Battery

Abstract

The present application relates to the technical field of batteries. Specifically disclosed is a battery. A mounting hole and a plurality of support platforms are provided on a cover plate body or a case of the battery, an explosion-proof valve is arranged in the mounting hole, the plurality of support platforms are arranged in the circumferential direction of the mounting hole, the plurality of support platforms are spaced apart from the mounting hole, and two adjacent support platforms are also spaced apart from each other. A plastic member is arranged on the side of the cover plate body or the case close to an accommodating cavity, and the ends of the support platforms facing away from the cover plate body or the case all extend towards the plastic member. After thermal runaway occurs in the battery and the plastic member is melted, the plurality of support platforms arranged on the cover plate body or the case can continue to support an electrode group, thereby preventing the mounting hole from being blocked by the electrode group, and allowing a high-temperature and high-pressure gas to flow to the mounting hole and be directionally discharged by means of the explosion-proof valve arranged in the mounting hole; therefore, the explosion-proof valve has a high exhaust rate, and can realize rapid pressure relief, and the battery then has good safety.

Description

A type of battery

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. CN202510094725.X, filed on January 21, 2025, entitled "A Battery", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of battery technology, and more particularly to a battery. Background Technology

[0004] Lithium-ion batteries have become representative of high-performance batteries due to their advantages such as high operating voltage, high specific energy, large capacity, low self-discharge, good cycle performance, long service life, light weight, and small size. The structure of a conventional lithium-ion battery includes a cover plate, a casing, electrode assembly, and insulating components. The cover plate and casing are welded together to form a sealed space protecting the electrode assembly. An explosion-proof valve is integrated into the cover plate, which can directionally discharge high-temperature, high-pressure gas from the sealed space in the event of thermal runaway. The insulating components are located within the sealed space formed by the casing and cover plate, and are positioned between the cover plate and the electrode assembly. On one hand, the insulating components support the electrode assembly, preventing it from wobbling within the casing, thus providing good fixation; on the other hand, the insulating components prevent short circuits between the electrode assembly and the cover plate, ensuring the electrical safety of the battery.

[0005] However, insulating components are generally made of plastic materials (such as PP), which have limited strength and high-temperature resistance, and typically melt at around 150°C. When a battery experiences thermal runaway, the temperature inside the sealed space is high, causing the insulating components to melt and fail. At this point, only the still-solid electrode assembly remains in the sealed space. The gap between the electrode assembly and the cover plate increases, and due to the lack of support from the insulating components, the electrode assembly has a high degree of freedom within the casing. When high-temperature, high-pressure gas is vented through the explosion-proof valve, the electrode assembly will move with the high-temperature, high-pressure gas flow, posing a risk of blocking the explosion-proof valve's venting passage, reducing the valve's venting efficiency, and resulting in low safety performance.

[0006] Application content

[0007] In view of this, the purpose of this application is to provide a battery that can prevent the explosion-proof valve from being blocked due to the movement of the electrode assembly when the battery experiences thermal runaway. The explosion-proof valve has high venting efficiency and good safety performance.

[0008] In a first aspect, this application provides a battery comprising:

[0009] Explosion-proof valve;

[0010] The cover plate body and the housing are connected and enclosed to form an accommodating cavity. One of the cover plate body and the housing is provided with a mounting hole and a support structure. The mounting hole is used to install the explosion-proof valve. The support structure includes multiple support platforms. The multiple support platforms are arranged around the mounting hole, and each support platform is spaced apart from the inner wall of the mounting hole. An exhaust channel is formed between two adjacent support platforms.

[0011] A plastic part is disposed on the side of the cover plate body or the housing near the receiving cavity, and the end of the support platform away from the cover plate body or the housing extends toward the plastic part;

[0012] Wherein, along the direction perpendicular to the end face of the cover plate body or the housing, the sum of the projected areas of all the support platforms on the end face of the cover plate body or the housing is S1, and the projected area of ​​the mounting hole on the end face of the cover plate body or the housing is S2.

[0013] The condition S1 and S2 satisfy: 2.0 ≤ S2 / S1 ≤ 3.5.

[0014] Beneficial effects: After thermal runaway and melting of plastic parts, the multiple support platforms on the cover plate or shell can continue to support the electrode assembly, preventing the electrode assembly from flowing randomly with the high-temperature and high-pressure gas and causing the mounting holes on the cover plate to be blocked by the electrode assembly. The high-temperature and high-pressure gas can pass through the exhaust channel between two adjacent support platforms on the cover plate, and then flow to the mounting hole and be discharged in a directional manner through the explosion-proof valve installed in the mounting hole. The flow path of the high-temperature and high-pressure gas is smooth and the flow speed is fast. The high exhaust rate of the explosion-proof valve can achieve rapid pressure relief, and the battery safety is good.

