Battery

Abstract

To provide a battery with suitably improved reliability.SOLUTION: According to a preferred aspect, a battery 100 disclosed herein comprises: an electrode body 10 having positive and negative electrodes; a case body 2 which has an opening 3 and houses the electrode body 10; a sealing plate 4 which has a terminal fitting hole 8 and seals the opening 3; a collector terminal 20 which has one end electrically connected to the positive or negative electrode inside the case body 2, and the other end inserted through the terminal fitting hole 8 so as to be exposed to an outer surface 7 of the sealing plate 4; and an insulation member 30 which insulates at least part of the sealing plate 4 and the collector terminal 20. The sealing plate 4 is provided with a plurality of recesses 4a. The recesses 4a are filled with the insulation member 30 which faces the recesses 4a.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a battery.

Background Art

[0002] In recent years, batteries such as lithium-ion secondary batteries have been suitably used as portable power sources for personal computers, mobile terminals, etc., and power sources for driving vehicles such as battery electric vehicles (BEVs), hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), etc. Such a battery includes, for example, an insulating member for insulating an electrode terminal and a sealing plate. For example, Patent Document 1 below discloses a battery having such a configuration.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, according to the study of the present inventor, a force acting around its rotation axis (hereinafter, also simply referred to as "torque") may be applied to the electrode terminal due to vibrations of the traveling vehicle during module fastening or after restraint, and as a result, it has been found that there is a risk of damage to the joint portion of the electrode terminal-insulating member-sealing plate or the insulating member.

[0005] The present disclosure has been made in view of such circumstances, and its main object is to provide a battery with suitably improved reliability.

Means for Solving the Problems

[0006] To achieve this objective, the present disclosure provides a battery comprising: an electrode body having positive and negative electrodes; a battery case having an opening and housing the electrode body; a sealing plate having terminal mounting holes and sealing the opening; an electrode terminal having one end electrically connected to either the positive or negative electrode inside the battery case and the other end inserted through the terminal mounting hole and exposed to the outside of the sealing plate; and an insulating member insulating at least a part of the sealing plate and the electrode terminal, wherein one or more recesses are formed in at least one of the sealing plate and the insulating member, and if the recess is formed in the sealing plate, the insulating member facing the recess is filled in the recess, and if the recess is formed in the insulating member, the sealing plate facing the recess is embedded in the recess.

[0007] Thus, by providing a recess in at least one of the sealing plate and the insulating member, the load generated by the torque applied to the electrode terminals can be suitably received by the recess. This allows the torque applied to the electrode terminals to be distributed, thereby suitably suppressing damage to the joint and insulating member as described above. Therefore, according to this disclosure, a battery with suitably improved reliability can be provided. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic perspective view showing a battery according to the first embodiment. [Figure 2] Figure 2 is a schematic longitudinal cross-sectional view along the line II-II in Figure 1. [Figure 3] Figure 3 is a schematic top view showing the sealing plate of Figure 1. [Figure 4] Figure 4 is a schematic top view showing a sealing plate according to the second embodiment. [Figure 5] Figure 5 is a schematic longitudinal cross-section along the VV line in Figure 4. [Figure 6] Figure 6 is a diagram corresponding to Figure 2 according to the third embodiment. [Figure 7] Figure 7 is a diagram corresponding to Figure 2 according to the fourth embodiment. [Figure 8] Figure 8 is a schematic diagram showing the configuration of the second flange portion in Figure 7. [Modes for carrying out the invention]

[0009] Hereinafter, with reference to the drawings, several preferred embodiments of the technology disclosed herein will be described. Matters other than those specifically mentioned herein but necessary for the implementation of this disclosure (e.g., general battery configurations and manufacturing processes not characterizing this disclosure) can be understood as design matters for those skilled in the art based on the prior art. This disclosure can be implemented based on the content disclosed herein and common technical knowledge in the art. Furthermore, the embodiments described herein are, of course, not intended to limit this disclosure in any way.

