Battery end cover structure and battery

Abstract

The utility model relates to the technical field of power batteries, and particularly discloses a battery end cover structure and a battery. Wherein the battery end cover structure covers an opening of the battery shell, a pole group is arranged in the battery shell, and the battery end cover structure comprises a cover plate, a plastic plate and a supporting block. The cover plate is provided with an anti-explosion valve; the plastic plate is connected with the cover plate and provided with a limiting cavity. And the supporting block is arranged in the limiting cavity and is suitable for being abutted between the cover plate and the pole group under the condition that the plastic plate is melted due to thermal runaway of the battery, so that an exhaust channel communicated with the ventilation opening of the explosion-proof valve is formed between the cover plate and the pole group. According to the scheme, the pole group is prevented from blocking the explosion-proof valve under the impact extrusion of airflow, adverse consequences caused by thermal runaway of the battery are relieved, and the safety performance of the battery is improved. In addition, the battery comprises the battery end cover structure, so that the battery has all the beneficial effects of the battery end cover structure.

Description

Technical Field

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

[0002] At present, with the increasing maturity of lithium-ion battery technology, lithium-ion batteries have been widely used as power batteries in the field of electric vehicles. Therefore, people's requirements for the safety performance of lithium-ion batteries are increasing.

[0003] In the traditional lithium-ion battery structure, the cover plate and the shell are welded to encapsulate the electrode group inside the shell; the plastic plate of the cover plate is against the electrode group, which plays the role of limiting the electrode group. However, when the battery has thermal runaway, the internal temperature of the battery increases, and the gas generation increases, causing the explosion-proof valve to automatically open for exhaust; at this time, the plastic plate may melt at high temperature, thereby losing its limiting effect on the electrode group, and the electrode group may block the explosion-proof valve under the impact of the airflow, aggravating the battery runaway and posing a greater safety risk. Utility Model Content

[0004] In view of this, the utility model provides a battery end cover structure and a battery to solve the existing problem that when thermal runaway occurs in the battery, the pole group may block the explosion-proof valve under the impact of airflow, aggravating the battery runaway and posing a greater safety risk.

[0005] In the first aspect, the utility model provides a battery end cover structure. Specifically, the battery end cover structure is covered on the opening of the battery housing, and a pole group is arranged inside the battery housing. The battery end cover structure includes a cover plate, a plastic plate and a support block. Among them, the cover plate is provided with an explosion-proof valve; the plastic plate is arranged between the cover plate and the pole group, and one side of the plastic plate is fixedly connected to the cover plate, and the other side abuts against the pole group; the plastic plate is provided with a limiting cavity, and the limiting cavity is recessed in the direction away from the cover plate; the support block is resistant to high temperature and electrolyte, and the support block is fixed in the limiting cavity. The support block is suitable for abutting between the cover plate and the pole group when the plastic plate melts due to thermal runaway of the battery, so that an exhaust channel connected to the air vent of the explosion-proof valve is formed between the cover plate and the pole group.

[0006] In an optional embodiment, the exhaust channel extends along the length direction of the cover plate, and both ends of the exhaust channel have air flow inlets, and the sum of the areas of the two air flow inlets is greater than or equal to the area of ​​the explosion-proof valve air vent.

[0007] In an optional embodiment, the explosion-proof valve vent is a strip hole extending along the length direction of the cover plate, the support block extends along the width direction of the cover plate, and the length of the support block is greater than the width of the explosion-proof valve vent; and / or, two pole ears are provided at intervals along the length direction of the plastic plate at one end of the pole group facing the plastic plate, the position of the explosion-proof valve vent corresponds to the position between the two pole ears, and support blocks are provided on the outer sides of the two pole ears respectively.

[0008] In an optional embodiment, a flap is provided on one side of the limiting cavity, and a flip cover is provided at the opening of the limiting cavity. One of the flap and the other side of the limiting cavity is provided with a buckle, and the other one is provided with a snap-on step, and the buckle can be snap-on with the snap-on step.

