Battery seal and battery

Abstract

The present disclosure accelerates the response timing of a PTC element. The disclosed battery closure body (30) is provided with: a closure plate (31), a lid (44), a PTC element unit (45) sandwiched between the closure plate (31) and the lid (44) and having a first main surface (45a) abutting against the closure plate (31) and a second main surface (45b) abutting against the lid (44), and a gasket (47) provided at the outer peripheral portions of the closure plate (31) and the lid (44). The closure plate (31) and the lid (44) are electrically connected via the PTC element unit (45). The abutting area between the closure plate (31) and the first main surface (45a) is set as S1, and the abutting area between the lid (44) and the second main surface (45b) is set as S2, S1>S2 is established.

Description

Technical Field

[0001] This disclosure relates to a sealing body for batteries and batteries. Background Technology

[0002] Previously, battery sealing bodies for sealing openings in battery casings were known (e.g., Patent Document 1). Patent Document 1 discloses "a battery sealing plate comprising: a sealing plate member formed by sequentially stacking a cap, a PTC element, and a filter having a spacer and an aluminum valve body; a liner inserted into the outer periphery of the sealing plate member; and a sealant coated between the liner and the sealing plate member, characterized in that a conductive member for connecting the cap to the PTC element or the PTC element to the filter is provided on at least one surface of a first contact portion where the cap contacts the PTC element and a second contact portion where the PTC element contacts the filter."

[0003] Prior art literature

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2009-266530 Summary of the Invention

[0006] -The problem the invention aims to solve-

[0007] In the battery with the sealing plate described in Patent Document 1, when heat is generated due to internal short circuits or the like, this heat is transferred to the PTC element, causing the resistance of the PTC element to increase, thereby suppressing overcurrent. In this case, the earlier the response timing of the PTC element, the better, and further improvement is desired. Under these circumstances, one of the objectives of this disclosure is to accelerate the response timing of the PTC element.

[0008] -Methods for solving problems-

[0009] One aspect of this disclosure relates to a battery sealing body. The battery sealing body includes: a sealing plate; a cover; a PTC element unit sandwiched between the sealing plate and the cover, having a first main surface abutting against the sealing plate and a second main surface abutting against the cover; and a gasket disposed on the outer periphery of the sealing plate and the cover, the sealing plate and the cover being electrically connected via the PTC element unit, wherein the abutment area between the sealing plate and the first main surface is defined as S1, and the abutment area between the cover and the second main surface is defined as S2, where S1 > S2.

[0010] Another aspect of this disclosure relates to a battery. The battery comprises: the aforementioned battery sealing body; a bottomed cylindrical housing having an opening sealed by the battery sealing body; an electrode group housed in the housing, having a first electrode and a second electrode; and a lead wire electrically connecting the sealing plate of the battery sealing body and the first electrode.

[0011] -Invention Effects-

[0012] According to this disclosure, the response timing of PTC elements can be accelerated. Attached Figure Description

[0013] Figure 1 This is a schematic cross-sectional view of the battery according to Embodiment 1.

[0014] Figure 2 This is a cross-sectional view showing the battery sealing body of Embodiment 1, and only the left side of the central axis is shown.

[0015] Figure 3 This is a cross-sectional view showing the battery sealing body of Embodiment 2, and only the left side of the central axis is shown.

[0016] Figure 4 This is a cross-sectional view showing the battery sealing body of Embodiment 3, and only the left side of the central axis is shown.

[0017] Figure 5 This is a cross-sectional view showing the battery sealing body of Embodiment 4, and only the left side of the central axis is shown.

[0018] Figure 6 This is a cross-sectional view showing the battery sealing body of Embodiment 5, and only the left side of the central axis is shown.

[0019] Figure 7 This is a diagram of the battery sealing body according to embodiment 6. Figure 7 (a) is the top view of the lid. Figure 7 (b) is a cross-sectional view of the battery sealing body.

[0020] Figure 8 This is a diagram of the battery sealing body of Modification 1 of Embodiment 6. Figure 8 (a) is the top view of the lid. Figure 8 (b) is a cross-sectional view of the battery sealing body.

[0021] Figure 9 This is a top view of the cover of variant 2 of embodiment 6. Figure 9 (a) is a top view of an example lid. Figure 9 (b) is a top view of the cover in another example.

[0022] Figure 10This is a cross-sectional view showing the battery sealing body of Embodiment 7, and only the left side of the central axis is shown.

[0023] Figure 11 This is a cross-sectional view showing the battery sealing body of embodiment 8, and only the left side of the central axis is shown.

[0024] Figure 12 This is a cross-sectional view showing the battery sealing body of Embodiment 9, and only the left side of the central axis is shown.

[0025] Figure 13 This is a cross-sectional view showing the battery sealing body of Embodiment 10, and only the left side of the central axis is shown.

[0026] Figure 14 This is a cross-sectional view of a battery sealing body showing a modified example of embodiment 10, and only the left side of the central axis is shown.

[0027] Figure 15 This is a cross-sectional view showing the battery sealing body of Embodiment 11.

[0028] Figure 16 This is a cross-sectional view showing the battery sealing body of Embodiment 12.

[0029] Figure 17 This is a cross-sectional view showing the battery sealing body of Embodiment 13.

[0030] Figure 18 This is a cross-sectional view showing the battery sealing body of embodiment 14, and only the left side of the central axis is shown. Detailed Implementation

[0031] The following examples illustrate embodiments of the battery sealing body and the battery involved in this disclosure. However, this disclosure is not limited to the examples described below. In the following description, specific values ​​and materials are sometimes illustrated, but other values ​​and materials can be applied as long as the effects of this disclosure are achieved.