[0010] Furthermore, each figure is a schematic diagram and does not necessarily faithfully reflect the actual product. In the following, the same reference numerals are used for components and parts that perform the same function, and redundant explanations are omitted or simplified as appropriate. Here, in the figures, front, back, up, down, left, and right are represented by F, Rr, U, D, L, and R, respectively. However, front, back, up, down, left, and right are merely directions for the sake of explanation and do not limit the battery installation configuration, etc. Also, the rotation direction D1 in the figures is merely a direction for the sake of explanation and does not limit the rotation direction of the current collection terminal (electrode terminal). Furthermore, the following explanation is not intended to limit the technology disclosed herein to the following embodiments. In addition, the notation "A~B" indicating a range in this specification includes not only the meaning of A or greater and B or less, but also the meaning of "greater than A" and "less than B".

[0011] In this specification, "battery" refers to all energy storage devices capable of extracting electrical energy, and is a concept that encompasses both primary and secondary batteries. Furthermore, in this specification, "secondary battery" refers to all energy storage devices capable of repeated charging and discharging by the movement of charge carriers between the positive and negative electrodes via an electrolyte. The electrolyte may be a liquid electrolyte, a gel electrolyte, or a solid electrolyte. Such secondary batteries include not only so-called storage batteries (chemical batteries) such as lithium-ion secondary batteries and nickel-metal hydride batteries, but also capacitors (physical batteries) such as electric double-layer capacitors. The following describes embodiments that focus on lithium-ion secondary batteries.

[0012] <Battery configuration> Figure 1 is a schematic perspective view of a battery 100. As shown in Figure 1, the battery 100 comprises a battery case 1, an electrode body 10, a current collector terminal 20 (electrode terminal), and an insulating member 30. In Figure 1, the assembly part (hereinafter referred to as the sealing plate assembly 4A), which is a part of the battery case 1 in which the current collector terminal 20 and the insulating member 30 are integrally molded, is shown separately from the other parts. Furthermore, in Figure 1, the sealing plate 4, the current collector terminal 20, and the insulating member 30 are shown separately with respect to the negative electrode.

[0013] The battery case 1 comprises a case body 2 and a sealing plate 4. The case body 2 and the sealing plate 4 are examples of case components that make up the battery case 1. The case body 2 houses the electrode body 10 and the electrolyte. The case body 2 is a roughly rectangular, flat, rectangular container. In other embodiments, the shape of the battery case 1 may be cylindrical or other shapes. The case body 2 has an opening on one side between a pair of sides that form opposing wide surfaces. For example, the case body 2 can be made of metal such as aluminum or an aluminum alloy.

[0014] The sealing plate 4 is a component that seals the opening 3 of the case body 2. In Figure 1, it is shown in a separated state, but in the finished battery 100, the sealing plate 4 is joined to the periphery of the opening 3 of the case body 2. For the sealing plate 4, a metal such as aluminum or an aluminum alloy can be used. The sealing plate 4 has an inner surface 6 facing the inside of the battery 100 and an outer surface 7 facing the outside. The sealing plate 4 also has terminal mounting holes 8 that penetrate the inner surface 6 and the outer surface 7. One terminal mounting hole 8 is provided on the positive electrode side and one on the negative electrode side of the sealing plate 4. The inside and outside of the battery case 1 are in communication through the terminal mounting holes 8. The shape of the terminal mounting holes 8 is cylindrical here, but it may be various shapes such as rectangular. While not particularly limited, the thickness of the sealing plate 4 (see S1 in Figure 2) can be, for example, 0.5 mm or more, and is preferably 1 mm or more, and may be, for example, 2 mm or more, from the viewpoint of easily forming the recess 4a described later. Furthermore, the upper limit of the thickness of the sealing plate 4 is, for example, 10 mm or less, and is preferably 5 mm or less from the viewpoint of suitably maintaining the volume capacity of the battery 100.

[0015] The sealing plate 4 is equipped with a thin-walled safety valve 5 that is designed to release the internal pressure of the battery case 1 when the internal pressure rises above a predetermined level. The battery case 1 is also provided with an injection hole 9 for injecting electrolyte.

[0016] The electrode body 10 is housed in the case body 2. The electrode body 10 is housed in the case body 2 in a state covered with, for example, an insulating film (not shown). The electrode body 10 includes a positive electrode sheet 11, a negative electrode sheet 12, and a separator sheet (not shown) disposed between the positive electrode sheet 11 and the negative electrode sheet 12. The positive electrode sheet 11, the negative electrode sheet 12, and the separator sheet are each a long strip-shaped member. The positive electrode sheet 11, the negative electrode sheet 12, and the separator sheet are stacked and wound inside the case body 2. Note that the technology disclosed here can also be applied, for example, when the electrode body is a laminated electrode body in which the positive electrode sheet and the negative electrode sheet are stacked via a separator sheet. Also, as the positive electrode sheet and the negative electrode sheet, for example, those having tabs can also be used.

