Insulating plate for battery and battery

Abstract

A battery 100 according to the present disclosure comprises: an exterior can 1; an electrode group 4 that is wound and housed in the exterior can 1; a sealing body 8 that seals the exterior can 1; a lead 5c that is connected to the electrode group 4 and the sealing body 8; and an insulating plate 10 that is disposed between the electrode group 4 and the sealing body 8. The insulating plate 10 includes: a disk-shaped base part 11 including a lead hole 13 through which the lead 5c penetrates; and an upright wall part 12 that is upright from the base part 11. The upright wall part 12 is disposed on the outer peripheral side of the lead hole 13 in a radial direction from a central axis O of the battery 100, and has a curved arcuate shape along the circumferential direction around the central axis O. When viewed from a direction parallel to the central axis O, an angle α formed by a first virtual straight line connecting one end of the upright wall part 12 with the central axis O and a second virtual straight line connecting the other end of the upright wall part 12 with the central axis O is between 90° and 180°inclusive.

Description

Insulating Plate for Battery and Battery

[0001] The present disclosure relates to an insulating plate for a battery and a battery.

[0002] A cylindrical battery generally includes an electrode group formed by winding a positive electrode, a negative electrode, and a separator around a bottomed cylindrical outer can, an electrolyte, and seals an opening of the outer can with a sealing body. A positive electrode lead led out from the positive electrode is connected to the sealing body. In Patent Document 1, an electrode group obtained by winding a laminate in which a positive electrode and a negative electrode to which a positive electrode lead is connected are laminated via a separator in a spiral shape is housed in a battery case, the positive electrode lead is welded to a substrate of the sealing body, a non-aqueous electrolyte is injected into the battery case, and then the sealing body is disposed at an opening of the battery case to seal the battery case, thereby manufacturing a cylindrical lithium ion secondary battery.

[0003] International Publication No. 2013 / 099295

[0004] As described in Patent Document 1, a method of manufacturing a battery includes a step of welding a positive electrode lead led out from a positive electrode to a sealing body and a step of sealing a battery case with the sealing body. Here, after the step of welding the positive electrode lead and before the step of sealing, the positive electrode lead holds the sealing body floating above the outer can. During the manufacture of the battery, the assembled battery is placed on a conveying device such as a belt conveyor and conveyed. At this time, the positive electrode lead may be bent or twisted due to the wind pressure received by the positive electrode lead and the sealing body during conveyance. Depending on the directions of these bends and twists, the quality of the battery may deteriorate, and there has been a problem that productivity deteriorates.

[0005] The present disclosure provides a battery that can prevent deterioration of quality and improve productivity.

[0006] This disclosure provides a battery comprising: an outer casing; a group of electrodes wound and housed in the outer casing; a sealing body for sealing the outer casing; leads connected to the group of electrodes and the sealing body; and an insulating plate disposed between the group of electrodes and the sealing body, wherein the insulating plate includes a disc-shaped base portion having lead holes through which the leads pass, and a vertical wall portion rising from the base portion, the vertical wall portion being positioned on the outer circumference of the lead holes in the radial direction with respect to the central axis of the battery, and having an arc-shaped curve along the circumferential direction of the central axis, and the angle α between a first virtual straight line connecting one end of the vertical wall portion in the circumferential direction to the central axis and a second virtual straight line connecting the other end of the vertical wall portion in the circumferential direction to the central axis, viewed from a direction parallel to the central axis, is 90° or more and 180° or less.

[0007] The technology disclosed herein can provide batteries that prevent quality degradation and improve productivity.

