Battery

Abstract

The invention relates to the technical field of batteries, and particularly discloses a battery, a cover plate body or a shell of the battery is provided with a mounting hole and a plurality of supporting tables, an anti-explosion valve is arranged in the mounting hole, the plurality of supporting tables are arranged in the circumferential direction of the mounting hole, the plurality of supporting tables and the mounting hole are arranged at intervals, and every two adjacent supporting tables are also arranged at intervals. The plastic part is arranged on the side, close to the containing cavity, of the cover plate body or the shell. The end, away from the cover plate body or the shell, of the supporting table extends towards the plastic part. After the battery is subjected to thermal runaway and the plastic part is melted, the plurality of supporting tables arranged on the cover plate body or the shell can continuously support the pole group, so that the mounting hole is prevented from being shielded by the pole group, high-temperature and high-pressure gas can flow to the mounting hole and is directionally discharged through the anti-explosion valve arranged in the mounting hole, the exhaust rate of the anti-explosion valve is high, rapid pressure relief can be realized, and the service life of the battery is prolonged. And the safety of the battery is good.

Description

Technical Field

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

[0002] Lithium-ion batteries have become the representative of high-performance batteries due to their advantages such as high operating voltage, high specific energy, large capacity, low self-discharge, good cyclability, long service life, light weight and small size. The structure of a conventional lithium-ion battery includes a cover body, a shell, a pole group and an insulating member. The cover body and the shell are welded to form a closed space to protect the pole group. An explosion-proof valve is integrated on the cover body, which can directional discharge the high-temperature and high-pressure gas in the closed space when the battery has thermal runaway. The insulating member is arranged in the sealed space formed by the shell and the cover body, and the insulating member is located between the cover body and the pole group. On the one hand, the pole group can be supported by the insulating member to prevent the pole group from shaking in the shell, and the fixing effect is good; on the other hand, the insulating member can prevent the pole group from short-circuiting with the cover body to ensure the electrical safety of the battery.

[0003] However, the insulating parts are generally made of plastic materials (for example, PP materials), which have limited strength and high temperature resistance, and generally melt at around 150°C. When the battery has thermal runaway, the temperature in the enclosed space is high, and the insulating parts will melt and fail. At this time, only the pole group, which is still solid, is left in the enclosed space, and the gap between the pole group and the cover plate body increases. In addition, due to the lack of support for the pole group by the insulating parts, the pole group has a high degree of freedom in the shell. When the high-temperature and high-pressure gas is exhausting in a direction through the explosion-proof valve, the pole group will move with the high-temperature and high-pressure airflow, and there is a risk of blocking the exhaust channel of the explosion-proof valve, which reduces the exhaust efficiency of the explosion-proof valve and has low safety performance. Summary of the invention

[0004] The object of the present invention is to provide a battery which can prevent the explosion-proof valve from being blocked due to the movement of the pole group when the battery has thermal runaway, and the explosion-proof valve has high exhaust efficiency and good safety performance.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention provides a battery, comprising:

[0007] Explosion-proof valve;

[0008] A cover plate body and a shell, wherein the cover plate body is connected to the shell and is surrounded to form a containing cavity, wherein one of the cover plate body and the shell is provided with a mounting hole and a supporting structure, wherein the mounting hole is used to mount the explosion-proof valve, and the supporting structure comprises a plurality of supporting platforms, wherein the plurality of supporting platforms are arranged in the circumference of the mounting hole, and each of the supporting platforms is spaced apart from the inner wall of the mounting hole, and an exhaust passage is formed between two adjacent supporting platforms;

[0009] A plastic part is arranged on a side of the cover body or the shell close to the accommodating cavity, and the ends of the support platform away from the cover body or the shell both extend toward the plastic part;

[0010] Wherein, along the direction perpendicular to the end surface of the cover body or the shell, the sum of the projection areas of all the support platforms on the end surface of the cover body or the shell is S1, and the projection area of ​​the mounting hole on the end surface of the cover body or the shell is S2;

[0011] S1 and S2 satisfy: 2.0≤S2 / S1≤3.5.