[0017] The positive electrode sheet 11 is a member in which a positive electrode active material layer containing a positive electrode active material is formed on both surfaces of a metal foil (for example, aluminum foil) having a predetermined width and thickness. In other embodiments, the positive electrode active material layer may be formed on only one surface of the positive electrode sheet. The positive electrode active material is, for example, in a lithium-ion secondary battery, a material such as a lithium transition metal composite material that can release lithium ions during charging and absorb lithium ions during discharging. The positive electrode active material has generally been proposed in various forms other than lithium transition metal composite materials and is not particularly limited.

[0018] The negative electrode sheet 12 is a member in which a negative electrode active material layer containing a negative electrode active material is formed on both surfaces of a metal foil (for example, copper foil) having a predetermined width and thickness. In other embodiments, the negative electrode active material layer may be formed on only one surface of the negative electrode sheet. The negative electrode active material is, for example, in a lithium-ion secondary battery, a material such as natural graphite that can occlude lithium ions during charging and release the lithium ions occluded during charging during discharging. The negative electrode active material has generally been proposed in various forms other than natural graphite and is not particularly limited.

[0019] For the separator sheet, for example, a porous resin sheet having the required heat resistance and through which the electrolyte can pass is used. Various separator sheets have been proposed and are not particularly limited.

[0020] As the electrolytic solution, those conventionally known and usable in this type of battery can be used. For example, a solution containing a supporting salt in an organic solvent (non-aqueous solvent) can be used.

[0021] The positive electrode sheet 11 wound inside the case body 2 is arranged such that one end comes near the left end inside the case body 2. The negative electrode sheet 12 is arranged such that one end comes near the right end inside the case body 2. Although shown in a separated state in FIG. 1, in the completed battery 100, one current collecting terminal 20 is welded to each of the positive electrode sheet 11 and the negative electrode sheet 12.

[0022] The sealing plate assembly 4A is an assembly part in which the sealing plate 4, the current collecting terminal 20, and the insulating member 30 are assembled by integral molding (insert molding). That is, the electrode terminal 20 and the insulating member 30 are provided as an integral molded product. According to such a configuration, the sealing plate assembly 4A can be easily removed, which is preferable from the viewpoint of workability. A part of the current collecting terminal 20 is arranged inside the battery case 1, and another part is arranged outside the battery case 1. Although not shown as described above, the current collecting terminal 20 is connected to the electrode body 10 inside the battery case 1. The current collecting terminal 20 on the negative electrode side is formed of, for example, copper or a copper alloy. The current collecting terminal 20 on the positive electrode side is formed of, for example, aluminum or an aluminum alloy.

[0023] FIG. 2 is a cross-sectional view near the terminal mounting hole 8 of the sealing plate 4. FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 1. As shown in FIG. 2, the current collecting terminal 20 includes a pedestal portion 21, an electrode body connection portion 22, a shaft portion 23, and an external connection portion 24. Hereinafter, the configuration near the terminal mounting hole 8 for taking out the electrode of the electrode body 10 to the outside of the battery case 1 is also referred to as an "electrode extraction portion".

[0024] The base portion 21 is constructed in a rectangular, flat plate shape and extends horizontally. As shown in Figure 2, the length of the base portion 21 in the front-to-back direction is longer than the terminal mounting hole 8. Although not shown in the figure, the length of the base portion 21 in the left-to-right direction is also longer than the terminal mounting hole 8. The radial size of the base portion 21 is larger than that of the terminal mounting hole 8.

[0025] The electrode connection portion 22 is located inside the battery case 1 and is connected to the electrode body 10. As shown in Figure 1, the electrode connection portion 22 is formed in a plate shape and extends downward from the rear end of the base portion 21. The electrode connection portion 22 is bent forward in its middle section. Below the bent portion, the electrode connection portion 22 extends downward again. Due to this bend, the tip of the electrode connection portion 22 is located in the center of the base portion 21 in the front-to-back direction.

