Battery

Abstract

The invention relates to the technical field of batteries, and particularly discloses a battery, a cover plate body of the battery is provided with a mounting hole and a supporting structure, an anti-explosion valve is arranged in the mounting hole, the supporting structure comprises two first supporting tables and a supporting plate, and the supporting plate is connected to the first supporting tables. The plastic part abuts against the end face, deviating from the cover plate body, of the supporting plate. The pole group is located on the side, deviating from the cover plate body, of the plastic part. After the battery is in thermal runaway and a plastic part is melted, the middle position of the pole group in the first direction and the positions, close to the two ends in the first direction, of the pole group have large enough contact areas with the supporting plate, and the supporting plate can continuously support the pole group, so that mounting holes in the cover plate body are prevented from being shielded by the pole group; and high-temperature and high-pressure gas can be quickly and directionally exhausted from the explosion-proof valve arranged in the mounting hole, so that the exhaust efficiency is high, and the safety of the battery is good.

Description

Technical Field

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

[0002] Lithium-ion batteries have become the representatives of high-performance batteries due to their advantages such as high working voltage, high specific energy, large capacity, small self-discharge, good cycle performance, long service life, light weight, and small volume. The structure of a conventional lithium-ion battery includes a cover body, a housing, an electrode assembly, and an insulating member. After the cover body and the housing are welded, a sealed space for protecting the electrode assembly is formed. An explosion-proof valve is integrated on the cover body, and the explosion-proof valve can direct the discharge of high-temperature and high-pressure gas in the sealed space when the battery undergoes thermal runaway. The insulating member is arranged in the sealed space formed by the housing and the cover body, and the insulating member is located between the cover body and the electrode assembly. On the one hand, the electrode assembly can be supported by the insulating member to prevent the electrode assembly from shaking in the housing, and the fixing effect is good; on the other hand, the insulating member can prevent the electrode assembly from being short-circuited with the cover body to ensure the electrical safety of the battery.

[0003] However, the insulating member is generally made of a plastic material (for example, PP material), and its strength and high-temperature resistance are limited, and it will generally melt at about 150°C. When the battery undergoes thermal runaway, the temperature in the sealed space is relatively high, and the insulating member will melt and fail. At this time, only the still-solid electrode assembly remains in the sealed space, the gap between the electrode assembly and the cover body increases, and due to the lack of the supporting effect of the insulating member on the electrode assembly, the degree of freedom of the electrode assembly in the housing is relatively high. When the high-temperature and high-pressure gas is discharged directionally through the explosion-proof valve, the electrode assembly will move with the high-temperature and high-pressure gas flow, there is a risk of blocking the pressure relief channel of the explosion-proof valve, reducing the exhaust efficiency of the explosion-proof valve and having low safety performance. Summary of the Invention

[0004] The purpose of the present invention is to provide a battery, which can avoid the situation that the explosion-proof valve is blocked due to the movement of the electrode assembly when the battery undergoes thermal runaway, and the explosion-proof valve has a relatively 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, including:

[0007] A cover body, provided with an installation hole and a support structure, the installation hole is used for installing an explosion-proof valve, the support structure includes two first support platforms and a support plate, the two first support platforms are arranged on both sides of the installation hole along a first direction, and both ends of the support plate along the first direction are respectively connected to one of the first support platforms;

[0008] An electrode assembly, arranged on the side of the cover body where the support plate is provided;

[0009] Among them, the dimension of the electrode group in the first direction is A, and the dimension of the support plate in the first direction is C;

[0010] The relationship between A and C satisfies: 0.75 ≤ C / A ≤ 0.90; and 10mm ≤ (A - C) / 2 ≤ 15mm.

[0011] Optionally, the dimension of the electrode group in the second direction is B, and the dimension of the support plate in the second direction is D. The relationship between B and D satisfies: 0.65 ≤ D / B ≤ 0.75; and 8mm ≤ (B - D) / 2 ≤ 15mm.

[0012] Optionally, the dimension of the electrode group in the third direction is H, and the dimension of the support structure in the third direction is h; the value range of H is: 200mm ≤ H ≤ 650mm; the value range of h is: 2.5mm ≤ h ≤ 5.0mm.

[0013] Optionally, the height of the first support platform in the third direction is h2, and the thickness of the support plate in the third direction is h3, and h = h2 + h3;

[0014] The value range of h2 is: 1.5mm ≤ h2 ≤ 3.0mm;

[0015] The value range of h3 is: 1.0mm ≤ h3 ≤ 2.0mm.

[0016] Optionally, the thickness of the cover plate body in the third direction is h1, and h2 ≤ h1;

[0017] The value range of h1 is: 2.0mm ≤ h1 ≤ 5.0mm.

