Cover plate structure and battery

Abstract

The utility model relates to the technical field of batteries, and discloses a cover plate structure and a battery, the cover plate structure comprises a cover plate, an end plate, a lower insulating part and an elastic part; the cover plate is suitable for being connected to an opening of a shell of the battery, and an anti-explosion valve is arranged on the cover plate; the end plate is suitable for being arranged in the shell and is located between the cover plate and the pole group in the shell; the lower insulating part is connected between the cover plate and the end plate; and the elastic piece is connected to the lower insulating piece and is suitable for being propped between the pole group and the cover plate when the battery is in thermal runaway. According to the cover plate structure, when the battery is in thermal runaway and insulation protection structures such as the end plate are melted, the elastic piece abuts against the position between the pole group and the cover plate, the pole group is effectively prevented from moving in the direction where the anti-explosion valve is located, the pole group is prevented from shielding the anti-explosion valve, and an exhaust channel communicated with the anti-explosion valve is always formed between the cover plate and the pole group.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a cover plate structure and a battery. Background Art

[0002] Lithium-ion batteries have the characteristics of high energy density, low self-discharge, no memory effect, wide operating range, fast charging and discharging, long service life, and no environmental pollution. They are currently widely used in energy storage systems such as hydraulic, thermal, and wind power, as well as in power, aerospace and other fields.

[0003] Lithium-ion batteries generally include a shell, a pole group and a cover structure. The cover structure is connected to the opening of the shell and is provided with an explosion-proof valve. The pole group is arranged inside the shell, and an insulating protection structure is also provided inside the shell to insulate the pole group. The insulating protection structure can well protect the pole group during the battery manufacturing process and normal use to avoid abnormal overlap and short circuit inside the battery.

[0004] However, since the insulating protection structure is made of plastic material, when the battery experiences thermal runaway, the internal temperature can reach over 600°C in a short period of time, and the insulating protection structure made of plastic material inside the shell will quickly melt and fail. At this time, there is only the electrode group inside the shell. Under the action of the internal high-temperature and high-pressure gas, the electrode group loses balance. Since the pressure at the explosion-proof valve of the cover structure is relatively low, the electrode group is more likely to move in the direction of the explosion-proof valve, thereby blocking the explosion-proof valve, causing the battery to catch fire and explode due to failure to release pressure in time. Summary of the invention

[0005] In view of this, the present invention provides a cover plate structure and a battery to solve the problem that when the battery is thermally runaway, the pole group blocks the explosion-proof valve, causing the battery to catch fire or explode due to failure to release pressure in time.

[0006] In a first aspect, the present invention provides a cover plate structure, comprising a cover plate, an end plate, a lower insulating member and an elastic member; the cover plate is suitable for being connected to the opening of the battery shell, and an explosion-proof valve is provided on the cover plate; the end plate is suitable for being arranged inside the shell and located between the cover plate and the pole group inside the shell; the lower insulating member is connected between the cover plate and the end plate; the elastic member is connected to the lower insulating member, and is suitable for abutting between the pole group and the cover plate when the battery thermally runs away.

[0007] Beneficial effects: The elastic member is connected to the lower insulating member and is located between the cover plate and the end plate. When the battery is in thermal runaway and the insulating protection structures such as the end plate and the lower insulating member melt, the elastic member abuts between the pole group and the cover plate, effectively preventing the pole group from moving in the direction of the explosion-proof valve and preventing the pole group from blocking the explosion-proof valve, so that the cover plate and the pole group always form an exhaust channel connected to the explosion-proof valve, so that the explosion-proof valve has a good exhaust and heat dissipation effect, effectively delaying the speed of the battery heating up due to thermal runaway, reducing the peak temperature, alleviating the adverse consequences of the battery thermal runaway, greatly improving the safety performance of the battery, and also greatly improving the pass rate of the battery thermal runaway test. And because the elastic member has a certain elasticity, it can also buffer the movement of the pole group to avoid the risk of impact rupture caused by high-speed movement.

[0008] In an optional implementation, the elastic member is made of a metal material, and an insulating layer is provided on the surface of the elastic member.

[0009] Beneficial effects: The elastic member is made of metal material with a high melting point and is not easily melted by high temperature. The surface of the elastic member is provided with an insulating layer, which can ensure the insulation properties of the elastic member and avoid short circuit.