[0008] Figure 1 is a cross-sectional view of the battery according to this embodiment. Figure 2 is a perspective view of the upper insulating plate constituting the battery according to this embodiment. Figure 3 is a plan view of the upper insulating plate constituting the battery according to this embodiment. Figure 4 is a cross-sectional view at the position indicated by the line IV-IV in Figure 3. Figure 5A is a diagram illustrating the operation of the battery according to this embodiment. Figure 5B is a diagram illustrating the operation of the battery according to this embodiment. Figure 6A is a diagram illustrating the manufacturing method of the battery. Figure 6B is a diagram illustrating the manufacturing method of the battery. Figure 7 is a cross-sectional view of another example of the upper insulating plate constituting the battery according to this embodiment.

[0009] The embodiments of this disclosure will be described below with reference to the drawings. This disclosure is not limited to the embodiments described below.

[0010] In this specification, the side with the sealing body is referred to as "up" and the bottom side of the outer casing as "down" in the direction along the central axis of the battery.

[0011] Figure 1 is a cross-sectional view of a battery according to Embodiment 1. The cross-section in Figure 1 includes the central axis of the battery 100, which is a cylindrical battery. The battery 100 comprises an outer casing 1, an electrode group 4, and a sealing body 8. The electrode group 4 is housed in the outer casing 1. The sealing body 8 seals the opening of the outer casing 1 so as to seal the battery 100.

[0012] The electrode group 4 has a wound structure. The winding axis of the electrode group 4 typically coincides with the central axis of the battery 100. The electrode group 4 has a positive electrode 5, a negative electrode 6, and a pair of separators 7. The electrode group 4 is impregnated with electrolyte. The positive electrode 5 has a positive electrode current collector 5a and a positive electrode active material layer 5b. One end of the positive electrode lead 5c is connected to the positive electrode 5. The other end of the positive electrode lead 5c is connected to the back surface of the lid 2. The negative electrode 6 has a negative electrode current collector 6a and a negative electrode active material layer 6b. One end of the negative electrode lead 6c is connected to the negative electrode 6. The other end of the negative electrode lead 6c is connected to the bottom surface of the outer casing 1.

[0013] The sealing body 8 includes a lid 2 and a gasket 3. The lid 2 of the sealing body 8 seals the outer casing 1 via the gasket 3. The lid 2 serves as both a terminal and a safety valve. In the battery 100, the back surface of the lid 2 to which the positive electrode lead 5c is connected functions as a terminal. The structure of the lid 2 is not particularly limited as long as it can seal the inside of the battery 100 via the gasket 3; for example, it may be a structure in which multiple components, such as a component that serves as a terminal and a component that serves as a safety valve, are stacked. The gasket 3 is placed between the lid 2 and the opening of the outer casing 1. The gasket 3 is an annular component made of an insulating material such as resin.

[0014] The battery 100 comprises an upper insulating plate 10 positioned between the electrode group 4 and the sealing body 8, and a lower insulating plate 9 positioned between the bottom inner surface of the outer casing 1 and the electrode group 4. In the battery 100, the positive electrode lead 5c passes through a lead hole provided in the upper insulating plate 10 and is connected to the electrode group 4 and the sealing body 8.

[0015] Figure 2 is a perspective view of the upper insulating plate 10 constituting the battery 100 according to this embodiment. Figure 3 is a plan view of the upper insulating plate 10 constituting the battery 100 according to this embodiment. Figure 3 corresponds to a view of the upper insulating plate 10 from above in a direction parallel to the central axis of the battery 100. In Figure 3, the positive electrode lead 5c passing through the lead hole 13 is shown by a dashed line. The upper insulating plate 10 includes a disc-shaped base portion 11 and a vertical wall portion 12. The base portion 11 has a lead hole 13, which is a through hole for passing the positive electrode lead 5c. The vertical wall portion 12 rises from the base portion 11 toward the sealing body 8. The vertical wall portion 12 is positioned on the outer circumference side of the lead hole 13 in the radial direction with respect to the central axis O of the battery 100, and has an arc-shaped curve along the circumferential direction of the central axis O. When viewed from a direction parallel to the central axis O of the battery 100, the angle α between a first virtual line connecting one end of the vertical wall portion 12 and the central axis O in the circumferential direction, and a second virtual line connecting the other end of the vertical wall portion 12 and the central axis O, is between 90° and 180°.

