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. Specifically, the battery end cover structure covers an opening of a battery shell, and a pole group is arranged in the battery shell. The battery end cover structure comprises a cover plate, a plastic end plate and a supporting piece, wherein the cover plate is provided with an anti-explosion valve; the plastic end plate is attached to the plate face of the cover plate, and the plastic end plate is provided with a limiting groove body. The supporting piece is resistant to high temperature and electrolyte, and the supporting piece is fixed in the limiting groove body. The supporting piece is suitable for being connected between the cover plate and the pole group in an abutting mode under the condition that the plastic end plate is melted due to thermal runaway of the battery, so that an exhaust channel communicated with the ventilation opening of the anti-explosion 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 end 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 end plate may melt at high temperature, thereby losing the 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 end plate and a support member. Among them, the cover plate is provided with an explosion-proof valve; the plastic end plate is fitted with the cover plate surface, and the plastic end plate is provided with a limit groove body; the support member is resistant to high temperature and electrolyte, and the support member is fixed in the limit groove body.

[0006] In an optional embodiment, the dimension of the explosion-proof valve vent in the width direction of the cover plate is smaller than the dimension of the support member in the width direction of the cover plate; and / or, the limiting groove is located between the pole ear of the pole group and the side wall of the battery housing.

[0007] In an optional embodiment, the height of the support member is greater than 3 mm.

[0008] In an optional embodiment, the height of the support member is less than the depth of the limiting groove body; or, the height of the support member is greater than the depth of the limiting groove body, and the difference between the two is no more than 3 mm.

[0009] In an optional embodiment, the support member includes a support block, which is arranged inside the limiting groove body; the support member also includes a limiting cap fixed to the support block, and the limiting cap cover is arranged at the opening of the limiting groove body; and / or, the side wall of the limiting groove body is provided with a first clamping structure, the support block is provided with a second clamping structure, and the first clamping structure is clamped with the second clamping structure.

[0010] In an optional embodiment, an avoidance groove is provided at the opening of the limiting groove body, and the limiting cap is arranged in the avoidance groove.

[0011] In an optional embodiment, the first clamping structure is a first clamping rib, the second clamping structure is a second clamping rib, the top of the first clamping rib is provided with a first chamfer, and the bottom of the second clamping rib is provided with a second chamfer.

[0012] In an optional embodiment, the limiting groove body is provided with a side wall of the first clamping rib having a thickness of no more than 2 mm and no less than 0.5 mm.

[0013] In an optional implementation, the plastic end plate is provided with a plurality of limiting grooves, and the plurality of support members are provided in a one-to-one correspondence in the plurality of limiting grooves.

[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 cap structure of the first aspect, a support is added between the cover plate and the plastic end plate. When the plastic end plate melts due to thermal runaway of the battery, the support 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 cap structure of the first aspect, so the battery of the second aspect has all the beneficial effects of the battery end cap 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 1 An exploded view of the battery end cover structure according to an embodiment of the utility model;

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

[0019] Figure 3 for Figure 2 Cross-sectional view at AA in the middle;

[0020] Figure 4 for Figure 3 Enlarged view of point B in the middle.

[0021] Description of reference numerals:

[0022] 110. Battery end cover structure;

[0023] 111. cover plate; 112. plastic end plate; 113. support member;

[0024] 1111, explosion-proof valve; 1112, pole;

[0025] 1121. Limiting groove; 1122. Avoiding groove; 1123. First clamping rib;

[0026] 1131. Limiting cap; 1132. Support block; 1133. Second clamping rib. DETAILED DESCRIPTION

[0027] 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.

[0028] 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:

[0029] 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 end 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 end plate may melt at high temperature, thereby losing the 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.

[0030] Furthermore, batteries generally control their temperature through a dedicated temperature control circuit. When the temperature control circuit fails, the battery may suffer thermal runaway, intensifying the chemical reaction inside the battery and generating more gas. If the high temperature melts the plastic end plate at this time and the electrode group blocks the vent of the explosion-proof valve, the battery is in danger of exploding.

[0031] In order to alleviate the above technical problems, the utility model provides a battery end cover structure and a battery. Figures 1 to 4 The embodiments of the present utility model are described in detail.