[0032] (Battery sealing body)

[0033] The battery sealing body disclosed herein is used to seal the opening of a bottomed cylindrical casing of a battery. The battery sealing body disclosed herein includes: a sealing plate, a cover, a PTC element unit, and a gasket.

[0034] The sealing plate can also be connected to one of the electrodes of the battery's electrode group via leads when the battery sealing body is inserted into the battery. The sealing plate can also be made of metal, at least partially or entirely. The sealing plate can be composed of multiple parts or a single part. The sealing plate can also have a fracture pre-determined portion that will fracture if the internal pressure of the battery exceeds a given value.

[0035] The cover may also be exposed to the outside when the battery is inserted into the battery sealing body, functioning as an external terminal of one side. The cover may also be made of metal, at least partially or entirely. The cover may be composed of multiple parts or a single part. The cover may also have at least one gas vent for allowing gas to escape to the outside of the battery in the event of breakage of the sealing plate at a predetermined breakage point.

[0036] The PTC element unit is sandwiched between the sealing plate and the cap. The PTC element unit has a first main surface that abuts against the sealing plate and a second main surface that abuts against the cap. Thus, the sealing plate and the cap are electrically connected via the PTC element unit. The sealing plate and the cap may also be electrically connected solely via the PTC element unit. The PTC element unit may also have at least one PTC element. The PTC element is normally of low resistance; however, when heated above a certain temperature, its resistance increases sharply. The number of PTC elements in the PTC element unit is not particularly limited. The PTC element unit may also be formed in a ring shape, for example.

[0037] A gasket is installed on the outer periphery of the sealing plate and the cover. The gasket may also be made of an insulating resin material. When the battery is inserted into the battery sealing body, the gasket electrically insulates the battery casing from the sealing plate and the cover.

[0038] Let S1 be the contact area between the sealing plate and the first main surface of the PTC element unit, and S2 be the contact area between the cover and the second main surface of the PTC element unit, where S1 > S2. In the event of abnormal heating of the battery's electrode group, this heat is guided to the sealing plate via the leads and then transferred to the PTC element unit. Since the contact area S1 is relatively large, heat transfer from the sealing plate to the PTC element unit is efficient. On the other hand, heat transferred to the PTC element unit can be transferred to the cover, but this heat transfer is suppressed due to the relatively small contact area S2. In summary, since S1 > S2, heat from the electrode group is efficiently transferred to the PTC element unit and is difficult to dissipate from it. Therefore, the temperature of the PTC element unit (or the temperature of the PTC element within the PTC element unit) easily rises, accelerating the response timing of the PTC element (i.e., the timing of a sharp increase in the resistance value of the PTC element within the PTC element unit). Furthermore, in the structure of this disclosure, 1.3≤S1 / S2≤381, more preferably 1.5≤S1 / S2≤381.

[0039] Let the area of ​​the first principal surface be S3, and the area of ​​the second principal surface be S4. Alternatively, 0.21 ≤ S1 / S3 ≤ 1.0 and 0.001 ≤ S2 / S4 ≤ 0.73 can also hold true. By ensuring that the area ratios are within this range, the response timing of the PTC element can be significantly accelerated. Furthermore, 0.9 ≤ S3 / S4 ≤ 1.1 can also be further satisfied.

[0040] A conductive adhesive may be provided at least on one of the surfaces between the sealing plate and the first main surface, and between the cover and the second main surface. By providing a conductive adhesive at such locations, positional displacement of the PTC element unit can be suppressed. The conductive adhesive may, for example, be a resin composition in which conductive particles such as silver particles are dispersed. Furthermore, when the conductive adhesive is located between the sealing plate, the cover, and each main surface, the area of ​​the region where the components face each other through the conductive adhesive is considered as the contact area between the sealing plate, the cover, and each main surface.

[0041] The sealing plate may also have a first portion located radially outside the PTC element unit. A first insulating member may also be provided between the first portion and the PTC element unit to prevent electrical contact between the first portion and the PTC element unit. Here, if the sealing plate, the first portion, and the PTC element unit are in electrical contact, there is a concern that the sealing plate and the cover may be directly electrically connected. The first insulating member prevents such direct connection. The first insulating member may, for example, be formed in a ring shape.

[0042] A second insulating member can also be provided between the sealing plate and the cover to prevent electrical contact between them. The second insulating member can also be located between the sealing plate and the cover. For example, the second insulating member can be integrated with the gasket, integrated with the first insulating member, or it can be a separate component. The second insulating member prevents direct electrical contact between the sealing plate and the cover.

[0043] At least one of the sealing plate or the cap may also have an insulating layer that prevents electrical contact between the sealing plate and the cap. The insulating layer may also be formed by applying an insulating paste to a given portion of the surface of at least one of the sealing plate or the cap and allowing it to dry. The insulating layer prevents direct electrical contact between the sealing plate and the cap.

[0044] The cover may also have at least one protrusion that projects toward the PTC element unit and abuts against the second main surface. In this case, the contact area S2 between the cover and the second main surface of the PTC element unit becomes particularly small, and heat dissipation from the PTC element unit to the cover can be further suppressed. The number of protrusions is not particularly limited; for example, it may be more than one and less than six, or it may be three. When multiple protrusions are provided, the multiple protrusions may be arranged at equal intervals or unequal intervals in the circumferential direction. However, the cover may also not have such a protrusion.

[0045] Setting the area of ​​the second main surface as S4, it is also possible to have 0.001≤S2 / S4≤0.02. In this case, the contact area S2 between the PTC element unit and the cover is particularly small, and the heat dissipation from the PTC element unit to the cover can be further suppressed.