[0015] Optionally, the cover plate body is provided with the mounting hole and the support structure, and the explosion-proof valve includes two arc-shaped sides arranged opposite each other along the length direction of the cover plate body and a straight side arranged opposite each other along the width direction of the cover plate body, and each support platform is arranged close to the arc-shaped sides.

[0016] Optionally, the distance between the side of each support platform closest to the explosion-proof valve and the tangent of the arc-shaped edge is C, where C ranges from 3mm to 5mm.

[0017] Optionally, the support structure includes four support platforms, wherein every two support platforms symmetrically arranged along the central axis of the cover plate body along its length direction constitute a group, and the two groups of support platforms are symmetrically arranged along the central axis of the cover plate body along its width direction.

[0018] Optionally, the distance between the two support platforms spaced apart along the length of the cover plate body on their adjacent sides is W1, and the dimension of the mounting hole along the length of the cover plate body is A, wherein A and W1 satisfy the following condition: 0.70≤W1 / A≤0.85;

[0019] Where the value of A is in the range of: 20mm≤A≤60mm;

[0020] The value range of W1 is: 15mm≤W1≤50mm.

[0021] Optionally, the distance between the two support platforms spaced apart along the width direction of the cover plate body on their adjacent sides is W2, and the dimension of the mounting hole along the width direction of the cover plate body is B, wherein B and W2 satisfy the following condition: 0.35≤W2 / B≤0.50;

[0022] The value of B is in the range of 8mm≤B≤30mm;

[0023] The value range of W2 is: 3mm≤W2≤15mm.

[0024] Optionally, the height of the support platform is H in a direction perpendicular to the end face of the cover plate body or the housing;

[0025] The value range of H is: 1.5mm≤H≤3.0mm.

[0026] Optionally, when 2.0 ≤ S2 / S1 ≤ 3.0, the value range of H is 2.0 mm ≤ H ≤ 3.0 mm;

[0027] When 3.0≤S2 / S1≤3.5, the value range of H is 1.5mm≤H≤2.0mm.

[0028] Optionally, the plastic part is provided with a plurality of vent holes, which are arranged at intervals on the plastic part. Along a direction perpendicular to the end face of the cover plate body or the housing, the projection of the plurality of vent holes on the cover plate body or the housing at least partially overlaps with the projection of the mounting hole on the cover plate body or the housing.

[0029] Optionally, the plastic part has a clearance groove on the side facing the cover plate body or the housing, and the support platform is embedded in the clearance groove. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0031] Figure 1 is a structural schematic diagram of the cover plate body and plastic parts provided in Embodiment 1 of this application;

[0032] Figure 2 is a schematic diagram of the cover plate body provided in Embodiment 1 of this application;

[0033] Figure 3 is a magnified view of part A in Figure 2;

[0034] Figure 4 is a top view of the cover plate body provided in Embodiment 1 of this application;

[0035] Figure 5 is a schematic diagram of the battery structure provided in Embodiment 2 of this application;

[0036] Figure 6 is a partial enlarged view of the battery provided in Embodiment 2 of this application.

[0037] In the figure: 100, cover plate body; 110, mounting hole; 111, limiting flange; 120, support platform; 200, plastic part; 210, plastic part body; 211, vent hole; 220, first flange; 300, shell; 310, first side wall; 320, second side wall; 400, explosion-proof valve. Detailed Implementation

[0038] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0039] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this application; however, those skilled in the art will recognize the applicability of other processes and / or the use of other materials.

[0040] Example 1

[0041] As shown in Figures 1-3, this embodiment provides a battery, which includes an explosion-proof valve 400, a cover plate body 100, a housing 300, and a plastic part 200. The cover plate body 100 is connected to the housing 300 and together with the housing 300 forms a cavity for placing the electrode assembly.