[0009] In an optional implementation, the thickness of the connection between the flip cover and the limiting cavity is smaller than the thickness of the flip cover.

[0010] In an optional implementation, a side of the plastic plate facing the cover plate is provided with an avoidance groove, the avoidance groove covers the position of the limiting cavity, and the flip cover is arranged in the avoidance groove.

[0011] In an optional implementation, the thickness of the flap is not greater than the depth of the avoidance groove; or, the thickness of the flap is greater than the depth of the avoidance groove, and the difference between the two is not greater than 3 mm.

[0012] In an optional implementation, the height of the support block is not greater than the depth of the limiting cavity; or, the height of the support block is greater than the depth of the limiting cavity, and the difference between the height and the depth is not greater than 3 mm.

[0013] In an optional implementation, the plastic plate is provided with a plurality of limiting cavities, and the supporting blocks are provided in a plurality, and the plurality of supporting blocks are arranged in the plurality of limiting cavities in a one-to-one correspondence.

[0014] In a second aspect, the utility model further provides a battery, comprising a battery housing, a pole group disposed inside the battery housing, and a battery end cover structure, wherein the battery end cover structure covers an opening of the battery housing.

[0015] Beneficial effects: In the battery end cover structure of the first aspect, a support block is added between the cover plate and the plastic plate. When the plastic plate melts due to thermal runaway of the battery, the support block abuts between the cover plate and the pole group, so that an exhaust channel connected to the air vent of the explosion-proof valve is formed between the cover plate and the pole group, preventing the pole group from blocking the explosion-proof valve under the impact of the air flow, alleviating the adverse consequences of thermal runaway of the battery, and increasing the safety performance of the battery. In addition, the battery of the second aspect includes the battery end cover structure of the first aspect, so the battery of the second aspect has all the beneficial effects of the battery end cover structure of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] 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.

[0017] Figure 1This is a first exploded view of the battery end cover structure according to an embodiment of the utility model;

[0018] Figure 2 A second exploded view of the battery end cover structure according to an embodiment of the utility model;

[0019] Figure 3 A cross-sectional view of a battery end cover structure according to an embodiment of the utility model;

[0020] Figure 4 for Figure 3 The enlarged view of point B in the middle;

[0021] Figure 5 A top view of a battery according to an embodiment of the utility model;

[0022] Figure 6 for Figure 5 Cross-sectional view at AA in the middle;

[0023] Figure 7 for Figure 6 Enlarged view of point C in the middle.

[0024] Description of reference numerals:

[0025] 100. Battery;

[0026] 110. Battery end cover structure; 120. Battery housing; 130. Electrode group;

[0027] 111. cover plate; 112. plastic plate; 113. support block;

[0028] 1111, explosion-proof valve; 1112, pole;

[0029] 1121, limit cavity; 1122, flip cover; 1123, avoidance groove; 1124, buckle; 1125, clamping step; 1126, avoidance hole; 1127, thinning area;

[0030] 131. Extreme ears. DETAILED DESCRIPTION

[0031] 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.

[0032] In order to deepen the understanding of the solution of the utility model, it is necessary to elaborate on the technical problems in detail in combination with relevant technologies. The specific contents are as follows:

[0033] In the traditional lithium-ion battery structure, the cover plate and the shell are welded to encapsulate the electrode group inside the shell; the plastic plate of the cover plate is against the electrode group, which plays the role of limiting the electrode group. However, when the battery has thermal runaway, the internal temperature of the battery increases, and the gas generation increases, causing the explosion-proof valve to automatically open for exhaust; at this time, the plastic plate may melt at high temperature, thereby losing its limiting effect on the electrode group, and the electrode group may block the explosion-proof valve under the impact of the airflow, aggravating the battery runaway and posing a greater safety risk.

[0034] Furthermore, the battery temperature is generally controlled by a special temperature control circuit. When the temperature control circuit fails, the battery may suffer thermal runaway, the chemical reaction inside the battery will intensify, and more gas will be generated. If the high temperature melts the plastic plate at this time, the electrode group will block the vent of the explosion-proof valve and the battery will be in danger of exploding.