[0026] The shaft portion 23 is positioned between the electrode body connection portion 22 and the external connection portion 24 located outside the battery case 1, and is inserted through the terminal mounting hole 8. The shaft portion 23 extends upward from the base portion 21. As shown in Figure 2, the length of the shaft portion 23 in the front-to-back direction is shorter than the base portion 21 and the terminal mounting hole 8. Although not shown in the figure, the length of the shaft portion 23 in the left-to-right direction is also shorter than the base portion 21 and the terminal mounting hole 8. Therefore, the shaft portion 23 is spaced apart from the inner circumferential surface of the terminal mounting hole 8.

[0027] The external connection portion 24 is located above the shaft portion 23. The external connection portion 24 is exposed on the outer surface 7 of the sealing plate 4. As shown in Figure 2, the length of the external connection portion 24 in the front-rear direction is shorter than the base portion 21 and the terminal mounting hole 8, but longer than the shaft portion 23. Although not shown in the figure, in the left-right direction as well, the length of the external connection portion 24 is shorter than the base portion 21 and the terminal mounting hole 8, but longer than the shaft portion 23. The external connection portion 24 is sized to be insertable into the terminal mounting hole 8. Due to the size difference between the base portion 21, the shaft portion 23, and the external connection portion 24, the shaft portion 23 appears constricted relative to the base portion 21 and the external connection portion 24.

[0028] The insulating member 30 insulates at least a portion of the sealing plate 4 and the current collector terminal 20. In this embodiment, the insulating member 30 is positioned with at least a portion of it inserted through the terminal mounting hole 8. In this embodiment, the insulating member 30 is integrally molded with the sealing plate 4 and the current collector terminal 20 so as to fill the gap between the terminal mounting hole 8 and the current collector terminal 20. The insulating member 30 has a cylindrical portion 31 located between the terminal mounting hole 8 and the shaft portion 23 of the current collector terminal 20, a first flange portion 32 extending horizontally along the inner surface 6 of the sealing plate 4, and a second flange portion 33 extending horizontally along the outer surface 7 of the sealing plate 4. The cylindrical portion 31, the first flange portion 32, and the second flange portion 33 are integrally formed. As shown in Figure 2, the length of the first flange portion 32 and the second flange portion 33 in the front-rear direction is longer than that of the external connection portion 24. Although not shown in the diagram, in the left-right direction as well, the lengths of the first flange portion 32 and the second flange portion 33 are longer than the base portion 21 and the external connection portion 24 of the current collection terminal 20.

[0029] As shown in Figure 3, in this embodiment, a plurality (in this case, eight) of recesses 4a are formed on the outer surface 7 of the sealing plate 4. However, the number of recesses on the sealing plate 4 is not limited to this, and for example, there may be one. Also, as shown in Figure 2, at least a portion of the insulating member 30 facing the recesses 4a is filled into the recesses 4a. With this configuration, the load generated by the torque applied to the current collector terminal 20 can be suitably received by the recesses 4a. As a result, the torque applied to the current collector terminal 20 can be distributed, and damage to the joint between the current collector terminal 20, the insulating member 30, and the sealing plate 4, as well as damage to the insulating member 30, can be suitably suppressed. The sealing plate 4 having the recesses 4a can be manufactured, for example, by a mold.

[0030] While not particularly limited, the depth of the recess 4a (see T1 in Figure 2) is, for example, 1 / 10 or more of the thickness of the sealing plate 4 at the periphery of the recess 4a (see S1 in Figure 2), and is preferably 1 / 5 or more, or for example 1 / 4 or more, from the viewpoint of more favorably receiving the aforementioned load. Furthermore, the upper limit of the depth of the recess 4a is, for example, 1 / 2 or less of the thickness of the sealing plate 4, or 1 / 3 or less.

[0031] While not particularly limited, the area of ​​the bottom surface of each recess 4a is, for example, 1% or more of the area of ​​the outer surface 7 of the sealing plate 4 before the holes and recesses are made, when this area is taken as 100%. From the viewpoint of more effectively receiving the aforementioned load, it is preferably 2% or more, and may be, for example, 3% or more. Furthermore, the upper limit of the area of ​​the bottom surface of each recess 4a is, for example, 10% or less of the area of ​​the outer surface 7 of the sealing plate 4, and may be 7% or less or 5% or less.