[0042] The cover plate body 100 is provided with mounting holes 110 and a support structure. The explosion-proof valve 400 is disposed in the mounting hole 110. The support structure includes multiple support platforms 120, which are arranged circumferentially around the mounting hole 110. Each support platform 120 is spaced apart from the inner wall of the mounting hole 110, and adjacent support platforms 120 are also spaced apart to form an exhaust channel between adjacent support platforms 120. A plastic part 200 is disposed on the side of the cover plate body 100 near the receiving cavity. The ends of the support platforms 120 away from the cover plate body 100 extend toward the plastic part 200, and the plastic part 200 insulates the cover plate body 100 from the electrode assembly. With the above configuration, even after thermal runaway of the battery and melting of the plastic part 200, the multiple support platforms 120 on the cover body 100 can continue to support the electrode assembly, preventing the electrode assembly from randomly flowing with the high-temperature, high-pressure gas and causing the mounting hole 110 on the cover body 100 to be blocked by the electrode assembly. The high-temperature, high-pressure gas can pass through the exhaust channel between two adjacent support platforms 120 on the cover body 100, and then flow to the mounting hole 110 and be discharged directionally through the explosion-proof valve 400 installed in the mounting hole 110. The flow path of the high-temperature, high-pressure gas is smooth and the flow speed is fast. The high exhaust rate of the explosion-proof valve 400 can achieve rapid pressure relief, ensuring good battery safety. It should be noted that the explosion-proof valve 400 is in the open state at this time.

[0043] Furthermore, along the direction perpendicular to the end face of the cover plate body 100, the sum of the projected areas of all the support platforms 120 on the end face of the cover plate body 100 is S1, and the projected area of ​​the mounting holes 110 on the end face of the cover plate body 100 is S2. S1 and S2 satisfy the condition: 2.0 ≤ S2 / S1 ≤ 3.5. For example, the value of S2 / S1 can be 2.0, 2.5, 3.0, or 3.5, etc. The direction perpendicular to the end face of the cover plate body 100 is the Z-axis direction shown in Figure 1, which is referred to as the first direction in this embodiment for ease of explanation.

[0044] By controlling the values ​​of S2 / S1 within the above range, when the battery experiences thermal runaway and the plastic part 200 melts and fails, it can be ensured that the contact area between the support structure and the electrode assembly is large, which can provide good support for the electrode assembly and ensure that there is a large venting space between the electrode assembly and the cover plate body 100. The venting space is connected to the venting channel between the two adjacent support platforms 120, so that high temperature and high pressure gas can be discharged to the mounting hole 110 through the venting channel, preventing the electrode assembly from moving towards the cover plate body 100 under the impact of high temperature and high pressure gas, which would cause the mounting hole 110 on the cover plate body 100 to be blocked. The explosion-proof valve 400 has high venting efficiency, which greatly improves the safety performance of the battery.

[0045] As an optional technical solution, the explosion-proof valve 400 in this embodiment includes two arc-shaped edges arranged opposite each other along the length direction of the cover plate body 100, and straight edges arranged opposite each other along the width direction of the cover plate body 100. Each support platform 120 is located close to the arc-shaped edges. The length direction of the cover plate body 100 is the X-axis direction shown in Figure 1, which is referred to as the second direction in this embodiment for ease of explanation; the width direction of the cover plate body 100 is the Y-axis direction shown in Figure 1, which is referred to as the third direction in this embodiment for ease of explanation.

[0046] Multiple support platforms 120 are formed on the cover plate body 100 by stamping. The distance C between the side of each support platform 120 closest to the explosion-proof valve 400 and the tangent of the arc-shaped edge is defined as C, where C ranges from 3mm to 5mm. For example, C can be 3mm, 4mm, or 5mm. By controlling the value of C within the above range, it can be ensured that the flatness of the surrounding area of ​​the mounting hole 110 on the cover plate body 100 is good after the support platform 120 is stamped, resulting in high assembly accuracy between the explosion-proof valve 400 and the cover plate body 100, high reliability of the explosion-proof valve 400, and a low risk of failure. Otherwise, if the value of C is too small, the distance between the support platform 120 and the mounting hole 110 will be too close, resulting in poor flatness of the surrounding area of ​​the mounting hole 110 on the cover plate body 100, affecting the welding quality between the explosion-proof valve 400 and the cover plate body 100, and posing a risk of sealing failure. Of course, the value of C should not be too large, otherwise the distance between the support platform 120 and the mounting hole 110 will be too far, the support effect of the pole group will decrease, and there is a risk that the pole group will block the mounting hole 110 on the cover plate body 100.

[0047] Referring again to Figures 1 and 2, a limiting flange 111 is provided on the inner wall of the mounting hole 110. The explosion-proof valve 400 can be inserted into the mounting hole 110 from one side of the cover plate body 100 and abut against the limiting flange 111 on the inner wall of the mounting hole 110. This indicates that the explosion-proof valve 400 is installed in place and can be welded to the cover plate body 100. The limiting flange 111 ensures accurate positioning between the explosion-proof valve 400 and the cover plate body 100, resulting in high assembly precision. In addition, the limiting flange 111 can also temporarily fix the explosion-proof valve 400, facilitating the welding operation between the explosion-proof valve 400 and the cover plate body 100. It should be noted that since the four edges of the explosion-proof valve 400 are welded to the inner wall of the mounting hole 110, the distance between the side of the support platform 120 near the explosion-proof valve 400 and the tangent of the inner wall of the mounting hole 110 is also C.