[0035] In order to alleviate the above technical problems, the utility model provides a battery end cover structure and a battery. Figures 1 to 7 The embodiments of the present utility model are described in detail.

[0036] First, refer to Figures 1 to 3 The utility model provides a battery end cover structure 110. Specifically, the battery end cover structure 110 is covered at the opening of the battery housing 120, and the battery housing 120 is provided with a pole group 130 inside. The battery end cover structure 110 includes a cover plate 111, a plastic plate 112 and a support block 113. Among them, the cover plate 111 is provided with an explosion-proof valve 1111; the plastic plate 112 is arranged between the cover plate 111 and the electrode group 130, and one side of the plastic plate 112 is fixedly connected to the cover plate 111, and the other side is abutted against the electrode group 130; the plastic plate 112 is provided with a limiting cavity 1121, and the limiting cavity 1121 is recessed in a direction away from the cover plate 111; the support block 113 is resistant to high temperature and electrolyte, and the support block 113 is fixed in the limiting cavity 1121. The support block 113 is suitable for abutting between the cover plate 111 and the electrode group 130 when the plastic plate 112 melts due to thermal runaway of the battery 100, so that an exhaust channel connected to the air vent of the explosion-proof valve 1111 is formed between the cover plate 111 and the electrode group 130.

[0037] Specifically, a support block 113 is added between the cover plate 111 and the plastic plate 112. When the plastic plate 112 melts due to thermal runaway of the battery 100, the support block 113 abuts between the cover plate 111 and the electrode group 130, so that an exhaust channel connected to the air vent of the explosion-proof valve 1111 is formed between the cover plate 111 and the electrode group 130, thereby preventing the electrode group 130 from clogging the explosion-proof valve 1111 under the impact of airflow, alleviating the adverse consequences brought about by thermal runaway of the battery 100, and increasing the safety performance of the battery 100.

[0038] More specifically, the support block 113 is received in the limiting cavity 1121 of the plastic plate 112, thereby reducing the additional space occupied by the support block 113 inside the battery housing 120 and having little impact on the overall volume of the battery 100; moreover, the limiting cavity 1121 wraps and limits the support block 113 to prevent the support block 113 from moving inside the battery housing 120 and damaging the electrode group 130.

[0039] Furthermore, the plastic plate 112 is a soft material, and when the battery 100 is subjected to external impact, the plastic plate 112 will deform; the support block 113 is arranged in the limiting cavity 1121 of the plastic plate 112, which can increase the strength of the plastic plate 112 to reduce the deformation of the plastic plate 112.

[0040] In some embodiments, reference Figure 1 and Figure 2 The exhaust channel extends along the length direction of the cover plate 111 , and has air flow inlets at both ends of the exhaust channel. The sum of the areas of the two air flow inlets is greater than or equal to the area of ​​the air vent of the explosion-proof valve 1111 .

[0041] Specifically, in this solution, the sum of the areas of the multiple air flow inlets is greater than or equal to the area of ​​the air vent of the explosion-proof valve 1111, so that the exhaust rate is not affected and the exhaust can be normal.

[0042] More specifically, after the plastic plate 112 melts due to thermal runaway of the battery 100, the support block 113 is supported between the cover plate 111 and the electrode group 130 to form an exhaust channel; the gas generated inside the battery housing 120 enters the exhaust channel from the air flow inlet, and the gas flow directions at different air flow inlets are different, but all converge at the explosion-proof valve 1111, and then are discharged from the battery housing 120 from the explosion-proof valve 1111.

[0043] Preferably, the exhaust channel extends along the length direction of the cover plate 111, the middle part of the exhaust channel is connected to the air vent when the explosion-proof valve 1111 is opened, and the two ends of the exhaust channel in the length direction are the main air flow inlets, so the air flow inlet area mainly depends on the height of the support block 113.

[0044] More preferably, the height of the support block 113 is greater than 3 mm.

