Battery

Abstract

The invention relates to the technical field of batteries, and particularly discloses a battery, the battery comprises an explosion-proof valve, a cover plate body, a shell and a plastic part, the cover plate body is connected with the shell, and the cover plate body and the shell jointly form an accommodating cavity for placing a pole group. The cover plate body or the shell is provided with a mounting hole and a plurality of supporting tables, the plastic part is arranged on the side, close to the containing cavity, of the cover plate body or the shell, and the ends, away from the cover plate body or the shell, of the supporting tables abut against the plastic part. Through the arrangement, after thermal runaway of a battery occurs and a plastic part is melted, the supporting table can continuously support the pole group, so that the pole group is prevented from randomly flowing along with high-temperature and high-pressure gas and blocking the mounting hole in the cover plate body, and a gap is reserved between the mounting hole of the cover plate body and the pole group; high-temperature and high-pressure gas can be conveniently and directionally discharged from the explosion-proof valve arranged in the mounting hole, so that the exhaust effect of the explosion-proof valve is improved, and the safety of the battery is high.

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 body and a shell, wherein the cover body and the shell are connected and enclose a receiving cavity, one of the cover body and the shell is provided with a mounting hole and a plurality of support platforms, the explosion-proof valve is arranged in the mounting hole, the plurality of support platforms are arranged on both sides of the mounting hole along a first direction, the plurality of support platforms are arranged at intervals along the first direction, and all the support platforms extend along a second direction;

[0009] A plastic part, wherein the plastic part is arranged on a side of the cover body or the shell close to the accommodating cavity, and an end of the support platform away from the cover body or the shell along the third direction abuts against the plastic part;

[0010] Along the first direction, the sum of the dimensions of all the support platforms is L1, the length of the cover body or the shell is L2, and the relationship between L1 and L2 satisfies: 0.2≤L1 / L2≤0.4;

[0011] Among them, the value range of L1 is: 15mm≤L1≤80mm;

[0012] The value range of L2 is: 90mm≤L2≤200mm.

[0013] Optionally, the plurality of support platforms are symmetrically arranged on both sides of the mounting hole along the first direction, the sizes of the plurality of support platforms along the first direction are equal, the size of each support platform is L11, and the number of the support platforms is n;

[0014] The calculation formula for the sum of the dimensions of all the support platforms, L1, is: L1 = n·L11;

[0015] The value range of L11 is: 5mm≤L11≤10mm.

[0016] Optionally, the cover body is provided with the mounting hole and a plurality of the support platforms, and along the second direction, the distance between the end of the support platform in the length direction and the adjacent side edge of the cover body is A, and the width of the cover body is F;

[0017] A and F satisfy: 0.12≤A / F≤0.2;

[0018] The value range of A is: 5mm≤A≤10mm;

[0019] The value range of F is: 25mm≤F≤75mm.

[0020] Optionally, along the second direction, the size of the support platform is E, the size of the mounting hole is G, and E and G satisfy: 1.5≤E / G≤2.0;

[0021] The value range of E is: 15mm≤E≤60mm;

[0022] The value range of G is: 8mm≤G≤30mm.

[0023] Optionally, along the first direction, a distance between a side of the support platform adjacent to the mounting hole close to the mounting hole and an adjacent side edge of the mounting hole is C;

[0024] The value range of C is: 8mm≤C≤15mm.

[0025] Optionally, along the first direction, a distance between two adjacent sides of the support platforms that are close to each other is B, and a value range of B is: 8mm≤B≤15mm.

[0026] Optionally, along the first direction, a distance between the support platform adjacent to a side edge of the cover body or the shell and the side edge is D, and a value range of D is: 8 mm ≤ D ≤ 25 mm.

[0027] Optionally, along the third direction, the height of the support platform is H;

[0028] The value range of H is 3mm≤H≤5mm.

[0029] Optionally, the plastic part is provided with a plurality of ventilation holes, which are arranged at intervals on the plastic part; along the third direction, 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.

[0030] 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.

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

[0032] The present invention provides a battery, comprising an explosion-proof valve, a cover body, a shell and a plastic part, wherein the cover body is connected to the shell and together with the shell forms a receiving cavity for placing an electrode group. The cover body or the shell is provided with a mounting hole and a plurality of support platforms, the plastic part is arranged on one side of the cover body or the shell close to the receiving cavity, the end of the support platform away from the cover body or the shell abuts against the plastic part, and the cover body is insulated from the electrode group by the plastic part.