[0048] Referring again to Figures 2 and 4, the support structure in this embodiment includes four support platforms 120. Each pair of support platforms 120 symmetrically arranged along the central axis of the second direction (marked as e in Figure 4) forms a group, and the two groups of support platforms 120 are symmetrically arranged along the central axis of the third direction (marked as f in Figure 4).

[0049] The distance between the two support platforms 120 spaced apart along the second direction and their closest sides is W1. The dimension of the mounting hole 110 along the second direction is A. A and W1 satisfy the condition: 0.70 ≤ W1 / A ≤ 0.85. For example, the value of W1 / A can be 0.70, 0.75, 0.80, or 0.85, etc. By controlling the value of W1 / A within the above range, the exhaust channel between the two support platforms 120 spaced apart along the second direction is larger, meeting the flow requirements of high-temperature, high-pressure gas diffusing along the third direction. This avoids the support platforms 120 generating significant resistance to the high-temperature, high-pressure gas, accelerates the flow of the high-temperature, high-pressure gas towards the explosion-proof valve 400, and allows the internal pressure of the battery to be released quickly, preventing an explosion and ensuring good safety.

[0050] Optionally, in this embodiment, the value range of A is 20mm ≤ A ≤ 60mm, and the value range of W1 is 15mm ≤ W1 ≤ 50mm. For example, when A is 20mm, the value of W1 can be 15mm, 16mm, or 17mm. When A is 60mm, the value of W1 can be 42mm, 45mm, 48mm, or 50mm.

[0051] Furthermore, the distance between the two support platforms 120 spaced apart along the third direction and their closest sides is W2, and the dimension of the mounting hole 110 along the third direction is B. B and W2 satisfy the condition: 0.35 ≤ W2 / B ≤ 0.50. For example, the value of W2 / B can be 0.35, 0.40, 0.45, or 0.50, etc. By controlling the value of W2 / B within the above range, the exhaust channel between the two support platforms 120 spaced apart along the third direction is larger, meeting the flow requirements of high-temperature, high-pressure gas diffusing along the second direction. This avoids the support platforms 120 generating significant resistance to the high-temperature, high-pressure gas, accelerates the flow of the high-temperature, high-pressure gas towards the explosion-proof valve 400, and allows the internal pressure of the battery to be released quickly, preventing an explosion and ensuring good safety.

[0052] Optionally, in this embodiment, the value range of B is: 8mm ≤ B ≤ 30mm, and the value range of W2 is: 3mm ≤ W2 ≤ 15mm. For example, when B is 8mm, the value of W2 can be 3.0mm, 3.5mm, or 4.0mm. When B is 30mm, the value of W2 can be 10.5mm, 11.0mm, 11.0mm, 11.0mm, or 15.0mm.

[0053] Furthermore, along the third direction, the distance between the end of the support platform 120 facing away from the mounting hole 110 and the adjacent side of the cover body 100 is D, and the value of D is in the range of 5mm≤D≤10mm. For example, the value of D can be 5mm, 6mm, 8mm, or 10mm, etc. By limiting the value of D to the above range, a certain space is ensured between the support platform 120 and the side of the cover body 100 along the third direction, which facilitates the assembly of the cover body 100 and the housing 300. At the same time, it also makes the resistance of high temperature and high pressure gas flowing along the second direction smaller, so that it can be discharged to the mounting hole 110, ensuring that the explosion-proof valve 400 can open smoothly and that the exhaust is relatively smooth. It should be noted that the value of A should not be too small, otherwise the flow of high temperature and high pressure gas along the second direction will be obstructed, and the explosion-proof valve 400 may fail to open in time, posing a safety risk; the value of A should also not be too large, otherwise the support platform 120 will not provide good support for the electrode group, the mounting hole 110 on the cover plate body 100 may be blocked by the electrode group, and the explosion-proof valve 400 will not be able to vent properly.

[0054] Referring again to Figures 2 and 3, along the third direction, the height of the support platform 120 is H, and the value of H is in the range of 1.5mm ≤ H ≤ 3.0mm. For example, the value of H can be 1.5mm, 2.0mm, 2.5mm, or 3.0mm, etc. By limiting the value of H to the above range, the flow area of ​​the exhaust channel formed between two adjacent support platforms 120 is larger. Consequently, when the support platform 120 abuts against the electrode assembly after the plastic part 200 is melted, the exhaust space between the cover plate body 100 and the electrode assembly is larger, which is beneficial to improving the exhaust efficiency of the explosion-proof valve 400 and ensuring high safety.