[0010] In an optional embodiment, a connecting hole is provided on the lower insulating member, and a corresponding avoidance groove is provided on the end plate, with the notch of the avoidance groove facing the connecting hole; the elastic member is connected to the connecting hole, and at least part of the elastic member extends into the avoidance groove.

[0011] Beneficial effects: The setting of the connection hole can position and connect the elastic member, prevent the elastic member from falling out of the connection hole, and prevent the elastic member from being damaged or damaging other structures due to movement or shaking. Since the lower insulating member itself is relatively thin, the setting of the avoidance groove can provide sufficient avoidance space and accommodation space for the elastic member, so that the elastic member does not occupy too much space, and avoids enlarging the cover plate structure due to the elastic member.

[0012] In an optional embodiment, the elastic member is a spring.

[0013] Beneficial effect: The elastic member is a spring, which can abut between the electrode group and the cover plate when the battery is thermally runaway to prevent the explosion-proof valve from being blocked, and due to the shape of the spring, the exhaust space is larger.

[0014] In an optional embodiment, the axial direction of the spring is consistent with the axial direction of the connecting hole, the connecting hole is a blind hole in the shape of a groove, a clamping hole is provided on the bottom of the connecting hole close to the end plate, the spring is rotatably clamped with the clamping hole, one end of the spring is arranged in the connecting hole, and the other end is extended in the avoidance groove.

[0015] The spring is rotatably connected to the clamping hole, which is convenient for disassembly, installation and fixing of the spring, and the axial direction of the spring is parallel to the axial direction of the connection hole. The spring has good supporting and blocking effects and good elasticity in the axial direction. The clamping hole also ensures the gas flow of the lower insulating part at the connection hole.

[0016] In an optional embodiment, the elastic member includes a plurality of springs, and the snap-in holes are provided with a plurality of springs, and the springs and the snap-in holes are provided in a one-to-one correspondence; a partition is also provided in the connecting hole, and two adjacent springs are separated by the partition.

[0017] Beneficial effect: Multiple springs are separated by partitions to prevent the springs from being entangled or interfering with each other.

[0018] In an optional embodiment, the spring is a cylindrical spring.

[0019] In an optional embodiment, the spring is a conical spring.

[0020] In an optional embodiment, the axial direction of the spring is perpendicular to the axial direction of the connecting hole, the connecting hole is a through hole, and positioning protrusions are provided on two oppositely arranged hole walls of the connecting hole, and the two positioning protrusions are respectively detachably plugged into the two ends of the spring.

[0021] Beneficial effects: The two positioning protrusions can be provided to position and fix the spring, thereby preventing the spring from falling out of the connecting hole and the avoidance groove, or preventing the spring from being damaged or damaging other structures due to movement or shaking.

[0022] In an optional embodiment, the elastic member is a folded spring sheet.

[0023] In an optional embodiment, the elastic member is an elastic tube.

[0024] In an optional embodiment, a through hole is provided on the bottom of the avoidance groove.

[0025] Beneficial effect: Through holes are provided on the bottom of the avoidance groove to maintain the fluidity of the gas at the end plate.

[0026] In an optional implementation, the connecting hole is arranged at a position close to the explosion-proof valve.

[0027] Beneficial effect: The connection hole and the avoidance groove are arranged near the explosion-proof valve, so that the elastic member can be placed close to the explosion-proof valve, which can prevent damage to the elastic member under normal circumstances and support a larger flow space near the explosion-proof valve in case of thermal runaway.

[0028] In a second aspect, the present invention further provides a battery, comprising a shell, a pole group and the above-mentioned cover plate structure, wherein the pole group is arranged in the shell, and the cover plate structure is connected to the opening of the shell. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the specific implementation methods of the present invention 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 present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 A partial schematic diagram of a cover plate structure according to an embodiment of the present invention;

[0031] Figure 2 for Figure 1 A is a partial enlarged schematic diagram;

[0032] Figure 3 It is a partial installation explosion diagram of a cover plate structure according to an embodiment of the present invention;

[0033] Figure 4 A partial top view of a cover plate structure according to an embodiment of the present invention;