[0033] Through the above arrangement, after the battery has thermal runaway and the plastic parts are melted, the support platform can continue to support the electrode group, preventing the electrode group from randomly flowing with the high-temperature and high-pressure gas, causing the electrode group to block the mounting hole on the cover body, and ensuring that there is a gap between the mounting hole of the cover body and the electrode group, so as to facilitate the directional discharge of high-temperature and high-pressure gas from the explosion-proof valve arranged in the mounting hole, thereby improving the exhaust effect of the explosion-proof valve and increasing the safety of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the contents of the embodiments of the present invention and these drawings without paying any creative work.

[0035] 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;

[0036] Figure 2 for Figure 1 A partial enlarged view of the middle A;

[0037] Figure 3 A top view of the cover plate body provided in the first embodiment of the present invention;

[0038] Figure 4 A bottom view of the plastic part provided in the first embodiment of the present invention;

[0039] Figure 5 This is a schematic diagram of the structure of a battery provided in Embodiment 2 of the present invention;

[0040] Figure 6 This is a partial enlarged view of the battery provided in the second embodiment of the present invention.

[0041] In the figure:

[0042] 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; 230, second flange; 231, avoidance groove; 300, shell; 310, first side wall; 320, second side wall. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0044] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. 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.

[0045] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0046] In the description of the present invention, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or are the positions or positional relationships in which the inventive product is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do 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 cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0047] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "disposed" 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. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0049] 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.

[0050] like Figure 1-Figure 3 As shown, this embodiment provides a battery, which includes an explosion-proof valve, 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.

[0051] The cover body 100 is provided with a mounting hole 110 and a plurality of support platforms 120. The explosion-proof valve is arranged in the mounting hole 110. The plurality of support platforms 120 are arranged on both sides of the mounting hole 110 along the first direction. The plurality of support platforms 120 are arranged at intervals along the first direction, and all support platforms 120 extend along the second direction. The plastic part 200 is arranged on one side of the cover body 100 close to the accommodating cavity. The end of the support platform 120 away from the cover body 100 along the third direction abuts against the plastic part 200, and the cover body 100 is insulated from the pole group by the plastic part 200. Among them, the first direction is the length direction of the cover body 100, that is, Figure 1 The second direction is the X-axis direction shown in FIG. 1 , and the second direction is the width direction of the cover body 100 , that is, Figure 1 The third direction is the height direction of the cover body 100, that is, Figure 1 The Z-axis direction shown in .

[0052] 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 electrode group, so as to prevent the electrode group from randomly flowing with the high-temperature and high-pressure gas, resulting in the mounting hole 110 on the cover body 100 being blocked by the electrode group, and to ensure that there is a gap between the mounting hole 110 of the cover body 100 and the electrode group, so as to facilitate the directional discharge of high-temperature and high-pressure gas from the explosion-proof valve arranged in the mounting hole 110, thereby improving the exhaust effect of the explosion-proof valve. It should be noted that the explosion-proof valve is in the open state at this time.

[0053] Optionally, along the first direction, the sum of the dimensions of all support platforms 120 is L1, the length of the cover body 100 is L2, and the relationship between L1 and L2 satisfies: 0.2≤L1 / L2≤0.4. For example, the value of L1 / L2 can be 0.20, 0.25, 0.30, 0.35 or 0.40. The value range of L1 is: 15mm≤L1≤80mm, and the value range of L2 is: 90mm≤L2≤200mm. That is, when the value of L1 is 15mm, the value of L2 can be 38mm, 50mm, 60mm, 70mm or 75mm, etc. When the value of L1 is 40mm, the value of L2 can be 100mm, 130mm, 160mm or 200mm, etc. When the value of L1 is 80mm, the value of L2 can be 90mm, 105mm or 120mm.

[0054] By controlling the value of L1 / L2 within the above range, it is possible to ensure that the exhaust space formed between the cover body 100 and the electrode group is large, and at the same time, the support platform 120 can provide a good support effect on the electrode group. When the battery has thermal runaway and the plastic part 200 melts and fails, the electrode group moves toward the cover body 100 under the impact of high-temperature and high-pressure gas. The multiple support platforms 120 arranged at intervals on the cover body 100 can effectively block the electrode group, prevent the mounting hole 110 on the cover body 100 from being blocked, reduce the exhaust efficiency of the explosion-proof valve, and greatly improve the safety performance of the battery.