[0016] In this disclosure, "curved in an arc along the circumferential direction" means that when observed from a direction parallel to the central axis O, it is curved in an arc that is convex from the central axis O toward the outer circumference, that is, the central part of the vertical wall portion 12 is toward the outer circumference than the imaginary line connecting the two ends of the vertical wall portion 12 in the circumferential direction, and is not limited to a form that is curved with the same curvature as the outer circumference. Furthermore, in this disclosure, "angle α is 90° or more and 180° or less" means that in the projection image obtained by orthogonally projecting the battery 100 onto a plane perpendicular to the central axis O, the interior angle between the first imaginary line and the second imaginary line in the figure enclosed by the first imaginary line connecting one end of the vertical wall portion 12 and the center point (center point O) of the upper insulating plate 10 that coincides with the central axis O, the other end of the vertical wall portion 12 and the center point O, and the arc-shaped outer edge of the vertical wall portion 12 is 90° or more and 180° or less. The central axis O of the battery 100 coincides with the winding axis of the electrode group 4. The center of the base portion 11 coincides with the central axis O of the battery 100.

[0017] In the manufacturing process of cylindrical batteries, when the outer casing is sealed with a sealing body, the leads that are led out from the electrode group and welded to the sealing body are folded. That is, in cylindrical batteries, the leads led out from the electrode group are usually folded and welded to the sealing body 8. Therefore, in the battery manufacturing process, if the leads are bent or twisted in the opposite direction to the direction in which they are originally folded, problems such as misalignment of the weld between the leads and the sealing body and short circuits due to the leads contacting the outer casing can occur, which may worsen the productivity of the batteries. For example, in the battery manufacturing process, when batteries under assembly are placed on a conveying device such as a belt conveyor and transported, the wind pressure from the transport is applied to the leads and the sealing body welded to the leads, causing the leads to bend or twist in an undesirable direction. According to the configuration of this embodiment, even if the positive electrode lead 5c that penetrates the lead hole 13 is subjected to wind pressure, for example, it is supported by the vertical wall portion 12, thereby suppressing the occurrence of undesirable bending or twisting of the positive electrode lead 5c in the battery manufacturing process.

[0018] The angle α may be between 90° and 170°, or between 90° and 150°.

[0019] The lead hole 13 preferably has a shape that includes an arc portion 13r whose periphery is curved in an arc shape along the circumferential direction of the central axis O. The lead hole 13 may also have an opening shape that is curved in an arc shape along the circumferential direction. In the upper insulating plate 10 shown in Figures 2 and 3, the lead hole 13 is formed in a substantially semicircular arc shape on one half of the base portion 11, and its periphery includes an arc portion 13r. The lead hole 13 is formed between the vertical wall portion 12 and the central axis O. The lead hole 13 is formed to a size into which a positive electrode lead 5c can be inserted. The lead hole 13 preferably has an arc shape, a fan shape, or a semicircular shape, and more preferably it has an arc shape, a fan shape, or a semicircular shape centered on the central axis O. In addition to the lead hole 13, the upper insulating plate 10 preferably has holes for gas venting. The number and shape of the gas venting holes are not particularly limited. The upper insulating plate 10 shown in Figures 2 and 3 has oval-shaped central holes 14 and 15 with an opening area smaller than the lead holes 13. The central hole 14 is formed in the center of the base portion 11, and four holes 15 are formed circumferentially on the other half of the base portion 11. The central hole 14 and 15 are through holes and serve as gas vents.

[0020] In the projection image obtained by orthogonally projecting the upper insulating plate 10 onto a plane perpendicular to the central axis O, the aperture ratio for all openings, including the lead holes 13, central hole 14, and hole 15, is not particularly limited, but may be, for example, 10% or more, or 20% or more. This allows for sufficient gas venting. The aperture ratio in the upper insulating plate 10 may be, for example, 70% or less, or 60% or less. This allows the upper insulating plate 10 to have sufficient strength and insulation properties.