[0012] Optionally, the cover body is provided with the mounting hole and the supporting structure, the explosion-proof valve includes two arcuate edges arranged opposite to each other along the length direction of the cover body, and straight edges arranged opposite to each other along the width direction of the cover body, and each support platform is arranged close to the arcuate edge.

[0013] Optionally, a distance between a side of each support platform close to the explosion-proof valve and a tangent line of the arc-shaped edge is C, and a value range of C is 3mm≤C≤5mm.

[0014] Optionally, the support structure includes four support platforms, wherein every two support platforms symmetrically arranged along the central axis in the length direction of the cover plate body form a group, and two groups of support platforms are symmetrically arranged along the central axis in the width direction of the cover plate body.

[0015] Optionally, the distance between the two sides of the support platforms spaced apart along the length direction of the cover body and close to each other is W1, the dimension of the mounting hole along the length direction of the cover body is A, and A and W1 satisfy: 0.70≤W1 / A≤0.85;

[0016] Among them, the value range of A is: 20mm≤A≤60mm;

[0017] The value range of W1 is: 15mm≤W1≤50mm.

[0018] Optionally, the distance between the two sides of the support platforms spaced apart along the width direction of the cover body and close to each other is W2, the dimension of the mounting hole along the width direction of the cover body is B, and B and W2 satisfy: 0.35≤W2 / B≤0.50;

[0019] Among them, the value range of B is: 8mm≤B≤30mm;

[0020] The value range of W2 is: 3mm≤W2≤15mm.

[0021] Optionally, along a direction perpendicular to an end surface of the cover body or the shell, a height of the support platform is H;

[0022] The value range of H is: 1.5mm≤H≤3.0mm.

[0023] Optionally, when 2.0≤S2 / S1≤3.0, the value range of H is 2.0mm≤H≤3.0mm;

[0024] When 3.0≤S2 / S1≤3.5, the value range of H is 1.5mm≤H≤2.0mm.

[0025] Optionally, the plastic part is provided with a plurality of ventilation holes, which are arranged at intervals on the plastic part, and along a direction perpendicular to the end face of the cover body or the shell, the projections of the plurality of ventilation holes on the cover body or the shell at least partially overlap with the projections of the mounting holes on the cover body or the shell.

[0026] Optionally, a side of the plastic part facing the cover body or the shell is provided with an avoidance groove, and the support platform is embedded in the avoidance groove.

[0027] The beneficial effects of the present invention are:

[0028] The present invention provides a battery, including an explosion-proof valve, a cover body, a shell and a plastic part. The cover body is connected to the shell and forms a housing cavity for placing a pole group together with the shell. A mounting hole and a support structure are provided on the cover body or the shell. The explosion-proof valve is arranged in the mounting hole. The support structure includes a plurality of support platforms, and the plurality of support platforms are arranged in the circumference of the mounting hole. The plurality of support platforms are arranged at intervals from the mounting hole, and two adjacent support platforms are also arranged at intervals to form an exhaust channel between the two adjacent support platforms. The plastic part is arranged on one side of the cover body or the shell close to the housing cavity, and the ends of the support platforms facing away from the cover body or the shell extend toward the plastic part. After the battery has thermal runaway and the plastic parts are melted, the multiple support platforms arranged on the cover body or the shell can continue to support the electrode group, preventing the electrode group from flowing randomly with the high-temperature and high-pressure gas, causing the mounting holes on the cover body to be blocked by the electrode group. The high-temperature and high-pressure gas can pass through the exhaust channel between two adjacent support platforms on the cover body, and then flow to the mounting hole and be discharged in a direction through the explosion-proof valve arranged in the mounting hole. The flow path of the high-temperature and high-pressure gas is smooth and the flow speed is fast. The exhaust rate of the explosion-proof valve is high, which can achieve rapid pressure relief and the battery has good safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic structural diagram of the cover body and the plastic part provided in the first embodiment of the present invention;

[0030] Figure 2 This is a schematic structural diagram of the cover plate body provided in the first embodiment of the present invention;

[0031] Figure 3 for Figure 2 A partial enlarged view of the middle A;

[0032] Figure 4 A top view of the cover plate body provided in the first embodiment of the present invention;

[0033] Figure 5 This is a schematic diagram of the structure of a battery provided in Embodiment 2 of the present invention;

[0034] Figure 6 This is a partial enlarged view of the battery provided in the second embodiment of the present invention.