[0055] As an optional technical solution, multiple support platforms 120 are formed on the cover body 100 by stamping. And the multiple support platforms 120 are symmetrically arranged on both sides of the mounting hole 110 along the first direction, and the multiple support platforms 120 have equal sizes along the first direction. The size of each support platform 120 is L11, and the number of support platforms 120 is n. The calculation formula of the sum of the sizes L1 of all support platforms 120 is: L1=n·L11.

[0056] The value range of L11 is: 5mm≤L11≤10mm. For example, the value of L11 can be 5mm, 6mm, 7mm, 8mm, 9mm or 10mm, etc. By limiting the value of L11 within the above range, the area in which each support platform 120 contacts the pole group is larger, ensuring that the support platform 120 has a good support effect on the pole group, and the support platform 120 will not be too sharp and easy to stamp into shape. Otherwise, when the value of L11 is too small, the support effect of the support platform 120 on the pole group decreases, and there is a risk that the pole group blocks the mounting hole 110 on the cover plate body 100, the explosion-proof valve is not vented smoothly, and the support platform 120 is not easy to stamp into shape on the cover plate body 100, and the processing yield is low.

[0057] Furthermore, a limiting flange 111 is provided on the inner wall of the mounting hole 110, and the explosion-proof valve 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, which indicates that the explosion-proof valve is installed in place, and the explosion-proof valve can be welded to the cover body 100. The setting of the limiting flange 111 ensures that the positioning between the explosion-proof valve 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, which facilitates the welding operation of the explosion-proof valve and the cover body 100.

[0058] Continue to see Figure 3, along the second direction, the distance between the end of the support platform 120 and the adjacent side of the cover body 100 is A, the width of the cover body 100 is F, and A and F satisfy: 0.12≤A / F≤0.2. For example, the value of A / F can be 0.12, 0.14, 0.16, 0.18 or 0.20, etc. Among them, the value range of A is: 5mm≤A≤10mm, and the value range of F is: 25mm≤F≤75mm. That is, when the value of A is 5mm, the value of F can be 25mm, 30mm, 35mm, 40mm or 42mm, etc. When the value of A is 10mm, the value of F can be 50mm, 60mm, 70mm or 75mm, etc.

[0059] By limiting the value of A / F 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 second direction, which is convenient for the assembly of the cover body 100 and the shell 300, avoiding the interference between the support platform 120 and the shell 300, and at the same time, the resistance of the high-temperature and high-pressure gas flowing along the first direction is small, and it can be discharged to the mounting hole 110, ensuring that the explosion-proof valve is opened smoothly and the exhaust is relatively smooth. It should be noted that the value of A / F should not be too small, otherwise the flow of high-temperature and high-pressure gas along the first direction is blocked, and the explosion-proof valve may not be opened in time, which poses a safety risk; the value of A / F should not be too large, otherwise the size of each support platform 120 along the second direction is small, the support effect on the pole group is not good, the mounting hole 110 on the cover body 100 is at risk of being blocked by the pole group, and the explosion-proof valve is not exhausting smoothly.

[0060] Further, along the second direction, the size of the support platform 120 is E, and the size of the mounting hole 110 is G, and E and G satisfy: 1.5≤E / G≤2.0; for example, the value of E / G can be 1.5, 1.6, 1.7, 1.8, 1.9 or 2.0. Among them, the value range of E is: 15mm≤E≤60mm, and the value range of G is: 8mm≤G≤30mm. That is, when the value of E is 15mm, the value of G can be 8.5mm, 9.5mm or 10.0mm. When the value of E is 30mm, the value of G can be 15mm, 18mm or 20mm. When the value of E is 60mm, the value of G can be 30mm.