[0055] It should be noted that the height H of the support platform 120 along the third direction is related to the projected area of ​​the support platform 120 on the cover plate body 100 along the third direction. In this embodiment, four support platforms 120 with the same shape and size are used as an example. The sum of the projected areas of the four support platforms 120 on the cover plate body 100 along the third direction is S1, and the projected area of ​​each support platform 120 on the cover plate body 100 along the third direction is S1 / 4.

[0056] To ensure the support effect of the support platform 120 on the electrode assembly and meet the safety requirements during battery venting, the relationship between the sum of the projected areas S1 of all support platforms 120 along the third direction on the cover plate body 100 and the projected area S2 of the mounting hole 110 along the third direction on the end face of the cover plate body 100 must satisfy: 2.0≤S2 / S1≤3.0. In this case, the value range of H is 2.0mm≤H≤3.0mm. That is, the height H of the support platform 120 can be 2.0mm, 2.5mm, or 3.0mm, etc., to ensure that the support platform 120 provides good support for the electrode assembly, meets the battery venting requirements, and ensures good safety.

[0057] When the sum of the projected areas S1 of all support platforms 120 along the third direction on the cover body 100 and the projected area S2 of the mounting holes 110 along the third direction on the end face of the cover body 100 satisfy the following condition: 3.0≤S2 / S1≤3.5, the value range of H is 1.5mm≤H≤2.0mm. That is, at this time, the height H of the support platform 120 can be 1.5mm, 1.8mm or 2.0mm, etc., to ensure that the support platform 120 provides good support for the electrode group, meets the battery venting requirements, and ensures good safety.

[0058] Furthermore, the plastic part 200 is provided with a plurality of vent holes 211, which are spaced apart on the plastic part 200 along a direction perpendicular to the end face of the cover plate body 100 (i.e., the third direction). The projections of the plurality of vent holes 211 on the cover plate body 100 at least partially coincide with the projections of the mounting holes 110 on the cover plate body 100. After the battery experiences thermal runaway, before the internal temperature of the battery rises to the melting point of the plastic part 200, the plastic part 200 maintains its pre-melting form to support the electrode assembly. At this time, the high-temperature and high-pressure gas in the accommodating cavity can be discharged to the explosion-proof valve 400 through the vent holes 211, so that the explosion-proof valve 400 opens and releases pressure.

[0059] Furthermore, the plastic part 200 has a clearance groove on the side facing the cover body 100, and the support platform 120 can be embedded in the clearance groove. By setting the clearance groove, the waste of space in the accommodating cavity can be avoided, the space occupied by the cover body 100 can be reduced, which is conducive to increasing the volume of the electrode assembly and improving the energy density of the battery.

[0060] In this embodiment, the plastic part 200 includes a plastic part body 210, a first flange 220 and a second flange (not shown in the figure). A vent 211 is provided on the plastic part body 210. The first flange 220 and the second flange are provided on the side of the plastic part body 210 facing the cover plate body 100. The first flange 220 is arranged around the circumference of the plastic part body 210. The second flange is connected to the first flange 220, and the second flange, the first flange 220 and the plastic part body 210 together form a clearance groove. The support platform 120 can be embedded in the clearance groove.

[0061] The following uses samples of different design sizes to verify the thermal runaway values ​​of the relevant parameters S2 / S1 and H of the cover body 100 of the above-mentioned battery. The verification results are shown in Table 1.

[0062] Table 1

[0063] From the above results, it can be concluded that in samples 1, 2, and 3, the relationship between the sum of the projected areas S1 of all support platforms 120 along the third direction on the cover plate body 100 and the projected area S2 of the mounting holes 110 along the third direction on the end face of the cover plate body 100 satisfies: 2.0≤S2 / S1≤3.0. However, the value of H is less than the minimum value of its corresponding range 2.0mm≤H≤3.0mm. At this time, the support platform 120 does not provide good support for the electrode group, and cannot maintain the design gap between the cover plate body 100 and the electrode group. The explosion-proof valve 400 is not able to vent properly, which can easily lead to the risk of explosion. The pass rate of the battery thermal runaway test is low, and the battery product is defective.

