Cover plate assembly and battery

Abstract

The utility model relates to the technical field of batteries, and discloses a cover plate assembly and a battery, the cover plate assembly comprises a cover plate, a lower plastic cement and a support member, the inner side wall of the cover plate is provided with a first groove; the lower plastic is arranged on the inner side wall of the cover plate; the lower plastic is provided with a second concave groove, and the lower plastic opposite to the second groove is provided with a first convex part; the first protruding part is arranged in the first groove in a matched mode. The supporting piece is made of a high-temperature-resistant electrolyte-resistant material; the supporting piece is arranged in the second groove, and a second protruding part matched with the first protruding part is arranged on the supporting piece. The cover plate assembly with the structure is applied to the battery, when the battery is in thermal runaway, the supporting piece moves towards the cover plate, the second convex part is embedded in the first groove, and the supporting piece is limited to freely move in the shell, so that the supporting piece is relatively stably kept between the cover plate and the pole group, the supporting effect of the supporting piece is ensured, the pole group is prevented from blocking the pressure relief structure, and the service life of the battery is prolonged. And the pressure relief effect and the safety of the battery are ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a cover plate assembly and a battery. Background Art

[0002] Lithium-ion batteries include cover, shell, pole group, end plate, side plate, bare cell insulation sheet, pole group, electrolyte and other components. The cover is integrated with an explosion-proof valve, and the side plate, bare cell insulation sheet, end plate and lower plastic constitute the insulation protection structure of the pole group, so that the battery cell can avoid short circuit and other problems caused by overlapping the pole group with the shell or cover during normal use.

[0003] The insulating protection structures of the electrode group are all made of plastic and have poor high temperature resistance. When the battery is in thermal runaway, the internal temperature rises rapidly, and the insulating protection structures such as the side panels, bare cell insulation sheets, end panels, and lower plastic will quickly melt and fail. At this time, there is only the electrode group inside the shell, and there is no obstruction between the electrode group and the cover. Under the action of high temperature and high pressure gas inside the shell, the electrode group will lose balance. Because the pressure at the explosion-proof valve on the cover is relatively low, the electrode group can easily move toward the explosion-proof valve, thereby blocking the explosion-proof valve and causing the explosion-proof valve to be unable to open.

[0004] In the prior art, a support member made of high temperature resistant material is arranged between the lower plastic and the cover plate, so that after the end plate and the lower plastic are melted, the support member is supported between the cover plate and the electrode group to prevent the electrode group from blocking the explosion-proof valve after being pressed against the cover plate. However, the support member of this structure is supported between the cover plate and the electrode group, and is easily moved under the action of the high pressure airflow inside the battery housing, which affects its support effect. Utility Model Content

[0005] In view of this, the utility model provides a cover plate assembly and a battery to solve the problem in the prior art that the supporting member of the battery is easy to move and affect the supporting effect of the electrode group.

[0006] In a first aspect, the utility model provides a cover plate assembly, comprising:

[0007] A cover plate, the inner side wall of which is provided with a first groove; the cover plate is provided with a pressure relief structure;

[0008] A lower plastic is arranged on the inner side wall of the cover plate; a second concave groove is arranged on the lower plastic, and a first convex protrusion is arranged on the lower plastic at a position opposite to the second groove; the first protrusion is embedded in the first groove;

[0009] The support member is made of a high temperature resistant and electrolyte resistant material; the support member is arranged in the second groove, and a second protrusion matching the first protrusion is provided on the support member; when the battery thermally runs away, the second protrusion is suitable for being embedded in the first groove.