[0018] Optionally, the support plate has two first side surfaces arranged oppositely in the second direction, and an exhaust gap is formed between one side of each first side surface facing the cover plate body and the end surface of the cover plate body facing the support plate; a plurality of exhaust holes are provided on the support plate;

[0019] Among them, the sum of the flow areas of all the exhaust gaps is S11, the sum of the flow areas of all the exhaust holes is S12, and S1 = S11 + S12; the flow area of the pressure relief channel of the explosion-proof valve is S2;

[0020] The relationship between S1 and S2 satisfies: 2.0 ≤ S1 / S2 ≤ 4.0.

[0021] Optionally, along the first direction, the length of the cover plate body is F, and the relationship between F and C satisfies: 0.6 ≤ C / F ≤ 0.8, and F - C > 20mm;

[0022] And / or, along the second direction, the width of the cover plate body is E;

[0023] The relationship between E and D satisfies: 0.6≤D / E≤0.8, and ED>10mm.

[0024] Optionally, the support structure further includes two second support platforms, each of which is sandwiched between one of the first support platforms and the mounting hole, and a side of the second support platform facing away from the cover body is connected to the support plate.

[0025] Optionally, along the second direction, the length of the mounting hole is L1, the length of the first support platform is L2, and the length of the second support platform is L3;

[0026] L1, L2 and L3 satisfy: L1≥L2>L3;

[0027] And 5mm≤L2-L3≤10mm.

[0028] Optionally, along the first direction, the width of the mounting hole is W1, the width of the first support platform is W2, and the width of the second support platform is W3;

[0029] W1, W2 and W3 satisfy: W1≥W2>W3;

[0030] The relationship between W2 and W3 satisfies: 0.1≤(W2+W3) / C≤0.2.

[0031] The beneficial effects of the present invention are:

[0032] The present invention provides a battery, comprising a cover plate body, an electrode group and a plastic part. The cover plate body is provided with a mounting hole and a support structure, an explosion-proof valve is arranged in the mounting hole, the support structure comprises two first support platforms and a support plate, the end of the support plate along the first direction is connected to the first support platform, an exhaust space is formed between the support plate and the cover plate body, the exhaust space is connected to the pressure relief channel after the explosion-proof valve is opened, an exhaust gap is formed between the first side surface of the support plate oppositely arranged along the second direction facing the cover plate body and the end surface of the cover plate body facing the support plate, and the exhaust gap connects the accommodating cavity with the exhaust space. The plastic part abuts against the end surface of the support plate away from the cover plate body, and the electrode group is located on the side of the plastic part away from the cover plate body. After the battery has thermal runaway and the plastic part is melted, the support plate arranged on the cover plate body can continue to support the electrode group, so as to avoid the mounting hole on the cover plate body being blocked by the electrode group, and the high-temperature and high-pressure gas can pass through the exhaust gap and the exhaust space, and then flow to the mounting hole and be discharged directionally through the explosion-proof valve arranged in the mounting hole, the explosion-proof valve has a good exhaust effect, can achieve rapid pressure relief, and the battery has good safety.

[0033] Further, the dimension A of the electrode group in the first direction and the dimension C of the support plate in the first direction satisfy: 0.75 ≤ C / A ≤ 0.90, and 10 mm ≤ (A - C) / 2 ≤ 15 mm. This ensures that there is a sufficiently large contact area between the middle position of the electrode group in the first direction and the positions of the electrode group near both ends in the first direction and the support plate, avoiding the ends of the electrode group in the first direction from being burned and deformed due to a decrease in strength when the battery undergoes thermal runaway. The support plate can provide good support for the electrode group after the plastic part fails. Description of the Drawings

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the content of the embodiments of the present invention and these drawings.

[0035] Figure 1 Structural schematic diagram of the battery provided in the embodiment of the present invention;

[0036] Figure 2 Exploded view of the cover body and the plastic part provided in the embodiment of the present invention;

[0037] Figure 3 Structural schematic diagram of the cover body provided in the embodiment of the present invention;

[0038] Figure 4 Top view of the cover body provided in the embodiment of the present invention;

[0039] Figure 5 Side view of the cover body provided in the embodiment of the present invention;

[0040] Figure 6 For Figure 5 Local enlarged view at Ι in;

[0041] Figure 7 Top view of the cover body (when the support plate is not shown) provided in the embodiment of the present invention.

[0042] In the figure:

[0043] 100, cover body; 110, mounting hole; 111, limiting flange; 120, first support platform; 130, second support platform; 140, support plate; 1401, first side; 1411, exhaust gap; 1402, second side; 141, first exhaust hole; 142, second exhaust hole; 200, electrode group; 300, plastic part; 301, through hole; 400, explosion-proof valve. Detailed Embodiments

[0044] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0045] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of 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. Moreover, the first feature being "above", "over" and "on" the second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature has a higher horizontal height than the second feature. The first feature being "below", "under" and "beneath" the second feature includes the first feature being directly below and obliquely below the second feature, or simply indicating that the first feature has a lower horizontal height than the second feature.

