secondary batteries

Abstract

To provide a reliable secondary battery with a more stable working pressure of a current interruption mechanism.SOLUTION: A conductive member 61 having a conductive member opening 61f on an electrode body side is located on an inner battery side of a sealing plate 2 through a first insulation member 10. An insertion part 7b of a positive electrode terminal 7 is inserted into a third terminal insertion hole 61c of the conductive member 61 and connected to the conductive member 61. The conductive member 61 has a pressing protrusion 61e protruding toward the first insulation member 10 at a portion opposite the first insulation member 10. An end on an electrode body side of the insertion part 7b is caulked and fixed to the conductive member 61. A first groove 10x provided on the first insulation member 10 is positioned outside of the insertion part 7b from the outer edge of the caulked portion of the insertion part 7b in a surface direction perpendicular to the thickness direction of the sealing plate 2. A second groove 10y is provided on the other side of the first groove 10x in the first insulation member 10. The distance from the terminal insertion hole to the first groove 10x differs from the distance from the terminal insertion hole to the second groove 10y.SELECTED DRAWING: Figure 18

Description

[Technical Field]

[0001] The present invention relates to a secondary battery. [Background technology]

[0002] For driving power sources in electric vehicles (EVs) and hybrid electric vehicles (HEVs, PHEVs) In this regard, secondary batteries such as alkaline secondary batteries and non-aqueous electrolyte secondary batteries are used.

[0003] These prismatic secondary batteries include a cylindrical prismatic exterior body with a bottom and an opening, and a sealing member for sealing the opening. The battery case is composed of a positive electrode plate, a negative electrode plate, and a separator. The electrode assembly, which is made up of a cathode and an anode, is housed together with an electrolyte. The positive terminal is electrically connected to the positive plate via the positive current collector, and the negative terminal is It is electrically connected to the negative electrode plate via a current collector.

[0004] When the pressure inside the battery case exceeds a certain value due to overcharging, etc., it activates and separates the electrode body and terminals. A prismatic secondary battery equipped with a current interruption mechanism that cuts off the conductive path between the electrodes and interrupts the current has been proposed. (Patent Document 1 below). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-157099 Summary of the Invention [Problem to be solved by the invention]

[0006] By providing a current interruption mechanism in the secondary battery, it becomes a highly reliable secondary battery against overcharging, etc. However, there is a need to develop more reliable secondary batteries.

[0007] The present invention provides a highly reliable secondary battery with a more stable operating pressure for a current interruption mechanism. The main purpose is to [Means for solving the problem]

[0008] a sealing plate that seals the opening; a conductive member disposed on the electrode body side of the sealing plate via a first insulating member; a current collecting member that electrically connects the positive electrode plate or the negative electrode plate to the conductive member; and a terminal that is electrically connected to the positive electrode plate or the negative electrode plate via the current collecting member and the conductive member, wherein the terminal is inserted into a terminal mounting hole provided in the sealing plate, a terminal insertion hole provided in the first insulating member, and a terminal insertion hole provided in the conductive member, and is connected to the conductive member, and at least one of the conductive member and the sealing plate has a pressing protrusion that protrudes toward the first insulating member at a portion facing the first insulating member, and the first insulating member is a portion that is disposed between the sealing plate and the conductive member, a first groove portion at a position farther from the terminal insertion hole provided in the first insulating member than the portion pressed by the pressing protrusion, an end portion of the terminal on the electrode body side is crimped and fixed to the conductive member, the first groove portion is arranged outside the terminal from the outer peripheral edge of the crimped portion of the terminal in a plane direction perpendicular to the thickness direction of the sealing plate, the first insulating member has a second groove portion in a portion arranged between the sealing plate and the conductive member and at a position farther from the terminal insertion hole provided in the first insulating member than the portion pressed by the pressing protrusion, the first groove portion is arranged on a surface of the first insulating member facing one of the sealing plate and the conductive member, the second groove portion is arranged on a surface of the first insulating member facing the other of the sealing plate and the conductive member, and the first groove portion and the second groove portion are at different distances from the terminal insertion hole.

[0009] In one embodiment of the secondary battery of the present invention, a pressing protrusion is formed on at least one of the conductive member and the sealing plate at a position facing the first insulating member, so that the first insulating member arranged between the conductive member and the sealing plate is pressed more strongly by the pressing protrusion, thereby suppressing the movement of gas. [Effects of the Invention]

[0010] According to the present invention, a highly reliable secondary battery can be provided. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a perspective view of a secondary battery according to an embodiment; [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] FIG. 2 is a plan view of a positive electrode plate according to the embodiment. [Figure 4] FIG. 2 is a plan view of a negative electrode plate according to the embodiment. [Figure 5] FIG. 2 is a plan view of an electrode element according to an embodiment. [Figure 6] FIG. 2 is a perspective view of a positive electrode terminal, an outer insulating member, a sealing plate, a first insulating member, and a conductive member. [Figure 7] FIG. 10 is a bottom view of the sealing plate after the components have been attached. [Figure 8] 8A is a cross-sectional view taken along line VIIIA-VIIIA in FIG. 7, FIG. 8B is a cross-sectional view taken along line VIIIB-VIIIB in FIG. 7, and FIG. 8C is a cross-sectional view taken along line VIIIC-VIIIC in FIG. [Figure 9] FIG. [Figure 10] FIG. 10A is a perspective view of the first positive electrode current collector and the second insulating member before assembly, FIG. 10B is a perspective view of the first positive electrode current collector and the second insulating member after assembly, and FIG. 10C is a perspective view of the first positive electrode current collector and the second insulating member after fixing. [Figure 11] 8B is an enlarged view of the vicinity of the connection portion between the deformation plate and the first positive electrode current collector in FIG. 8A. FIG. [Figure 12]FIG. 2 is a perspective view of a sealing plate with components attached thereto. [Figure 13] FIG. 2 is a cross-sectional view taken along the longitudinal direction of the sealing plate in the vicinity of the negative electrode terminal. [Figure 14] 10A and 10B are diagrams showing a method of attaching a tab to a current collecting member. [Figure 15] FIG. [Figure 16] FIG. 16A is a view before the cover portion is attached to the first insulating member and the second insulating member, and FIG. 16B is a view after the cover portion has been attached to the first insulating member and the second insulating member. [Figure 17] Figure 17A is a cross-sectional view along the longitudinal direction of the sealing plate near the positive electrode terminal after the cover part has been attached, and Figure 17B is a cross-sectional view along the lateral direction of the sealing plate near the connection part between the cover part and the first insulating member. [Figure 18] 8B is an enlarged view of the vicinity of the connection portion between the positive electrode terminal and the conductive member in FIG. 8A. [Figure 19] Figure 19A is a diagram of the secondary battery according to the modified example before the cover portion is attached to the first insulating member and the second insulating member, and Figure 19B is a diagram of the secondary battery according to the modified example after the cover portion is attached to the first insulating member and the second insulating member. [Figure 20] FIG. 10 is a cross-sectional view of the vicinity of a current interruption mechanism of a secondary battery according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0012] The configuration of a prismatic secondary battery 20 as a secondary battery according to the embodiment will be described below. The present invention is not limited to the following embodiments.

[0013] FIG. 1 is a perspective view of a prismatic secondary battery 20. FIG. 2 is a cross-sectional view taken along line II-II in FIG. As shown in FIGS. 1 and 2, the prismatic secondary battery 20 has a rectangular outer periphery in the form of a rectangular cylinder with an opening and a bottom. The battery includes a battery case 100 made up of a housing 1 and a sealing plate 2 that seals the opening of the rectangular housing 1. The rectangular exterior body 1 and the sealing plate 2 are preferably made of metal, for example, aluminum. The rectangular exterior body 1 contains a positive electrode plate and a negative electrode plate. A laminated electrode assembly 3, in which plates are stacked with separators interposed therebetween, is housed together with an electrolyte. An insulating sheet 14 made of resin is disposed between the pole body 3 and the rectangular exterior body 1.

[0014] A positive electrode tab 40 and a negative electrode tab 50 are provided at the end of the electrode body 3 on the sealing plate 2 side. The positive electrode tab 40 is electrically connected to the positive electrode terminal 7 via the second positive electrode current collector 6b and the first positive electrode current collector 6a. The negative electrode tab 50 is connected to the second negative electrode current collector 8b and the first negative electrode current collector 8a. The first positive electrode current collector 6a and the second positive electrode current collector 6b are electrically connected to the negative electrode terminal 9. The first negative electrode current collector 8a and the second negative electrode current collector 6b constitute the positive electrode current collector 6. 8b constitutes the negative electrode current collecting member 8. In addition, the positive electrode current collecting member 6 can be made into one component. The negative electrode current collecting member 8 can also be made into a single component.