[0034] Figure 5 for Figure 4 A cross-sectional view of

[0035] Figure 6 A schematic diagram of a lower insulating member of a cover plate structure according to an embodiment of the present invention from a first perspective;

[0036] Figure 7 A schematic diagram of a lower insulating member of a cover plate structure according to an embodiment of the present invention from a second viewing angle;

[0037] Figure 8 is a schematic diagram of a lower insulating member of a cover plate structure according to an embodiment of the present invention from a third viewing angle;

[0038] Fig. 9 for Figure 8 A cross-sectional view of

[0039] Fig.10 A schematic diagram of an elastic member of a cover plate structure according to an embodiment of the present invention;

[0040] Fig.11 Another schematic diagram of an elastic member of a cover plate structure according to an embodiment of the present invention;

[0041] Fig.12 Schematic diagram of a cover plate structure according to an embodiment of the present invention.

[0042] Description of reference numerals:

[0043] 1. Cover plate; 11. Explosion-proof valve; 2. End plate; 21. Avoidance groove; 22. Through hole; 3. Lower insulating member; 31. Connection hole; 32. Snap-in hole; 33. Partition plate; 34. Positioning protrusion; 4. Elastic member; 5. Pole. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0045] Combine the following Figures 1 to 12 , describing an embodiment of the present invention.

[0046] According to an embodiment of the present invention, on the one hand, a cover plate structure is provided, including a cover plate 1, an end plate 2, a lower insulating member 3 and an elastic member 4; the cover plate 1 is suitable for being connected to the opening of the battery shell, and an explosion-proof valve 11 is provided on the cover plate 1; the end plate 2 is connected to the cover plate 1, suitable for being arranged inside the shell, and located between the cover plate 1 and the pole group inside the shell; the lower insulating member 3 is connected between the cover plate 1 and the end plate 2; the elastic member 4 is connected to the lower insulating member 3, and suitable for abutting between the pole group and the cover plate 1 when the battery thermally runs away.

[0047] The elastic member 4 is connected to the lower insulating member 3 and is located between the cover plate 1 and the end plate 2. When the battery is in thermal runaway and the insulating protection structures such as the end plate 2 and the lower insulating member 3 melt, the elastic member 4 abuts between the pole group and the cover plate 1, effectively preventing the pole group from moving in the direction of the explosion-proof valve 11, and preventing the pole group from blocking the explosion-proof valve 11, so that the cover plate 1 and the pole group always form an exhaust channel connected to the explosion-proof valve 11, so that the explosion-proof valve 11 has a good exhaust and heat dissipation effect, effectively delaying the speed of the battery heating up due to thermal runaway, reducing the peak temperature, alleviating the adverse consequences of the battery thermal runaway, greatly improving the safety performance of the battery, and also greatly improving the pass rate of the battery thermal runaway test. And because the elastic member 4 has a certain elasticity, it can also buffer the movement of the pole group to avoid the risk of impact rupture caused by high-speed movement. The lower insulating member 3 is arranged between the cover plate 1 and the end plate 2, mainly playing the role of insulation. In this embodiment, it can also play the role of fixing the elastic member 4.

[0048] In one embodiment, the elastic member 4 is made of metal material, and an insulating layer is provided on the surface of the elastic member 4 .

[0049] The elastic member 4 is made of a metal material with a high melting point and is not easily melted by high temperature. An insulating layer is provided on the surface of the elastic member 4 to ensure the insulating property of the elastic member 4 and avoid short circuit.

[0050] Specifically, the insulating layer may be sprayed on the surface of the elastic member 4 , or the insulating layer may be adhered to the surface of the elastic member 4 .

[0051] In one embodiment, the elastic member 4 is a spring, preferably an aluminum spring.

[0052] The elastic member 4 is a spring, which can abut between the electrode group and the cover plate 1 when the battery is thermally runaway to prevent the explosion-proof valve 11 from being blocked, and the shape of the spring can also lead to a larger exhaust space.

[0053] As a changeable implementation, the elastic member 4 may also be a metal elastic mesh, and an insulating layer is provided on the surface of the metal elastic mesh.

[0054] Specifically, there may be one or more elastic members 4 , and the multiple elastic members 4 may be disposed in one connecting hole 31 , or respectively disposed in multiple connecting holes 31 .