[0046] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "mounted", "connected" and "coupled" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0047] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the accompanying drawings, in which 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 by referring to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention.

[0048] As Figures 1-4As shown, this embodiment provides a battery, which includes a cover body 100, a shell, a pole group 200 and a plastic part 300. At least one end of the shell is provided with an opening, and the cover body 100 is connected to the end of the shell provided with the opening and forms a receiving chamber together with the shell. The plastic part 300 and the pole group 200 are both arranged in the receiving chamber, and the plastic part 300 is clamped between the pole group 200 and the cover body 100. The cover body 100 is provided with a mounting hole 110 and a support structure, and the explosion-proof valve 400 is arranged in the mounting hole 110. The support structure includes two first support platforms 120 and a support plate 140. The two first support platforms 120 are arranged on both sides of the mounting hole 110 along the first direction. Both ends of the support plate 140 along the first direction are respectively connected to a first support platform 120. An exhaust space is formed between the support plate 140 and the cover body 100, and the exhaust space is connected to the pressure relief channel after the explosion-proof valve 400 is opened. The above-mentioned first direction refers to Figure 1 The X-axis direction shown in FIG. 1 is also the length direction of the cover body 100 .

[0049] The support plate 140 has two first side surfaces 1401 arranged opposite to each other along the second direction, and a second side surface 1402 arranged opposite to each other along the first direction. The first side surface 1401 and the second side surface 1402 are adjacent to each other, and the first side surface 1401 and the second side surface 1402 together constitute the peripheral side wall of the support plate 140. The second direction is Figure 1 The Y-axis direction shown in is the width direction of the cover body 100. A gas exhaust gap 1411 is formed between the side of each first side surface 1401 facing the cover body 100 and the end surface of the cover body 100 facing the support plate 140. There are two gas exhaust gaps 1411, which are respectively located on the opposite sides of the support plate 140 along the second direction. The gas exhaust gaps 1411 connect the accommodating cavity with the gas exhaust space.

[0050] The plastic part 300 abuts against the end surface of the support plate 140 away from the cover body 100, and the electrode group 200 is located on the side of the plastic part 300 away from the cover body 100. The cover body 100 and the electrode group 200 are insulated by the plastic part 300 to ensure the electrical safety of the battery. At the same time, the support plate 140 provides good support for the plastic part 300.

[0051] With the above settings, after the battery undergoes thermal runaway and the plastic part 300 is melted, the support plate 140 provided on the cover body 100 can continue to support the electrode group 200, preventing the electrode group 200 from flowing randomly with the high-temperature and high-pressure gas, which may cause the mounting holes 110 on the cover body 100 to be blocked by the electrode group 200. The high-temperature and high-pressure gas can pass through the exhaust gap 1411 and the exhaust space, then flow to the mounting holes 110 and be discharged directionally through the explosion-proof valve 400 provided in the mounting holes 110. The flow path of the high-temperature and high-pressure gas is smooth, the flow velocity is fast, the exhaust effect of the explosion-proof valve 400 is good, rapid pressure relief can be achieved, and the safety of the battery is good. It should be noted that at this time, the explosion-proof valve 400 is in an open valve state.

[0052] Further, the dimension of the electrode group 200 in the first direction is A, and the dimension of the support plate 140 in the first direction is C. The relationship between A and C satisfies: 0.75 ≤ C / A ≤ 0.90, and 10 mm ≤ (A - C) / 2 ≤ 15 mm. For example, the value of C / A can be 0.75, 0.80, 0.85, 0.90, etc. The value of (A - C) / 2 can be 10 mm, 12 mm, 14 mm, 15 mm, etc. Among them, in some embodiments, the value range of A is 80 mm ≤ A ≤ 180 mm. The value range of C is 70 mm ≤ C ≤ 165 mm. Thus, there is a sufficiently large contact area between the middle position of the electrode group 200 in the first direction and the positions of the electrode group 200 near both ends in the first direction and the support plate 140, preventing the ends of the electrode group 200 in the first direction from being burned and deformed due to reduced strength when the battery undergoes thermal runaway. The support plate 140 can provide good support for the electrode group 200 after the plastic part 300 fails. Otherwise, when the value of C / A is too small, the electrode plates at the ends of the electrode group 200 in the first direction may break and fall off, blocking the flow path of the high-temperature and high-pressure gas and affecting the exhaust effect. When the value of C / A is too large, the ends of the support plate 140 in the first direction may interfere with the housing, resulting in a decrease in the assembly yield rate of the cover body 100 and the housing.