[0015] The positive electrode terminal 7 is fixed to the sealing plate 2 via an external insulating member 11 made of resin. The terminal 9 is fixed to the sealing plate 2 via an external insulating member 13 made of resin. It is preferable that the material is made of metal, and more preferably made of aluminum or an aluminum alloy. The negative electrode terminal 9 is preferably made of a metal, more preferably made of copper or a copper alloy. preferable.

[0016] When the pressure inside the battery case 100 reaches or exceeds a predetermined value, the conductive path between the positive electrode plate and the positive electrode terminal 7 is When the positive electrode plate is turned on, a current interruption mechanism 60 is provided to interrupt the conductive path between the positive electrode plate and the positive electrode terminal 7. It is preferable to provide a current interruption mechanism in the conductive path between the negative electrode plate and the negative electrode terminal 9. That's fine.

[0017] The sealing plate 2 has a structure that breaks when the pressure inside the battery case 100 exceeds a predetermined value, and A gas exhaust valve 17 is provided to exhaust gas from the battery case 100 to the outside. The operating pressure of the gas exhaust valve 17 is set to a value greater than the operating pressure of the current interruption mechanism 60 .

[0018] The sealing plate 2 is provided with an electrolyte injection hole 15. The electrolyte injection hole 15 is used to inject the electrolyte into the battery case 1. After the electrolyte is poured into the electrolyte injection hole 15, the electrolyte injection hole 15 is sealed with a sealing plug 16. It is preferable to use a blind rivet as 16.

[0019] Next, a method for manufacturing the prismatic secondary battery 20 and the details of each component will be described.

[0020] [Preparation of positive electrode plate] The positive electrode active material is lithium nickel cobalt manganese composite oxide, and the binder is polycarbonate. Polyvinylidene difluoride (PVdF), carbon material as a conductive agent, and N-methylcellulose as a dispersion medium. A positive electrode slurry containing methyl-2-pyrrolidone (NMP) is prepared. The paste is applied to both sides of a rectangular aluminum foil with a thickness of 15 μm as the positive electrode substrate. By drying it, the NMP in the positive electrode slurry is removed, and the positive electrode active material is left on the positive electrode substrate. Then, the positive electrode active material mixture layer is compressed to a predetermined thickness. The positive electrode plate thus obtained is cut into a predetermined shape.

[0021] FIG. 3 is a plan view of the positive electrode plate 4 produced by the above-mentioned method. As shown in FIG. The battery has a main body portion in which positive electrode active material mixture layers 4b are formed on both sides of a rectangular positive electrode substrate 4a. The positive electrode core 4a protrudes from the end of the main body, and the protruding positive electrode core 4a is connected to the positive electrode tab 4. 0. The positive electrode tab 40 may be a part of the positive electrode substrate 4a as shown in FIG. Alternatively, another member may be connected to the positive electrode core 4a to form the positive electrode tab 40. In the portion 40 adjacent to the positive electrode active material mixture layer 4b, the electric resistance of the positive electrode active material mixture layer 4b is It is preferable to provide a positive electrode protection layer 4d having an electrical resistance greater than that of the positive electrode protection layer 4d.

[0022] [Preparation of negative electrode plate] Graphite as the negative electrode active material, styrene butadiene rubber (SBR) as a binder, and a thickener A negative electrode slurry containing carboxymethyl cellulose (CMC) as a binder and water is prepared. This negative electrode slurry was applied to both sides of a rectangular copper foil with a thickness of 8 μm, which served as a negative electrode substrate. Then, the negative electrode slurry is dried to remove water, and the negative electrode is formed on the negative electrode substrate. The negative electrode active material mixture layer is then compressed to a predetermined thickness. The negative electrode plate thus obtained is cut into a predetermined shape.

[0023] FIG. 4 is a plan view of the negative electrode plate 5 produced by the above-mentioned method. As shown in FIG. The negative electrode battery has a main body portion in which negative electrode active material mixture layers 5b are formed on both sides of a rectangular negative electrode substrate 5a. The negative electrode core 5a protrudes from the end of the main body, and the protruding negative electrode core 5a is connected to the negative electrode tab 5 0. Note that the negative electrode tab 50 may be a part of the negative electrode substrate 5a as shown in FIG. Alternatively, another member may be connected to the negative electrode substrate 5a to form the negative electrode tab 50.

[0024] [Fabrication of electrode elements] 50 positive electrode plates 4 and 51 negative electrode plates 5 were prepared by the above-mentioned method, and these were then mixed with polyolefin. The electrodes are stacked with rectangular separators made of polyethylene interposed therebetween to prepare stacked electrode elements (3a, 3b). As shown in FIG. 5, the stacked electrode elements (3a, 3b) have a positive electrode at one end. The positive electrode tabs 40 of the electrode plates 4 are stacked, and the negative electrode tabs 50 of the negative electrode plates 5 are stacked. Separators are placed on both outer surfaces of the electrode body elements (3a, 3b), and the respective The electrode plates and separators can be fixed in a stacked state. An adhesive layer is provided to bond the separator to the positive electrode plate 4 and the separator to the negative electrode plate 5, respectively. It can also be set to

[0025] The size of the separator in plan view is the same as or larger than the negative electrode plate 5. It is preferable to place the positive electrode plate 4 between two separators and heat the periphery of the separator. After the welding, the positive electrode plate 4 and the negative electrode plate 5 may be stacked. , 3b) When producing the separator, a long separator is used, and the long separator is The positive electrode plate 4 and the negative electrode plate 5 can be stacked in a folded state. Alternatively, the positive electrode plate 4 and the negative electrode plate 5 can be stacked on top of each other while winding a long separator using a roller.

[0026] [Installing each part on the sealing plate (positive electrode side)] 2 and 6 to 8, the attachment of the positive electrode terminal 7 and the first positive electrode current collector 6a to the sealing plate 2 will be described. The following describes the method of attaching the positive terminal 7 and the structure around the positive terminal 7. 7 is a perspective view of an outer insulating member 11, a sealing plate 2, a first insulating member 10, and a conductive member 61. FIG. 7 is a view showing the inner surface of the battery of the sealing plate 2 after each component has been attached. 8A, the positive electrode tab 40 and the negative electrode tab 50 are not shown. 8A is a cross-sectional view of the positive electrode terminal 7 and its vicinity taken along line VIIIA-VIIIA. 8B is a cross-sectional view of the positive electrode terminal 7 and its vicinity taken along line VIIIB-VIIIB in FIG. 8 is a cross-sectional view of the vicinity of the positive electrode terminal 7 taken along line VIIIC-VIIIC in FIG.

[0027] In the sealing plate 2, an external insulating member 11 is provided on the outer surface of the battery near the positive electrode terminal mounting hole 2a. and a first insulating member 10 and a conductive member 21 are disposed on the inner surface of the battery in the vicinity of the positive electrode terminal mounting hole 2a. Next, insert the insertion portion 7b provided on one side of the flange portion 7a of the positive terminal 7. , the first terminal insertion hole 11a of the outer insulating member 11, the positive electrode terminal attachment hole 2a of the sealing plate 2, The second terminal insertion hole 10d of the insulating member 10 and the third terminal insertion hole 61c of the conductive member 61 are Then, the tip of the insertion portion 7b is crimped onto the conductive member 61. The positive electrode terminal 7, the outer insulating member 11, the sealing plate 2, the first insulating member 10, and the conductive member 61 are fixed. In addition, since the insertion portion 7b of the positive electrode terminal 7 is crimped, the tip side of the insertion portion 7b The conductive member 61 has an expanded diameter portion formed therein, the expanded diameter portion having an outer diameter larger than the inner diameter of the third terminal insertion hole 61c. The crimped portion of the insertion portion 7b of the positive terminal 7 and the conductive member 61 are laser welded. It is preferable that the first insulating member 10 and the outer insulating member 11 are welded by the following method. Each of them is preferably made of resin.

[0028] As shown in FIGS. 6 and 8, the first insulating member 10 is disposed so as to face the sealing plate 2. The first insulating member body 10a has a length of the sealing plate 2. A pair of first side walls 10b are provided at both ends in the hand direction. A pair of second side walls 10c are provided at both ends of the sealing plate 2 in the short direction of the portion 10a. The first insulating member body 10a is provided with a second terminal insertion hole 10d. A first connecting portion 10e is provided on the outer surface of the wall 10c. It is preferable that the second side wall 10c is provided at the center in the longitudinal direction of the plate 2. A second connecting portion 10f is provided on the outer surface of the second side wall 10c. It is preferable that the second side wall 10c is provided at the end of the second side wall 10c in the longitudinal direction of the sealing plate 2. The insulating member main body 10a has a first groove 10x on the surface thereof facing the sealing plate 2. A second groove 10y is provided on the surface of the main body 10a facing the conductive member 61. 0y is located on the outer circumferential side of the first groove portion 10x. The side surface has recesses 10g at the four corners.