[0035] In the figure:

[0036] 100, cover 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 DESCRIPTION

[0037] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions, and the first feature "above", "above" and "above" the second feature include the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. The first feature "below", "below" and "below" the second feature include the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0039] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0041] Embodiment 1

[0042] like Figure 1-Figure 3 As shown, this embodiment provides a battery, which includes an explosion-proof valve 400, a cover body 100, a shell 300 and a plastic part 200. The cover body 100 is connected to the shell 300 and forms a receiving cavity for placing the electrode group together with the shell 300.

[0043] The cover body 100 is provided with a mounting hole 110 and a support structure, the explosion-proof valve 400 is arranged in the mounting hole 110, and the support structure includes a plurality of support platforms 120, which are arranged in the circumference of the mounting hole 110, and each support platform 120 is spaced apart from the inner wall of the mounting hole 110, and two adjacent support platforms 120 are also spaced apart to form an exhaust channel between the two adjacent support platforms 120. The plastic part 200 is arranged on one side of the cover body 100 close to the accommodating cavity, and the end of the support platform 120 away from the cover body 100 extends toward the plastic part 200, and the cover body 100 is insulated from the pole group through the plastic part 200. Through the above arrangement, after the battery has thermal runaway and the plastic part 200 is melted, the multiple support platforms 120 arranged on the cover body 100 can continue to support the pole group, so as to prevent the pole group from flowing randomly with the high-temperature and high-pressure gas, resulting in the mounting hole 110 on the cover body 100 being blocked by the pole group. The high-temperature and 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 in a direction through the explosion-proof valve 400 arranged in the mounting hole 110. The flow path of the high-temperature and high-pressure gas is smooth, the flow speed is fast, and the exhaust rate of the explosion-proof valve 400 is high, which can achieve rapid pressure relief and good safety of the battery. It should be noted that the explosion-proof valve 400 is in the open valve state at this time.

[0044] Furthermore, along the direction perpendicular to the end surface of the cover body 100, the sum of the projected areas of all the support platforms 120 on the end surface of the cover body 100 is S1, and the projected area of ​​the mounting holes 110 on the end surface of the cover body 100 is S2, and S1 and S2 satisfy: 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. Among them, the direction perpendicular to the end surface of the cover body 100 is Figure 1 The Z-axis direction shown in is referred to as the first direction in this embodiment for the convenience of explanation.

[0045] By controlling the value of S2 / S1 within the above range, when the battery undergoes thermal runaway and the plastic part 200 melts and fails, the contact area between the support structure and the electrode group can be ensured to be large, which can provide a good support effect on the electrode group and ensure that there is a large exhaust space between the electrode group and the cover body 100. The exhaust space is connected to the exhaust channel between the two adjacent support platforms 120, so that the high-temperature and high-pressure gas can be discharged to the mounting hole 110 through the exhaust channel, thereby preventing the electrode group from moving toward the cover body 100 under the impact of the high-temperature and high-pressure gas, resulting in the mounting hole 110 on the cover body 100 being blocked. The explosion-proof valve 400 has high exhaust efficiency, which greatly improves the safety performance of the battery.

[0046] As an optional technical solution, the explosion-proof valve 400 in this embodiment includes two arc-shaped edges arranged opposite to each other along the length direction of the cover body 100, and straight edges arranged opposite to each other along the width direction of the cover body 100, and each support platform 120 is arranged close to the arc-shaped edge. Figure 1 The X-axis direction shown in FIG. 1 is referred to as the second direction in this embodiment for the convenience of explanation; the width direction of the cover body 100 is Figure 1 The Y-axis direction shown in is recorded as the third direction in this embodiment for the convenience of explanation.