[0010] Beneficial effects: The cover plate assembly of this structure is used in a battery, and the lower plastic is located between the pole group and the cover plate. When the battery thermally runs away, the temperature inside the battery shell rises rapidly. After the lower plastic melts, the pole group moves toward the cover plate under the action of high-temperature and high-pressure airflow. Since the support member is resistant to high temperatures and the first protrusion is embedded in the first groove, it is convenient for the second protrusion of the support member to be embedded in the first groove after the lower plastic melts. Under the action of the high-pressure airflow inside the pole group and the shell, the support member moves toward the cover plate, and the second protrusion is embedded in the first groove, which limits the support member from moving freely inside the shell, so that the support member is relatively stably maintained between the cover plate and the pole group, thereby ensuring the supporting effect of the support member, preventing the pole group from being close to the cover plate to block the pressure relief structure, and ensuring the pressure relief and heat dissipation effect and safety performance of the battery during thermal runaway.

[0011] In an optional embodiment, the first groove is in the shape of an elongated strip.

[0012] Beneficial effect: When the battery thermally runs away, the area of ​​the first groove is sufficient so that when the support member moves or shakes, the second protrusion can also be embedded in the first groove, preventing the support member from detaching from the first groove during movement, ensuring that the support member is stably maintained in the area where the first groove is located, and ensuring the supporting effect of the support member.

[0013] In an optional embodiment, the first groove is waist-shaped, and the first protrusion is cylindrical.

[0014] Beneficial effect: It is convenient for the first protrusion to be embedded in the first groove.

[0015] In an optional implementation, the width of the first groove is a, the diameter of the first protrusion is D, and 0.6≤D / a≤0.95.

[0016] Beneficial effect: The first protrusion has a moderate size, which is convenient for embedding in the first groove. At the same time, the size difference between the two is not too large, so that the first groove can limit the first protrusion to prevent the lower plastic from moving.

[0017] In an optional implementation, the groove depth of the first groove is H, the height of the first protrusion is h, Hh≥0.1 mm, and h / d≥0.75.

[0018] Beneficial effect: The depth of the first groove is greater than the height of the first protrusion, but the size aberration between the two is not large, which facilitates the first protrusion to be inserted into the first groove. At the same time, the height of the first protrusion is not too small, and the matching depth of the two is sufficient to prevent the first protrusion from falling out of the first groove when shaking.

[0019] In an optional embodiment, the support member and the lower plastic are integrally injection molded.

[0020] Beneficial effects: the lower plastic and the support are easy to manufacture, the process is simple, and the support can be stably and firmly held on the lower plastic.

[0021] In an optional embodiment, the wall thickness of the second groove and the first protrusion is t, 0.5mm≤t≤3mm.

[0022] Beneficial effects: The wall thickness of the second groove and the first protrusion is moderate, which is convenient for injection molding; at the same time, the strength of the lower plastic can be guaranteed.

[0023] In an optional embodiment, an end plate is further included, the end plate is arranged on the inner side wall of the lower plastic, a third groove is arranged at a position of the end plate corresponding to the second groove, and the second groove is embedded in the third groove.

[0024] In an optional embodiment, the second groove and the third groove are both rectangular grooves, the outer wall of the second groove has a length of e, a width of g, and a height of f, and the inner wall of the third groove has a length of E, a width of G, and a height of F; 0.6≤e / E≤0.95, 0.75≤g / G≤0.9, 0.5≤f / F≤0.85.

[0025] Beneficial effect: The outer wall size of the second groove is smaller than the inner wall size of the third groove, which facilitates the installation of the groove wall of the second groove in the third groove. At the same time, the size difference between the two is not large, so that the second groove can be relatively stably maintained on the end plate to prevent the lower plastic from shaking relative to the end plate.

[0026] In a second aspect, the utility model further provides a battery, comprising the cover plate assembly, shell and pole group as described in any one of the above, wherein the shell is provided with an opening, the cover plate assembly is arranged on the opening, and the pole group is arranged in the shell.

[0027] Beneficial effect: When the battery of this structure experiences thermal runaway, the support member moves toward the cover plate, and the second protrusion is embedded in the first groove, limiting the support member from moving freely inside the shell, so that the support member is relatively stably maintained between the cover plate and the pole group, thereby ensuring the supporting effect of the support member, preventing the pole group from blocking the pressure relief structure, and ensuring the pressure relief effect of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1This is an exploded view from a first angle of a cover plate assembly according to an embodiment of the utility model;

[0030] Figure 2 This is a second angle exploded view of a cover plate assembly according to an embodiment of the utility model;

[0031] Figure 3 A top view of a cover plate assembly according to an embodiment of the utility model;

[0032] Figure 4 for Figure 3 AA section view;

[0033] Figure 5 for Figure 4 BB section view.