[0046] The sealing plate or cover may also have at least one of a second portion located on the outer side of the outer peripheral surface of the PTC element unit and a third portion located on the inner side of the inner peripheral surface of the PTC element unit. For example, a structure in which the sealing plate has the second and third portions, a structure in which the cover has the second portion, and a structure in which the sealing plate has the third portion are all considered, but are not limited to these. According to the second and third portions, they act as stoppers, which can suppress radial positional displacement of the PTC element unit.

[0047] The sealing plate may also include: a metal plate that abuts against the PTC element unit; a valve body disposed on the side of the metal plate opposite to the PTC element unit; and a base plate disposed on the side of the valve body opposite to the PTC element unit, having a main body portion that abuts against the valve body and a retaining portion that holds the outer periphery of the metal plate and the valve body. The valve body may also have the aforementioned breakage pre-determining portion. The base plate may also be connected to leads extending from the electrode group when a battery is inserted into the battery sealing body. In this structure, heat generated in the electrode group is transferred to the PTC element unit via the leads, the base plate, the valve body, and the metal plate.

[0048] The sealing plate can also be a single component made of a metallic material. The thermal conductivity of the metallic material can also be 140 W / (m·K) or higher. Examples of such metallic materials include aluminum or aluminum alloys. A portion of the single component (e.g., the central portion) can also be formed with a thinner wall than the remaining portion, forming the aforementioned pre-fracture portion. In this structure, the heat generated in the electrode group is transferred to the PTC element unit via leads and the single component. As metallic materials, JIS A 1000 series O materials are particularly preferred as pure aluminum, and JIS A 6000 series aluminum-magnesium-silicon (Al-Mg-Si) alloys (especially JIS A 6063 O material) are preferred as aluminum alloys, JIS A 3000 series aluminum-manganese (Al-Mn) alloys (especially JIS A 3003 O material) are preferred, and JIS A 8000 series lithium-added aluminum alloys (especially JIS A 8011, JIS A 8021, and JIS A 8079) are preferred. These metallic materials can be easily formed into thin-walled sections and protruding sections by stamping a circular base material, and due to their high thermal conductivity, they are particularly suitable for constructing sealing plates from a single material.

[0049] A PTC element unit can also have multiple overlapping PTC elements. In this case, for example, the thickness of the PTC element unit can be appropriately set by increasing or decreasing the number of PTC elements. This allows for appropriate setting of the distance between the sealing plate and the cap, increasing the design freedom of the battery sealing body. The multiple PTC elements can be of the same type or different types. However, a PTC element unit can also have only one PTC element.

[0050] (Battery)

[0051] The battery disclosed herein is, for example, a primary lithium battery, but is not limited thereto; it may also be other types of primary or secondary batteries. The battery disclosed herein includes the aforementioned battery seal, casing, electrode assembly, and leads.

[0052] The casing is formed into a bottomed cylindrical shape and has an opening that is sealed by a battery sealing body. The casing may also be made of a metal such as stainless steel. The battery sealing body and gasket can be riveted and fixed through the opening of the casing.

[0053] The electrode assembly is housed in a casing. The electrode assembly may also be housed in the casing along with the electrolyte. The electrode assembly has a first electrode and a second electrode. The electrode assembly may also be a wound type, formed by winding the strip-shaped first electrode and second electrode together with a strip-shaped separator. One of the first and second electrodes is a positive electrode, and the other is a negative electrode. The positive electrode may also have a positive electrode core material and a mixture of active materials, primarily manganese dioxide, filled in the positive electrode core material. The negative electrode may also be made of lithium metal.

[0054] A lead wire electrically connects the sealing plate of the battery sealing body to the first electrode of the electrode group. When the first electrode is positive, the lead wire is a positive lead wire; when the first electrode is negative, the lead wire is a negative lead wire. If heat is generated in the electrode group, this heat is transferred to the battery sealing body via this lead wire. As described above, the transferred heat is easily transferred to the PTC element unit of the battery sealing body and is difficult to dissipate from there. Therefore, in the battery according to this disclosure, the response timing of the PTC element can also be accelerated.

[0055] As described above, according to this disclosure, by specifying the size relationship between the contact areas S1 and S2, the response timing of the PTC element can be accelerated.

[0056] Hereinafter, an example of a battery sealing body and a battery according to the present disclosure will be specifically described with reference to the accompanying drawings. The aforementioned constituent elements can be applied to the constituent elements of the battery sealing body and battery in the example described below. The constituent elements of the battery sealing body and battery in the example described below can be modified based on the above description. Furthermore, the matters described below can also be applied to the above-described embodiments. Constituent elements of the battery sealing body and battery in the example described below that are not essential to the battery sealing body and battery involved in the present disclosure may be omitted. In addition, the figures shown below are schematic and do not accurately reflect the shape and number of actual components. Furthermore, in the following description, terms such as "upper" and "lower" indicating specific directions are sometimes used, but this is for ease of explanation and does not constitute any limitation on the present disclosure.

[0057] Implementation Method 1

[0058] Embodiment 1 of this disclosure will be described. The battery 10 in this embodiment is configured as a primary lithium battery, but is not limited thereto. Figure 1 as well as Figure 2 As shown, the battery 10 includes: a casing 11, an electrode group 16, a positive electrode lead 21, a negative electrode lead 22, and a battery sealing body 30.

[0059] The housing 11 is formed into a bottomed cylindrical shape and has an opening sealed by the battery sealing body 30. The housing 11 has: a bottom 12, a cylindrical portion 13 rising from the bottom 12, and an opening edge 15 connected to the cylindrical portion 13 via a narrowing portion 14 that narrows radially inward. The end of the opening edge 15 is chamfered, and the battery sealing body 30 is held in place by the chamfered portion and the narrowing portion 14. The cylindrical portion 13 is formed into a cylindrical shape symmetrical about the central axis O.