[0053] Continue to refer to Figure 1 and Figure 4, the dimension of the electrode group 200 in the second direction is B, and the dimension of the support plate 140 in the second direction is D. The relationship between B and D satisfies: 0.65 ≤ D / B ≤ 0.75, and 8mm ≤ (B - D) / 2 ≤ 15mm. For example, the value of D / B can be 0.65, 0.70, 0.75, etc. The value of (B - D) / 2 can be 8mm, 10mm, 12mm, 14mm, 15mm, etc. Among them, in some embodiments, the value range of B is 14mm ≤ B ≤ 75mm. The value range of D is 6mm ≤ D ≤ 60mm. Thus, there is a sufficiently large contact area between the middle position of the electrode group 200 in the second direction and the positions near both ends of the electrode group 200 in the second direction and the support plate 140, avoiding the end of the electrode group 200 in the second direction from being burned and its strength being reduced and deformed when the battery undergoes thermal runaway. The support plate 140 can provide good support for the electrode group 200 after the plastic part 300 fails. Otherwise, when the value of D / B is too small, the electrode tabs at the ends of the electrode group 200 in the second direction may break and fall off, resulting in the blockage of the flow path of high-temperature and high-pressure gases and affecting the exhaust effect. When the value of D / B is too large, the end of the support plate 140 in the second direction may interfere with the housing, and the assembly yield of the cover body 100 and the housing will decrease.

[0054] See Figure 1 , Figure 5 and Figure 6 , the dimension of the electrode group 200 in the third direction is H, and the dimension of the support structure in the third direction is h. Optionally, the value range of H is: 200mm ≤ H ≤ 650mm. For example, the value of H can be 200mm, 300mm, 400mm, 500mm, 600mm, 650mm, etc. The value range of h is: 2.5mm ≤ h ≤ 5.0mm. For example, the value of h can be 2.5mm, 3.5mm, 4.5mm, 5.0mm, etc. By restricting the value of h to meet the above range, a relatively large exhaust space is formed between the support plate 140 and the cover body 100, ensuring that the gas generation amount during the thermal runaway of the electrode group 200 matches the exhaust space. The exhaust space meets the flow requirements of high-temperature and high-pressure gases, and the high-temperature and high-pressure gases can quickly be discharged from the explosion-proof valve 400 out of the accommodation cavity, avoiding the risk of explosion. Otherwise, when the value of H is large and the value of h is too small, the gas generation amount of the electrode group 200 is large, and the exhaust space formed between the support plate 140 and the cover body 100 is insufficient, and the high-temperature and high-pressure gases cannot be discharged in time, posing a risk of fire and explosion.

[0055] It should be noted that the value of h is related to the value of H. When the dimension H of the pole group 200 in the third direction is less than 400 mm, the value of h satisfies 2.5 mm ≤ h ≤ 4.0 mm. When the dimension H of the pole group 200 in the third direction is greater than 400 mm, it is necessary to ensure that the value of h satisfies 4.0 mm < h ≤ 5.0 mm to ensure that after the pole group 200 moves, the exhaust space formed between the support plate 140 and the cover body 100 can still meet the exhaust requirements.

[0056] In this embodiment, the dimension of the support structure in the third direction is the sum of the height of the first support platform 120 in the third direction and the thickness of the support plate 140 in the third direction. Specifically, the height of the first support platform 120 in the third direction is h2, the thickness of the support plate 140 in the third direction is h3, and h = h2 + h3. Optionally, the value range of the height h2 of the first support platform 120 in the third direction is: 1.5 mm ≤ h2 ≤ 3.0 mm. For example, the value of h2 can be 1.5 mm, 2.0 mm, 2.5 mm, or 3.0 mm, etc. By limiting the value of h2 within the above range, when the plastic part 300 is melted and the support plate 140 on the cover body 100 abuts against the pole group 200, the flow area of the exhaust gap 1411 is relatively large, and the exhaust space formed between the support plate 140 and the cover body 100 is relatively large, which is beneficial to improving the exhaust efficiency of the explosion-proof valve 400 and has high safety. The value range of the thickness h3 of the support plate 140 in the third direction is: 1.0 mm ≤ h3 ≤ 2.0 mm. For example, the value of h3 can be 1.0 mm, 1.5 mm, or 2.0 mm, etc. By limiting the value of h3 within the above range, the mechanical strength of the support plate 140 is relatively high, and the support plate 140 is not easily deformed when abutting against the pole group 200, so as to maintain the existence of the exhaust space between the cover body 100 and the support plate 140 and facilitate the exhaust of high-temperature and high-pressure gases.

[0057] See Figure 6 and Figure 7, in this embodiment, a mounting hole 110 is provided in the middle of the cover body 100 along the first direction, and two first support platforms 120 are symmetrically arranged on both sides of the mounting hole 110 along the first direction. The mounting hole 110 can be formed by cutting the cover body 100, and the first support platform 120 can be formed by stamping the cover body 100. 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 the side of the cover body 100 facing the plastic part 300 and abutted against the limiting flange 111 on the inner wall of the mounting hole 110. At this time, it indicates 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 ensured to be accurate, and the assembly precision is relatively high. In addition, the limiting flange 111 can also play a role in temporarily fixing the explosion-proof valve 400, facilitating the welding operation of the explosion-proof valve 400 and the cover body 100.