[0021] The vertical wall portion 12 may be formed using the same material as the base portion 11, or it may be formed integrally with the base portion 11. When the vertical wall portion 12 is formed integrally with the base portion 11, it means that the base portion 11 and the vertical wall portion 12 cannot be separated without destruction. For example, the upper insulating plate 10 is a molded body formed by injection molding or the like using an insulating material. The upper insulating plate 10 may be formed from an insulating material such as glass fiber reinforced phenolic resin (glass phenolic resin) or polypropylene. Preferably, the insulating material is glass fiber reinforced phenolic resin. This allows the effects of this disclosure, provided by the inclusion of the vertical wall portion 12, to be fully realized. Furthermore, the manufacturing of the upper insulating plate 10 may be facilitated.

[0022] It is desirable that the vertical wall portion 12 is curved to follow the shape of the periphery of the lead hole 13. The vertical wall portion 12 may be curved in an arc shape, for example. The closer the distance between the vertical wall portion 12 and the lead hole 13, the better, and it is desirable that the vertical wall portion 12 is provided close to the periphery of the lead hole 13. In the upper insulating plate 10 shown in Figures 2 and 3, the vertical wall portion 12 is positioned close to the periphery of the lead hole 13 and is curved along the arc portion 13r of the periphery of the lead hole 13.

[0023] When the width of the positive electrode lead 5c is defined as La, the length of the vertical wall portion 12 in the circumferential direction is defined as Lb, and the length of the arc portion 13r at the periphery of the lead hole 13 is defined as Lc, the condition La ≤ Lb ≤ Lc may be satisfied. The above configuration is suitable for suppressing bending and twisting of the positive electrode lead 5c because the lead hole 13 can accommodate the positive electrode lead 5c and the vertical wall portion 12 can support the entire width of the positive electrode lead 5c. In addition, since Lb is not excessively large, the vertical wall portion 12 does not affect the gas vent holes such as the central hole 14 and hole 15. Lb is the curved length of the vertical wall portion 12.

[0024] Figure 4 is a cross-sectional view taken at the position indicated by the line IV-IV in Figure 3. The vertical wall portion 12 has a pair of main surfaces, consisting of a first main surface 12s located on the side closer to the lead hole 13 and a second main surface 12t located on the side further from the lead hole 13. The inner wall of the lead hole 13 and the first main surface 12s of the vertical wall portion 12 are continuous. In the upper insulating plate 10 shown in Figure 4, the first main surface 12s of the vertical wall portion 12 is perpendicular to the base portion 11. That is, the angle between the first main surface 12s and the base portion 11 is 90°. The first main surface 12s may be inclined to some extent towards the lead hole 13 side or the outer circumference side, but it is desirable that it is not inclined at least until the battery 100 is sealed by the sealing body 8. With the above configuration, the vertical wall portion 12 can support the positive electrode lead 5c with its surface, and the occurrence of bending and twisting of the positive electrode lead 5c can be further suppressed.

[0025] When the length from the upper end to the lower end of the vertical wall portion 12 is defined as L1 and the width of the lead hole 13 is defined as L2, the condition L1 ≤ L2 may be satisfied. The lower end of the vertical wall portion 12 is the position where it contacts the surface of the base portion 11 of the vertical wall portion 12. L1 is the height of the vertical wall portion 12. L2 is the length in the direction perpendicular to the length Lc. In the upper insulating plate 10 shown in Figures 2 to 4, the lead hole 13 is an arc shape centered on the central axis O, and L2 is the distance between the periphery of the lead hole 13 in the radial direction with respect to the central axis O. When L1 and L2 satisfy the above relationship, even if the vertical wall portion 12 is pushed toward the lead hole 13 by, for example, the sealing body 8 when the battery 100 is sealed, the opening of the lead hole 13 will not be completely closed. As a result, even if the upper insulating plate 10 has a vertical wall portion 12, the lead hole 13 can also function as a gas vent hole.