[0047] A plurality of support platforms 120 are formed on the cover body 100 by stamping. The distance between the side of each support platform 120 close to the explosion-proof valve 400 and the tangent of the arc edge is C, and the value range of C is 3mm≤C≤5mm. For example, the value of C can be 3mm, 4mm or 5mm, etc. By controlling the value of C within the above range, it can be ensured that after the support platform 120 is stamped, the flatness of the surrounding positions of the mounting hole 110 on the cover body 100 is good, the assembly accuracy between the explosion-proof valve 400 and the cover body 100 is high, the reliability of the explosion-proof valve 400 is high, and it is not easy to fail. Otherwise, when the value of C is too small, the distance between the support platform 120 and the mounting hole 110 is too close, and the flatness of the surrounding positions of the mounting hole 110 on the cover body 100 is poor, which affects the welding quality between the explosion-proof valve 400 and the cover body 100, and there is 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 supporting effect for the electrode group will be reduced, and there is a risk that the electrode group will block the mounting hole 110 on the cover plate body 100.

[0048] Continue to see Figure 1 and Figure 2 , a limiting flange 111 is provided on the inner wall of the mounting hole 110, and the explosion-proof valve 400 can be installed into the mounting hole 110 from one side of the cover body 100, and abut against the limiting flange 111 on the inner wall of the mounting hole 110. At this time, it means that the explosion-proof valve 400 is installed in place, and the explosion-proof valve 400 can be welded to the cover body 100. Through the setting of the limiting flange 111, the positioning between the explosion-proof valve 400 and the cover body 100 is accurate, and the assembly accuracy is high. In addition, the limiting flange 111 can also play the role of temporarily fixing the explosion-proof valve 400, which facilitates the welding operation of the explosion-proof valve 400 and the cover body 100. It should be noted that since the 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 close to the explosion-proof valve 400 and the tangent of the inner wall of the mounting hole 110 is also C.

[0049] Continue to see Figure 2 and Figure 4 The support structure in this embodiment includes four support platforms 120, two of which are along the central axis of the second direction ( Figure 4 The supporting platforms 120 symmetrically arranged in the middle (marked by e) are a group, and the two groups of supporting platforms 120 are arranged along the central axis ( Figure 4 The two components are symmetrically arranged (marked with f in the figure).

[0050] The distance between the two support platforms 120 spaced apart along the second direction and the sides close to each other is W1, and the size of the mounting hole 110 along the second direction is A, and A and W1 satisfy: 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, which meets the circulation needs of the high-temperature and high-pressure gas diffusing along the third direction, avoids the support platform 120 from generating greater resistance to the high-temperature and high-pressure gas, speeds up the flow of the high-temperature and high-pressure gas to the explosion-proof valve 400, and quickly releases the pressure inside the battery to avoid explosion, with good safety.

[0051] 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.

[0052] Furthermore, the distance between the two support platforms 120 spaced apart along the third direction and the sides close to each other is W2, and the size of the mounting hole 110 along the third direction is B, and B and W2 satisfy: 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 passage between the two support platforms 120 spaced apart along the third direction is larger, which meets the circulation needs of the high-temperature and high-pressure gas diffused along the second direction, avoids the support platform 120 from generating greater resistance to the high-temperature and high-pressure gas, speeds up the flow of the high-temperature and high-pressure gas to the explosion-proof valve 400, and quickly releases the pressure inside the battery, avoiding explosions and ensuring good safety.

[0053] 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.