[0060] Electrode group 16 is housed in housing 11. Electrode group 16 has a strip-shaped positive electrode 17, a negative electrode 18, and a separator 19. In this embodiment, electrode group 16 is a wound type electrode group formed by winding the positive electrode 17 and the negative electrode 18 with the separator 19 in between. The positive electrode 17 has a positive electrode core material and a mixture of active materials, mainly manganese dioxide, filled in the positive electrode core material. The negative electrode 18 is made of lithium metal. The positive electrode 17 is an example of a first electrode. The negative electrode 18 is an example of a second electrode. An electrolyte (not shown) is housed in housing 11 together with electrode group 16.

[0061] The positive electrode lead 21 is formed in the shape of a strip or a thin strip, electrically connecting the positive electrode 17 of the electrode group 16 to the battery seal 30. Thus, the battery seal 30 functions as the external positive terminal of the battery 10. The positive electrode lead 21 is an example of a lead.

[0062] The negative electrode lead 22 is formed in the form of a strip or a thin strip, electrically connecting the negative electrode 18 of the electrode group 16 to the housing 11. Thus, the housing 11 functions as the external terminal of the negative electrode of the battery 10.

[0063] The battery sealing body 30 seals the opening of the housing 11. The battery sealing body 30 includes: a sealing plate 31, a cover 44, a PTC element unit 45, and a gasket 47.

[0064] The sealing plate 31 has a metal plate 32, a valve body 36, and a base plate 37. The metal plate 32 is formed into a disc shape with a through hole in the center, and abuts against the first main surface 45a (described later) of the PTC element unit 45. The valve body 36 is disposed on the side of the metal plate 32 opposite to the PTC element unit 45. Figure 1 as well as Figure 2 (Lower side of the middle). The valve body 36 is a metal component formed in the shape of a circular plate, which breaks when the internal pressure of the battery 10 exceeds a given value and rises. The base plate 37 is located on the side of the valve body 36 opposite to the PTC element unit 45. Figure 1 as well as Figure 2 (Lower side of the PTC element unit 45). The base plate 37 has: a main body portion 37a, which abuts against the valve body 36 and is connected to the positive lead 21; and a retaining portion 37b, which retains the metal plate 32 and the outer periphery of the valve body 36. A through hole is formed in the center of the base plate 37. The retaining portion 37b is located radially outward of the PTC element unit 45. The retaining portion 37b is an example of the first part.

[0065] The cover 44 is electrically connected to the sealing plate 31 via the PTC element unit 45. That is, the cover 44 is electrically connected to the positive electrode 17 of the electrode group 16 via the PTC element unit 45, the sealing plate 31, and the positive lead 21. The cover 44 is exposed to the outside of the battery 10. The cover 44 is a metal component formed in the shape of a cap. The cover 44 has at least one gas vent 44c (see reference). Figure 7 The gas vent is used to allow gas to escape to the outside of the battery 10 in the event that the valve body 36 breaks due to an increase in internal pressure of the battery 10.

[0066] The PTC element unit 45 is sandwiched between the sealing plate 31 and the cover 44. The PTC element unit 45 has a first main surface 45a that abuts against the sealing plate 31 (more specifically, the metal plate 32 of the sealing plate 31). Figure 1 as well as Figure 2 The upper surface of the middle), and the second main surface 45b that abuts against the cover 44. Figure 1 as well as Figure 2 (The lower surface of the PTC element). In this embodiment, the PTC element unit 45 is composed of a single PTC element 46 formed in a ring or disk shape.

[0067] A gasket 47 is disposed on the outer periphery of the sealing plate 31 and the cover 44. The gasket 47 is made of an insulating resin material. The gasket 47 electrically insulates the housing 11 from the sealing plate 31 and the cover 44. The gasket 47 in this embodiment is a one-piece component, but it is not limited to this, and it is also considered to provide a segmented gasket composed of multiple components.

[0068] A conductive adhesive (not shown) is provided on at least one of the sealing plate 31 and the first main surface 45a of the PTC element unit 45, and on the other of the cover 44 and the second main surface 45b of the PTC element unit 45.

[0069] The contact area between the sealing plate 31 and the first main surface 45a of the PTC element unit 45 is set as S1, and the contact area between the cover 44 and the second main surface 45b of the PTC element unit 45 is set as S2, where S1>S2.

[0070] In addition, the area of ​​the first main surface 45a of the PTC element unit 45 is set as S3, and the area of ​​the second main surface 45b of the PTC element unit 45 is set as S4, and 0.21≤S1 / S3≤1.0 and 0.001≤S2 / S4≤0.73 are satisfied.

[0071] Implementation Method 2

[0072] Embodiment 2 of this disclosure will be described. The structure of the gasket 47 of the battery sealing body 30 in this embodiment differs from that in Embodiment 1 described above. Specifically, as follows... Figure 3 As shown, the gasket 47 of this embodiment has a gasket extension 48 that extends radially inward between the sealing plate 31 and the cover 44, preventing electrical contact between the sealing plate 31 and the cover 44. The gasket extension 48 is provided throughout the entire circumference, but is not limited thereto. The gasket extension 48 is an example of a second insulating member. Alternatively, the gasket 47 may be divided into two parts. Figure 3 The figure shows a structure that can be easily implemented in the case of an upper portion including a padding extension 48 and a lower portion not including a padding extension 48.