[0026] The length L1 is, for example, 0.1 mm or more and 5 mm or less, preferably 1 mm or more and 5 mm or less. When L1 is 1 mm or more, the vertical wall portion 12 can support the positive electrode lead 5c more adequately. When L1 is 5 mm or less, it does not significantly affect other elements constituting the battery 100, and the battery 100 can be sealed in a configuration similar to that of conventional batteries.

[0027] Figures 5A and 5B illustrate the operation of the battery 100 of this embodiment. Figure 5A shows the battery 100 before the positive electrode lead 5c and the sealing body 8 are welded together. According to this embodiment, since the upper insulating plate 10 has a vertical wall portion 12, even if it is subjected to wind pressure in the direction indicated by the black arrow in Figure 5A, for example, it is possible to suppress bending or twisting of the positive electrode lead 5c. Therefore, the battery 100 of this embodiment is less prone to producing defective products, prevents a decline in quality, and improves productivity.

[0028] Figure 5B shows the battery 100 before sealing, with the positive electrode lead 5c and the back surface of the sealing body 8 welded together. In conventional batteries, after the sealing body 8 is welded to the positive electrode lead 5c, before sealing, both the positive electrode lead 5c and the sealing body 8 are subjected to wind pressure, making the positive electrode lead 5c prone to bending or twisting. According to this embodiment, since the upper insulating plate 10 has a vertical wall portion 12, even if subjected to wind pressure in the direction indicated by the black arrow in Figure 5B, for example, bending or twisting of the positive electrode lead 5c can be suppressed. Therefore, the battery 100 of this embodiment is less prone to defects, prevents quality degradation, and improves productivity.

[0029] As shown in Figures 5A and 5B, the first main surface 12s of the vertical wall portion 12 may face the direction in which it receives wind pressure. For example, when the battery 100 is subjected to wind pressure during the manufacturing process, the vertical wall portion 12 may be positioned to receive wind pressure from the first main surface 12s side. As a result, even if the positive electrode lead 5c is subjected to the wind pressure described above, it is supported by the vertical wall portion 12, thus preventing it from bending. If, for example, wind pressure is received in the opposite direction, the positive electrode lead 5c may bend toward the center of the battery 100, but this is the direction in which the positive electrode lead 5c is naturally folded when sealed, so no particular problem arises. As described above, the battery 100 of this embodiment reduces defects caused by wind pressure received during the manufacturing process, for example. As a result, batteries can be manufactured regardless of the transport direction during manufacturing, and the occurrence of defective products can be reduced, thereby preventing a decline in quality and increasing productivity.

[0030] The battery 100 of this embodiment can be manufactured, for example, as follows.

[0031] First, the electrode group is housed in the outer casing. Next, the insulating plate is housed in the outer casing. The leads extending from the electrode group are welded to the sealing body. Finally, the outer casing is sealed.

[0032] The electrode group is the electrode group 4 described above. The lead is the positive electrode lead 5c. The electrode group 4, to which one end of the positive electrode lead 5c is connected, is housed in an outer container.

[0033] The insulating plate is the upper insulating plate 10 described above. The upper insulating plate 10 is housed in the outer casing 1 by passing the positive electrode lead 5c through the lead hole 13 formed in the upper insulating plate 10. This places the upper insulating plate 10 on top of the electrode group 4, resulting in the state shown in Figure 5A.

[0034] Next, the other end of the positive electrode lead 5c is welded to the sealing body 8. More specifically, the other end of the positive electrode lead 5c is welded to the back surface of the lid 2 in the sealing body. The back surface of the lid 2 is the main surface of the lid 2 that faces the inside of the battery 100 in the completed battery 100.