[0032] First, refer to Figure 1 The utility model provides a battery end cover structure 110. Specifically, the battery end cover structure 110 is covered on the opening of the battery housing, and a pole group is arranged inside the battery housing. The battery end cover structure 110 includes a cover plate 111, a plastic end plate 112 and a support member 113. Among them, the cover plate 111 is provided with an explosion-proof valve 1111; the plastic end plate 112 is fitted with the plate surface of the cover plate 111, and the plastic end plate 112 is provided with a limiting groove body 1121; the support member 113 is resistant to high temperature and electrolyte, and the support member 113 is fixed in the limiting groove body 1121.

[0033] Specifically, a support member 113 is added between the cover plate 111 and the plastic end plate 112. When the plastic end plate 112 melts due to thermal runaway of the battery, the support member 113 abuts against between the cover plate 111 and the electrode group, 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, preventing the electrode group from clogging the explosion-proof valve 1111 under the impact of airflow, alleviating the adverse consequences of thermal runaway of the battery and increasing the safety performance of the battery.

[0034] More specifically, the support member 113 is received in the limiting groove 1121 of the plastic end plate 112, thereby reducing the additional space occupied by the support member 113 inside the battery casing and having little impact on the overall volume of the battery; moreover, the limiting groove 1121 wraps and limits the support member 113 to prevent the support member 113 from moving inside the battery casing and damaging the electrode group.

[0035] Furthermore, the plastic end plate 112 is a soft material, and when the battery is subjected to external impact, the plastic end plate 112 will deform; the support member 113 is arranged in the limiting groove 1121 of the plastic end plate 112, which can increase the strength of the plastic end plate 112 to reduce the deformation of the plastic end plate 112.

[0036] In some embodiments, reference Figure 1 and Figure 3, the dimension of the air vent of the explosion-proof valve 1111 in the width direction of the cover plate 111 is smaller than the dimension of the support member 113 in the width direction of the cover plate 111; and / or, the limiting groove 1121 is located between the pole ear of the pole group and the side wall of the battery shell.

[0037] In particular, “and / or” means that the options before “and / or” and the options after “and / or” are set alternatively or simultaneously.

[0038] Specifically, the size of the air vent of the explosion-proof valve 1111 in the width direction of the cover plate 111 is smaller than the size of the support member 113 in the width direction of the cover plate 111, to prevent the support member 113 from being flushed out of the explosion-proof valve 1111 by the airflow inside the battery shell after the plastic end plate 112 melts due to thermal runaway of the battery.

[0039] 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 member 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 member 113, which can meet the requirement that the support member 113 is not impacted out of the battery casing by the airflow; the above embodiments all fall within the scope of protection of this patent.

[0040] In addition, two pole ears 131 are arranged at intervals along the length direction of the plastic end plate 112 at one end of the pole group facing the plastic end plate 112, the position of the air vent of the explosion-proof valve 1111 corresponds to between the two pole ears 131 or is located on one side of the two pole ears, and the limiting groove 1121 is located on the side of the pole ear of the pole group away from the explosion-proof valve 1111; after the plastic end plate 112 melts due to thermal runaway of the battery, the pole ear 131 has a blocking effect on the support member 113, preventing the support member 113 from being impacted by the airflow and running away, thereby also preventing the support member 113 from being impacted out of the battery casing from the explosion-proof valve 1111.

[0041] 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 .

[0042] In particular, refer to Figure 2 When designing the battery cell, the explosion-proof valve 1111 can be located between the two pole ears, or on the outside of one of the pole ears, and the explosion-proof valve 1111 is not necessarily on the positive electrode side, but may also be on the negative electrode side.

[0043] In some embodiments, reference Figure 1 and Figure 3 , the height of the support member 113 is greater than 3 mm.

[0044] Specifically, in this solution, the height of the support member 113 is greater than 3 mm, ensuring that the areas of the multiple air flow inlets of the exhaust channel are 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 exhaust can be performed normally.

[0045] It should be noted that after the plastic end plate 112 melts due to thermal runaway of the battery, the support member 113 is supported between the cover plate 111 and the pole group to form an exhaust channel; the gas generated inside the battery housing enters the exhaust channel from the airflow inlet, and the gas flows in different directions at different airflow inlets, but all converge at the explosion-proof valve 1111, and then discharges from the battery housing from the explosion-proof valve 1111. The exhaust channel extends along the length direction of the cover plate 111, and the middle part of the exhaust channel is connected to the air vent when the explosion-proof valve 1111 is opened. The two ends of the exhaust channel in the length direction are the main airflow inlets, so the airflow inlet area mainly depends on the height of the support member 113.