[0029] As shown in FIGS. 6 and 8, the conductive member 61 is disposed so as to face the first insulating member main body 10a. The conductive member base portion 61a is disposed as shown in FIG. The cross section of the tubular portion 61b parallel to the sealing plate 2 is The shape may be circular or rectangular. The tubular portion 61b has a flange portion 61d at the end on the electrode body 3 side. The surface of the conductive member base portion 61a facing the first insulating member 10 is provided with an opening 61f. The pressing protrusion 61e is provided on the first insulating member 10. The pressing protrusion 61e presses the first insulating member 10 against the sealing plate 2. The pressing protrusion 61e presses the edge of the third terminal insertion hole 61c or the It is preferable that the electrode be formed in the vicinity of the electrode.

[0030] Next, the deforming plate 62 is placed so as to close the conductive member opening 61f of the conductive member 61, and the periphery of the deforming plate 62 is welded to the conductive member 61 by laser welding or the like. The conductive member opening 61f is sealed by the deforming plate 62. 62 are preferably made of metal, such as aluminum or an aluminum alloy. It is more preferable that

[0031] 9 is a perspective view of the deforming plate 62. In FIG. 9, the upper side is the electrode body 3 side, and the lower side is the 9, the deformable plate 62 has a central portion on the sealing plate 2 side, which protrudes toward the electrode body 3 side. The stepped protrusion 62a is provided with a first protrusion 62a1. , which has a smaller outer diameter than the first protruding portion 62a1 and protrudes from the first protruding portion 62a1 toward the electrode body 3. The deformable plate 62 includes a second protrusion 62a2. The deformable plate 62 has an annular rib 62 on its outer periphery that protrudes toward the electrode body 3. The deformable plate 62 has an annular thin portion 62c on the surface facing the electrode body 3. The deforming plate 62 may have any shape that can seal the conductive member opening 61f of the conductive member 61. That's fine.

[0032] Next, a method for fixing the second insulating member 63 and the first positive electrode current collector 6a will be described with reference to FIG. In FIG. 10, the surface of the prismatic secondary battery 20 that is disposed on the electrode body 3 side faces upward. The surface that is disposed on the sealing plate 2 side is positioned downward.

[0033] 10A, the first positive electrode current collector 6a has a connection hole 6c. The edge of the connection hole 6c is welded to the deformable plate 62. Four fixing holes 6d are provided around the periphery of the fixing hole 6d. However, it is preferable that two or more are provided. In addition, a misalignment prevention hole 6e is provided around the connection hole 6c. Although one hole 6e may be provided, it is preferable to provide at least two holes. It is preferable that the fixing hole 6d is disposed between the fixing hole 6d and the fixing hole 6d. It is preferable that the small diameter portion 6d1 and the large diameter portion 6d2 have an inner diameter larger than that of the small diameter portion 6d1. The large diameter portion 6d2 is preferably disposed closer to the electrode body 3 than the small diameter portion 6d1.

[0034] As shown in FIGS. 8 and 10A, the second insulating member 63 is disposed so as to face the deformable plate 62. and a second insulating member region 63x disposed opposite the sealing plate 2. a third insulating region connecting the first insulating region and the second insulating region; The insulating member first region 63x has a first insulating member opening 63a at the center thereof. In the insulating member first region 63x, a third insulating member is provided at an end of the sealing plate 2 in the longitudinal direction. The third wall portion 63b is provided with a third connection portion 63d. In addition, in the insulating member first region 63x, a fourth insulating member is provided at both ends of the sealing plate 2 in the short direction. The fourth wall portion 63c is provided with a fourth connection portion 63e. In addition, four fixing protrusions 63f are provided on the surface of the insulating member first region 63x facing the electrode body 3. Also, two projections 63g for preventing displacement are provided. Four claws 63h are provided on the surface of the region 63x facing the sealing plate 2. The second region 63y is disposed closer to the sealing plate 2 than the first region 63x of the insulating member. In the insulating member second region 63y, a portion facing the electrolyte injection hole 15 provided in the sealing plate 2 is At the position, a second opening 63i of the insulating member is provided. An insulating member annular rib 63k is provided extending toward the electrode body 3 side.

[0035] As shown in FIG. 10B, the fixing protrusion 63f of the second insulating member 63 is fixed to the first positive electrode current collector 6a. The second insulating member 63 is disposed in the fixing hole 6d, and the projection 63g for preventing displacement of the first positive electrode current collector The first positive electrode current collector 6 is placed on the second insulating member 63 so as to be disposed in the hole 6e for preventing displacement of the first positive electrode current collector 6. Then, the tip of the fixing projection 63f of the second insulating member 63 is thermally caulked or the like. As a result, as shown in FIGS. 8C and 10C, the second insulating member 6 The third fixing projection 63f has an enlarged diameter portion 63f1 formed at its tip, which fixes the second insulating member 63 and the first positive electrode current collector 6a.

[0036] As shown in FIG. 8C, the fixing projection 63f of the second insulating member 63 has a tip end. It is preferable that the expanded diameter portion 63f1 is disposed within the large diameter portion 6d2 of the fixing hole 6d.

[0037] The slippage prevention projection 63g of the second insulating member 63 is thermally caulked like the fixing projection 63f. do not have.

[0038] The outer diameter of the fixing projection 63f is preferably larger than the outer diameter of the slippage prevention projection 63g. In addition, the inner diameter of the small diameter portion 6d1 of the fixing hole 6d of the first positive electrode current collector 6a is preferably It is preferable that the inner diameter is larger than the inner diameter of the hole 6e for preventing displacement of the electric conductor 6a.

[0039] Next, as shown in FIGS. 8A to 8C, the second insulating member 6 to which the first positive electrode current collector 6a is fixed is 3 is connected to the first insulating member 10 and the conductive member 61.

[0040] As shown in FIG. 8B, the fourth connecting portion 63e of the second insulating member 63 is connected to the first connecting portion 63e of the first insulating member 10. 8C, the claw portion 63h of the second insulating member 63 is connected to the connecting portion 10e. is connected to the flange portion 61d of the conductive member 61. As a result, the second insulating member 63 is The second insulating member 63 is connected to the first insulating member 10 and the conductive member 61. However, it is not necessary to connect to both the first insulating member 10 and the conductive member 61. The second insulating member 63 is connected to at least one of the first insulating member 10 and the conductive member 61. This allows the prismatic secondary battery 20 to withstand strong shocks and vibrations. Therefore, it is possible to prevent a load from being applied to the weak part of the first positive electrode current collector 6a. Damage and breakage of the weak part of a can be suppressed.

[0041] The deformable plate 62 is connected to the first positive electrode current collector 6a by welding. 11 is an enlarged view of the vicinity of the connection portion between the plate 62 and the first positive electrode current collector 6a. The second protrusion 62a2 of the first positive electrode current collector 62 is disposed in the connection hole 6c of the first positive electrode current collector 6a. The second protrusion 62a2 of the deformable plate 62 and the edge of the connection hole 6c of the first positive electrode current collector 6a are aligned with each other. The connection between the deformable plate 62 and the first positive electrode current collector 6a is made by welding or the like. The second insulating member 63 is formed at a position corresponding to the first insulating member opening 63a.

[0042] In addition, in the first positive electrode current collector 6a, a thin portion 6f is provided around the connection hole 6c. The thin portion 6f is provided with an annular notch 6g surrounding the connection hole 6c. An annular connecting rib 6h is formed on the edge of the connecting hole 6c. The first positive electrode current collector 6a and the deformable plate 62 are welded together. The entire circumference of the In addition, the first positive electrode current collector 6a and the deformable plate 62 may have a portion at the edge of the connection hole 6c. In this case, the welding may be performed at a plurality of separated locations.

[0043] Here, the operation of the current interruption mechanism 60 will be described. As a result, the central portion of the deformable plate 62 is deformed so as to move toward the sealing plate 2. When the pressure inside the battery case 100 reaches or exceeds a predetermined value, the deformation plate 62 deforms, and the first positive The notch 6g provided in the thin portion 6f of the electrode current collector 6a breaks. The conductive path from the first positive electrode collector to the positive electrode terminal 7 is cut off. The prismatic secondary battery 20 is in an overcharged state and the current is When the pressure inside the battery case 100 rises, the current interruption mechanism 60 is activated, and the positive electrode plate 4 By cutting the conductive path to terminal 7, further progress of overcharging is prevented. The operating pressure at which the current interruption mechanism 60 operates can be determined appropriately.