[0061] By controlling the value of E / G within the above range, it is ensured that the contact area between the support platform 120 and the electrode group is large, the supporting effect on the electrode group is good, the mounting hole 110 on the cover body 100 is not blocked, and the explosion-proof valve is vented smoothly. Otherwise, when the value of E / G is too small, the size of the support platform 120 along the second direction is small, the supporting effect on the electrode group is not good, the mounting hole 110 on the cover body 100 is blocked, the explosion-proof valve is not vented smoothly, the exhaust efficiency is reduced, and the risk of explosion is prone to occur. Of course, the value of E / G should not be too large, otherwise the size of the support platform 120 along the second direction is too large, which will have resistance to the high-temperature and high-pressure gas flowing along the first direction, the exhaust efficiency of the explosion-proof valve will also be reduced, and the safety is poor.

[0062] See also Figure 3 , along the first direction, the distance between the side of the support platform 120 adjacent to the mounting hole 110 close to the mounting hole 110 and the adjacent side edge of the mounting hole 110 is C, and the value range of C is: 8mm≤C≤15mm. For example, the value of C can be 8mm, 10mm, 12mm or 15mm.

[0063] 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 and the cover body 100 is high, the reliability of the explosion-proof valve 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 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 is too far, the support effect on the pole group is reduced, and there is a risk that the pole group blocks the mounting hole 110 on the cover body 100.

[0064] Further, along the first direction, the distance between the sides of the two adjacent support platforms 120 that are close to each other is B, and the value range of B is: 8mm≤B≤15mm. For example, the value of B can be 8mm, 10mm, 12mm or 15mm. By controlling the value of B within the above range, it can be ensured that the support platform 120 is smoothly stamped and formed on the cover body 100, and the position where the support platform 120 is not set on the cover body 100 has good flatness. Otherwise, when the value of B is too small, the distance between the two adjacent support platforms 120 is too close, it is not easy to process and form, the forming yield is low, and the flatness of the cover body 100 after forming is also poor, which affects the welding quality when the cover body 100 is welded to the shell 300, and there is a risk of sealing failure. Of course, the value of B should not be too large, otherwise the distance between the two adjacent support platforms 120 is too far, the support effect for the pole group is reduced, and there is a risk that the pole group blocks the mounting hole 110 on the cover body 100.

[0065] Along the first direction, the distance between the support platform 120 adjacent to the side of the cover body 100 and the side is D, and the value range of D is: 8mm≤D≤25mm. For example, the value of D can be 8mm, 12mm, 16mm, 20mm or 25mm. By controlling the value of D within the above range, on the one hand, it is ensured that there is a certain space between the support platform 120 and the side of the cover body 100 along the first direction, which is convenient for the assembly of the cover body 100 and the shell 300. At the same time, it can also ensure that the support platform 120 is smoothly stamped and formed on the cover body 100, and the position where the support platform 120 is not set on the cover body 100 has good flatness. Otherwise, when the value of D is too small, interference may occur when the cover body 100 and the shell 300 are assembled, and the assembly yield is reduced. At the same time, the support platform 120 is not easy to process and form. After forming, the flatness of the cover body 100 is poor, which affects the welding quality when the cover body 100 and the shell 300 are welded, and there is a risk of sealing failure. Of course, the value of D should not be too large, otherwise the supporting effect of the support platform 120 on 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.

[0066] Continue to see Figure 2 , along the third direction, the height of the support platform 120 in this embodiment is H, and the value range of H is 3mm≤H≤5mm. For example, the value of H can be 3mm, 4mm or 5mm, etc. By limiting the value of H within the above range, after the plastic part 200 is melted and the cover body 100 abuts against the electrode group, the exhaust space enclosed between the cover body 100 and the electrode group is larger, which is beneficial to improving the exhaust efficiency of the explosion-proof valve and has high safety.

[0067] See also Figure 1 and Figure 4 In this embodiment, the plastic part 200 is provided with a plurality of vent holes 211, and the plurality of vent holes 211 are arranged at intervals on the plastic part 200. Along the third direction, the projection of the plurality of vent holes 211 on the cover body 100 at least partially overlaps with the projection of the mounting hole 110 on the cover body 100. 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 through the vent holes 211, so that the explosion-proof valve opens and releases pressure.

[0068] Furthermore, a side of the plastic part 200 facing the cover body 100 is provided with an escape groove 231, and the support platform 120 is embedded in the escape groove 231. By setting the escape groove 231, 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.