[0058] Furthermore, the thickness of the cover body 100 along the third direction is h1, and the relationship between h1 and h2 satisfies: h2 ≤ h1. This ensures that the cover body 100 has relatively high mechanical strength, and the first support platform 120 can be successfully stamped, with a relatively high forming yield. Otherwise, when the height of the first support platform 120 is too large, it is more difficult to stamp the first support platform 120 on the cover body 100, and the forming yield is relatively low. Optionally, the value range of the thickness h1 of the cover body 100 along the third direction is: 2.0 mm ≤ h1 ≤ 5.0 mm. For example, when h1 is 2.0, the value of h2 can be 1.5 mm or 2.0 mm. When h1 is 3.5, the value of h2 can be 2.0 mm, 2.5 mm, 3.0 mm or 3.5 mm, etc. When h1 is 5.0, the value of h2 can be 3.5 mm or 4.0 mm, 4.5 mm or 5.0 mm, etc.

[0059] Continue to refer to Figures 2-4, a plurality of exhaust holes are provided on the support plate 140. The exhaust holes can also communicate the accommodation cavity with the exhaust space. The arrangement of the exhaust holes increases the flow rate of the high-temperature and high-pressure gas flowing to the explosion-proof valve 400. The flow path of the high-temperature and high-pressure gas is smooth and the flow velocity is fast, so that rapid pressure relief can be achieved and the safety of the battery is good. Among them, the exhaust gap 1411 and the exhaust holes can both serve as the exhaust channels for the explosion-proof valve 400 to achieve the exhaust function. The sum of the flow areas of all the exhaust gaps is S11, the sum of the flow areas of all the exhaust holes is S12, and the total flow area of all the exhaust gaps and all the exhaust holes can be denoted as S1, and S1 = S11 + S12. That is to say, the total flow area of the exhaust channels for realizing the exhaust function is S1. The flow area of the pressure relief channel of the explosion-proof valve 400 is S2, and S1 and S2 satisfy: 2.0 ≤ S1 / S2 ≤ 4.0. For example, the value of S1 / S2 can be 2.0, 2.5, 3.0, 3.5 or 4.0, etc. Thus, it is ensured that the total flow area of the exhaust channels matches the flow area of the pressure relief channel of the explosion-proof valve 400, meeting the flow requirements of the high-temperature and high-pressure gas. The explosion-proof valve 400 can open the valve in time to avoid explosion caused by excessive pressure in the accommodation cavity, with high safety. At the same time, the mechanical strength of the support structure is high and it is not easy to have deformation problems.

[0060] Exemplarily, the exhaust holes on the support plate 140 include a first exhaust hole 141 and a second exhaust hole 142. Among them, a plurality of the first exhaust holes 141 are arranged at intervals. Along the third direction ( Figure 1 the Z-axis direction shown in the figure, that is, the thickness direction of the cover body 100), the projection of the first exhaust hole 141 on the cover body 100 at least partially coincides with the explosion-proof valve 400. A plurality of through holes 301 arranged at intervals are provided at the positions corresponding to the mounting holes 110 on the plastic part 300. Along the third direction, the through holes 301 are directly opposite to the explosion-proof valve 400, so that the high-temperature and high-pressure gas can directly act on the explosion-proof valve 400 before the plastic part 300 is melted, so that the explosion-proof valve 400 can respond in time and open the valve quickly to ensure the safety of the battery. Thus, after the plastic part 300 is melted, the high-temperature and high-pressure gas can pass through the pressure relief channel of the explosion-proof valve 400 to achieve rapid pressure relief and ensure the safety of the battery.

[0061] Optionally, the first exhaust hole 141 in this embodiment is along the second direction ( Figure 1In the Y-axis direction shown in the figure, that is, the width direction of the cover body 100, there are three rows, and each row is provided with two first exhaust holes 141. A plurality of second exhaust holes 142 are also provided. The plurality of second exhaust holes 142 are arranged in two rows along the second direction, and the plurality of second exhaust holes 142 in each row are arranged at intervals along the first direction. For example, each row can be provided with eight second exhaust holes 142, and every four second exhaust holes 142 are in a group. The two groups of second exhaust holes 142 are respectively arranged on both sides of the mounting hole 110. Through the arrangement of the second exhaust holes 142, the flow area of the high-temperature and high-pressure gas flowing along the third direction is increased, which is beneficial to realizing rapid pressure relief.

[0062] Further, the shapes of the first exhaust holes 141 and the second exhaust holes 142 can be circular holes, triangular holes, quadrilateral holes, pentagonal holes or hexagonal holes, etc., as long as the sum of the opening areas of the first exhaust holes 141 and the second exhaust holes 142 is equal to S12. And in order to make the gas flow distribution of the high-temperature and high-pressure gas more balanced, it should be ensured that the opening sizes of the first exhaust holes 141 and the second exhaust holes 142 are approximately equal.