[0044] Before welding the deformable plate 62 and the first positive electrode current collector 6a, the terminal formed on the positive electrode terminal 7 By supplying gas to the inside of the conductive member 61 through the through hole 7c, the conductive member 61 and The deformed plate 62 can be inspected for leaks at the welded portion. The terminal through-hole 7c is sealed by the terminal sealing member 7x. The terminal sealing member 7x is preferably made of a metal member 7y and a rubber member 7z. I wish.

[0045] FIG. 12 shows a first insulating member 10, a conductive member 61, a deforming plate 62, a second insulating member 63, and a first insulating member 64. 12 is a perspective view of the sealing plate 2 to which the positive electrode current collector 6a is attached. The edge member 63 is provided with a third connection portion 63d at an end portion in the longitudinal direction of the sealing plate 2. In the insulating member 10, second connection portions 10f are provided at both ends of the sealing plate 2 in the short direction. do.

[0046] [Installing each part on the sealing plate (negative electrode side)] 2 and 13, the negative electrode terminal 9 and the first negative electrode current collector 8a are attached to the sealing plate 2. The method is as follows. The outer surface of the battery is placed near the negative terminal mounting hole 2b provided in the sealing plate 2. The inner insulating member 13 is disposed on the inner surface of the battery near the negative terminal mounting hole 2b. Next, the negative electrode terminal 9 is placed between the outer insulating member 13 and the first negative electrode current collector 8a. the through hole, the negative electrode terminal mounting hole 2b of the sealing plate 2, the through hole of the inner insulating member 12, and the first negative electrode Then, the tip of the negative electrode terminal 9 is inserted into each of the through holes of the first negative electrode current collector 8a. 8a. As a result, the outer insulating member 13, the sealing plate 2, the inner insulating member 12, and The first negative electrode current collector 8a is fixed to the negative electrode terminal 9. The negative electrode current collector 8a is preferably welded by laser welding or the like. The member 12 and the outer insulating member 13 are preferably made of resin.

[0047] [Connection between current collector and tab] FIG. 14 shows a method of connecting the positive electrode tab 40 to the second positive electrode current collector 6b, and a method of connecting the negative electrode tab 40 to the second negative electrode current collector 8b. 10 is a diagram showing a method for connecting the negative electrode tab 50. Two electrode body elements are prepared by the above-mentioned method, and These are referred to as the first electrode element 3a and the second electrode element 3b. The first and second electrode body elements 3a and 3b may have the same configuration, or may have different configurations. Here, the plurality of positive electrode tabs 40 of the first electrode body element 3a constitute a first positive electrode tab group 40a. The plurality of negative electrode tabs 50 of the first electrode body element 3a constitute a first negative electrode tab group 50a. The plurality of positive electrode tabs 40 of the second electrode body element 3b constitute a second positive electrode tab group 40b. The plurality of negative electrode tabs 50 of this electrode body element 3b constitute a second negative electrode tab group 50b.

[0048] Between the first electrode body element 3a and the second electrode body element 3b, a second positive electrode current collector 6b and a second negative electrode current collector 6c are disposed. Then, the current collector 8b is placed. Then, the stacked multiple sheets protruding from the first electrode body element 3a are The first positive electrode tab group 40a consisting of the positive electrode tabs 40 is placed on the second positive electrode current collector 6b, and the first A first negative electrode tab group 50 consisting of a plurality of stacked negative electrode tabs 50 protruding from the electrode body element 3a a is placed on the second negative electrode current collector 8b. A second positive electrode tab group 40b consisting of the plurality of positive electrode tabs 40 is disposed on the second positive electrode current collector 6b. The second negative electrode element 3b is made up of a plurality of stacked negative electrode tabs 50 protruding from the second electrode element 3b. The electrode tab group 50b is disposed on the second negative electrode current collector 8b. The tab group 40b is welded to the second positive electrode current collector 6b, forming welded connections 90. The first negative electrode tab group 50a and the second negative electrode tab group 50b are each welded to the second negative electrode current collector 8b. The connection is made to form a welded connection 90. The welded connection can be made as follows.

[0049] The stacked tabs (first positive electrode tab group 40a, second positive electrode tab group 40b, first negative electrode tab group 50a, second negative electrode tab group 50b) and the current collectors (second positive electrode current collector 6b, second negative electrode current collector 8b) are sandwiched between welding jigs from above and below, and welding is performed. The welding method here is preferably ultrasonic welding or resistance welding. Note that the pair of welding jigs is a pair of resistance welding electrodes in the case of resistance welding, and a horn and anvil in the case of ultrasonic welding. Note that the tabs (first positive electrode tab group 40a, second positive electrode tab group 40b, first negative electrode tab group 50a, second negative electrode tab group 50b) and the current collectors (second positive electrode current collector 6b, second negative electrode current collector 8b) can also be connected by laser welding.

[0050] As shown in FIG. 14, the second positive electrode current collector 6b has a first current collector region 6b1 and a second current collector region 6b2. The positive electrode tab 40 is connected to the current collector first region 6b1. The current collector first region 6b1 and the current collector second region 6b2 are provided with a current collector second opening 6z. The second positive electrode current collector 6b is connected to the first positive electrode current collector 6b by a third region 6b3. After connecting to the current collector 6a, the second current collector opening 6z is inserted into the electrolyte injection hole 15 provided in the sealing plate 2. The current collector second region 6b2 is provided with a current collector first opening 6y. A current collector first recess 6m is provided around the current collector first opening 6y. In addition, in the short-side direction of the sealing plate 2, there are target holes 6 on both sides of the current collector first opening 6y. k is provided.

[0051] As shown in FIG. 14, the second negative electrode current collector 8b is made up of a current collector first region 8b1 and a current collector second region 8b2. The negative electrode tab 50 is connected to the current collector first region 8b1. The current collector first opening 8y is provided in the 8b2. In the short direction of the sealing plate 2, the current collector first recess 8f is provided. Target holes 8e are provided on both sides of the first opening 8y.

[0052] [Connection between the first and second positive electrode current collectors] As shown in FIGS. 2, 7, 8, etc., the current collector protrusions 6x of the first positive electrode current collector 6a are The second positive electrode current collector 6b is connected to the second insulating film 6c so as to be positioned within the first current collector opening 6y of the current collector 6b. The first positive electrode current collector 6a is disposed on the edge member 63. Then, the current collector protrusions 6x of the first positive electrode current collector 6a and the second positive electrode current collector The edge of the current collector first opening 6y of the body 6b is welded by irradiation with an energy beam such as a laser. This connects the first positive electrode current collector 6a and the second positive electrode current collector 6b. At the portion 6m, the first positive electrode current collector 6a and the second positive electrode current collector 6b are welded together. preferable.

[0053] As shown in FIGS. 2 and 8, the sealing plate 2 and the current collector The distance between the first region 6b1 is smaller than the distance between the sealing plate 2 and the current collector second region 6b2. With this configuration, the space occupied by the current collecting part can be made smaller, resulting in a higher volumetric energy density. This results in a highly efficient prismatic secondary battery.

[0054] The first positive electrode current collector 6a and the second positive electrode current collector 6b are welded together by irradiation with an energy beam such as a laser. In this case, it is preferable to use the target hole 6k as a target for image correction.

[0055] As shown in FIG. 8A, the surface of the first positive electrode current collector 6a facing the second insulating member 63, A second current collector recess 6w is formed on the rear side of the current collector protrusion 6x. This is preferable because it makes it easier to form a larger welded joint between the current collector 6a and the second positive electrode current collector 6b. In addition, since the second current collector recess 6w is formed, the first positive electrode current collector 6a and the second positive electrode current collector 6b are When the positive electrode current collector 6b is welded, the second insulating member 63 may be damaged by heat during welding. This can prevent the following.

[0056] [Connection between the first negative electrode current collector and the second negative electrode current collector] As shown in FIG. 13, the second negative electrode current collector 8b is made up of a current collector first region 8b1 and a current collector second region 8b2. The negative electrode tab 50 is connected to the current collector first region 8b1. The current collector first opening 8y is provided in the current collector first region 8b1 and the current collector second region 8b2. The regions 8b2 are connected by the current collector third region 8b3.

[0057] As shown in FIG. 13, the current collector protrusions 8x of the first negative electrode current collector 8a are in contact with the second negative electrode current collector 8b. The second negative electrode current collector 8b is attached to the inner insulating member 12 so as to be positioned within the first current collector opening 8y. Then, the current collector protrusions 8x of the first negative electrode current collector 8a and the current collector protrusions 8x of the second negative electrode current collector 8b are aligned. The edge of the first opening 8y of the electric body is welded by irradiating it with an energy beam such as a laser. The first negative electrode current collector 8a and the second negative electrode current collector 8b are connected to each other. It is preferable that the first negative electrode current collector 8a and the second negative electrode current collector 8b are connected by welding. The positive electrode current collector 8b is provided with a target hole 8e, similar to the second positive electrode current collector 6b. In the direction perpendicular to the sealing plate 2, the distance between the sealing plate 2 and the current collector first region 8b1 is It is smaller than the distance between the plate 2 and the second current collector region 8b2. First, the second negative electrode current collector 8 b can be connected to the negative electrode terminal 9 .

