the first terminal by laser welding.   The battery according to claim 2, wherein the protruding portion of the second terminal has a cylindrical shape.   The battery according to claim 2, wherein the protruding portion of the second terminal has a flat side surface.   The battery according to claim 2, wherein the protruding portion of the second terminal has a screw shape. A plurality of the batteries according to any one of claims 1 to 6,
And a bus bar for electrically connecting the second terminals of the battery.

Images