[0063] Continue to refer to Figure 4 , along the first direction, the length of the cover body 100 is F, and the size of the support plate 140 is C. The relationship between F and C satisfies: 0.6 ≤ C / F ≤ 0.8, and F - C > 20 mm. For example, the value of C / F can be 0.6, 0.65, 0.7, 0.75 or 0.8, etc. By limiting the value of C / F within the above range, it is to ensure that the size of the support plate 140 along the first direction is larger, and it can provide good support for the electrode group 200 or the plastic part 300. Further, the value of F - C can be 21 mm, 30 mm, 40 mm, etc. By limiting the value of F - C within the above value range, it is to ensure that installation spaces can be reserved on both sides of the cover body 100 in the length direction (i.e., the first direction), to avoid interference when the support plate 140 is assembled with the housing, and at the same time to avoid the thermal influence on the connection strength between the support plate 140 and the cover body 100 when the cover body 100 is welded to the housing.

[0064] Optionally, the value range of F is: 100 mm ≤ A ≤ 200 mm. For example, in some embodiments, the value of F can be 120 mm, and the value of C can be 90 mm, 92 mm or 96 mm, etc. In some embodiments, the value of F can be 200 mm, and the value of C can be 120 mm, 130 mm, 140 mm, 150 mm or 160 mm, etc.

[0065] In the second direction, the width of the cover plate body 100 is E, and the size of the support plate 140 is D. The relationship between E and D satisfies: 0.6 ≤ D / E ≤ 0.8, and E - D > 10 mm. For example, the value of D / E can be 0.6, 0.65, 0.7, 0.75, 0.8, etc. By limiting the value of D / E within the above range, it is to ensure that the width of the support plate 140 is relatively large, the contact area with the electrode group 200 or the plastic part 300 is relatively large, and it can provide good support for the electrode group 200 or the plastic part 300. For example, the value of E - D can be 11 mm, 20 mm, 30 mm, 40 mm, etc. By limiting the value of E - D within the above value range, installation spaces can be reserved on both sides in the width direction (i.e., the second direction) of the cover plate body 100, avoiding interference between the support plate 140 and the housing, and also avoiding the heat generated when the cover plate body 100 is welded to the housing from affecting the connection strength between the support plate 140 and the cover plate body 100.

[0066] Optionally, in this embodiment, the value range of E is: 35 mm ≤ E ≤ 75 mm. For example, in some embodiments, the value of E can be 35 mm, and the value of D can be 21 mm, 22 mm, 23 mm, 24 mm, 24.9 mm, etc. In some embodiments, the value of E can be 75 mm, and the value of D can be 45.5 mm, 50 mm, 55 mm, 60 mm, etc.

[0067] See Figure 2 and Figure 7 , the support structure further includes two second support platforms 130. Each second support platform 130 is clamped between a first support platform 120 and the mounting hole 110. The height of the second support platform 130 in the third direction is the same as the height of the first support platform 120 in the third direction. The side of the second support platform 130 facing away from the cover plate body 100 is connected to the support plate 140. Through the arrangement of the second support platform 130, stronger support is provided for the support plate 140, and the support structure is more stable and firm.

[0068] In the second direction, the length of the mounting hole 110 is L1, the length of the first support platform 120 is L2, and the length of the second support platform 130 is L3. L1, L2, and L3 satisfy: L1 ≥ L2 > L3. This can ensure the smooth flow of high-temperature and high-pressure gas flowing along the length direction (the first direction) of the cover plate body 100, and avoid the first support platform 120 or the second support platform 130 from blocking the high-temperature and high-pressure gas flowing along the length direction of the cover plate body 100, resulting in a decrease in flow rate and a reduction in exhaust efficiency.

[0069] In addition, the relationship between L2 and L3 also satisfies: 5 mm ≤ L2 - L3 ≤ 10 mm. For example, the value of L2 - L3 can be 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, etc. The value range of L3 is: 20 mm ≤ L3 ≤ 60 mm. In some embodiments, when the value of L1 is 25 mm, the value of L2 can be 25 mm, and the value of L3 can be 20 mm. In some embodiments, when the value of L1 is 30 mm, the value of L2 can be 30 mm, and the value of L3 can be 25 mm, 20 mm, etc. In some embodiments, when the value of L1 is 65 mm, the value of L2 can be 65 mm, and the value of L3 can be 60 mm, 55 mm, etc., which will not be listed one by one here.