[0046] In some embodiments, reference Figure 1 and Figure 4 , the height of the support member 113 is less than the depth of the limiting groove 1121; or, the height of the support member 113 is greater than the depth of the limiting groove 1121, and the difference between the two is not greater than 3 mm.

[0047] Specifically, the support member 113 is resistant to high temperatures and electrolytes, and is not limited to metals, high-temperature resistant rubber blocks, ceramics, mica, rubber, etc.; if the support member 113 is made of rubber material, such as fluororubber, the height of the upper surface of the support member 113 after installation shall not exceed the upper surface of the limiting groove 1121 of the plastic end plate 112 by more than 3 mm to prevent the plastic end plate 112 and the cover plate 111 from having an uneven fitting surface after installation, causing the plastic end plate 112 to move downward and damage the electrode group; if the support member 113 is made of a hard material, the upper surface of the support block 1132 must be lower than the upper surface of the limiting groove 1121 of the plastic end plate 112 to prevent the support member 113 from colliding or scratching the cover plate 111 after the plastic end plate 112 and the cover plate 111 are fitted, and metal chips may fall off to cause a micro-short circuit inside the battery.

[0048] It should be noted that it is best not to use aluminum material for the support member 113 on the negative electrode side to prevent the negative electrode potential from dropping when the battery is slightly short-circuited, and the negative electrode aluminum support member 113 is embedded with lithium and corroded, resulting in fixation failure.

[0049] In particular, the support member 113 maintains a distance from the pole group or the interference amount with the pole group shall not be greater than 2 mm to prevent the pole group from being crushed.

[0050] In some embodiments, reference Figure 1 and Figure 4The support member 113 includes a support block 1132, which is arranged inside the limiting groove 1121; the support member 113 also includes a limiting cap 1131 fixed to the support block 1132, and the limiting cap 1131 covers the opening of the limiting groove 1121; and / or, the side wall of the limiting groove 1121 is provided with a first clamping structure, the support block 1132 is provided with a second clamping structure, and the first clamping structure is clamped with the second clamping structure.

[0051] Specifically, this solution is a specific implementation of the support member 113, which has a reasonable structure and a firm connection.

[0052] It should be noted that the support block 1132 can be hollowed out to reduce weight.

[0053] In some embodiments, reference Figure 1 The opening of the limiting groove body 1121 is provided with an avoidance groove 1122 , and the limiting cap 1131 is arranged in the avoidance groove 1122 .

[0054] Specifically, the opening of the limiting groove body 1121 is provided with an avoidance groove 1122, and the limiting cap 1131 is arranged in the avoidance groove 1122. The avoidance groove 1122 stores and limits the limiting cap 1131, thereby achieving the purpose of reducing space occupancy and fixing.

[0055] In some embodiments, reference Figure 1 and Figure 4 The first clamping structure is the first clamping rib 1123, and the second clamping structure is the second clamping rib 1133. The top of the first clamping rib 1123 is provided with a first chamfer, and the bottom of the second clamping rib 1133 is provided with a second chamfer; that is, the first clamping rib 1123 is provided with a first chamfer on the side of the opening of the limiting groove body 1121, and the second clamping rib 1133 is provided with a second chamfer on the side facing away from the limiting cap 1131.

[0056] Specifically, this solution is a specific implementation of the clip-on structure, and the clip-on ribs are chamfered to facilitate sliding in and clipping.

[0057] In some embodiments, reference Figure 1 and Figure 4 The limiting groove body 1121 is provided with a first clamping rib 1123 whose side wall thickness is not greater than 2 mm and not less than 0.5 mm.

[0058] Specifically, the side wall thickness of the first clamping rib 1123 provided in the limiting groove body 1121 shall not be greater than 2 mm, otherwise when the support block 1132 is pressed in, the first clamping rib cannot rebound to avoid it, and the support block 1132 is difficult to press-fit; at the same time, the side wall thickness of the first clamping rib 1123 provided in the limiting groove body 1121 shall not be less than 0.5 mm, otherwise when the support block 1132 is pressed in, the first clamping rib will undergo plastic deformation and damage and will be unable to rebound to clamp the support block 1132.