[0073] Implementation Method 3

[0074] Embodiment 3 of this disclosure will be described. The battery sealing body 30 of this embodiment differs from Embodiment 1 in that it includes a first insulating ring 51. Specifically, as... Figure 4As shown, the battery sealing body 30 of this embodiment has a first insulating ring 51, which is disposed between the holding portion 37b of the sealing plate 31 and the PTC element unit 45 to prevent electrical contact between the holding portion 37b and the PTC element unit 45. The first insulating ring 51 is made of an insulating resin material, but is not limited to this. Examples of materials that can be used to construct the first insulating ring 51 include polyolefin, polyimide, polyetheretherketone, silicone resin, fluoropolymer, phenolic resin, PPS resin, and butyl rubber. The first insulating ring 51 is an example of a first insulating member.

[0075] Implementation Method 4

[0076] Embodiment 4 of this disclosure will be described. The structure of the first insulating ring 51 of the battery sealing body 30 in this embodiment differs from that in Embodiment 3 described above. Specifically, as follows... Figure 5 As shown, the first insulating ring 51 of this embodiment has a ring extension 52 that extends radially outward between the sealing plate 31 and the cover 44, preventing electrical contact between the sealing plate 31 and the cover 44. The ring extension 52 is provided throughout the entire circumference, but is not limited thereto. Examples of materials constituting the ring extension 52 include polyolefins, polyimides, polyetheretherketones, silicone resins, fluoropolymers, phenolic resins, PPS resins, and butyl rubber. The ring extension 52 is an example of a second insulating member.

[0077] Implementation Method 5

[0078] Embodiment 5 of this disclosure will be described. The structure of the sealing plate 31 of the battery sealing body 30 in this embodiment differs from that in Embodiment 1 described above. Specifically, as follows... Figure 6 As shown, in this embodiment, the sealing plate 31 has an insulating layer 38 provided on the surface of its holding portion 37b. This insulating layer 38 prevents electrical contact between the sealing plate 31 and the cover 44. Alternatively, or in addition to this, an insulating layer may be provided in the area of ​​the cover 44 opposite to the holding portion 37b. Examples of materials constituting the insulating layer 38 include polyimide, polyetheretherketone, silicone resin, fluoropolymer resin, phenolic resin, PPS resin, silica, and alumina.

[0079] Implementation Method 6

[0080] Embodiment 6 of this disclosure will be described. The structure of the cover 44 of the battery sealing body 30 in this embodiment differs from that in Embodiment 1 described above. Specifically, as follows... Figure 7As shown, the cover 44 of this embodiment has at least one (one in this example) protrusion 44a that protrudes toward the PTC element unit 45 and abuts against the second main surface 45b. The protrusion 44a of this embodiment is formed throughout the entire circumference. The abutment area between the cover 44 and the second main surface 45b of the PTC element unit 45 is set as S2, and the area of ​​the second main surface 45b of the PTC element unit 45 is set as S4; preferably, 0.001 ≤ S2 / S4 ≤ 0.02. Furthermore, in Figure 7 In (a), the area that abuts against the second main surface 45b of the PTC element unit 45 is shown with dotted shading.

[0081] Variation 1 of Implementation Method 6

[0082] A variation of embodiment 6 of this disclosure will be described. For example... Figure 8 As shown, in this modified example, the protrusion 44a of the battery sealing body 30 is formed to reach the outer edge of the cover 44. The other structures are the same as in embodiment 6 described above. Furthermore, in Figure 8 In (a), the area that abuts against the second main surface 45b of the PTC element unit 45 is shown with dotted shading.

[0083] Variation 2 of Implementation Method 6

[0084] A variation 2 of embodiment 6 of this disclosure will be described. For example... Figure 9 As shown in (a), in this modified example, the battery sealing body 30 provides a plurality of (three in this example) protrusions 44a1 to 44a3 spaced apart in the circumferential direction. This further reduces the area S2. Furthermore, viewed from the direction extending from the central axis O (or from the axial direction of the battery 10), one protrusion 44a1 is located on an imaginary straight line connecting the center of the cover 44 and the gas vent 44c. Figure 9On the single-dot dashed line extending vertically in (a). Preferably, the distance between the protrusion 44a1 located on this straight line (or, the protrusion 44a1 that is closest to the gas outlet 44c among the multiple protrusions 44a1 to 44a3) and the positive electrode lead 21 (more specifically, the portion of the positive electrode lead 21 that is connected to the base plate 37) is longer than the distance between the other protrusions 44a2, 44a3 and the positive electrode lead 21 (more specifically, the portion of the positive electrode lead 21 that is connected to the base plate 37). In this case, heat dissipation from the PTC element unit 45 can be suppressed, and the responsiveness of the PTC element unit 45 when the electrode group 16 is abnormally heated can be further improved. Furthermore, from the viewpoint of improving the responsiveness of the PTC element unit 45, it is particularly preferable that the portion of the protrusion 44a1, the gas vent 44c, and the portion of the positive lead 21 connected to the base plate 37 are located on the aforementioned hypothetical straight line. Further, as... Figure 9 As shown in (b), when three gas discharge holes 44c are provided, the responsiveness of the PTC element unit 45 can be further improved by making the protrusions 44a1 to 44a3 close to each gas discharge hole 44c (or by making the circumferential positions of the protrusions 44a1 to 44a3 substantially consistent with the circumferential positions of the gas discharge holes 44c). The other structures are the same as in embodiment 6 described above. Furthermore, in Figure 9 In the diagram, the area that abuts against the second main surface 45b of the PTC element unit 45 is shown with dotted shading.