[0054] Furthermore, along the third direction, the distance between the end of the support platform 120 away from the mounting hole 110 and the adjacent side of the cover body 100 is D, and the value range of D is: 5mm≤D≤10mm. For example, the value of D can be 5mm, 6mm, 8mm or 10mm, etc. By limiting the value of D within the above range, it is ensured that there is a certain space between the support platform 120 and the side of the cover body 100 along the third direction, which is convenient for the assembly of the cover body 100 and the shell 300. At the same time, it also makes the resistance of high-temperature and high-pressure gas flowing along the second direction smaller, and it can be discharged to the mounting hole 110, ensuring that the explosion-proof valve 400 is opened smoothly and the exhaust is relatively smooth. It should be noted that the value of A should not be too small, otherwise the high-temperature, high-pressure gas will be blocked from flowing in the second direction, and the explosion-proof valve 400 may fail to open in time, posing a safety risk; the value of A should not be too large, otherwise the support platform 120 will not support the pole group well, and the mounting hole 110 on the cover body 100 may be blocked by the pole group, resulting in poor exhaust of the explosion-proof valve 400.

[0055] Continue to see Figure 2 and Figure 3 , along the third direction, the height of the support platform 120 is H, and the value range of H is: 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 within the above range, the flow area of ​​the exhaust channel formed between two adjacent support platforms 120 is larger, and then when the support platform 120 abuts against the pole group after the plastic part 200 is melted, the exhaust space between the cover body 100 and the pole group is larger, which is beneficial to improve the exhaust efficiency of the explosion-proof valve 400 and has high safety.

[0056] It should be noted that the height H of the support platform 120 along the third direction is related to the projection area of ​​the support platform 120 along the third direction on the cover body 100. In this embodiment, four support platforms 120 with the same shape and size are used as an example for illustration, and the sum of the projection areas of the four support platforms 120 along the third direction on the cover body 100 is S1, and the projection area of ​​each support platform 120 along the third direction on the cover body 100 is S1 / 4.

[0057] In order to ensure that the support platform 120 has a good supporting effect on the electrode group and meets the safety requirements during battery exhaust, when the relationship between the sum of the projection areas S1 of all support platforms 120 on the cover body 100 along the third direction and the projection area S2 of the mounting holes 110 on the end surface of the cover body 100 along the third direction satisfies; 2.0≤S2 / S1≤3.0, the value range of H is 2.0mm≤H≤3.0mm, that is, at this time 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 has a good supporting effect on the electrode group, meets the exhaust requirements of the battery, and has good safety.

[0058] When the relationship between the sum S1 of the projection areas of all support platforms 120 on the cover body 100 along the third direction and the projection area S2 of the mounting holes 110 on the end surface of the cover body 100 along the third direction satisfies; 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 has a good supporting effect on the electrode group, meets the exhaust needs of the battery, and has good safety.

[0059] Furthermore, the plastic part 200 is provided with a plurality of vent holes 211, which are arranged at intervals on the plastic part 200, and along the direction perpendicular to the end surface of the cover body 100 (i.e., the third direction), the projections of the plurality of vent holes 211 on the cover body 100 and the projections of the mounting holes 110 on the cover body 100 at least partially overlap. After the battery has thermal runaway, when the internal temperature of the battery has not yet risen to the melting point of the plastic part 200, the plastic part 200 maintains its pre-melting shape to support the electrode group, and 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.

[0060] Furthermore, a side of the plastic part 200 facing the cover body 100 is provided with an escape groove, and the support platform 120 can be embedded in the escape groove. By setting the escape groove, it is possible to avoid wasting space in the accommodating cavity, reduce the space occupied by the cover body 100, and help increase the volume of the electrode group and improve the energy density of the battery.

[0061] The plastic part 200 in this embodiment includes a plastic body 210, a first flange 220 and a second flange (not shown in the figure), the vent hole 211 is arranged on the plastic body 210, the first flange 220 and the second flange are arranged on the side of the plastic body 210 facing the cover body 100, the first flange 220 is arranged around the circumference of the plastic body 210, the second flange is connected to the first flange 220, and the second flange, the first flange 220 and the plastic body 210 together form an avoidance groove, and the support platform 120 can be embedded in the avoidance groove.

[0062] The thermal runaway control of the relevant parameters S2 / S1 and H of the cover body 100 of the above-mentioned battery is verified using samples of different design sizes. The verification results are shown in Table 1.