[0045] In some embodiments, reference Figure 1 and Figure 3 , the air vent of the explosion-proof valve 1111 is a strip hole extending along the length direction of the cover plate 111, the support block 113 extends along the width direction of the cover plate 111, and the length of the support block 113 is greater than the width of the air vent of the explosion-proof valve 1111; and / or, two pole ears 131 are provided at intervals along the length direction of the plastic plate 112 at one end of the pole group 130 facing the plastic plate 112, the position of the air vent of the explosion-proof valve 1111 corresponds to the position between the two pole ears 131, and the outer sides of the two pole ears 131 are respectively provided with support blocks 113.

[0046] In particular, “and / or” means that the options before “and / or” and the options after “and / or” are set alternatively or simultaneously.

[0047] Specifically, the air vent of the explosion-proof valve 1111 is a strip hole extending along the length direction of the cover plate 111, and the support block 113 extends along the width direction of the cover plate 111. The length of the support block 113 is greater than the width of the air vent of the explosion-proof valve 1111 to prevent the support block 113 from being flushed out of the explosion-proof valve 1111 by the airflow inside the battery housing 120 after the plastic plate 112 melts due to thermal runaway of the battery 100.

[0048] It should be noted that the air vent of the explosion-proof valve 1111 can be a circular hole, a waist-shaped hole, etc., or an irregularly shaped opening. The shape of the air vent is not limited here. The length of the support block 113 is greater than the maximum inner diameter of the air vent of the explosion-proof valve 1111, that is, the length of the longest line segment connecting the inner edges of the air vent is less than the length of the support block 113, which can meet the requirement that the support block 113 is not impacted out of the battery casing 120 by the airflow; the above embodiments are all within the scope of protection of this patent.

[0049] In addition, two pole ears 131 are arranged at intervals along the length direction of the plastic plate 112 at one end of the pole group 130 facing the plastic plate 112, the position of the air vent of the explosion-proof valve 1111 corresponds to the position between the two pole ears 131, and the outer sides of the two pole ears 131 are respectively provided with support blocks 113; after the thermal runaway of the battery 100 causes the plastic plate 112 to melt, the pole ears 131 have a blocking effect on the support block 113, preventing the support block 113 from being impacted by the airflow and running away, thereby also preventing the support block 113 from being impacted out of the battery casing 120 from the explosion-proof valve 1111.

[0050] Furthermore, the cover plate 111 is provided with a pole 1112 corresponding to the pole lug 131 , and the pole 1112 is electrically connected to the pole lug 131 .

[0051] In some embodiments, reference Figure 1 , Figure 2 , Figure 4 and Figure 7A flip cover 1122 is provided on one side of the limiting cavity 1121, and the flip cover 1122 is arranged at the opening of the limiting cavity 1121. One of the flip cover 1122 and the other side of the limiting cavity 1121 is provided with a buckle 1124, and the other side is provided with a clamping step 1125, and the buckle 1124 can be clamped with the clamping step 1125.

[0052] Specifically, in this solution, the support block 113 is fixed by clamping the limiting cavity 1121 with the flip cover 1122, which is simple to manufacture, easy to operate, and firmly fixed.

[0053] Preferably, one end of the flip cover 1122 is rotatably connected to one side of the limiting cavity 1121, and the remaining edges of the flip cover 1122 are separated from the plastic plate 112; in the initial state, the other end of the flip cover 1122 is provided with a buckle 1124 protruding toward the cover plate 111, and the other side of the limiting cavity 1121 is provided with a snap-on step 1125 protruding toward the pole group 130, and an avoidance hole 1126 is opened near the snap-on step 1125; the opening of the limiting cavity 1121 faces the cover plate 111, and after the flip cover 1122 is folded to provide the opening of the limiting cavity 1121, the buckle 1124 is penetrated by the avoidance hole 1126 and is snap-connected with the snap-on step 1125.

[0054] More specifically, the interference between the buckle 1124 and the snap-fit ​​step 1125 is between 0 mm and 0.4 mm, and the height of the snap-fit ​​step 1125 is preferably 1.5 mm to ensure effective snap-fit.