[0085] Implementation Method 7

[0086] Embodiment 7 of this disclosure will be described. The structure of the sealing plate 31 of the battery sealing body 30 in this embodiment differs from that in Embodiment 1 described above. Specifically, as follows... Figure 10 As shown, the metal plate 32 of the sealing plate 31 in this embodiment has an inner protrusion 33 located on the inner side (or radially inner side) of the inner circumferential surface of the PTC element unit 45. The protrusion height of the inner protrusion 33 is smaller than the thickness of the PTC element unit 45, but it is not limited thereto. The inner protrusion 33 is formed all over the circumference, but it is not limited thereto. For example, multiple (e.g., 3) inner protrusions 33 may be provided at intervals in the circumferential direction. The inner protrusion 33 is an example of the third part.

[0087] Implementation Method 8

[0088] Embodiment 8 of this disclosure will be described. The structure of the sealing plate 31 of the battery sealing body 30 in this embodiment differs from that in Embodiment 1 described above. Specifically, as follows... Figure 11As shown, the metal plate 32 of the sealing plate 31 in this embodiment has an outer protrusion 34 located on the outer side (or radially outer side) of the outer peripheral surface of the PTC element unit 45. The protrusion height of the outer protrusion 34 is smaller than the thickness of the PTC element unit 45. Here, the height position of the upper surface of the outer protrusion 34 (the surface opposite to the cover 44) can be the same as the height position of the upper end of the retaining portion 37b, or it can be lower than the height position of the upper end of the retaining portion 37b. The outer protrusion 34 is formed all around the circumference, but it is not limited to this, and multiple (for example, 3) outer protrusions 34 can also be provided at intervals in the circumferential direction. The outer protrusion 34 is an example of the second part.

[0089] Implementation Method 9

[0090] Embodiment 9 of this disclosure will be described. The structure of the sealing plate 31 of the battery sealing body 30 in this embodiment differs from that in Embodiment 1 described above. Specifically, as follows... Figure 12 As shown, the metal plate 32 of the sealing plate 31 in this embodiment has a stepped portion 35 that decreases in a stepped manner from the radially outer side to the radially inner side. The PTC element unit 45 is disposed on the radially inner side of the stepped portion 35. The stepped portion 35 is formed all around the circumference, but is not limited thereto. The stepped portion 35 is an example of Part 2.

[0091] Implementation Method 10

[0092] Embodiment 10 of this disclosure will be described. The structure of the cover 44 of the battery sealing body 30 in this embodiment differs from that in Embodiment 1 described above. Specifically, as follows... Figure 13 As shown, the cover 44 of this embodiment has a bulge 44b located on the outer side (or radially outer side) of the outer peripheral surface of the PTC element unit 45. The bulge 44b faces the sealing plate 31 side ( Figure 13 (The lower side of the middle) bulges out. Furthermore, the outer peripheral end of the second main surface 45b and the inner peripheral surface of the bulge 44b can be as follows: Figure 11 The bulges 44b are shown to be separated from each other, but they may also abut each other at least partially. The bulges 44b are formed all around the circumference, but are not limited to this; multiple (e.g., three) bulges 44b may also be arranged at intervals in the circumferential direction. The bulges 44b are an example of the second part.

[0093] Variations of Implementation Method 10

[0094] A variation of embodiment 10 of this disclosure will be described. For example... Figure 14 As shown, in this modified example, the bulge 44b of the battery sealing body 30 extends to the outer edge of the cover 44. The other structures are the same as in embodiment 10 described above.

[0095] Implementation Method 11

[0096] Embodiment 11 of this disclosure will be described. The structure of the sealing plate 31 of the battery sealing body 30 in this embodiment differs from that in Embodiment 2 described above. Specifically, as follows... Figure 15 As shown, the sealing plate 31 of this embodiment is a single component made of a metallic material (aluminum in this example) with a thermal conductivity of 140 W / (m·K) or higher. The sealing plate 31 has a thin-walled portion 41, which functions similarly to the valve body 36 of Embodiment 2 described above. The lower surface of the thin-walled portion 41 is flush with the lower surface of the remaining portion of the sealing plate 31. The sealing plate 31 has at least one protrusion 42 to which the positive electrode lead 21 is connected. In this embodiment, two protrusions 42 are arranged perpendicular to the plane of the paper, but this is not a limitation. Furthermore, in Figure 15 The figure shows the shape of the outer periphery of the sealing plate 31 rising towards the cover 44 (upper part in the figure), but it is not limited to this. It is also possible that the surface of the sealing plate 31 that abuts against the first main surface 45a is designed to extend flush with the outer edge, and the cover 44 has a portion in which the surface that extends continuously to the outer periphery is formed as a bulge 44b (see reference). Figure 14 The structure is designed so that the outer periphery of the sealing plate 31 and the lower surface of the bulge 44b are opposite each other.

[0097] Implementation Method 12

[0098] Embodiment 12 of this disclosure will be described. The structure of the sealing plate 31 of the battery sealing body 30 in this embodiment differs from that in Embodiment 11 described above. Specifically, in the sealing plate 31 of this embodiment, as follows: Figure 16 As shown, the thin-walled portion 41 is disposed on the upper side of the sealing plate 31, and the upper surface of the thin-walled portion 41 is flush with the upper surface of the remaining portion of the sealing plate 31.

[0099] Implementation Method 13

[0100] Embodiment 13 of this disclosure will be described. The structure of the sealing plate 31 of the battery sealing body 30 in this embodiment differs from that in Embodiment 11 described above. Specifically, as follows... Figure 17 As shown, in this embodiment, the area of ​​the thin-walled portion 41 of the sealing plate 31 faces the cover 44 side ( Figure 17 The thin-walled portion 41 is raised above the PTC element unit 45 and positioned closer to the cover 44 than the cover 44. A raised portion 43 is formed around the thin-walled portion 41. A second insulating ring 53 is provided between the raised portion 43 and the PTC element unit 45 to electrically insulate them. The second insulating ring 53 is made of an insulating resin material, but is not limited to this.