[0058] As shown in FIG. 13, the surface of the first negative electrode current collector 8a facing the inner insulating member 12 is A second current collector recess 8w is formed on the rear side of the current collector protrusion 8x. This is preferable because it makes it easier to form a larger welded joint between the first negative electrode current collector 8a and the second negative electrode current collector 8b. Furthermore, since the current collector second recess 8w is formed, the first negative electrode current collector 8a and When the second negative electrode current collector 8b is welded, the inner insulating member 12 may be damaged by heat during welding. This can prevent this from happening.

[0059] The current collector protrusions 6x and 8x each have a non-circular shape in plan view. Preferably, the shape is rectangular, elliptical or track-shaped.

[0060] [Installing the cover] 15 is a perspective view of the sealing plate 2 and the cover part 80 to which the various components are attached. In the example shown in FIG. 15, the positive electrode tab 40 is not shown. The cover portion 80 covers the first positive electrode current collector 6 a, and a cover body 80a arranged to face the sealing plate 2 of the cover body 80a. The cover has a pair of arms 80b extending from both ends in the short side direction toward the sealing plate 2. The cover part 80 extends from the end of the cover part main body 80a in the longitudinal direction of the sealing plate 2 toward the sealing plate 2. The arm portion 80b has a cover wall portion 80e extending therefrom. A connecting protrusion 80c is provided on the inner surface of the arm portion 80b. In the cover body 80a, a base opening 80 is provided near the base of the arm portion 80b. The cover wall 80e is provided with a wall opening 80f.

[0061] As shown in FIGS. 16A and 16B, the cover body 80a of the cover 80 is The cover portion 80 is connected to the first insulating member 10 and the second insulating member 63 so as to face the electric body 6a. The pair of arm portions 80b of the cover portion 80 are connected to the first insulating member by connecting projections 80c. The cover wall portion 80e of the cover portion 80 is connected to the second connection portion 10f of the member 10. It is connected to the third connecting portion 63d of the member 63.

[0062] As shown in FIG. 17A, the third connection portion 63d is a protrusion provided on the third wall portion 63b. The third connecting portion 63d is fitted into the wall opening 80f of the cover wall portion 80e, thereby forming a first insulating The edge member 10 and the cover portion 80 are connected. As shown in FIG. 17B, the first insulating member 10 The connecting protrusion 80c provided on the arm portion 80b of the cover portion 80 is hooked onto the second connecting portion 10f. The connection is made so that

[0063] The cover 80 is preferably made of resin. It is preferable that the composition is:

[0064] As shown in FIGS. 17A and 17B, the first positive electrode current collector 6a and the cover portion 80 are It is preferable that a gap is formed between the upper surfaces of the bodies 80a. This allows gas to flow smoothly under the deformable plate 62, so that when the pressure inside the battery case 100 reaches or exceeds a predetermined value, the deformable plate 62 deforms more smoothly. It is not a necessary configuration.

[0065] As shown in FIG. 17B, a base opening 80d is provided in the cover body 80a of the cover 80. This allows the gas to flow smoothly under the deformable plate 62. Therefore, when the pressure inside the battery case 100 reaches or exceeds a predetermined value, the deformable plate 62 moves more smoothly. However, the base opening 80d is not an essential component.

[0066] [Electrode body fabrication] In FIG. 14, the upper surface of the first electrode element 3a and the upper surface of the second electrode element 3b are not directly connected to each other. The first positive electrode tab group 40a, the second positive electrode tab group 40b, and the first positive electrode tab group 40c are connected via an insulator or other member. The negative electrode tab group 50a and the second negative electrode tab group 50b are bent. The first electrode element 3a and the second electrode element 3b are combined to form one electrode body 3. It is preferable to bundle the first electrode element 3a and the second electrode element 3b together with tape or the like. The first electrode element 3a and the second electrode element 3b are formed into a box-like or bag-like insulating shell. It is preferable to arrange them in a port 14 and combine them into one.

[0067] [Assembly of prismatic secondary batteries] The electrode body 3 attached to the sealing plate 2 is covered with an insulating sheet 14 and inserted into the rectangular exterior body 1. The insulating sheet 14 is formed by bending a flat plate into a box or bag shape. Then, the sealing plate 2 and the rectangular outer casing 1 are joined by laser welding or the like, and the rectangular outer casing The opening of the sealing plate 2 is then sealed. The electrolyte is poured into the electrolyte pouring hole 15 provided in the electrode 11. The electrolyte pouring hole 15 is then closed with a sealing plug 16. In this way, the prismatic secondary battery 20 is produced.

[0068] [About the prismatic secondary battery 20] As shown in FIGS. 8, 17, and 18, the conductive member 61 faces the first insulating member 10. A pressing protrusion 61e that protrudes toward the first insulating member 10 is provided at the portion where the first insulating member 10 is inserted. As a result, the pressing protrusion 61e presses the first insulating member 10 against the sealing plate 2 more strongly. Therefore, the gas present around the electrode body 3 is absorbed between the sealing plate and the first insulating member or through the first insulating member. Therefore, it is possible to prevent the conductive member from moving to the vicinity of the connection portion between the conductive member and the terminal through the gap between the conductive member and the terminal. The gas passes between the conductive member 61 and the positive electrode terminal 7 and is then transferred by the conductive member 61 and the deformation plate 62. Therefore, the movement of the particles into the space formed can be prevented. Therefore, when the pressure inside the rectangular exterior body 1 increases, the current interruption mechanism 60 can be activated more stably. This makes it possible to provide a more reliable prismatic secondary battery 20.

[0069] The pressing protrusion 61e is formed on the conductive member base portion 61a of the conductive member 61 so as to contact the sealing plate 2. The conductive member 61 and the positive electrode terminal 7 are formed on the surface of the sealing plate 2 from a direction perpendicular to the sealing plate 2. 7, the pressing protrusion 61e and the crimped portion 7d of the insertion portion 7b of the positive electrode terminal 7 are It is preferable that the pressing protrusion 6 is positioned so that it overlaps with the expanded diameter portion. It is preferable that the portion 1e is formed on the edge of the third terminal insertion hole 61c of the conductive member 61. The pressing protrusion 61e is formed at a portion of the conductive member 61 away from the edge of the third terminal insertion hole 61c. It is preferable that the pressing protrusion 61e has a ring-shaped shape in a plan view. However, the pressing protrusion 61e does not necessarily have to have a ring-shaped shape in a plan view, and a part of the ring may be removed. For example, the length of the pressing protrusion may be reduced by The length of the pressing protrusion 61e can be set to 70% or more. By providing the pressure projection 61e on the conductive member 61, it is possible to easily form the pressure projection 61e in a desired shape. preferable.

[0070] When the first insulating member 10 pressed by the pressing protrusion 61e is deformed so as to escape in the horizontal direction (the direction parallel to the sealing plate 2, that is, the left direction in FIG. 18), the first insulating member 10 A gap is formed between the strain sealing plate 2 and the first insulating member 10 or between the first insulating member 10 and the conductive member 61. Such a problem may occur when the sealing plate 2 and the conductive member 6 are in contact with the first insulating member 10. 1, and in the radial direction of the second terminal insertion hole 10d of the first insulating member 10. This can be solved by providing a groove on the outside of the pressing protrusion 61e. In the edge member 10, it is preferable to provide a first groove portion 10x on the surface facing the sealing plate 2. In addition to the first groove portion 10x, or instead of the first groove portion 10x, the first insulating member 10 In this case, it is preferable to provide the second groove portion 10y on the surface facing the conductive member 61. The first insulating member 10 may be provided with only one of the first groove portion 10x and the second groove portion 10y. In addition, a second groove portion 10y is provided on the surface of the first insulating member 10 facing the sealing plate 2, The first groove portion 10x may be provided on the surface facing the conductive member 61. The x and second groove portion 10y are not essential structures.

[0071] The first groove portion 10x preferably has a ring-shaped shape in a plan view. It is preferable that the shape in a plan view is annular. However, the first groove portion 10x and the second groove portion 10y are The shape in plan view does not necessarily have to be annular, but may be a shape with a part of the annular shape removed. For example, the length of the first groove portion 10x to the second groove portion 10x can be set to be equal to or smaller than the length of the annular groove portion 10x. The length of 10y can be made to be 70% or more of the length.

[0072] When grooves are provided on both sides of the first insulating member 10, the second terminal insertion hole 1 In the radial direction of 0d, it is preferable that one groove portion is provided more outward than the other groove portion. That is, when grooves are provided on both sides of the first insulating member 10, the second terminal insertion portion of the first insulating member 10 is The distance from the hole 10d to one of the grooves is It is preferable that the distance between the grooves is greater than the distance to the grooves on either side.