[0034] Description of reference numerals:

[0035] 1. Cover plate; 101. First groove; 2. Lower plastic; 201. Second groove; 202. First protrusion; 203. Leakage hole; 3. Support member; 301. Second protrusion; 4. End plate; 401. Third groove. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0037] Combine the following Figures 1 to 5 , describing an embodiment of the utility model.

[0038] According to an embodiment of the present utility model, on the one hand, a cover plate assembly is provided, such as Figure 1 and Figure 2 As shown, it includes a cover plate 1, a lower plastic 2 and a support member 3, wherein a first groove 101 is provided on the inner wall of the cover plate 1; a pressure relief structure is provided on the cover plate 1; the lower plastic 2 is arranged on the inner wall of the cover plate 1; an inwardly concave second groove 201 is provided on the lower plastic 2, and an outwardly convex first protrusion 202 is provided on the lower plastic 2 at a position opposite to the second groove 201; the first protrusion 202 is embedded in the first groove 101; the material of the support member 3 is a high temperature and electrolyte resistant material; the support member 3 is arranged in the second groove 201, and a second protrusion 301 cooperating with the first protrusion 202 is provided on the support member 3; when the battery is thermally runaway, the second protrusion 301 is suitable for being embedded in the first groove 101.

[0039] The cover plate assembly of this structure is used in a battery, and the lower plastic 2 is located between the electrode group and the cover plate 1. When the battery is in thermal runaway, the temperature inside the battery shell rises rapidly. After the lower plastic 2 melts, the electrode group moves toward the cover plate 1 under the action of high-temperature and high-pressure airflow. Since the support member 3 is resistant to high temperatures and the first protrusion 202 is embedded in the first groove 101, it is convenient for the second protrusion 301 of the support member 3 to be embedded in the first groove 101 after the lower plastic 2 melts. Under the action of the high-pressure airflow inside the electrode group and the shell, the support member 3 moves toward the cover plate 1, and the second protrusion 301 is embedded in the first groove 101, which limits the support member 3 from moving freely inside the shell, so that the support member 3 is relatively stably maintained between the cover plate 1 and the electrode group, thereby ensuring the supporting effect of the support member 3, preventing the electrode group from being close to the cover plate 1 to block the pressure relief structure, and ensuring the exhaust and heat dissipation effect and safety performance of the battery during thermal runaway.

[0040] Optionally, in one embodiment, Figure 1 and Figure 5 As shown, the first groove 101 is in the shape of an elongated strip. When the battery is in thermal runaway, the area of ​​the first groove 101 is sufficient for the second protrusion 301 to be embedded in the first groove 101 when the support member 3 moves or shakes, preventing the support member 3 from being separated from the first groove 101 during movement, ensuring that the support member 3 is stably maintained in the area where the first groove 101 is located, and ensuring the supporting effect of the support member 3.

[0041] In other embodiments, the first groove 101 may also be circular or square, in which case the shapes of the first protrusion 202 and the second protrusion 301 are adapted thereto.

[0042] Preferably, in one embodiment, the first groove 101 is waist-shaped, and the first protrusion 202 is cylindrical, so that the first protrusion 202 can be easily embedded in the first groove 101 .

[0043] In other embodiments, the first groove 101 may also be rectangular.

[0044] like Figure 1 As shown, in one embodiment, the width of the first groove 101 is a, the diameter of the first protrusion 202 is D, 0.6≤D / a≤0.95, the first protrusion 202 is of moderate size, and is convenient for being embedded in the first groove 101. At the same time, the difference in size between the two is not too large, so that the first groove 101 can limit the first protrusion 202 to prevent the lower plastic 2 from moving.