[0064] In samples 4 to 7, the relationship between the sum of the projected areas S1 of all support platforms 120 along the third direction on the cover plate body 100 and the projected area S2 of the mounting holes 110 along the third direction on the end face of the cover plate body 100 satisfies: 2.0≤S2 / S1≤3.0, and the value of H satisfies its corresponding range of 2.0mm≤H≤3.0mm. At this time, the support platform 120 has a significant supporting effect on the electrode group, the exhaust space formed between the cover plate body 100 and the electrode group is large, the explosion-proof valve 400 exhausts smoothly and has high exhaust efficiency, the battery thermal runaway test is passed, no explosion occurs, and the battery product is good.

[0065] In samples 8 to 11, the relationship between the sum of the projected areas S1 of all support platforms 120 along the third direction on the cover body 100 and the projected area S2 of the mounting holes 110 along the third direction on the end face of the cover body 100 satisfies: 3.0≤S2 / S1≤3.5, and the value of H satisfies its corresponding range of 1.5mm≤H≤2.0mm. At this time, the support platform 120 has a significant supporting effect on the electrode group, the exhaust space formed between the cover body 100 and the electrode group is large, the explosion-proof valve 400 exhausts smoothly and has high exhaust efficiency, the battery thermal runaway test is passed, no explosion occurs, and the battery product is good.

[0066] It can be seen that when the values ​​of S2 / S1 and H both meet their respective ranges and are matched with each other, the support platform 120 provides good support for the electrode group, the battery is safe, and both can pass the thermal runaway test without exploding.

[0067] The following uses samples of different design sizes to verify the thermal runaway values ​​of relevant parameters W1 / A and W2 / B of the cover body 100 of the above-mentioned battery. The verification results are shown in Table 2.

[0068] Table 2

[0069] From the above results, it can be concluded that in sample 1, the value of W1 / A is less than the minimum value of its corresponding range 0.70≤W1 / A≤0.85, and the value of W2 / B satisfies its corresponding range 0.35≤W2 / B≤0.50. At this time, the distance between the two support platforms 120 spaced apart along the second direction is too close, the exhaust channel between the two support platforms 120 spaced apart along the second direction is small, the resistance of the high temperature and high pressure gas diffused along the third direction is large, the exhaust rate of the explosion-proof valve 400 is reduced, the pressure inside the battery cannot be released in time, there is a risk of explosion, and the safety is poor.

[0070] In samples 2, 3, and 4, the value of W1 / A satisfies the corresponding range of 0.70 ≤ W1 / A ≤ 0.85, and the value of W2 / B satisfies the corresponding range of 0.35 ≤ W2 / B ≤ 0.50. At this time, the support platform 120 has a significant supporting effect on the electrode group. The exhaust channel between the two support platforms 120 spaced apart along the second direction is large, and the exhaust channel between the two support platforms 120 spaced apart along the third direction is also large. The resistance of the high temperature and high pressure gas diffused along the third direction and the second direction is small. The exhaust rate of the explosion-proof valve 400 is high, and the internal pressure of the battery can be released quickly. The battery thermal runaway test is passed, there is no risk of explosion, and the battery product is good.

[0071] In sample 5, the value of W1 / A is greater than the maximum value of its corresponding range 0.70≤W1 / A≤0.85, and the value of W2 / B meets the corresponding range 0.35≤W2 / B≤0.50. At this time, the distance between the two support platforms 120 set at intervals along the second direction is too large, the support platform 120 does not provide good support for the electrode group, and cannot maintain the design gap between the cover plate body 100 and the electrode group. The explosion-proof valve 400 does not exhaust smoothly, which easily leads to the risk of explosion. The pass rate of the battery thermal runaway test is low, and the battery product is defective.

[0072] In sample 6, the value of W2 / B is less than the minimum value of its corresponding range 0.35≤W2 / B≤0.50, and the value of W1 / A satisfies its corresponding range 0.70≤W1 / A≤0.85. At this time, the distance between the two support platforms 120 spaced apart along the third direction is too close, the exhaust channel between the two support platforms 120 spaced apart along the third direction is small, the resistance of the high temperature and high pressure gas diffused along the second direction is large, the exhaust rate of the explosion-proof valve 400 is reduced, the pressure inside the battery cannot be released in time, there is a risk of explosion, and the safety is poor.

[0073] In samples 7 and 8, the values ​​of W1 / A satisfy the corresponding range of 0.70≤W1 / A≤0.85, and the values ​​of W2 / B satisfy the corresponding range of 0.35≤W2 / B≤0.50. At this time, the support platform 120 has a significant supporting effect on the electrode group. The exhaust channel between the two support platforms 120 spaced apart along the second direction is large, and the exhaust channel between the two support platforms 120 spaced apart along the third direction is also large. The resistance of the high temperature and high pressure gas diffused along the third direction and the second direction is small. The exhaust rate of the explosion-proof valve 400 is high, and the internal pressure of the battery can be released quickly. The battery thermal runaway test is passed, there is no risk of explosion, and the battery product is good.