[0073] In addition, in the radial direction of the second terminal insertion hole 10d of the first insulating member 10, the center of one of the grooves The distance between the center of the groove and the center of the other groove (distance D in Figure 18) is 0.5 mm to 10 mm. It is preferable that the thickness is 0.5 mm to 5 mm, and more preferable that the thickness is 0.5 mm to 5 mm.

[0074] For example, in the first insulating member 10, the diameter of the second terminal insertion hole 10d of the first insulating member 10 is In the direction, the second groove portion 10y is located outside the first groove portion 10x. As shown, the distance D between the center of the first groove portion 10x in the width direction and the center of the second groove portion 10y in the width direction is It is preferably 0.5 mm to 10 mm, and more preferably 0.5 mm to 5 mm. It is preferable that the width of the first groove portion 10x and the second groove portion 10y (the width in the left-right direction in FIG. 18) is preferably 0.5 mm to 2 mm.

[0075] When the first insulating member 10 is viewed from above, a part of the first groove portion 10x and a part of the second groove portion 10y are However, when the first insulating member 10 is viewed from above, the first groove portion It is preferable that the grooves 10x and the second grooves 10y do not completely overlap each other. In this configuration, the bending of the first insulating member 10 can be more effectively suppressed.

[0076] The width of the pressing protrusion 61e in the radial direction of the third terminal insertion hole 61c of the conductive member 61 is It is preferable that the thickness is 5 mm or less, and more preferably 2 mm. The distance between the pressing protrusion 61e and the first groove portion 10x in the radial direction of the third terminal insertion hole 61c is 0. It is preferably 0.5 mm to 5 mm, and more preferably 0.5 mm to 2 mm. It is more preferable that the thickness is 0.5 mm to 1 mm.

[0077] In addition, when the first insulating member 10 is relatively soft, for example, perfluoroalkoxyal Particularly effective when made of polytetrafluoroethylene (PFA), polytetrafluoroethylene (PTFE), etc. is.

[0078] As shown in FIG. 18, a terminal is inserted into the end of the third terminal insertion hole 61c of the conductive member 61 on the electrode body 3 side. In this configuration, the positive electrode terminal 7 and the conductive part 61g are preferably provided. A gap is unlikely to occur between the positive electrode terminal 7 and the conductive member 61, and gas is prevented from passing between the positive electrode terminal 7 and the conductive member 61. can be suppressed more effectively.

[0079] The conductive member 61 is preferably made of aluminum or an aluminum alloy. The pole terminal 7 is preferably made of aluminum or an aluminum alloy.

[0080] As shown in FIG. 10, the fixing protrusion 63f of the second insulating member 63 fixes the first positive electrode current collector 6a. When inserted into the fixing hole 6d, the tip of the fixing protrusion 63f is expanded in diameter to form an expanded diameter portion 63f1. As a result, the second insulating member 63 and the first positive electrode current collector 6a are fixed together. In this case, when a strong impact or vibration is applied to the prismatic secondary battery 20, the first positive electrode current collector 6a is This can prevent a load from being applied to weak parts such as the thin-walled part 6f and the notch 6g. The second insulating member 63 is connected to at least one of the first insulating member 10 and the conductive member 61. It is preferable that

[0081] When the second insulating member 63 is made of resin, the fixing protrusion 63f of the second insulating member 63 is fixed to the first positive electrode collector. After being inserted into the fixing hole 6d of the electric body 6a, when the tip of the fixing protrusion 63f is expanded in diameter, Due to distortion or shrinkage of the protrusion 63f, a gap may be formed between the side surface of the fixing protrusion 63f and the inner surface of the fixing hole 6d. If such a gap exists, the prismatic secondary battery 20 may be subjected to a strong impact or When vibration is applied, the second insulating member 63 is moved in a direction parallel to the sealing plate 2. In addition, when the tip of the fixing projection 63f is heated, When the diameter is increased by the heat, the part of the fixing projection 63f arranged in the fixing hole 6d It tends to shrink and cause the gaps mentioned above.

[0082] In the prismatic secondary battery 20, the second insulating member 63 has a projection 63g for preventing disengagement. The misalignment prevention protrusion 63g is disposed in the misalignment prevention hole 6e of the first positive electrode current collector 6a. Therefore, the displacement prevention projection 63g does not expand in diameter like the fixing projection 63f. Even if a gap occurs between the fixing projection 63f and the fixing hole 6d, the slippage prevention projection 63g prevents the slippage. By fitting into the prevention hole 6e, the first positive electrode current collector 6a is prevented from being in contact with the second insulating member 63. This can effectively prevent the risk of

[0083] The fixing protrusions 63f are arranged in a plurality of shapes around the connection portion between the deformable plate 62 and the first positive electrode current collector 6a. It is preferable that the number of the grooves is four or more, and it is particularly preferable that the grooves are provided at four or more places. The protrusions 63g are preferably formed on both sides of the connection portion between the deformable plate 62 and the first positive electrode current collector 6a. In addition, the slippage prevention projections 63g are formed between the fixing projections 63f. It is preferable that this be done.

[0084] Furthermore, it is preferable that the diameter of the fixing projection 63f is larger than the diameter of the slippage prevention projection 63g. stomach.

[0085] When two displacement prevention holes 6e are formed, the inner diameter of one is made larger than the inner diameter of the other. In addition, when two projections 63g for preventing slippage are formed, the outermost projection 63g can be The diameter can be larger than the outer diameter of the other.

[0086] The ratio of the outer diameter of the displacement prevention protrusion 63g to the inner diameter of the displacement prevention hole 6e is 0.9 It is preferable that the inner diameter of the displacement prevention hole 6e and the displacement prevention protrusion 63g are 5 to 1. The difference in outer diameter is preferably 0.1 mm or less.

[0087] In addition, when a plurality of fitting portions between the misalignment prevention holes 6e and the misalignment prevention protrusions 63g are provided, , the difference between the inner diameter of the misalignment prevention hole 6e and the outer diameter of the misalignment prevention protrusion 63g in one fitting portion, The difference between the inner diameter of the slippage prevention hole 6e and the outer diameter of the slippage prevention protrusion 63g in the other fitting portion is set to be different. The value can be:

[0088] The misalignment prevention hole 6e is not a notch provided at the edge of the second insulating member 63, but a hole for preventing misalignment. It is preferable that the edge of the stop hole 6e is annular. It is preferable that the second insulating member 63 is present all around the circumference. This effectively reduces deviation.

[0089] In the short direction of the sealing plate 2, there is a misalignment on both sides of the connection part between the deformable plate 62 and the first positive electrode current collector 6a. It is preferable that a hole 6e for preventing displacement is provided. The connection portion between the deformable plate 62 and the first positive electrode current collector 6a is arranged, and two misalignment prevention holes 6e are provided. It is preferable that the connection portion between the deformable plate 62 and the first positive electrode current collector 6a is disposed on the connecting line. As a result, the connection portion between the deformable plate 62 and the first positive electrode current collector 6a, the thin portion 6f, and the notch 6g are subjected to a load. This makes it possible to more reliably prevent load from being applied.

[0090] The slippage prevention protrusion 63g has a recess at the tip before the tip is expanded. In this configuration, a load is applied to the base side of the slippage prevention projection 63g. This allows the tip of the slippage prevention projection 63g to have an expanded diameter while preventing the tip from slipping.

[0091] As shown in FIGS. 16 and 17, a cover portion 80 is provided between the first positive electrode current collector 6a and the electrode body 3. With this configuration, the prismatic secondary battery 20 is protected from strong shocks and vibrations. Even if the electrode body 3 moves toward the sealing plate 2 due to the applied force, the electrode body 3 will not contact the first positive electrode current collector 6a. The contact between the first positive electrode current collector 6a and the thin portion 6f, the notch 6g, and other weak portions of the first positive electrode current collector 6a and the deformable plate 62 and the first This prevents the connection portion of the positive electrode current collector 6a from being damaged or broken. It is preferable that the cover portion 80 is made of resin. Preferably, the portion 80 is electrically insulating.

[0092] The cover portion 80 is preferably a separate part from the first insulating member 10 and the second insulating member 63. For example, if the cover portion 80 is a separate part from the first insulating member 10 and the second insulating member 63, This makes it possible to assemble the secondary battery more easily. By making it a separate part, a protrusion is provided on the surface of the second insulating member 63 on the side of the first positive electrode current collector 6a. This protrusion provides a stronger connection between the second insulating member 63 and the first positive electrode current collector 6a. It is possible.