[0032] In this embodiment, the recesses 4a are formed around the current collector terminal 20 at points symmetrical to each other with respect to the electrode terminal 20 as the center point (see Figure 3; for convenience, the current collector terminal is omitted in Figure 3). With this configuration, the aforementioned load can be received more effectively by the recesses 4a, thereby more effectively suppressing damage to the joint between the current collector terminal 20, the insulating member 30, and the sealing plate 4, as well as to the insulating member 30. However, in other embodiments, the recesses do not have to be formed at points symmetrical to each other with respect to the current collector terminal 20 as the center point.

[0033] As shown in Figure 3, in this embodiment, the recess 4a is circular when viewed from its opening. However, the shape of the recess when viewed from its opening is not limited to this, and may be elliptical, rectangular, triangular, or any other shape. Among these, when the shape of the recess when viewed from its opening is circular or elliptical, it is preferable because it does not have corners, thus preventing stress concentration at the corners. Furthermore, if there are multiple recesses in the sealing plate, the shapes of the multiple recesses when viewed from their openings may all be the same or different.

[0034] The insulating member 30 is formed from a resin such as PFA (peralkoxyalkane) resin. However, the insulating member 30 can be any material that has moldability, insulating properties, sealing properties, and resistance to electrolytes, and is not limited to PFA resin. Other suitable materials for the insulating member 30 include, for example, PPS (polyphenylene sulfide) resin. Considering the difference between the temperature at which the insulating member 30 is molded and the temperature at which the battery 100 is used, it is preferable that the linear expansion coefficient of the sealing plate 4 and the linear expansion coefficient of the insulating member 30 are close. Therefore, preferably, in addition to PFA resin, a filler (for example, an insulating filler) to adjust the linear expansion coefficient may be added to the insulating member 30.

[0035] One example of such a filler is a glass filler composed mainly of glass components. Here, "composed mainly of glass components" means that, when the filler as a whole is considered to be 100% by mass, the glass component is contained in an amount of, for example, 90% or more, 95% or more, or 99% or more by mass (it may also be 100% by mass). Examples of glass components include SiO2-Al2O3-CaO-SrO glass and SiO2-B2O3-ZnO-Na2O glass. The average particle size of the glass filler can be, for example, in the range of 1 μm to 20 μm or 5 μm to 10 μm. In this specification, "average particle size" means, for example, the particle size corresponding to 50% of the cumulative value from the smallest particle size in a volume-based particle size distribution based on laser diffraction and scattering. Commercially available glass fillers can be used, for example.

[0036] <Battery manufacturing method> The battery 100 described above can be manufactured, for example, by a manufacturing method that includes (1) a preparation step and (2) a laser welding step. Here, the preparation step further includes (1A) an insert molding step.

[0037] (1) In the preparation step, the battery case 1 and the sealing plate 4 are prepared. In addition, other necessary components as described above are prepared. Here, the sealing plate 4 has multiple circular recesses 4a when viewed from the opening, and the multiple recesses 4a are formed to be point-symmetric with respect to the current collection terminal 20.

[0038] (1A) In the insert molding process, the current collector terminal 20 and the insulating member 30 are integrated into the sealing plate 4 to produce an assembly part (for example, a sealing plate assembly 4A). The sealing plate assembly 4A can be produced by insert molding the sealing plate 4, the current collector terminal 20, and the insulating member 30. This reduces the number of parts and allows for the formation of conductive paths more easily compared to the conventional method using rivets. Insert molding can be carried out according to conventionally known methods, such as those described in Japanese Patent Publication No. 2021-086813, Japanese Patent Publication No. 2021-086814, Japanese Patent No. 3986368, Japanese Patent No. 6648671, etc. For example, it can be produced by a molding die having a lower mold and an upper mold, and including a parts setting step, a positioning step, an upper mold setting step, an injection molding step, an upper mold release step, and a parts removal step.

[0039] In the parts setting process, the current collector terminal 20 is inserted through the terminal mounting hole 8 of the sealing plate 4, and then the sealing plate 4 is mounted on the lower mold. In the positioning process, the current collector terminal 20 is positioned and fixed. In the upper mold setting process, the upper mold is mounted together with the lower mold so as to sandwich the sealing plate 4 and the current collector terminal 20 in the vertical direction. In the injection molding process, the mold is first heated. Next, molten resin is injected into the mold. The molten resin flows from the upper mold through the terminal mounting hole 8 to the lower mold. After that, the mold and the molded product are cooled. This integrates the insulating member 30, the sealing plate 4, and the current collector terminal 20. In the upper mold release process, the upper mold is separated from the lower mold. In the parts removal process, the molded product is removed from the lower mold.