[0055] In one embodiment, Figures 1 to 5 As shown, the axial direction of the spring is parallel to the axial direction of the connecting hole 31. The connecting hole 31 is a blind hole in the shape of a groove. A snap-fitting hole 32 is provided on the bottom of the connecting hole 31 near the end plate 2. The spring is rotatably snap-fitted with the snap-fitting hole 32. One end of the spring is arranged in the connecting hole 31, and the other end is extended in the avoidance groove 21.

[0056] The spring is rotatably connected to the clamping hole 32, which is convenient for disassembly, installation and fixing of the spring, and the axial direction of the spring is consistent with the axial direction of the connecting hole 31. The spring can have a good supporting and blocking effect and good elasticity in the axial direction. The clamping hole 32 also ensures the gas flowability of the lower insulating member 3 at the connecting hole 31.

[0057] Specifically, the connection hole 31 is a blind hole, one end of the connection hole 31 in the axial direction is open and set as the hole mouth of the connection hole 31, and the other end is closed and set as the hole bottom of the connection hole 31. The hole mouth is set close to the cover plate 1, and the hole bottom is set close to the end plate 2.

[0058] In one embodiment, the elastic member 4 includes a plurality of springs, and a plurality of corresponding snap-in holes 32 are provided, and the springs and the snap-in holes 32 are provided in a one-to-one correspondence; a partition plate 33 is also provided in the connecting hole 31, and two adjacent springs are separated by the partition plate 33.

[0059] The multiple springs are separated by the partition 33 to prevent the springs from being entangled or interfering with each other. The partition 33 can also serve as a reinforcing rib in the connecting hole 31 to increase the strength of the lower insulating member 3.

[0060] Specifically, the partition plate 33 may be integrally formed on the hole wall of the connecting hole 31 to divide the connecting hole 31 into a plurality of hole segments.

[0061] In one embodiment, an abutment plate is connected to one end of the spring away from the avoidance groove 21. The abutment plate can increase the contact area of ​​the end of the spring away from the avoidance groove 21 to prevent the sharp end of the spring from scratching the cover plate 1 or the explosion-proof valve 11 and other structures.

[0062] In one embodiment, the spring is a cylindrical spring.

[0063] In one embodiment, the spring is a conical spring.

[0064] In one embodiment, Figures 6 to 9 As shown, the axial direction of the spring is perpendicular to the axial direction of the connecting hole 31, the connecting hole 31 is a through hole 22, and the two oppositely arranged hole walls of the connecting hole 31 are provided with positioning protrusions 34, and the two positioning protrusions 34 are respectively detachably plugged with the two ends of the spring. The spring can have a good supporting and blocking effect, and can have good elasticity in the direction perpendicular to the hole depth, and also maintain a certain elasticity in the axial direction.

[0065] The two positioning protrusions 34 can be provided to position and fix the spring, thereby preventing the spring from coming out of the connecting hole 31 and the avoidance groove 21, or preventing the spring from being damaged or damaging other structures due to movement or shaking.

[0066] Specifically, the positioning protrusion 34 is a positioning column, or the positioning protrusion 34 is a positioning sheet. The connecting hole 31 is a rectangular hole. The positioning protrusion 34 is arranged on one end of the connecting hole 31 close to the avoidance groove 21, a part of the spring is arranged in the connecting hole 31, and the other part is arranged in the avoidance groove 21.

[0067] As a convertible embodiment, a positioning protrusion 34 may be provided on one hole wall of the connecting hole 31, one end of the spring is plugged into the positioning protrusion 34, and the other end abuts against the other opposite hole wall.

[0068] In one embodiment, Fig.10 As shown, the elastic member 4 is a folded spring sheet.

[0069] In one embodiment, Fig.11 As shown, the elastic member 4 is an elastic tube.

[0070] In one embodiment, a through hole 22 is provided on the bottom of the avoidance groove 21 .

[0071] A through hole 22 is provided on the bottom of the avoidance groove 21 to maintain the fluidity of the gas at the end plate 2 .

[0072] Specifically, the through hole 22 may be a circular hole or a bar-shaped hole, and there may be a plurality of through holes 22 .