[0059] More specifically, the lower surface of the limiting cap 1131 cooperates with the avoidance groove 1122 of the plastic end plate 112 to limit the position, and stops the support block 1132 from continuing to be pressed downward; the distance between the lower surface of the limiting cap 1131 and the lower surface of the second clamping rib 1133 is slightly larger than the distance between the avoidance groove 1122 and the lower surface of the first clamping rib 1123, but must not exceed 0.5mm, otherwise it will be loose and cause the support block 1132 to shake; at the same time, the thickness of the clamping ribs of the two is not less than 0.5mm and not more than 3mm to ensure the clamping strength; the length of the second clamping rib 1133 does not exceed 3mm, so as to facilitate the press-fitting and prevent the rib strength from being too large and the press-fitting from being too laborious.

[0060] Preferably, the length of the first clamping rib 1123 is equal to the length of the side wall of the limiting groove body 1121, the length of the second clamping rib 1133 is smaller than the length of the first clamping rib 1123, and the clamping spacing between the two is 0mm to 1mm, which is convenient for limiting the support block 1132.

[0061] In some embodiments, the plastic end plate 112 is provided with a plurality of limiting grooves 1121 , and there are a plurality of support members 113 , and the plurality of support members 113 are disposed in the plurality of limiting grooves 1121 in a one-to-one correspondence.

[0062] Specifically, this solution can make the flow cross-section of the exhaust channel uniform after the battery thermal runaway, and further increase the overall structural strength.

[0063] More specifically, the limiting groove 1121 and the support member 113 do not affect the structural design of other components of the battery.

[0064] In particular, when the support block 1132 is made of rubber, the length direction of the support block 1132 matches the length direction of the plastic end plate 112 cavity, leaving a gap of 0.05mm to 1mm or an interference amount of no more than 0.2mm for insertion. When the support block 1132 is made of hard material, leaving a gap of 0.05mm to 1mm for easy insertion and maintaining the limiting effect.

[0065] Secondly, the utility model further provides a battery, including a battery housing, a pole group arranged inside the battery housing, and a battery end cover structure 110, wherein the battery end cover structure 110 covers the opening of the battery housing.

[0066] Specifically, the battery in this solution includes a battery end cover structure 110, so the battery has all the beneficial effects of the battery end cover structure 110. In addition, the battery in this solution also includes other components such as a battery protection board, and only the components related to this solution are listed here, but it does not limit the composition of the battery.

[0067] 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 end plate, the plastic end plate is in contact with the cover plate surface, and the plastic end plate is provided with a limiting groove; The support member is resistant to high temperature and electrolyte, and is fixed in the limiting groove body.

2. The battery end cover structure according to claim 1, characterized in that: The dimension of the explosion-proof valve vent in the width direction of the cover plate is smaller than the dimension of the support member in the width direction of the cover plate; And / or, the limiting groove is located between the pole lug of the pole group and the side wall of the battery housing.

3. The battery end cover structure according to claim 1, characterized in that: The height of the support member is greater than 3 mm.

4. The battery end cover structure according to claim 1, characterized in that: The height of the support member is less than the depth of the limiting groove; Alternatively, the height of the support member is greater than the depth of the limiting groove, and the difference between the two is no greater than 3 mm.

5. The battery end cover structure according to claim 1, characterized in that: The support member comprises a support block, and the support block is arranged inside the limiting groove body; The support member further comprises a limiting cap fixed to the support block, and the limiting cap cover is arranged at the opening of the limiting groove body; And / or, the side wall of the limiting groove body is provided with a first clamping structure, the supporting block is provided with a second clamping structure, and the first clamping structure is clamped with the second clamping structure.

6. The battery end cover structure according to claim 5, characterized in that: The opening of the limiting groove body is provided with an avoidance groove, and the limiting cap is arranged in the avoidance groove.

7. The battery end cover structure according to claim 5, characterized in that: The first clamping structure is a first clamping rib, the second clamping structure is a second clamping rib, the top of the first clamping rib is provided with a first chamfer, and the bottom of the second clamping rib is provided with a second chamfer.

8. The battery end cover structure according to claim 7, characterized in that: The side wall thickness of the limiting groove body provided with the first clamping rib is not greater than 2 mm and not less than 0.5 mm.

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

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