[0035] After housing the upper insulating plate 10 in the outer can 1, the electrolyte may be poured into the outer can 1 before welding the positive electrode lead 5c and the sealing body 8. Alternatively, the electrolyte may be poured into the outer can 1 after welding the positive electrode lead 5c and the sealing body 8.

[0036] The outer can 1 is sealed by attaching the sealing body 8 to the opening of the outer can 1.

[0037] Each of the above steps is performed while the battery being assembled is transported by a conveying device such as a belt conveyor. In the battery manufacturing method of this embodiment, from the step of housing the upper insulating plate 10 in the outer can 1 to the step of sealing the outer can 1, the transport direction may include a direction in which the upper insulating plate 10 receives wind pressure from the direction facing the first main surface 12s of the vertical wall portion 12. When the upper insulating plate 10 receives wind pressure from the direction facing the first main surface 12s, the positive electrode lead 5c is located upwind of the vertical wall portion 12. The positive electrode lead 5c will receive wind pressure in a direction that could cause it to bend toward the outer circumference of the upper insulating plate 10, but the vertical wall portion 12 supports it, which suppresses bending and twisting of the positive electrode lead 5c. Figures 6A and 6B are diagrams illustrating the battery manufacturing method. Figures 6A and 6B show the outer casing 1 (battery 100 under assembly) containing the electrode group 4 and upper insulating plate 10, with a sealing body 8 welded to the positive electrode lead 5c, as transported by a transport device in the battery manufacturing method according to this embodiment, along with the transport direction and the direction of the air pressure. Figure 6B is a perspective view of Figure 6A from a different orientation. In Figures 6A and 6B, the direction of the air pressure is indicated by a black arrow, and the transport direction is indicated by a white arrow. As it is transported, it is typically subjected to air pressure in a direction opposite to the transport direction.

[0038] The transport direction may always be the direction in which the first main surface 12s faces the wind pressure during the above process, or it may be a different direction for a period of time. That is, the battery manufacturing method of this embodiment may include transporting the upper insulating plate 10 in a direction such that the vertical wall portion 12 receives wind pressure from the first main surface 12s side for at least a portion of the time from when the upper insulating plate 10 is placed in the outer can 1 until the outer can 1 is sealed.

[0039] For example, during at least a portion of the period from the process of housing the upper insulating plate 10 in the outer can 1 to the process of welding the upper insulating plate 10 and the sealing body 8, the vertical wall portion 12 may be transported in a direction in which it receives wind pressure from the first main surface 12s side and the positive electrode lead 5c, which is subjected to wind pressure, is supported by the vertical wall portion 12. Even if transported in the above direction, bending and twisting of the positive electrode lead 5c before welding to the sealing body 8 can be suppressed, and misalignment of the welding position in the subsequent process of welding the positive electrode lead 5c and the sealing body 8 can be prevented. During at least a portion of the period from the process of welding the upper insulating plate 10 and the sealing body 8 to the process of sealing, the vertical wall portion 12 may be transported in a direction in which it receives wind pressure from the first main surface 12s side and the positive electrode lead 5c, which is subjected to wind pressure, is supported by the vertical wall portion 12. After connecting the sealing body 8 to the positive electrode lead 5c, the sealing body 8 is also subjected to air pressure, making the positive electrode lead 5c prone to bending. However, the presence of the vertical wall portion 12 reduces bending and twisting of the positive electrode lead 5c. Therefore, the battery manufacturing method of this embodiment can reduce the occurrence of defective products. Furthermore, since batteries can be manufactured without being affected by the transport direction (the direction in which they are subjected to air pressure), there is no need to control the orientation of the outer casing and the contained electrode group during transport, allowing for efficient battery manufacturing. The battery manufacturing method of this embodiment can improve productivity.