[0073] In one embodiment, the connection hole 31 and the avoidance groove 21 are arranged at a position close to the explosion-proof valve 11 .

[0074] The connecting hole 31 and the avoidance groove 21 are arranged near the explosion-proof valve 11, so that the elastic member 4 can be close to the explosion-proof valve 11, which can prevent the elastic member 4 from being damaged under normal circumstances and support a larger flow space near the explosion-proof valve 11 in case of thermal runaway.

[0075] According to an embodiment of the present invention, on the other hand, a battery is provided, comprising a housing, an electrode group and the above-mentioned cover plate structure, wherein the electrode group is arranged in the housing, and the cover plate structure is connected to the opening of the housing. A pole 5 is also arranged on the cover plate 1 of the cover plate structure, and the pole 5 is connected to the electrode group. The cover plate 1 can be a plain aluminum plate.

[0076] The elastic member 4 is connected to the lower insulating member 3 and is located between the cover plate 1 and the end plate 2. When the battery is in thermal runaway and the insulating protection structures such as the end plate 2 and the lower insulating member 3 melt, the elastic member 4 abuts between the pole group and the cover plate 1, effectively preventing the pole group from moving in the direction of the explosion-proof valve 11, and preventing the pole group from blocking the explosion-proof valve 11, so that the cover plate 1 and the pole group always form an exhaust channel connected to the explosion-proof valve 11, so that the explosion-proof valve 11 has a good exhaust and heat dissipation effect, effectively delaying the speed of the battery heating up due to thermal runaway, reducing the peak temperature, alleviating the adverse consequences of the battery thermal runaway, greatly improving the safety performance of the battery, and also greatly improving the pass rate of the battery thermal runaway test. And because the elastic member 4 has a certain elasticity, it can also buffer the movement of the pole group to avoid the risk of impact rupture caused by high-speed movement. The lower insulating member 3 is arranged between the cover plate 1 and the end plate 2, mainly playing the role of insulation. In this embodiment, it can also play the role of fixing the elastic member 4.

[0077] Although the embodiments of the present invention have been 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 structure, characterized in that: include: A cover plate, adapted to be connected to the opening of the battery housing, wherein the cover plate is provided with an explosion-proof valve; An end plate, adapted to be arranged inside the shell and located between the cover plate and the pole group inside the shell; a lower insulating member connected between the cover plate and the end plate; The elastic member is connected to the lower insulating member and is suitable for abutting between the electrode group and the cover plate when the battery is in thermal runaway.

2. The cover plate structure according to claim 1, characterized in that: The lower insulating member is provided with a connecting hole, and the end plate is correspondingly provided with an avoiding groove, the notch of the avoiding groove faces the connecting hole; the elastic member is connected to the connecting hole, and at least part of the elastic member extends into the avoiding groove.

3. The cover plate structure according to claim 2, characterized in that: The elastic member is a spring.

4. The cover plate structure according to claim 3, characterized in that: The axial direction of the spring is parallel to the axial direction of the connecting hole. The connecting hole is a blind hole in the shape of a groove. A clamping hole is provided on the bottom of the connecting hole close to the end plate. The spring is rotatably clamped with the clamping hole. One end of the spring is arranged in the connecting hole, and the other end is extended in the avoidance groove.

5. The cover plate structure according to claim 4, characterized in that: The elastic member comprises a plurality of springs, and the clamping holes are provided with a plurality of springs correspondingly, and the springs and the clamping holes are provided in a one-to-one correspondence; a partition is also provided in the connecting hole, and two adjacent springs are separated by the partition.

6. The cover plate structure according to claim 3, characterized in that: The axial direction of the spring is perpendicular to the axial direction of the connecting hole. The connecting hole is a through hole. Positioning convex parts are provided on two oppositely arranged hole walls of the connecting hole. The two positioning convex parts are respectively detachably plugged into the two ends of the spring.

7. The cover plate structure according to claim 2, characterized in that: The elastic member is a folded spring sheet.

8. The cover plate structure according to claim 2, characterized in that: The elastic member is an elastic tube.

9. The cover plate structure according to any one of claims 1 to 8, characterized in that: The elastic member is made of metal material, and an insulating layer is provided on the surface of the elastic member.

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

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