[0063] Table 1

[0064]

[0065] From the above results, it can be concluded that in Sample 1, Sample 2 and Sample 3, the relationship between the sum of the projection areas S1 of all support platforms 120 on the cover body 100 along the third direction and the projection area S2 of the mounting holes 110 on the end surface of the cover body 100 along the third direction satisfies; 2.0≤S2 / S1≤3.0, but the value of H is less than the minimum value of its corresponding value range of 2.0mm≤H≤3.0mm. At this time, the support platform 120 has a poor supporting effect on the electrode group, and the designed gap cannot be maintained between the cover body 100 and the electrode group. The explosion-proof valve 400 has poor exhaust, which is prone to explosion risk. The pass rate of the battery thermal runaway test is low, and the battery product is defective.

[0066] In samples 4 to 7, the relationship between the sum of the projection areas S1 of all the support platforms 120 on the cover body 100 along the third direction and the projection area S2 of the mounting holes 110 on the end surface of the cover body 100 along the third direction satisfies; 2.0≤S2 / S1≤3.0, and the value of H satisfies its corresponding value range of 2.0mm≤H≤3.0mm. At this time, the support platform 120 has an obvious supporting effect on the electrode group, and the exhaust space formed between the cover body 100 and the electrode group is large. The explosion-proof valve 400 exhausts smoothly and has a high exhaust efficiency. The battery thermal runaway test has been passed without explosion, and the battery product is good.

[0067] In samples 8 to 11, the relationship between the sum of the projection areas S1 of all the support platforms 120 on the cover body 100 along the third direction and the projection area S2 of the mounting holes 110 on the end surface of the cover body 100 along the third direction satisfies; 3.0≤S2 / S1≤3.5, and the value of H satisfies its corresponding value range of 1.5mm≤H≤2.0mm. At this time, the support platform 120 has an obvious supporting effect on the electrode group, and the exhaust space formed between the cover body 100 and the electrode group is large. The explosion-proof valve 400 exhausts smoothly and has a high exhaust efficiency. The battery thermal runaway test has been passed without explosion, and the battery product is good.

[0068] It can be seen that when the values ​​of S2 / S1 and H satisfy their corresponding value ranges and match each other, the support platform 120 has a good supporting effect on the electrode group, the battery has good safety, and can pass the thermal runaway test without explosion.

[0069] The thermal runaway test of the values ​​of the relevant parameters W1 / A and W2 / B of the cover body 100 of the above-mentioned battery is carried out using samples of different design sizes. The test results are shown in Table 2.

[0070] Table 2

[0071]

[0072] 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 value range of 0.70≤W1 / A≤0.85, and the value of W2 / B satisfies its corresponding value range of 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, and the resistance of the high-temperature and high-pressure gas diffusing along the third direction is large. The exhaust rate of the explosion-proof valve 400 is reduced, and the pressure inside the battery cannot be released in time, there is a risk of explosion, and the safety is poor.

[0073] In samples 2, 3 and 4, the value of W1 / A satisfies its corresponding value range of 0.70≤W1 / A≤0.85, and the value of W2 / B satisfies its corresponding value range of 0.35≤W2 / B≤0.50. At this time, the support platform 120 has an obvious supporting effect on the electrode group, the exhaust channel between the two support platforms 120 spaced apart along the second direction is larger, and the exhaust channel between the two support platforms 120 spaced apart along the third direction is also larger. The resistance of high-temperature and high-pressure gas diffusing along the third and second directions is small, the exhaust rate of the explosion-proof valve 400 is high, the pressure inside 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 5, the value of W1 / A is greater than the maximum value of its corresponding value range of 0.70≤W1 / A≤0.85, and the value of W2 / B satisfies its corresponding value range of 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 large, and the support platform 120 has a poor supporting effect on the electrode group, and the designed gap cannot be maintained between the cover body 100 and the electrode group. The explosion-proof valve 400 has poor exhaust, and there is a risk of explosion. The pass rate of the battery thermal runaway test is low, and the battery product is defective.