[0070] It should be noted that the values of L2 and L3 should not be too large. Otherwise, the end of the first support platform 120 along the second direction is too close to the side of the cover plate body 100 along the second direction, and the end of the second support platform 130 along the second direction is too close to the side of the cover plate body 100 along the second direction. When the plastic part 300 is heat-melted and fixed to the cover plate body 100, affected by the accuracy of the processing equipment, the risk of interference between the support plate 140 and the plastic part 300 is relatively high, and the assembly accuracy decreases. Of course, the values of L2 and L3 should not be too small either. Otherwise, the supporting effect of the first support platform 120 and the second support platform 130 on the support plate 140 is not good, and the risk of deformation of the support plate 140 after being pressed by the electrode group 200 increases, which may affect exhaust and pose a safety risk.

[0071] Furthermore, along the first direction, the width of the mounting hole 110 is W1, the width of the first support platform 120 is W2, and the width of the second support platform 130 is W3. W1, W2, and W3 satisfy: W1 ≥ W2 > W3. This can ensure smooth flow of high-temperature and high-pressure gas flowing along the width direction (second direction) of the cover plate body 100, with a relatively high flow rate of high-temperature and high-pressure gas and high exhaust efficiency.

[0072] In addition, the relationship between W2 and W3 satisfies: 0.1 ≤ (W2 + W3) / C ≤ 0.2. For example, the value of (W2 + W3) / C can be 0.1, 0.15, 0.2, etc. By restricting the values of W2, W3, and C to satisfy the above relationship, it is ensured that the contact area between the first support platform 120, the second support platform 130, and the support plate 140 is relatively large. The first support platform 120 and the second support platform 130 can provide good support for the support plate 140. When the support plate 140 is impacted by the electrode group 200 or the plastic part 300, it is not easily deformed, and the exhaust gap 1411 and the exhaust holes are not blocked, facilitating the flow of high-temperature and high-pressure gases. It should be noted that the value of (W2 + W3) / C should not be too small, otherwise the widths of the first support platform 120 and the second support platform 130 in the first direction are relatively small, making it difficult to form by stamping, and the support effect of the first support platform 120 and the second support platform 130 on the support plate 140 is poor. Of course, the value of (W2 + W3) / B should not be too large, otherwise the widths of the first support platform 120 and the second support platform 130 in the first direction are too large, which poses a resistance to the flow of high-temperature and high-pressure gases in the second direction, presenting an explosion risk.

[0073] Optionally, the value range of W1 is: 15 mm ≤ W1 ≤ 40 mm. The value range of W2 is: 15 mm ≤ W2 ≤ 20 mm, and the value range of W3 is: 15 mm ≤ W3 ≤ 20 mm. In some embodiments, when the value of C is 150 mm, the value of W1 can be 20 mm, the value of W2 can be 18 mm, and the value of W3 can be 15 mm.

[0074] The following uses some samples with different design dimensions to verify the thermal runaway of the above battery to determine whether the battery can successfully pass the safety test. Among them, the standard for passing the safety test is that the explosion-proof valve 400 of the battery can open smoothly, the opening pressure is accurate, and no explosion occurs. The results are shown in Table 1.

[0075] Table 1

[0076]

[0077] From the above results, it can be concluded that in Sample 1, the value of D / B is less than the minimum value of 0.65 ≤ D / B ≤ 0.75, and the value of (B - D) / 2 is less than the minimum value of 8 mm ≤ (B - D) / 2 ≤ 15 mm. The two sides of the support plate 140 in the second direction cannot provide good support for the electrode group 200. When the electrode group 200 moves, it may block the exhaust gap 1411, affecting the flow of high-temperature and high-pressure gases towards the explosion-proof valve 400. Moreover, after disassembling the battery, it is found that there are broken electrode plates blocking the pressure relief channel of the explosion-proof valve 400, which may ultimately cause the explosion-proof valve 400 to fail to open and relieve pressure in a timely manner, presenting a safety risk. The passing rate of the battery's safety test is low, and the battery is defective.

[0078] In Sample 2, the value of C / A is less than the minimum value of 0.75 ≤ C / A ≤ 0.90, and the value of (A - C) / 2 is less than the minimum value of 10 mm ≤ (A - C) / 2 ≤ 15 mm. On both sides of the support plate 140 along the first direction, it cannot provide good support for the electrode group 200. When the electrode group 200 moves around, it may squeeze the support plate 140 and cause it to deform, reducing the exhaust space, affecting the flow of high-temperature and high-pressure gas to the explosion-proof valve 400. Moreover, after disassembling the battery, it is found that there are broken electrode sheets blocking the pressure relief channel of the explosion-proof valve 400, which may ultimately lead to the explosion-proof valve 400 being unable to open and relieve pressure in a timely manner, posing a safety risk, with a low passing rate of the battery's safety test and the battery being defective.

[0079] In Sample 5, the value of H is 400 mm, and the value of h is less than 2.5 mm. The exhaust space formed between the support plate 140 and the cover body 100 is relatively small, unable to meet the exhaust requirements during battery thermal runaway, with low exhaust efficiency, posing a safety risk of explosion, a low passing rate of the battery's safety test, and the battery being defective.