[0045] In one embodiment, the groove depth of the first groove 101 is H, the height of the first protrusion 202 is h, Hh≥0.1mm, and h / d≥0.75, that is, the depth of the first groove 101 is greater than the height of the first protrusion 202, but the dimensional aberration between the two is not large, which facilitates the insertion of the first protrusion 202 into the first groove 101. At the same time, the height of the first protrusion 202 is not too small, and the matching depth of the two is sufficient to prevent the first protrusion 202 from detaching from the first groove 101 when shaking.

[0046] Optionally, the support member 3 and the lower plastic 2 are integrally injection molded, and the lower plastic 2 and the support member 3 are easy to manufacture with a simple process, and the support member 3 can be stably and firmly held on the lower plastic 2 .

[0047] In one embodiment, the wall thickness of the second groove 201 and the first protrusion 202 is t, 0.5mm≤t≤3mm, and the wall thickness of the second groove 201 and the first protrusion 202 is moderate, which is convenient for injection molding and can ensure the strength of the lower plastic 2.

[0048] like Figure 1 , Figure 2 , Figure 4 and Figure 5 As shown, the cover assembly further includes an end plate 4 , which is disposed on the inner wall of the lower plastic 2 . A third groove 401 is disposed at a position of the end plate 4 corresponding to the second groove 201 , and the second groove 201 is embedded in the third groove 401 .

[0049] Optionally, in one embodiment, Figure 4 and Figure 5 As shown, the second groove 201 and the third groove 401 are both rectangular grooves, the length of the outer wall of the second groove 201 is e, the width is g, and the height is f, and the length of the inner wall of the third groove 401 is E, the width is G, and the height is F; 0.6≤e / E≤0.95, 0.75≤g / G≤0.9, 0.5≤f / F≤0.85. When installing the battery, the end plate 4 is first fixed on the electrode group, and then the lower plastic 2 is installed on the end plate 4. The outer wall size of the second groove 201 is smaller than the inner wall size of the third groove 401, which is convenient for the groove wall of the second groove 201 to be installed in the third groove 401. At the same time, the size difference between the two is not large, which can make the second groove 201 relatively stable on the end plate 4, and prevent the lower plastic 2 from shaking relative to the end plate 4.

[0050] like Figure 2 , Figure 4 and Figure 5 As shown, optionally, the support member 3 is in a rectangular block shape, and the second protrusion 301 is arranged in the middle of a side of the support member 3 facing the cover plate 1 .

[0051] In other embodiments, the support member 3 may also be in any shape such as a hollow shape, as long as the support member 3 can be stably supported between the cover plate 1 and the electrode group when the battery thermal runaway occurs.

[0052] Optionally, in one embodiment, the cover plate 1 is a rectangular cover plate 1, and accordingly, the lower plastic 2 and the end plate 4 are also rectangular. The support member 3 is in a rectangular block shape, the long side of the support member 3 extends along the width direction of the lower plastic 2, the wide side of the support member 3 extends along the length direction of the lower plastic 2, and the first groove 101 extends along the length direction of the cover plate 1.

[0053] In one embodiment, Figure 1 and Figure 2 As shown, a support member 3 is disposed on the lower plastic 2 .

[0054] In other embodiments, a plurality of support members 3 may be spaced apart in the length direction of the lower plastic 2 .

[0055] The support member 3 can be set at any position of the lower plastic 2 except the position corresponding to the pole. The explosion-proof notch on the rectangular explosion-proof valve of the cover plate 1 extends along the length direction of the cover plate 1, and the wide side of the explosion-proof notch extends along the width direction of the cover plate 1. When the support member 3 is set below the straight section of the explosion-proof notch, the long side of the support member 3 is parallel to the wide side of the explosion-proof notch, and the length of the support member 3 needs to be greater than the width of the explosion-proof notch, so that the two ends of the long side of the support member 3 can abut against the cover plate 1, preventing the support member 3 from flying out of the cover plate 1 from the explosion-proof valve under the action of high-pressure airflow, thereby ensuring safety.