[0040] (2) In the laser welding process, after the electrode body 10 is housed inside the battery case 1, the sealing plate 4 is fitted into the opening 3 of the battery case 1. Next, the joint (fitting portion) between the battery case 1 and the sealing plate 4 is welded together with a laser. The type of laser light used for laser welding and the laser welding conditions are the same as in the conventional method and are not particularly limited. By welding the fitting portion all around, the sealing plate 4 and the battery case 1 are welded together without any gaps. After that, the electrolyte is injected through the injection hole 9 and the injection hole 9 is sealed with a sealing member to seal the battery 100. The battery 100 can be manufactured in this manner.

[0041] Battery 100 can be used for various applications, but is particularly suitable as a power source (driving power supply) for motors mounted on vehicles such as passenger cars and trucks. The type of vehicle is not particularly limited, but examples include plug-in hybrid electric vehicles (PHEVs), hybrid electric vehicles (HEVs), and battery electric vehicles (BEVs). It can also be used as a battery pack comprising multiple batteries 100.

[0042] Although several embodiments of the present disclosure have been described above, the first embodiment described above is merely an example. The present disclosure can be implemented in various other forms. The present disclosure can be implemented based on the content disclosed herein and common technical knowledge in the art. The technologies described in the claims include various modifications and changes to the embodiments illustrated above. For example, it is possible to replace parts of the above embodiments with other variations, and to add other variations to the above embodiments. Furthermore, technical features may be deleted as appropriate if they are not described as essential.

[0043] For example, in the first embodiment described above, a portion of the insulating member 30 facing the recess 4a of the sealing plate 4 is filled into the recess 4a of the sealing plate 4 on both the positive and negative electrode sides, but the invention is not limited to this. It is also possible to have such a configuration on only one of the positive or negative electrode sides. Furthermore, for example, in the first embodiment described above, the sealing plate assembly 4A is manufactured by integral molding (insert molding), but the invention is not limited to this. The technology disclosed herein can also be applied to sealing plate assemblies manufactured by methods other than integral molding.

[0044] Figure 4 is a schematic top view showing the sealing plate according to the second embodiment. Figure 5 is a schematic longitudinal cross-sectional view along the VV line in Figure 4. As shown in Figure 4, the terminal mounting hole 108 is formed in a cylindrical shape, and the portion of the current collector terminal 20 that is inserted into the terminal mounting hole 108 is also formed in a cylindrical shape. As shown in Figures 4 and 5, in the second embodiment, in each of the recesses 104, the corners of the opening (here, the edges 104a2) are rounded in shape at least in the portion facing the rotational direction (D1 direction in Figure 4) around the central axis of the cylindrical portion of the current collector terminal 20. This configuration is preferable because it more effectively relieves stress on the recess 104 and reinforces the strength of the joint between the current collector terminal 20, the insulating member 30, and the sealing plate 104. Although there are two edges 104a2 in the D1 direction here, there may be only one. Also, the other edges 104a1 are not rounded in shape here, but may be rounded in shape, for example. For other details regarding the recess 104 (e.g., size, depth, etc.), refer to the description of recess 4a as appropriate. While not particularly limited, the radius (R) of the edge 104a2 can generally be between 0.05 and 30 (e.g., 0.1 and 10). Even if the recess has a different shape (e.g., circular or elliptical), at least the corners facing the D1 direction can be given an R-shape.

[0045] For example, in the first embodiment described above, a recess 4a is formed on the outer surface 7 of the sealing plate 4, but the embodiment is not limited to this. Here, Figure 6 is a diagram corresponding to Figure 2 according to the third embodiment. As shown in Figure 6, in the third embodiment, a recess 204a is formed on the inner surface 206 of the sealing plate 204. Although not shown, the perspective view of the sealing plate in Figure 6 can be said to be a modification of Figure 3 where the label for the outer surface 7 is changed to the label for the inner surface 6. In other embodiments, a recess may be formed in the terminal mounting hole 8 of the sealing plate 4. For details on the configuration of these recesses (e.g., size, depth, etc.), refer to the description of the recess 4a as appropriate.