[0080] In Sample 6, the value of H is 500 mm, and the value of h is 4.0 mm. The gas generation amount of the electrode group 200 is relatively large, and the exhaust space formed between the support plate 140 and the cover body 100 is insufficient, unable to meet the exhaust requirements during battery thermal runaway, with low exhaust efficiency, posing a safety risk of explosion, a low passing rate of the battery's safety test, and the battery being defective.

[0081] In Samples 3, 4, 7, and 8, each parameter meets its corresponding value range. At this time, the support effect of the support structure on the electrode group 200 is obvious, the electrode sheets of the electrode group 200 do not break into pieces, and the exhaust space formed between the cover body 100 and the electrode group 200 is relatively large. The explosion-proof valve 400 exhausts smoothly, with relatively high exhaust efficiency. The safety tests of the batteries all pass, and no explosion occurs, and the battery products are good.

[0082] In summary, it can be seen that the size design and position arrangement of the support structure have a great impact on the support effect of the electrode group 200 and the exhaust effect of the explosion-proof valve 400. When the size design defined in this embodiment is adopted, it can ensure good support effect of the support structure on the electrode group 200, and at the same time, the exhaust of the explosion-proof valve 400 is not affected, significantly improving the problem that the explosion-proof valve 400 is blocked by the electrode group 200 and affects exhaust during battery thermal runaway, and the safety performance of the battery is high.

[0083] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limitations on the implementation manners of the present invention. For those of ordinary skill 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 enumerate all implementation manners here. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the claims of the present invention.

Claims

1. A battery, characterized in that, include: The cover plate body 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 two first supporting platforms and a supporting plate, wherein the two first supporting platforms are arranged on both sides of the mounting hole along the first direction, and both ends of the supporting plate along the first direction are respectively connected to one of the first supporting platforms; The pole group is arranged on one side of the cover plate body where the support plate is arranged; The dimension of the pole group along the first direction is A, and the dimension of the support plate along the first direction is C; A and C satisfy: 0.75≤C / A≤0.90; And 10mm≤(AC) / 2≤15mm.

2. The battery according to claim 1, wherein, The size of the pole group along the second direction is B, and the size of the support plate along the second direction is D; B and D satisfy: 0.65≤D / B≤0.75; And 8mm≤(BD) / 2≤15mm.

3. The battery according to claim 1, characterized in that, The dimension of the pole group along the third direction is H, and the dimension of the support structure along the third direction is h; The value range of H is: 200mm≤H≤650mm; The value range of h is: 2.5mm≤h≤5.0mm.

4. The battery according to claim 3, wherein The height of the first support platform along the third direction is h2, and the thickness of the support plate along the third direction is h3, where h=h2+h3; The value range of h2 is: 1.5mm≤h2≤3.0mm; The value range of h3 is: 1.0mm≤h3≤2.0mm.

5. The battery according to claim 4, characterized in that, The thickness of the cover plate body along the third direction is h1, h2≤h1; The value range of h1 is: 2.0mm≤h1≤5.0mm.

6. The battery according to claim 1, wherein The support plate has two first side surfaces that are arranged opposite to each other along the second direction, and a gas exhaust gap is formed between a side of each first side surface that faces the cover plate body and an end surface of the cover plate body that faces the support plate; a plurality of gas exhaust holes are provided on the support plate; The sum of the flow areas of all the exhaust gaps is S11, the sum of the flow areas of all the exhaust holes is S12, S1=S11+S12; the flow area of the pressure relief channel of the explosion-proof valve is S2; S1 and S2 satisfy the following condition: 2.0≤S1 / S2≤4.

0.

7. The battery according to claim 2, wherein Along the first direction, the length of the cover body is F, and the relationship between F and C satisfies: 0.6≤C / F≤0.8, and FC>20mm; and / or, along the second direction, the width of the cover body is E; The relationship between E and D satisfies: 0.6≤D / E≤0.8, and ED>10mm.

8. The battery according to claim 1, characterized in that, The support structure further includes two second support platforms, each of which is sandwiched between one of the first support platforms and the mounting hole, and the second support platform is connected to the support plate at a side away from the cover plate body.

9. The battery according to claim 8, characterized in that, Along the second direction, the length of the mounting hole is L1, the length of the first support platform is L2, and the length of the second support platform is L3; L1, L2 and L3 satisfy: L1≥L2>L3; And 5mm≤L2-L3≤10mm.

10. The battery according to claim 8, characterized in that, Along the first direction, the width of the mounting hole is W1, the width of the first support platform is W2, and the width of the second support platform is W3; Among W1, W2, and W3, the following relationship holds: W1 ≥ W2 > W3; The relationship between W2 and W3 satisfies: 0.1 ≤ (W2 + W3) / C ≤ 0.2.

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