[0055] It should be noted that interference generally refers to the possibility that adjacent parts in the assembly drawing may collide or be obstructed during assembly or operation, resulting in failure to assemble or operate, that is, interference occurs between parts.

[0056] In some embodiments, reference Figure 1 , the thickness of the connection between the flip cover 1122 and the limiting cavity 1121 is smaller than the thickness of the flip cover 1122 .

[0057] Specifically, the thickness of the connection between the flip cover 1122 and the limiting cavity 1121 is less than the thickness of the flip cover 1122 , so folding the flip cover 1122 is more labor-saving, and there will not be too much material stacking at the folding position, thereby avoiding the flip cover 1122 and the limiting cavity 1121 opening not fitting together.

[0058] Preferably, the flip cover 1122 and the plastic plate 112 are integrally formed, and a thinning area 1127 is provided on the side of the connection between the flip cover 1122 and the plastic plate 112 facing the electrode group 130, so as to realize the opening of the limit cavity 1121 when the flip cover is turned 180 degrees.

[0059] In particular, a rotating shaft may be provided between the flip cover 1122 and the plastic plate 112, or the two may be integrally formed, and the thinning area 1127 may be a V-shaped groove, a trapezoidal groove, etc., all of which fall within the protection scope of this patent.

[0060] In some embodiments, reference Figure 1 and Figure 2 A side of the plastic plate 112 facing the cover plate 111 is provided with an avoidance groove 1123 , the avoidance groove 1123 covers the position of the limiting cavity 1121 , and the flip cover 1122 is disposed in the avoidance groove 1123 .

[0061] Specifically, a side of the plastic plate 112 facing the cover plate 111 is provided with an avoidance groove 1123, which covers the position of the limiting cavity 1121, and the flip cover 1122 is arranged in the avoidance groove 1123, so as to reduce the influence of the flip cover 1122 on the thickness of the plastic plate 112 after flipping, and reduce the influence on other components of the battery 100.

[0062] In some embodiments, reference Figure 1 and Figure 2 , the thickness of the flap 1122 is not greater than the depth of the avoidance groove 1123; or, the thickness of the flap 1122 is greater than the depth of the avoidance groove 1123, and the difference between the two is not greater than 3 mm.

[0063] Specifically, this solution prevents the flip cover 1122 from protruding too much after being turned over, causing the plastic plate 112 and the cover plate 111 to not fit together and deform the plastic plate 112 , squeezing the electrode group 130 , and damaging the electrode group 130 .

[0064] Preferably, the flip cover 1122 is completely stored in the avoidance groove 1123 after being turned over.

[0065] In some embodiments, reference Figure 1 and Figure 2 , the height of the support block 113 is not greater than the depth of the limiting cavity 1121; or, the height of the support block 113 is greater than the depth of the limiting cavity 1121, and the difference between the two is not greater than 3 mm.

[0066] Specifically, this solution prevents the support block 113 from protruding too much from the limiting cavity 1121, so that the flip cover 1122 is difficult to close and snap into place after being flipped over.

[0067] In some embodiments, reference Figure 1 and Figure 3 The plastic plate 112 is provided with a plurality of limiting cavities 1121 , and the supporting blocks 113 are provided with a plurality of supporting blocks 113 , and the plurality of supporting blocks 113 are provided in the plurality of limiting cavities 1121 in a one-to-one correspondence.

[0068] Specifically, this solution can make the flow cross-section of the exhaust passage uniform after the battery 100 thermally runs away, and further increase the overall structural strength.

[0069] More specifically, the limiting cavity 1121 and the supporting block 113 do not affect the structural design of other components of the battery 100 .

[0070] In particular, the support block 113 can be but is not limited to ceramic, metal, rubber, plastic, or mica; when the support block 113 is made of a soft material, it can be inserted with an interference amount of no more than 0.2 mm with the side wall of the limiting cavity 1121 to make it tight, and an exhaust hole can be opened at the bottom of the limiting cavity 1121; when the support block 113 is made of a hard material, a gap of 0.05 mm to 1 mm is left between it and the limiting cavity 1121 to facilitate insertion and maintain the limiting effect. At the same time, in order to reduce the weight, the support block 113 can be made into a dumbbell shape or a hollow structure with the inside hollowed out.