[0101] Implementation Method 14

[0102] Embodiment 14 of this disclosure will be described. The structure of the PTC element unit 45 of the battery sealing body 30 in this embodiment differs from that in Embodiment 1 described above. Figure 18 As shown, the PTC element unit 45 of this embodiment has a plurality of overlapping PTC elements 46 (two in this example). In this embodiment, the plurality of PTC elements 46 are of the same type, but are not limited thereto. For example, it is possible to provide a plurality of PTC elements with different temperature characteristics or thicknesses.

[0103] Postscript

[0104] The following technology has been disclosed through the above description of the embodiments.

[0105] (Technology 1)

[0106] A battery sealing body, comprising:

[0107] Sealing board;

[0108] build;

[0109] The PTC element unit, sandwiched between the sealing plate and the cover, has a first main surface abutting against the sealing plate and a second main surface abutting against the cover; and

[0110] A gasket is provided on the outer periphery of the sealing plate and the cover.

[0111] The sealing plate and the cover are electrically connected via the PTC element unit.

[0112] Let S1 be the contact area between the sealing plate and the first main surface, and let S2 be the contact area between the cover and the second main surface, where S1>S2.

[0113] (Technology 2)

[0114] In the battery sealing body described in Technology 1

[0115] Let the area of ​​the first main surface be S3, and the area of ​​the second main surface be S4, and 0.21≤S1 / S3≤1.0 and 0.001≤S2 / S4≤0.73 are true.

[0116] (Technology 3)

[0117] In the battery sealing body described in technique 1 or 2

[0118] A conductive adhesive is provided between the sealing plate and the first main surface, and between the cover and the second main surface.

[0119] (Technology 4)

[0120] In any of the battery sealing bodies described in techniques 1 to 3,

[0121] The sealing plate has a first portion located radially outside the PTC element unit.

[0122] A first insulating member is provided between the first part and the PTC element unit to prevent electrical contact between the first part and the PTC element unit.

[0123] (Technology 5)

[0124] In any of the battery sealing bodies described in techniques 1 to 4,

[0125] A second insulating member is provided between the sealing plate and the cover to prevent electrical contact between the sealing plate and the cover.

[0126] (Technology 6)

[0127] In any of the battery sealing bodies described in techniques 1 to 5,

[0128] At least one of the sealing plate or the cover has an insulating layer that prevents electrical contact between the sealing plate and the cover.

[0129] (Technology 7)

[0130] In any of the battery sealing bodies described in techniques 1 to 6,

[0131] The cover has at least one protrusion that protrudes toward the PTC element unit and abuts against the second main surface.

[0132] (Technology 8)

[0133] In the battery sealing body described in Technique 7

[0134] The area of ​​the second main surface is set as S4, and the condition 0.001≤S2 / S4≤0.02 holds true.

[0135] (Technology 9)

[0136] In any of the battery sealing bodies described in techniques 1 to 8,

[0137] The sealing plate or the cover has at least one of a second portion located on the outer side of the outer peripheral surface of the PTC element unit and a third portion located on the inner side of the inner peripheral surface of the PTC element unit.

[0138] (Technology 10)

[0139] In any of the battery sealing bodies described in techniques 1 to 9,

[0140] The sealing plate has the following characteristics:

[0141] A metal plate abuts against the PTC element unit;

[0142] The valve body is disposed on the side of the metal plate opposite to the PTC element unit; and

[0143] The base plate is located on the side of the valve body opposite to the PTC element unit, and has a main body portion that abuts against the valve body and a retaining portion that holds the metal plate and the outer periphery of the valve body.

[0144] (Technology 11)

[0145] In any of the battery sealing bodies described in techniques 1 to 9,

[0146] The sealing plate is a single component made of metal.

[0147] The thermal conductivity of the metallic material is above 140 W / (m·K).

[0148] (Technology 12)

[0149] In any of the battery sealing bodies described in techniques 1 to 11,

[0150] The PTC element unit has multiple overlapping PTC elements.

[0151] (Technology 13)

[0152] A battery having:

[0153] The battery sealing body according to any one of techniques 1 to 12;

[0154] A bottomed cylindrical shell has an opening that is sealed by the battery sealing body;

[0155] An electrode group, housed in the housing, having a first electrode and a second electrode; and

[0156] A lead wire is used to electrically connect the sealing plate of the battery sealing body and the first electrode.

[0157] Example

[0158] Regarding the batteries of Examples 1 to 3 and the comparative examples shown below, their heating characteristics during short-circuit tests were evaluated. Specifically, for each battery, a test was performed five times in which five batteries were connected in series via a 2Ω resistor and substantially short-circuited. The average value of the highest temperature reached by the casing and the number of times the valve body or thin-walled portion of the sealing plate broke were evaluated.

[0159] Example 1

[0160] A short-circuit test was conducted on the battery corresponding to Embodiment 1 described above. The average maximum temperature reached by the casing was 102°C, and the average time to reach this temperature was 218 seconds. The valve body of the sealing plate broke 0 times in 5 tests.

[0161] Example 2

[0162] A short-circuit test was conducted on the battery corresponding to Embodiment 6 described above. However, instead of a single protrusion extending along the entire circumference, three protrusions were provided that were separated in the circumferential direction. The average maximum temperature reached by the casing was 96°C, and the average time to reach this temperature was 206 seconds. The valve body of the sealing plate broke 0 times in 5 tests.

[0163] Example 3

[0164] A short-circuit test was conducted on the battery corresponding to Embodiment 12 described above. The average highest temperature reached by the casing was 92°C, and the average time to reach this temperature was 187 seconds. The number of times the thin-walled portion of the sealing plate broke was 0 in 5 tests.