[0046] For example, in the first embodiment described above, a recess 4a is formed in the sealing plate 4, but the embodiment is not limited to this. Here, Figure 7 is a diagram corresponding to Figure 2 according to the fourth embodiment, and Figure 8 is a schematic diagram showing the configuration of the second flange portion in Figure 7. In Figure 8, 333A shows the outer surface of the second flange portion 333, and 333B shows the inner surface of the second flange portion 333. As shown in Figures 7 and 8, in the fourth embodiment, a plurality of recesses 333a (in this case, eight) are formed in the insulating member 330. In this case, a part of the sealing plate 304 facing the recess 333a is embedded in the recess 333a. With this configuration, the load generated by the torque applied to the current collector terminal 20 can be suitably received by the recess 333a. As a result, the torque applied to the current collector terminal 20 can be distributed, and damage to the joint between the current collector terminal 20, the insulating member 330, and the sealing plate 304, as well as damage to the insulating member 330, can be suitably suppressed. Such a configuration can be realized, for example, by using a sealing plate having a protrusion corresponding to the recess 333a, and by mold molding or the like. The shape of the opening of the recess can be one of the various shapes listed in the description of the recess 4a. In addition, at least the corners facing the D1 direction in the recess can be rounded.

[0047] While not particularly limited, the depth of the recess 333a (see T2 in Figure 7) is, for example, 1 / 10 or more of the thickness of the second flange portion 333 of the insulating member 330 at the periphery of the recess 333a (see S2 in Figure 7), and is preferably 1 / 5 or more, or for example 1 / 4 or more, from the viewpoint of more favorably receiving the load described above. Furthermore, the upper limit of the depth of the recess 333a is, for example, 1 / 2 or less of the thickness of the second flange portion 333, or for example 1 / 3 or less. Furthermore, while not particularly limited, the thickness S2 of the insulating member 330 (specifically the second flange portion 333) can be, for example 1 mm or more, and is preferably 2 mm or more, or for example 3 mm or more, from the viewpoint of easily forming the recess 333a. Furthermore, the upper limit of the thickness S2 of the second flange portion 333 is, for example 10 mm or less, or for example 5 mm or less.

[0048] While not particularly limited, the area of ​​the bottom surface of each recess 333a is, for example, 1% or more of the area of ​​the inner surface 333B of the second flange before the holes and recesses are made, with the area of ​​the inner surface 333B of the second flange being considered as 100%. From the viewpoint of more effectively receiving the aforementioned load, it is preferably 2% or more, and may be, for example, 3% or more. Furthermore, the upper limit of the area of ​​the bottom surface of each recess 333a is, for example, 10% or less of the area of ​​the inner surface 333B of the second flange, and may be 7% or less or 5% or less.

[0049] Furthermore, the effects of the technology disclosed herein can be suitably obtained by combining two or more of the first to fourth embodiments described above. Also, 105, 306, and 109 correspond to 5, 6, and 9 in Figure 1, respectively; 107, 207, and 307 correspond to 7 in Figure 1; and 230, 231, 331, 232, and 332 correspond to 30, 31, and 32 in Figure 1, respectively.