[0093] A gap is provided between the first positive electrode current collector 6a and the cover body 80a of the cover 80. It is preferable that the surface of the first positive electrode current collector 6a facing the electrode body and the surface of the cover portion main body 80a facing the sealing plate are The distance between the surfaces is preferably 0.1 mm to 5 mm, and more preferably 0.5 to 2 mm. is more preferable.

[0094] In addition, in the cover part 80, the part extending from the cover part main body 80a to the sealing plate 2 side is The first positive electrode current collector 6a is connected to at least one of the first insulating member 10 and the second insulating member 63. It is preferable that a gap is formed between the cover portion main body 80a and the cover portion main body 80b. Then, even if the electrode body 3 moves toward the sealing plate 2 and contacts the cover part 80, the cover part 8 Since the electrode body 3 can absorb shock to some extent, damage to the electrode body 3 can be prevented.

[0095] The cover portion 80 is connected to at least one of the first insulating member 10 and the second insulating member 63. It is preferable that the cover portion 80 is made of the first insulating member 10 and the second insulating member 63. For example, the cover 80 has a cover body 80a and a pair of arms 80b extending from the cover body 80a toward the sealing plate 2, It is preferable that the arm portion 80b is connected to the first insulating member 10. A cover wall portion 80e is provided on the main body 80a of the insulating member 60, and the cover wall portion 80e is attached to the second insulating member 63. Preferably connected.

[0096] It is preferable to provide a through hole in the cover body 80a. The gas flows smoothly under the mold plate 62. It is preferable to provide a base opening 80d as a through hole at the base of 80b.

[0097] When the positive electrode current collector includes a first positive electrode current collector 6a and a second positive electrode current collector 6b, the first positive electrode current collector The cover portion 80 is disposed between the connection portion of the second positive electrode current collector 6a and the second positive electrode current collector 6b and the electrode body 3. With this configuration, the prismatic secondary battery 20 is subjected to strong vibrations and shocks. Therefore, even if the electrode body 3 moves toward the sealing plate 2, the electrode body 3 is connected to the first positive electrode current collector 6a and the second positive electrode current collector 6b. The connection between the first positive electrode current collector 6a and the second positive electrode current collector 6b is damaged. The cover body 80a faces the first positive electrode current collector 6a. On the surface, the portion facing the connection portion of the first positive electrode current collector 6a and the second positive electrode current collector 6b is It is preferable that the portion of the deformable plate 62 facing the connection portion of the first positive electrode current collector 6a is recessed more than the portion of the deformable plate 62 facing the connection portion of the first positive electrode current collector 6a. stomach.

[0098] The second positive electrode current collector 6b to which the positive electrode tab 40 is connected is connected to the first positive electrode current collector 6b to which the positive electrode tab 40 is connected. After connecting to the positive electrode current collector 6a, the cover portion 80 is attached to the first insulating member 10 and the second insulating member 63. It is preferable to connect at least one of them.

[0099] As shown in FIG. 8 and FIG. 9, the deformable plate 62 has a conductor on the outer periphery thereof on the side of the electrode body 3 (upper part in FIG. 9). The annular rib 62b projects from the tubular portion of the conductive member 61. The deformable plate 61b is fitted to the end of the electrode body 3 side of the conductive member 61 and is welded to the conductive member 61. 62, an annular thin portion 62c is provided closer to the center than the annular rib 62b. With this configuration, even if the thickness of the deformed plate 62 is increased, the inside of the rectangular exterior body 1 This is preferable because the deformation plate 62 deforms more smoothly when the pressure exceeds a predetermined value. In addition, by increasing the thickness of the deformable plate 62, the heat capacity of the deformable plate 62 can be increased. Therefore, the occurrence of cracks can be prevented at weak portions such as the thin portion 6f and the notch 6g provided on the first positive electrode current collector 6a. Even if the first positive electrode current collector 6a is heated, the heat is transferred to the deformable plate 62 side and the thin film provided on the first positive electrode current collector 6a is This can prevent fragile portions such as the thick portion 6f and the notch 6g from melting. It is preferable that an annular connecting rib 6h is provided on the edge of the connecting hole 6c of a. Therefore, the thermal capacity in the vicinity of the weak parts such as the thin part 6f and the notch 6g provided on the first positive electrode current collector 6a is Since the amount can be increased, the thin portion 6f and the notch 6g provided on the first positive electrode current collector 6a can be This can more effectively prevent weak parts such as the above from melting.

[0100] The deformable plate 62 is inclined from the outer periphery toward the center with respect to the sealing plate 2. The annular thin portion 62c is preferably formed by forming a recess on the surface of the deformable plate 62 facing the electrode body 3. In this case, the deformation plate 62 is more The width of the annular thin portion 62c in plan view is 1 mm to 3 mm. It is preferable that the thickness is 1.5 mm to 2 mm, and more preferable that the thickness is 1.5 mm to 2 mm.

[0101] The gas release valve 17 breaks, and the gas inside the battery case 100 is released to the outside of the battery case 100. Even after being pulled out, the deforming plate 62 is not broken, and the conductive member opening 61f of the conductive member 61 is It is sealed by 2.

[0102] As shown in FIGS. 9 and 11, the deformation plate 62 has a first protrusion 62a1 and a second protrusion 62a2 at the center. The second protrusion 62a2 is fitted into a connection hole 6c provided in the first positive electrode current collector 6a. The outer diameter of the first protrusion 62a1 is The inner diameter of the first protrusion 62a1 is larger than the inner diameter of the first positive electrode current collector 6c, and the surface of the first protrusion 62a1 on the electrode body 3 side is In this configuration, the second protrusion 62a of the deformable plate 62 is in contact with the upper surface 6i. When an energy beam such as a laser is irradiated onto the connection portion between the first positive electrode current collector 6a and the connection hole 6c of the first positive electrode current collector 6a, In this case, the energy beam passes between the first protrusion 62a1 and the side wall of the connection hole 6c of the first positive electrode current collector 6a. and can prevent the energy rays from scattering on the upper surface side of the first positive electrode current collector 6a. This ensures that each component is protected from damage and destruction by energy rays. In addition, it is preferable that the stepped projection 62a has a stepped recess on the surface facing the sealing plate 2. In addition, it is preferable that the bottom 62d of the stepped recess is located closer to the sealing plate 2 than the upper surface 6i of the first positive electrode current collector 6a. Preferably, it is located to the side.

[0103] <<Variation 1>> The prismatic secondary battery according to Modification 1 has the same structure as the prismatic secondary battery 20 according to the embodiment, except for the shape of the cover portion. As shown in FIGS. 19A and 19B , the cover portion 81 according to Modification 1 has a cover portion main body 81a arranged to face the first positive electrode current collector 6a, and a pair of arms 81b extending from both ends of the cover portion main body 81a in the short direction of the sealing plate 2 toward the sealing plate 2. The cover portion has a cover wall portion 81e extending from an end of the cover portion main body 81a in the long direction of the sealing plate 2 toward the sealing plate 2. A connecting protrusion is provided on the inner surface of the arm portion 81b. This connecting protrusion is connected to the second connecting portion 10f of the first insulating member 10.

[0104] In the cover body 81a, a base opening 81d is provided near the base of the arm portion 81b. The cover wall 81e has a wall opening 81f. In the cover 81 of the secondary battery, a cover opening 81x is provided in the cover body 81a. The cover opening 81x is located at a position facing the connection portion between the deformable plate 62 and the first positive electrode current collector 6a. This allows the current cut-off mechanism to operate more smoothly.

[0105] <<Variation 2>> In the prismatic secondary battery 20 according to the above embodiment, the first insulating portion In this example, a pressing protrusion 61e is provided on the portion facing the substrate 10. Instead of providing a pressing protrusion on the conductive member, the pond is provided with a sealing plate facing the first insulating member 10. The structure is the same as that of the prismatic secondary battery 20 according to the above embodiment, except that a pressing protrusion is provided in the portion where the It has.

[0106] FIG. 20 is a cross-sectional view of the vicinity of a current interruption mechanism of a secondary battery according to Modification 2. 20 is a cross-sectional view corresponding to 8B of the sealing plate 102. A pressing protrusion 102x is provided on the portion facing the pressing portion 10. The pressure projection 102x presses the first insulating member 10 more strongly, and the conductive member 161 and the positive electrode terminal Therefore, the gas present in the vicinity of the electrode body can be prevented from moving to the connecting portion of the electrode body. The gas leaking into the space formed by the conductive member 161 and the deformable plate 62 is suppressed. Therefore, delay in the operation of the current interruption mechanism can be suppressed. When the pressing protrusions 102x are provided, the outer peripheral portion of the first insulating member 10 is warped toward the electrode body 3. In this way, deformation of the first insulating member 10 can be easily suppressed. It is preferable that the shape of the conductor is annular.