[0071] Secondly, refer to Figure 5 and Figure 6 The utility model further provides a battery 100 , including a battery housing 120 , an electrode group 130 disposed inside the battery housing 120 , and a battery end cover structure 110 , wherein the battery end cover structure 110 covers an opening of the battery housing 120 .

[0072] Specifically, the battery 100 in this solution includes a battery end cover structure 110, so the battery 100 has all the beneficial effects of the battery end cover structure 110. In addition, the battery 100 in this solution also includes other components such as a battery protection plate, and only the components related to this solution are listed here, but the composition of the battery 100 is not limited.

[0073] 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 battery end cover structure, covering the opening of a battery housing, wherein a pole group is arranged inside the battery housing, characterized in that: The battery end cover structure comprises: A cover plate, wherein the cover plate is provided with an explosion-proof valve; A plastic plate, the plastic plate is arranged between the cover plate and the electrode group, one side of the plastic plate is fixedly connected to the cover plate, and the other side of the plastic plate is in contact with the electrode group; the plastic plate is provided with a limiting cavity, and the limiting cavity is concave in a direction away from the cover plate; A support block, the support block is resistant to high temperature and electrolyte, the support block is fixed in the limiting cavity, and the support block is suitable for abutting between the cover plate and the pole group when the plastic plate melts due to thermal runaway of the battery, so that an exhaust channel connected to the air vent of the explosion-proof valve is formed between the cover plate and the pole group.

2. The battery end cover structure according to claim 1, characterized in that: The exhaust channel extends along the length direction of the cover plate, and both ends of the exhaust channel have air flow inlets, and the sum of the areas of the two air flow inlets is greater than or equal to the area of ​​the explosion-proof valve air vent.

3. The battery end cover structure according to claim 1, characterized in that: The explosion-proof valve vent is a strip-shaped hole extending along the length direction of the cover plate, the support block extends along the width direction of the cover plate, and the length of the support block is greater than the width of the explosion-proof valve vent; And / or, two pole ears are provided at intervals along the length direction of the plastic plate at one end of the pole group facing the plastic plate, the position of the explosion-proof valve air vent corresponds to the position between the two pole ears, and the outer sides of the two pole ears are respectively provided with the support blocks.

4. The battery end cover structure according to claim 1, characterized in that: A flip cover is provided on one side of the limiting cavity, and the flip cover is arranged at the opening of the limiting cavity. One of the flip cover and the other side of the limiting cavity is provided with a buckle, and the other one is provided with a clamping step, and the buckle can be clamped with the clamping step.

5. The battery end cover structure according to claim 4, characterized in that: The thickness of the connection between the flip cover and the limiting cavity is smaller than the thickness of the flip cover.

6. The battery end cover structure according to claim 4, characterized in that: The side of the plastic plate facing the cover plate is provided with an avoidance groove, the avoidance groove covers the position of the limiting cavity, and the flip cover is arranged in the avoidance groove.

7. The battery end cover structure according to claim 6, characterized in that: The thickness of the flap is not greater than the depth of the avoidance groove; Alternatively, the thickness of the flip cover is greater than the depth of the avoidance groove, and the difference between the two is no more than 3 mm.

8. The battery end cover structure according to claim 4, characterized in that: The height of the support block is not greater than the depth of the limiting cavity; Alternatively, the height of the support block is greater than the depth of the limiting cavity, and the difference between the height and the depth is no greater than 3 mm.

9. The battery end cover structure according to any one of claims 1 to 8, characterized in that: The plastic plate is provided with a plurality of limiting cavities, and the supporting blocks are provided in a plurality of ways, and the supporting blocks are arranged in the plurality of limiting cavities in a one-to-one correspondence.

10. A battery, characterized in that: The invention comprises a battery shell, a pole group arranged inside the battery shell, and a battery end cover structure according to any one of claims 1 to 9, wherein the battery end cover structure covers an opening of the battery shell.

Images