[0040] (Modification) Figure 7 is a cross-sectional view of another example of the upper insulating plate constituting the battery according to this embodiment. In the upper insulating plate 20 shown in Figure 7, the second main surface 12t, which is the main surface located on the side of the vertical wall portion 12 furthest from the lead hole 13, is a tapered surface that is inclined so that the thickness of the vertical wall portion 12 decreases towards the upper end. Thus, an insulating plate in which the lower end of the vertical wall portion 12 is thicker than the upper end can be easily manufactured. As shown in Figure 7, the upper insulating plate 20 in which the thickness of the lower end of the vertical wall portion 12 is increased due to the second main surface 12t being a tapered surface, and the first main surface 12s is a surface perpendicular to the base portion 11, can be easily manufactured and can further suppress the occurrence of bending and twisting of the positive electrode lead 5c.

[0041] (Other Embodiments) (Note) The above description of embodiments discloses the following technologies.

[0042] (Technology 1) A battery comprising: an outer can; an electrode group wound and housed in the outer can; a sealing body for sealing the outer can; a lead connected to the electrode group and the sealing body; and an insulating plate disposed between the electrode group and the sealing body, wherein the insulating plate includes a disc-shaped base portion having a lead hole through which the lead passes, and a standing wall portion rising from the base portion, the standing wall portion is disposed on the outer peripheral side of the lead hole in the radial direction with respect to the central axis of the battery, and has a shape curved in an arc along the circumferential direction of the central axis, and when viewed from a direction parallel to the central axis, the angle α formed by a first virtual straight line connecting one end of the standing wall portion in the circumferential direction and the central axis and a second virtual straight line connecting the other end of the standing wall portion in the circumferential direction and the central axis is 90° or more and 180° or less.

[0043] According to the technology of the present disclosure, a battery that is less likely to produce defective products, can prevent quality degradation, and can improve productivity can be provided.

[0044] (Technology 2) The battery according to Technology 1, wherein the standing wall portion is integrally formed with the base portion. According to the above configuration, the insulating plate can be easily manufactured.

[0045] (Technology 3) The battery according to Technology 1 or 2, wherein the lead hole has a shape including an arc portion whose periphery is curved in an arc along the circumferential direction, and the standing wall portion is disposed close to the periphery of the lead hole and curved along the arc portion. The battery of Technology 3 is less likely to produce defective products, can prevent quality degradation, and can improve productivity.

[0046] (Technology 4) The battery according to any one of Technologies 1 to 3, wherein the lead hole has an opening shape curved in an arc along the circumferential direction, when the width of the lead is defined as La, the length of the standing wall portion in the circumferential direction is defined as Lb, and the length of the arc portion of the periphery of the lead hole is defined as Lc, La ≤ Lb ≤ Lc is satisfied. The battery of Technology 4 is less likely to produce defective products, can prevent quality degradation, and can improve productivity.

[0047] (Technology 5) For the battery according to any one of Technologies 1 to 4, when the length from the upper end to the lower end of the standing wall portion is defined as L1 and the width of the lead hole is defined as L2, L1 ≤ L2 is satisfied. According to the above configuration, the lead hole can function sufficiently as a gas vent hole, and the quality of the battery can be improved.

[0048] (Technology 6) For the battery according to any one of Technologies 1 to 5, when, of the pair of main surfaces of the standing wall portion, the main surface located closer to the lead hole is defined as the first main surface and the main surface located farther from the lead hole is defined as the second main surface, the second main surface is a tapered surface inclined with respect to the first main surface such that the thickness of the standing wall portion decreases toward the upper end of the standing wall portion. The battery of Technology 6 is less likely to produce defective products, can prevent quality degradation, and can improve productivity. Further, according to the above configuration, the insulating plate can be easily manufactured.

[0049] (Technology 7) For the battery according to any one of Technologies 1 to 6, when, of the pair of main surfaces of the standing wall portion, the main surface located closer to the lead hole is defined as the first main surface and the main surface located farther from the lead hole is defined as the second main surface, the first main surface faces in the direction of receiving wind pressure. The battery of Technology 7 is less likely to produce defective products, can prevent quality degradation, and can improve productivity.