[0107] When the sealing plate 102 and the positive electrode terminal 7 are viewed from a direction perpendicular to the sealing plate 102, The pressure projection 102x and the crimped portion 7d (expanded diameter) of the insertion portion 7b of the positive electrode terminal 7 are It is preferable that the position of the first and second electrodes overlap each other.

[0108] In the prismatic secondary battery according to Modification 2, no pressing protrusions are provided on the conductive member 161. However, it is also possible to provide pressing protrusions on the conductive member 161.

[0109] <Other> The breakable portion that breaks due to the deformation of the deformable plate is a weak portion provided in the current collecting member, It is preferable that the weak part is a joint part of the deformation plate or a weak part provided on the deformation plate. For this purpose, a thin wall portion or a notch is preferable.

[0110] The first insulating member, the second insulating member, and the cover are preferably made of resin. Polypropylene, polyethylene, perfluoroalkoxyalkane (PFA), polytetrafluoroethylene It is possible to use a material made of fluoroethylene (PTFE), ethylene-tetrafluoroethylene copolymer (ETFE), or the like.

[0111] In the above-described embodiment, an example in which the electrode body 3 is made up of two electrode body elements 3a and 3b is shown. However, the present invention is not limited to this. The electrode body 3 may be a single laminated electrode body. The body 3 is a wound type battery in which a long positive electrode plate and a long negative electrode plate are wound with a separator interposed therebetween. The two electrode body elements 3a and 3b may be laminated electrode bodies. A wound electrode assembly in which a long positive electrode plate and a long negative electrode plate are wound with a separator interposed therebetween. may be.

[0112] In the case of a laminated electrode body having a plurality of positive electrode plates and a plurality of negative electrode plates, or When the electrode is wound and the winding axis is arranged perpendicular to the sealing plate In the electrode assembly, the end of the positive electrode plate, the end of the negative electrode plate, and the end of the separator are positioned on the sealing plate side. In this configuration, an electrolyte injection hole is provided in the sealing plate. In this case, the electrolyte is easily injected into the electrode body. The end of the separator on the sealing plate side protrudes toward the sealing plate 2 more than the end of the substance mixture layer on the sealing plate side. In the electrode assembly, it is preferable that the positive electrode active material mixture layer of the positive electrode plate is sealed. It is preferable that the end of the separator on the sealing plate side protrudes more toward the sealing plate side than the end on the end plate side. In addition, the positive electrode plate and the separator are bonded by an adhesive layer, and the negative electrode plate and the separator are bonded by an adhesive layer. In this configuration, the second insulating member is preferably bonded by a layer. The positive electrode active material mixture layer and the negative electrode active material mixture layer may come into contact with each other, damaging the positive electrode active material layer or the negative electrode active material layer. This can reliably prevent this from happening. [Explanation of symbols]

[0113] 20 Prismatic secondary battery 1. Rectangular exterior body 2...Sealing plate 2a Positive terminal mounting hole 2b Negative terminal mounting hole 100···Battery case 3...electrode body 3a... First electrode body element 3b... Second electrode body element 4. Positive electrode plate 4a...Positive electrode core 4b Positive electrode active material mixture layer 4d...Positive electrode protective layer 40 Positive electrode tab 40a···First positive electrode tab group 40b Second positive electrode tab group 5. Negative electrode plate 5a...Negative electrode core 5b: Negative electrode active material mixture layer 50 Negative electrode tab 50a···First negative electrode tab group 50b Second negative electrode tab group 6. Positive electrode current collecting member 6a...First positive electrode current collector 6c Connection hole 6d...Fixing hole 6d1...Small diameter part 6d2...Large diameter section 6e···Hole to prevent slippage 6f Thin section 6g...notch 6h···Connecting rib 6i...Top surface 6x...Current collector protrusion 6w... Current collector second recess 6b...Second positive electrode current collector 6b1... Current collector first region 6b2... Current collector second area 6b3...Current collector third area 6k target hole 6m... Current collector first recess 6y... Current collector first opening 6z... 2nd opening of current collector 7 Positive terminal 7a...Tsubabe 7b Insertion part 7c...Terminal through hole 7d. Crimped part 7x...Terminal sealing material 7y Metal parts 7z Rubber parts 8. Negative electrode current collecting member 8a...First negative electrode current collector 8x...Current collector protrusion 8w... Current collector second recess 8b...Second negative electrode current collector 8b1... Current collector first area 8b2... Current collector second area 8b3...Current collector third area 8e Target hole 8f... First recess of current collector 8y...Current collector first opening 9...Negative terminal 10. First insulating member 10a... First insulating member main body 10b...1st side wall 10c...Second side wall 10d Second terminal insertion hole 10e···First connection part 10f...Second connection part 10g···Concave 10x First groove 10y...Second groove 11. External insulating member 11a...First terminal insertion hole 12 Internal insulating member 13. External insulating member 14. Insulation sheet 15...Electrolyte injection hole 16 Sealing plug 17 Gas exhaust valve 60 Current interruption mechanism 61 Conductive member 61a...Conductive member base portion 61b...Tubular part 61c···Third terminal insertion hole 61d···Flange part 61e Pressing protrusion 61f Conductive member opening 61g...Tapered section 62 Deformed plate 62a...Stepped protrusion 62a1...1st protrusion 62a2...Second protrusion 62b Annular rib 62c: Thin-walled annular section 62d Bottom of stepped recess 63 Second insulating member 63x....Insulating member first area 63a... Insulating member first opening 63b...Third wall section 63c...4th wall section 63d Third connection part 63e···Fourth connection part 63f...Fixing protrusion 63f1... Expanded diameter part 63g···Protrusion to prevent slippage 63h...Claw part 63y: Second insulating member area 63i...Second opening of insulating member 63k···Insulating member annular rib 63z Insulating member third area 80···Cover part 80a···Cover body 80b...Arm 80c···Connection protrusion 80d···Base opening 80e···Cover wall 80f...Wall opening 81 Cover 81a···Cover body 81b...Arm 81d···Root opening 81e···Cover wall 81f...Wall opening 81x···Cover opening 90... Welded joint 102...Sealing plate 102x Pressing protrusion 161 Conductive member

Claims

1. an electrode assembly including a positive electrode plate and a negative electrode plate; an exterior body having an opening and accommodating the electrode body; a sealing plate that seals the opening; a conductive member having an opening on the electrode body side and arranged on the electrode body side of the sealing plate via a first insulating member; a deformable plate that seals the opening and deforms in response to an increase in pressure inside the exterior body; a current collecting member that electrically connects the positive electrode plate or the negative electrode plate to the deformation plate; a terminal electrically connected to the positive electrode plate or the negative electrode plate via the current collecting member, the deformation plate, and the conductive member; the terminal is inserted into a terminal mounting hole provided in the sealing plate, a terminal insertion hole provided in the first insulating member, and a terminal insertion hole provided in the conductive member, and is connected to the conductive member; At least one of the conductive member and the sealing plate has a pressing protrusion that protrudes toward the first insulating member at a portion facing the first insulating member, the first insulating member has a first groove portion at a portion disposed between the sealing plate and the conductive member, the first groove portion being located at a position farther from a terminal insertion hole provided in the first insulating member than a portion pressed by the pressing protrusion; the first insulating member has a second groove portion at a portion disposed between the sealing plate and the conductive member, the second groove portion being located farther from a terminal insertion hole provided in the first insulating member than a portion pressed by the pressing protrusion; the first groove portion is provided on a surface of the first insulating member that faces one of the sealing plate and the conductive member, the second groove portion is provided on a surface of the first insulating member that faces the other of the sealing plate and the conductive member, the first groove portion and the second groove portion are at different distances from the terminal insertion hole; The end of the terminal on the electrode body side is fixed to the conductive member by crimping, a terminal insertion hole into which the terminal is inserted in the conductive member has an end portion on the electrode body side, the end portion being provided with a tapered portion whose diameter is enlarged on the electrode body side; A secondary battery, wherein the deformation of the deformable plate cuts off the conductive path between the positive electrode plate or the negative electrode plate and the terminal.

2. The secondary battery according to claim 1 , wherein the terminal is connected to the conductive member by welding.

3. A secondary battery as described in claim 1 or 2, wherein the second groove portion is located at a position farther from the terminal insertion hole provided in the first insulating member than the first groove portion.

4. A secondary battery described in any of claims 1 to 3, wherein the first groove portion and the second groove portion are formed so that a portion of the first groove portion overlaps a portion of the second groove portion when the first insulating member is viewed in a plane.

5. 5. The secondary battery according to claim 1, wherein the pressing protrusion is provided on the conductive member.

6. 6. The secondary battery according to claim 5, wherein the conductive member has a conductive member base portion arranged to face the sealing plate and a tubular portion extending from the conductive member base portion toward the electrode body, and the pressing protrusion is provided on the conductive member base portion.

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