[0050] As described above, specific embodiments of the technology disclosed herein include those listed in the following items. Item 1: A battery comprising: an electrode body having positive and negative electrodes; a battery case having an opening and housing the electrode body; a sealing plate having terminal mounting holes and sealing the opening; an electrode terminal having one end electrically connected to either the positive or negative electrode inside the battery case and the other end inserted through the terminal mounting hole and exposed to the outside of the sealing plate; and an insulating member insulating the sealing plate and at least a portion of the electrode terminal, wherein one or more recesses are formed in at least one of the sealing plate and the insulating member, and if the recess is formed in the sealing plate, the insulating member facing the recess is filled in the recess, and if the recess is formed in the insulating member, the sealing plate facing the recess is embedded in the recess. Item 2: The battery according to Item 1, wherein if the recess is formed in the sealing plate, the depth of the recess is at least 1 / 5 of the thickness of the sealing plate at the periphery of the recess, and if the recess is formed in the insulating member, the depth of the recess is at least 1 / 5 of the thickness of the insulating member at the periphery of the recess. Item 3: The battery according to Item 1 or 2, wherein a plurality of recesses are formed in at least one of the sealing plate and the insulating member, and the plurality of recesses are each formed around the electrode terminal at point-symmetrical positions with respect to the electrode terminal as the center point. Item 4: The battery according to any one of items 1 to 3, wherein each of the one or more recesses is circular or elliptical when viewed from its opening. Item 5: The battery according to any one of Items 1 to 4, wherein the terminal mounting hole is formed in a cylindrical shape, the portion of the electrode terminal that is inserted into the terminal mounting hole is formed in a cylindrical shape, and in each of the recesses, at least in the portion facing the rotational direction of the cylindrical portion of the electrode terminal, the corner of the opening is formed in an R shape. Item 6: The battery described in any one of items 1 to 5, wherein the thickness of the sealing plate is 1 mm or more. Item 7: The battery according to any one of items 1 to 6, wherein the insulating material includes an insulating filler. Item 8: The battery according to any one of Items 1 to 7, wherein the electrode terminals and the insulating member are provided as an integrally molded product. [Explanation of symbols]

[0051] 1. Battery case (case component) 2. Case body (case components) 3 Opening 4,104,204,304 Sealing plate (case component) 4a, 104a, 204a, 333a recess 4A Sealing Plate Assembly 5,105 Safety valve 6,206,306 Inner surface 7,107,207,307 External surface 8,108 terminal mounting holes 9,109 Liquid injection hole 10 Electrode body 11 Positive electrode sheet 12 Negative electrode sheets 20 Current collector terminal (electrode terminal) 21 Base 22 Electrode connection section 23 Shaft section 24 External connection section 30,230,330 Insulating material 31,231,331 Cylindrical part 32,232,332 First guard section 33,233,333 Second guard section 100 batteries

Claims

1. An electrode body having positive and negative electrodes, A battery case having an opening and housing the electrode body, A sealing plate having terminal mounting holes and sealing the opening, One end of the electrode terminal is electrically connected to either the positive or negative electrode inside the battery case, and the other end is inserted through the terminal mounting hole and exposed to the outside of the sealing plate. An insulating member that insulates at least a portion of the sealing plate and the electrode terminal, A battery equipped with, The sealing plate, the electrode terminals, and the insulating member are provided as an integrally molded product. The terminal mounting hole is formed in a cylindrical shape. The portion of the electrode terminal that is inserted into the terminal mounting hole is formed in a cylindrical shape. One or more recesses are formed in at least one of the sealing plate and the insulating member. Each of the aforementioned recesses is rectangular in shape when viewed from the opening of the recess. In each of the recesses, at least in the portion facing the rotational direction of the cylindrical portion of the electrode terminal, the corner of the opening of the recess is formed in an R shape. If the recess is formed in the sealing plate, the insulating member facing the recess is filled into the recess. A battery in which, if the insulating member has the recess, the sealing plate facing the recess is embedded in the recess.

2. If the recess is formed in the sealing plate, the depth of the recess is at least 1 / 5 of the thickness of the sealing plate at the periphery of the recess. The battery according to claim 1, wherein, if the recess is formed in the insulating member, the depth of the recess is at least 1 / 5 of the thickness of the insulating member at the periphery of the recess.

3. The aforementioned recesses are formed in a plurality in at least one of the sealing plate and the insulating member. The battery according to claim 1 or 2, wherein the plurality of recesses are formed around the electrode terminal at positions that are point-symmetrical with respect to the electrode terminal as the center point.

4. The battery according to claim 1 or 2, wherein the thickness of the sealing plate is 1 mm or more.

5. The insulating member includes a glass filler as an insulating filler. The glass filler is SiO ２ - Al ２ O ３ -CaO-SrO-based glass and / or SiO ２ -B ２ O ３ -ZnO-Na ２ A battery according to claim 1 or 2, comprising O-based glass.

6. The battery according to claim 1, wherein the insulating member has a cylindrical portion located between the terminal mounting hole and the electrode terminal, a first flange portion extending horizontally along the inner surface of the sealing plate, and a second flange portion extending horizontally along the outer surface of the sealing plate, and these cylindrical portion, the first flange portion and the second flange portion are integrally formed.

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