[0075] In sample 6, the value of W2 / B is less than the minimum value of its corresponding value range of 0.35≤W2 / B≤0.50, and the value of W1 / A satisfies its corresponding value range of 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 diffusing along the second direction is large, the exhaust rate of the explosion-proof valve 400 is reduced, and the pressure inside the battery cannot be released in time, there is a risk of explosion, and the safety is poor.

[0076] In samples 7 and 8, the value of W1 / A satisfies its corresponding value range of 0.70≤W1 / A≤0.85, and the value of W2 / B satisfies its corresponding value range of 0.35≤W2 / B≤0.50. At this time, the support platform 120 has an obvious supporting effect on the electrode group, the exhaust channel between the two support platforms 120 spaced apart along the second direction is larger, and the exhaust channel between the two support platforms 120 spaced apart along the third direction is also larger. The resistance of high-temperature and high-pressure gases diffusing along the third and second directions is small, the exhaust rate of the explosion-proof valve 400 is high, the pressure inside the battery can be quickly released, the battery thermal runaway test is passed, there is no risk of explosion, and the battery product is good.

[0077] In sample 9, the value of W2 / B is greater than the maximum value of its corresponding value range of 0.35≤W2 / B≤0.50, and the value of W1 / A satisfies its corresponding value range of 0.70≤W1 / A≤0.85. At this time, the distance between the two support platforms 120 spaced along the third direction is too large, and the support platform 120 has a poor supporting effect on the electrode group, and the designed gap cannot be maintained between the cover body 100 and the electrode group. The explosion-proof valve 400 has poor exhaust, and there is a risk of explosion. The pass rate of the battery thermal runaway test is low, and the battery product is defective.

[0078] It can be seen that W1 and W2 must simultaneously satisfy 0.70≤W1 / A≤0.85 and 0.35≤W2 / B≤0.50 in order to meet the needs of supporting the electrode group while not affecting the exhaust channel and improving the safety performance of the battery.

[0079] Embodiment 2

[0080] This embodiment further provides a battery, which is different from the battery in the first embodiment in that the mounting hole 110 and the supporting structure in this embodiment are arranged on one of the side walls of the housing 300 .

[0081] See also Figure 5 and Figure 6 The battery in this embodiment may be a blade battery, and the housing 300 is arranged along the second direction ( Figure 5Openings are formed at both ends of the cover body 100 (in the X-axis direction shown in the figure), and two cover bodies 100 are provided. Each cover body 100 is connected to an opening of the shell 300 and seals the opening. The two cover bodies 100 and the shell 300 form a accommodating cavity for placing the pole group.

[0082] The housing 300 includes two first side walls 310 disposed opposite to each other along a first direction, and a first side wall 310 disposed along a third direction ( Figure 5 The first side wall 310 is connected to the second side wall 320, and the area of ​​the first side wall 310 is smaller than the area of ​​the second side wall 320. In this embodiment, the mounting hole 110 and the support structure are arranged on the first side wall 310 as an example for explanation. The support structure includes a plurality of support platforms 120, and the plurality of support platforms 120 are arranged in the circumference of the mounting hole 110, and each support platform 120 is arranged at intervals with the inner wall of the mounting hole 110, and the two adjacent support platforms 120 are also arranged at intervals to form an exhaust channel between the two adjacent support platforms 120. The plastic part 200 is arranged on the side of the first side wall 310 close to the accommodating cavity, and the support platform 120 abuts against the plastic part 200.

[0083] In the direction perpendicular to the end surface of the first side wall 310 (i.e., the first direction), the sum of the projected areas of all the support platforms 120 on the end surface of the first side wall 310 is S1, and the projected area of ​​the mounting hole 110 on the end surface of the first side wall 310 is S2, and S1 and S2 satisfy: 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.