[0074] In sample 9, the value of W2 / B is greater than the maximum value of its corresponding range 0.35≤W2 / B≤0.50, and the value of W1 / A meets its corresponding range 0.70≤W1 / A≤0.85. At this time, the distance between the two support platforms 120 set at intervals along the third direction is too large, the support platform 120 does not provide good support for the electrode group, and cannot maintain the design gap between the cover plate body 100 and the electrode group. The explosion-proof valve 400 does not exhaust smoothly, which easily leads to the risk of explosion. The pass rate of the battery thermal runaway test is low, and the battery product is defective.

[0075] It is evident that W1 and W2 must simultaneously satisfy 0.70≤W1 / A≤0.85 and 0.35≤W2 / B≤0.50 to meet the requirements of supporting the electrode assembly while not affecting the venting channel and improving the battery's safety performance.

[0076] Example 2

[0077] This embodiment also provides a battery, which differs from the battery in Embodiment 1 in that the mounting hole 110 and the support structure in this embodiment are provided on one of the side walls of the housing 300.

[0078] Referring to Figures 5 and 6, the battery in this embodiment can be a blade battery. The housing 300 has openings at both ends along the second direction (the X-axis direction shown in Figure 5). There are two cover plate bodies 100, each of which is connected to one opening of the housing 300 and seals the opening. The two cover plate bodies 100 and the housing 300 form a cavity for placing the electrode assembly.

[0079] The housing 300 includes two first sidewalls 310 disposed opposite each other along a first direction, and two second sidewalls 320 disposed opposite each other along a third direction (the Y-axis direction shown in FIG. 5). The first sidewalls 310 and the second sidewalls 320 are connected, and the area of ​​the first sidewall 310 is smaller than the area of ​​the second sidewall 320. In this embodiment, the mounting hole 110 and the support structure are disposed on the first sidewall 310 as an example. The support structure includes a plurality of support platforms 120, which are disposed circumferentially around the mounting hole 110. Each support platform 120 is spaced apart from the inner wall of the mounting hole 110, and adjacent support platforms 120 are also spaced apart to form an exhaust channel between adjacent support platforms 120. A plastic part 200 is disposed on the side of the first sidewall 310 near the receiving cavity, and the support platform 120 abuts against the plastic part 200.

[0080] Along the direction perpendicular to the end face of the first sidewall 310 (i.e., the first direction), the sum of the projected areas of all support platforms 120 on the end face of the first sidewall 310 is S1, and the projected area of ​​the mounting hole 110 on the end face of the first sidewall 310 is S2. S1 and S2 satisfy the condition: 2.0 ≤ S2 / S1 ≤ 3.5. For example, the value of S2 / S1 can be 2.0, 2.5, 3.0, or 3.5, etc.

[0081] By controlling the values ​​of S2 / S1 within the above range, when the battery experiences thermal runaway and the plastic part 200 melts and fails, it can be ensured that the contact area between the support structure and the electrode assembly is large, which can provide good support for the electrode assembly and ensure that there is a large venting space between the electrode assembly and the first sidewall 310. The venting space is connected to the venting channel between the two adjacent support platforms 120, so that high-temperature and high-pressure gas can be discharged to the mounting hole 110 through the venting channel, preventing the electrode assembly from moving towards the first sidewall 310 under the impact of high-temperature and high-pressure gas, which would cause the mounting hole 110 on the first sidewall 310 to be blocked. The explosion-proof valve 400 has high venting efficiency, which greatly improves the safety performance of the battery.

[0082] The plastic part 200 is provided with a plurality of vent holes 211, which are spaced apart on the plastic part 200. Along the first direction, the projection of the plurality of vent holes 211 on the first side wall 310 of the housing 300 at least partially coincides with the projection of the mounting hole 110 on the first side wall 310 of the housing 300. After the battery experiences thermal runaway, before the internal temperature of the battery rises to the melting point of the plastic part 200, the plastic part 200 maintains its pre-melting shape to support the electrode assembly. At this time, the high-temperature and high-pressure gas in the accommodating cavity can be discharged to the explosion-proof valve 400 through the vent holes 211, so that the explosion-proof valve 400 opens and releases pressure.

[0083] The plastic part 200 has a clearance groove on the side facing the first sidewall 310 of the housing 300, and the support platform 120 is embedded in the clearance groove. By setting the clearance groove, the space waste in the accommodating cavity can be avoided, the space occupied can be reduced, the volume of the electrode assembly can be increased, and the energy density of the battery can be improved.