[0056] Optionally, the pressure relief structure is an explosion-proof valve, a pressure relief hole is provided on the cover plate 1, and the explosion-proof valve is installed on the pressure relief hole. A pole is also provided on the cover plate 1.

[0057] Optionally, the cover plate 1 is a plain aluminum plate.

[0058] Optionally, the support member 3 is made of any material that is resistant to high temperatures and electrolytes, such as ceramics or aluminum alloy.

[0059] like Figure 1 As shown, in one embodiment, leakage holes 203 are provided at corresponding positions of the groove wall of the second groove 201 and the end plate 4 to prevent electrolyte accumulation.

[0060] According to an embodiment of the present utility model, on the other hand, a battery is provided, comprising the above-mentioned cover plate assembly, a shell and a pole group, wherein an opening is provided on the shell, the cover plate assembly is provided on the opening, and the pole group is provided in the shell.

[0061] For a battery of this structure, when it is in thermal runaway, the temperature inside the battery shell rises rapidly. After the lower plastic 2 melts, the electrode group moves toward the cover plate 1 under the action of the high-temperature and high-pressure airflow, and the support member 3 moves toward the cover plate 1. The second protrusion 301 is embedded in the first groove 101 to limit the support member 3 from moving freely inside the shell, so that the support member 3 is relatively stably maintained between the cover plate 1 and the electrode group, thereby ensuring the supporting effect of the support member 3, preventing the electrode group from blocking the pressure relief structure, and ensuring the pressure relief effect of the battery.

[0062] Although the embodiments of the present invention are described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A cover plate assembly, characterized in that: include: A cover plate, the inner side wall of which is provided with a first groove; the cover plate is provided with a pressure relief structure; A lower plastic is arranged on the inner side wall of the cover plate; a second concave groove is arranged on the lower plastic, and a first convex protrusion is arranged on the lower plastic at a position opposite to the second groove; the first protrusion is embedded in the first groove; The support member is made of a high temperature resistant and electrolyte resistant material; the support member is arranged in the second groove, and a second protrusion matching the first protrusion is provided on the support member; when the battery thermally runs away, the second protrusion is suitable for being embedded in the first groove.

2. The cover plate assembly according to claim 1, characterized in that: The first groove is in a long strip shape.

3. The cover plate assembly according to claim 2, characterized in that: The first groove is waist-shaped, and the first protrusion is cylindrical.

4. The cover plate assembly according to claim 3, characterized in that: The width of the first groove is a, the diameter of the first protrusion is D, and 0.6≤D / a≤0.

95.

5. The cover plate assembly according to claim 3 or 4, characterized in that: The groove depth of the first groove is H, the height of the first protrusion is h, Hh≥0.1 mm, and h / d≥0.

75.

6. The cover plate assembly according to any one of claims 1 to 4, characterized in that: The support member and the lower plastic are integrally injection-molded.

7. The cover plate assembly according to claim 6, characterized in that: The wall thickness of the second groove and the first protrusion is t, 0.5mm≤t≤3mm.

8. The cover plate assembly according to any one of claims 1 to 4, characterized in that: It also includes an end plate, which is arranged on the inner side wall of the lower plastic, and a third groove is arranged at a position of the end plate corresponding to the second groove, and the second groove is embedded in the third groove.

9. The cover plate assembly according to claim 8, characterized in that: The second groove and the third groove are both rectangular grooves, the outer wall of the second groove has a length of e, a width of g, and a height of f, and the inner wall of the third groove has a length of E, a width of G, and a height of F; 0.6≤e / E≤0.95, 0.75≤g / G≤0.9, 0.5≤f / F≤0.

85.

10. A battery, characterized in that: It comprises the cover plate assembly, shell and pole group according to any one of claims 1 to 9, wherein the shell is provided with an opening, the cover plate assembly is arranged on the opening, and the pole group is arranged in the shell.

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