[0084] By controlling the value of S2 / S1 within the above range, when the battery undergoes thermal runaway and the plastic part 200 melts and fails, the contact area between the support structure and the electrode group can be ensured to be large, which can provide a good support effect on the electrode group and ensure that there is a large exhaust space between the electrode group and the first side wall 310. The exhaust space is connected to the exhaust channel between two adjacent support platforms 120, so that high-temperature and high-pressure gas can be discharged to the mounting hole 110 through the exhaust channel, thereby preventing the electrode group from moving toward the first side wall 310 under the impact of high-temperature and high-pressure gas, resulting in the mounting hole 110 on the first side wall 310 being blocked. The explosion-proof valve 400 has high exhaust efficiency, which greatly improves the safety performance of the battery.

[0085] The plastic part 200 is provided with a plurality of vent holes 211, which are arranged at intervals on the plastic part 200. Along the first direction, the projections of the plurality of vent holes 211 on the first side wall 310 of the housing 300 at least partially overlap with the projections of the mounting holes 110 on the first side wall 310 of the housing 300. After the battery has thermal runaway, when the internal temperature of the battery has not yet risen to the melting point of the plastic part 200, the plastic part 200 maintains its pre-melting shape to support the electrode group. 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.

[0086] The plastic part 200 is provided with a relief groove on one side of the first side wall 310 of the housing 300, and the support platform 120 is embedded in the relief groove. By providing the relief groove, the space waste in the accommodating cavity can be avoided, the occupied space can be reduced, the volume of the electrode group can be increased, and the energy density of the battery can be improved.

[0087] The rest of the structure of the battery in this embodiment is the same as that in the first embodiment and will not be described again here.

[0088] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A battery, characterized in that: include: Explosion-proof valve; A cover plate body and a shell, wherein the cover plate body is connected to the shell and is surrounded to form a containing cavity, wherein one of the cover plate body and the shell is provided with a mounting hole and a supporting structure, wherein the mounting hole is used to mount the explosion-proof valve, and the supporting structure comprises a plurality of supporting platforms, wherein the plurality of supporting platforms are arranged in the circumference of the mounting hole, and each of the supporting platforms is spaced apart from the inner wall of the mounting hole, and an exhaust passage is formed between two adjacent supporting platforms; A plastic part is arranged on a side of the cover body or the shell close to the accommodating cavity, and the ends of the support platform away from the cover body or the shell both extend toward the plastic part; Wherein, along the direction perpendicular to the end surface of the cover body or the shell, the sum of the projection areas of all the support platforms on the end surface of the cover body or the shell is S1, and the projection area of ​​the mounting hole on the end surface of the cover body or the shell is S2; S1 and S2 satisfy: 2.0≤S2 / S1≤3.

5.

2. The battery according to claim 1, characterized in that The cover body is provided with the mounting hole and the supporting structure, the explosion-proof valve comprises two arcuate edges arranged oppositely along the length direction of the cover body, and straight edges arranged oppositely along the width direction of the cover body, and each of the supporting platforms is arranged close to the arcuate edges.

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

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

5. The battery according to claim 4, characterized in that The distance between the two support platforms spaced apart along the length direction of the cover body and close to each other is W1, the dimension of the mounting hole along the length direction of the cover body is A, and the relationship between A and W1 satisfies: 0.70≤W1 / A≤0.85; Among them, the value range of A is: 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 body and close to each other is W2, the dimension of the mounting hole along the width direction of the cover body is B, and the relationship between B and W2 satisfies: 0.35≤W2 / B≤0.50; Among them, the value range of B is: 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 along a direction perpendicular to the end surface of the cover body or the shell; 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 value range of H is 2.0mm≤H≤3.0mm; 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 ventilation holes, which are arranged at intervals on the plastic part. Along a direction perpendicular to the end face of the cover body or the shell, the projections of the plurality of ventilation holes on the cover body or the shell at least partially overlap with the projections of the mounting holes on the cover body or the shell.

10. The battery according to claim 1, characterized in that A side of the plastic part facing the cover body or the shell is provided with an escape groove, and the support platform is embedded in the escape groove.

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