[0084] The remaining structure of the battery in this embodiment is the same as that in Embodiment 1, and will not be described again here.

[0085] Obviously, the above embodiments of this application are merely examples for clear illustration and are not intended to limit the implementation of this application. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of the claims of this application. Industrial applicability

[0086] In this application, after the battery experiences thermal runaway and the plastic parts melt, multiple support platforms on the cover plate body or shell can continue to support the electrode assembly, preventing the electrode assembly from flowing randomly with the high-temperature and high-pressure gas and causing the mounting holes on the cover plate body to be blocked by the electrode assembly. The high-temperature and high-pressure gas can pass through the exhaust channel between two adjacent support platforms on the cover plate body, and then flow to the mounting hole and be discharged in a directional manner through the explosion-proof valve installed in the mounting hole. The flow path of the high-temperature and high-pressure gas is smooth and the flow speed is fast. The high exhaust rate of the explosion-proof valve can achieve rapid pressure relief, and the battery has good safety.

Claims

1. A battery, characterized in that, include: Explosion-proof valve; The cover plate body and the housing are connected and enclosed to form an accommodating cavity. One of the cover plate body and the housing is provided with a mounting hole and a support structure. The mounting hole is used to install the explosion-proof valve. The support structure includes multiple support platforms. The multiple support platforms are arranged around the mounting hole, and each support platform is spaced apart from the inner wall of the mounting hole. An exhaust channel is formed between two adjacent support platforms. A plastic part is disposed on the side of the cover plate body or the housing near the receiving cavity, and the end of the support platform away from the cover plate body or the housing extends toward the plastic part; Wherein, along the direction perpendicular to the end face of the cover plate body or the housing, the sum of the projected areas of all the support platforms on the end face of the cover plate body or the housing is S1, and the projected area of ​​the mounting hole on the end face of the cover plate body or the housing is S2. The condition S1 and S2 satisfy: 2.0 ≤ S2 / S1 ≤ 3.

5.

2. The battery according to claim 1, characterized in that, The cover plate body is provided with the mounting hole and the support structure. The explosion-proof valve includes two arc-shaped sides arranged opposite each other along the length direction of the cover plate body and a straight side arranged opposite each other along the width direction of the cover plate body. Each support platform is arranged close to the arc-shaped sides.

3. The battery according to claim 2, characterized in that, The distance between the side of each support platform closest to the explosion-proof valve and the tangent of the arc-shaped edge is C; The value of C is in the range of 3mm ≤ C ≤ 5mm.

4. The battery according to claim 2, characterized in that, The support structure includes four support platforms, wherein every two support platforms are symmetrically arranged along the central axis of the cover plate body along its length direction, and the two groups of support platforms are symmetrically arranged along the central axis of the cover plate body along its width direction.

5. The battery according to claim 4, characterized in that, The distance between the two support platforms that are spaced apart along the length of the cover plate body is W1, and the dimension of the mounting hole along the length of the cover plate body is A. The relationship between A and W1 is: 0.70≤W1 / A≤0.

85. Where the value of A is in the range of: 20mm≤A≤60mm; The value range of W1 is: 15mm≤W1≤50mm.

6. The battery according to claim 4, characterized in that, The distance between the two support platforms spaced apart along the width direction of the cover plate body and their sides that are close to each other is W2. The dimension of the mounting hole along the width direction of the cover plate body is B. The relationship between B and W2 is: 0.35≤W2 / B≤0.

50. The value of B is in the range of 8mm≤B≤30mm; The value range of W2 is: 3mm≤W2≤15mm.

7. The battery according to claim 1, characterized in that, The height of the support platform is H in a direction perpendicular to the end face of the cover plate body or the housing. The value range of H is: 1.5mm≤H≤3.0mm.

8. The battery according to claim 7, characterized in that, When 2.0 ≤ S2 / S1 ≤ 3.0, the range of H is 2.0 mm ≤ H ≤ 3.0 mm; When 3.0≤S2 / S1≤3.5, the value range of H is 1.5mm≤H≤2.0mm.

9. The battery according to claim 1, characterized in that, The plastic part is provided with a plurality of vent holes, which are arranged at intervals on the plastic part along a direction perpendicular to the end face of the cover plate body or the housing. The projection of the plurality of vent holes on the cover plate body or the housing at least partially overlaps with the projection of the mounting hole on the cover plate body or the housing.

10. The battery according to claim 1, characterized in that, The plastic part has a clearance groove on the side facing the cover plate body or the housing, and the support platform is embedded in the clearance groove.

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