[0165] Comparative Examples

[0166] Except for the fact that the PTC element unit is sandwiched between the retaining part of the bottom plate of the sealing plate and the cover, a short-circuit test was conducted on the same battery as Embodiment 1 described above (or the battery corresponding to Patent Document 1). In the comparative example battery, the contact area S1 between the sealing plate and the first main surface of the PTC element unit was smaller than the contact area between the cover and the second main surface of the PTC element unit (S1 < S2). The average maximum temperature reached by the casing was 124°C, and the average time to reach this temperature was 254 seconds. The valve body of the sealing plate broke twice in five tests.

[0167] As described above, the batteries of Examples 1-3 exhibited a lower average peak temperature of the casing compared to the comparative example batteries. Furthermore, while the valve body of the sealing plate sometimes fractured in the comparative example batteries, no fractures occurred in the valve body or thin-walled portion of the batteries of Examples 1-3. Therefore, it can be said that the superiority of each embodiment is evident.

[0168] Industrial availability

[0169] This disclosure can be used in battery sealing bodies and batteries.

[0170] -Explanation of Figure Markers-

[0171] 10: Battery

[0172] 11: Shell

[0173] 12: Bottom

[0174] 13: Cylinder section

[0175] 14: Narrowing section

[0176] 15: Opening edge

[0177] 16: Electrode Group

[0178] 17: Positive electrode (first electrode)

[0179] 18: Negative electrode (second electrode)

[0180] 19: Isolation component

[0181] 21: Positive lead (lead wire)

[0182] 22: Negative lead

[0183] 30: Battery sealing body

[0184] 31: Sealing plate

[0185] 32: Metal plate

[0186] 33: Inner convex part (Part 3)

[0187] 34: Outer convex part (Part 2)

[0188] 35: Steps (Part 2)

[0189] 36: Valve body

[0190] 37: Base Plate

[0191] 37a: Main body

[0192] 37b: Retention section (Part 1)

[0193] 38: Insulation layer

[0194] 41: Thin-walled section

[0195] 42: protrusion

[0196] 43: Vertical section

[0197] 44: Cover

[0198] 44a: Protrusion

[0199] 44b: Drum section (Part 2)

[0200] 44c: Gas vent

[0201] 45: PTC Component Unit

[0202] 45a: 1st main side

[0203] 45b: 2nd main side

[0204] 46: PTC element

[0205] 47: Padding

[0206] 48: Pad Extension (Second Insulation Member)

[0207] 51: First insulating ring (first insulating component)

[0208] 52: Ring extension (second insulating member)

[0209] 53: Second insulating ring

[0210] O: Central axis.

Claims

1. A battery sealing body, comprising: Sealing board; build; The PTC element unit is sandwiched between the sealing plate and the cover, and has a first main surface that abuts against the sealing plate and a second main surface that abuts against the cover; and A gasket is provided on the outer periphery of the sealing plate and the cover. The sealing plate and the cover are electrically connected via the PTC element unit. Let S1 be the contact area between the sealing plate and the first main surface, and let S2 be the contact area between the cover and the second main surface, where S1>S2.

2. The battery sealing body according to claim 1, wherein, Let the area of ​​the first main surface be S3, and the area of ​​the second main surface be S4, and 0.21≤S1 / S3≤1.0 and 0.001≤S2 / S4≤0.73 are true.

3. The battery sealing body according to claim 1 or 2, wherein, A conductive adhesive is provided between the sealing plate and the first main surface, and between the cover and the second main surface.

4. The battery sealing body according to claim 1 or 2, wherein, The sealing plate has a first portion located radially outside the PTC element unit. A first insulating member is provided between the first part and the PTC element unit to prevent electrical contact between the first part and the PTC element unit.

5. The battery sealing body according to claim 1 or 2, wherein, A second insulating member is provided between the sealing plate and the cover to prevent electrical contact between the sealing plate and the cover.

6. The battery sealing body according to claim 1 or 2, wherein, At least one of the sealing plate or the cover has an insulating layer that prevents electrical contact between the sealing plate and the cover.

7. The battery sealing body according to claim 1 or 2, wherein, The cover has at least one protrusion that protrudes toward the PTC element unit and abuts against the second main surface.

8. The battery sealing body according to claim 7, wherein, The area of ​​the second main surface is set as S4, and the condition 0.001≤S2 / S4≤0.02 holds true.

9. The battery sealing body according to claim 1 or 2, wherein, The sealing plate or the cover has at least one of a second portion located on the outer side of the outer peripheral surface of the PTC element unit and a third portion located on the inner side of the inner peripheral surface of the PTC element unit.

10. The battery sealing body according to claim 1 or 2, wherein, The sealing plate has the following characteristics: A metal plate abuts against the PTC element unit; The valve body is disposed on the side of the metal plate opposite to the PTC element unit; and The base plate is located on the side of the valve body opposite to the PTC element unit, and has a main body portion that abuts against the valve body and a retaining portion that holds the metal plate and the outer periphery of the valve body.

11. The battery sealing body according to claim 1 or 2, wherein, The sealing plate is a single component made of metal. The thermal conductivity of the metallic material is above 140 W / (m·K).

12. The battery sealing body according to claim 1 or 2, wherein, The PTC element unit has multiple overlapping PTC elements.

13. A battery, comprising: The battery sealing body according to claim 1 or 2; A bottomed cylindrical shell has an opening that is sealed by the battery sealing body; An electrode group, housed in the housing, has a first electrode and a second electrode; and A lead wire is used to electrically connect the sealing plate of the battery sealing body and the first electrode.

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