[0050] An insulating plate for a battery, comprising: a disc-shaped base portion having a lead hole that is a through hole; and a standing wall portion rising from the base portion, wherein the standing wall portion is disposed on the outer peripheral side of the lead hole in the radial direction with respect to the center of the base portion and has a shape curved in an arc along the circumferential direction of the center, and when viewed from a direction perpendicular to the base portion, the angle α formed by a first virtual straight line connecting one end of the standing wall portion in the circumferential direction and the center and a second virtual straight line connecting the other end of the standing wall portion in the circumferential direction and the center is 90° or more and 180° or less.

[0051] According to the technology of the present disclosure, it is possible to provide a battery in which defective products are less likely to occur, quality degradation is prevented, and productivity is improved.

[0052] The technology of the present disclosure is useful for cylindrical secondary batteries such as lithium-ion batteries and sodium-ion batteries.

Claims

1. A battery comprising: an outer casing; a group of electrodes wound and housed in the outer casing; a sealing body for sealing the outer casing; leads connected to the group of electrodes and the sealing body; and an insulating plate disposed between the group of electrodes and the sealing body, wherein the insulating plate includes a disc-shaped base portion having lead holes through which the leads pass, and a vertical wall portion rising from the base portion, the vertical wall portion being positioned on the outer circumference of the lead holes in the radial direction with respect to the central axis of the battery, and having an arc-shaped curve along the circumferential direction of the central axis, and the angle α between a first imaginary straight line connecting one end of the vertical wall portion in the circumferential direction to the central axis and a second imaginary straight line connecting the other end of the vertical wall portion in the circumferential direction to the central axis, viewed from a direction parallel to the central axis, is 90° or more and 180° or less.

2. The battery according to claim 1, wherein the vertical wall portion is integrally formed with the base portion.

3. The battery according to claim 1, wherein the lead hole has a shape including an arc portion whose periphery is curved in an arc shape along the circumferential direction, and the vertical wall portion is positioned close to the periphery of the lead hole and curves along the arc portion.

4. The battery according to claim 3, wherein the lead hole has an opening shape that is curved in an arc along the circumferential direction, and when the width of the lead is defined as La, the length of the vertical wall portion in the circumferential direction is defined as Lb, and the length of the arc portion at the periphery of the lead hole is defined as Lc, the condition La ≤ Lb ≤ Lc is satisfied.

5. The battery according to claim 3, wherein L1 ≤ L2 is satisfied when the length from the upper end to the lower end of the vertical wall portion is defined as L1 and the width of the lead hole is defined as L2.

6. The battery according to claim 1, wherein, of the pair of main surfaces of the vertical wall portion, the main surface located closer to the lead hole is defined as the first main surface, and the main surface located further away from the lead hole is defined as the second main surface, the second main surface is a tapered surface inclined with respect to the first main surface such that the thickness of the vertical wall portion decreases toward the upper end of the vertical wall portion.

7. The battery according to claim 1, wherein, of the pair of main surfaces of the vertical wall portion, the main surface located closer to the lead hole is defined as the first main surface, and the main surface located further away from the lead hole is defined as the second main surface, the first main surface faces in the direction of receiving wind pressure.

8. A battery insulating plate comprising: a disc-shaped base portion having a lead hole which is a through hole; and a vertical wall portion rising from the base portion, wherein the vertical wall portion is positioned on the outer circumference side of the lead hole in the radial direction with respect to the center of the base portion, and has an arc-shaped curve along the circumferential direction of the center, and the angle α between a first virtual line connecting one end of the vertical wall portion in the circumferential direction to the center and a second virtual line connecting the other end of the vertical wall portion in the circumferential direction to the center, when viewed from a direction perpendicular to the base portion, is 90° or more and 180° or less.

Images