[0069] Optionally, the plastic part 200 in this embodiment includes a plastic body 210, a first flange 220 and a second flange 230, the first flange 220 and the second flange 230 are both 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 230 extends along the second direction, and the two ends of the second flange 230 are connected to the first flange 220. A plurality of second flanges 230 are arranged at intervals along the first direction, wherein a plurality of vents 211 are arranged on the plastic body 210 between two second flanges 230 located in the middle along the first direction. On the one hand, the second flange 230, the first flange 220 and the plastic body 210 together form an avoidance groove 231, and one or more support platforms 120 can be arranged in each avoidance groove 231. In this embodiment, two support platforms 120 are arranged in each avoidance groove 231 as an example. On the other hand, the second flange 230 can also increase the mechanical strength of the plastic part 200, ensuring that the plastic part 200 has a good supporting effect on the cover body 100 and the electrode group, and the electrode group is well fixed in the shell 300 and is not easy to shake.

[0070] The thermal runaway control of the values ​​of the relevant parameters L1, L2, L1 / L2, and L11 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.

[0071] Table 1

[0072]

[0073] From the above results, it can be concluded that a support platform 120 is provided on the cover body 100 of samples 1 to 7, and the values ​​of relevant parameters L1, L2, L1 / L2, and L11 of the cover body 100 all meet their corresponding size restrictions. At this time, the support platform 120 has an obvious supporting effect on the electrode group, and the flow space formed between the cover body 100 and the electrode group is large. The explosion-proof valve exhausts smoothly, the exhaust efficiency is high, there is no risk of explosion, and the battery product is good.

[0074] Although a support platform 120 is provided on the cover body 100 of samples 8 to 10, the value of L1 / L2 is relatively small, which is smaller than the minimum value of the size range of 0.2≤L1 / L2≤0.4. The size of the support platform 120 along the first direction is relatively small, and the contact area with the electrode group is small. After the battery has thermal runaway and the plastic part 200 is melted, the cover body 100 has poor support effect on the electrode group, and the mounting hole 110 on the cover body 100 may still be blocked by the electrode group. The exhaust efficiency of the explosion-proof valve is low, there is a certain explosion risk, low safety, and the battery product is defective.

[0075] A support platform 120 is provided on the cover body 100 of sample 11 and sample 12, but the value of L1 / L2 is too large, which is larger than the maximum value of the size range of 0.2≤L1 / L2≤0.4. The space occupied by the support platform 120 is too large. After the battery has thermal runaway and the plastic part 200 is melted, the exhaust space formed between the cover body 100 and the pole group is small, the exhaust efficiency of the explosion-proof valve is low, there is a certain explosion risk, the safety is low, and the battery product is defective.

[0076] The thermal runaway of the relevant parameters C, A, F, and A / F of the cover body of the above-mentioned battery is verified using samples of different design sizes. The verification results are shown in Table 2.

[0077] Table 2

[0078]

[0079] From the above results, it can be concluded that a support platform 120 is provided on the cover body 100 of samples 1 to 7, and the values ​​of relevant parameters C, A, F, and A / F of the cover body 100 all meet their corresponding size restrictions. At this time, the support platform 120 has an obvious supporting effect on the electrode group, and the flow space formed between the cover body 100 and the electrode group is large. The explosion-proof valve exhausts smoothly, the exhaust efficiency is high, there is no risk of explosion, and the battery product is good.

[0080] Although a support platform 120 is provided on the cover body 100 of Samples 8 and 9, the value of the parameter C is too large, which is larger than the maximum value of the size range of 8mm≤C≤15mm. The distance between the support platform 120 and the mounting hole 110 along the first direction is far. After the battery has thermal runaway and the plastic part 200 is melted, the support platform 120 has poor support effect on the electrode group. The mounting hole 110 on the cover body 100 may still be blocked by the electrode group. The exhaust efficiency of the explosion-proof valve is low, there is a certain explosion risk, low safety, and the battery product is defective.

[0081] Although a support platform 120 is provided on the cover body 100 of Samples 10 and 11, the value of the parameter C is relatively small, which is smaller than the minimum value of its size range of 8mm≤C≤15mm. The support platform 120 affects the flatness of the cover body 100 during stamping, and the mounting hole 110 is prone to deformation, resulting in poor assembly accuracy between the explosion-proof valve and the mounting hole 110, and the explosion-proof valve is prone to failure, resulting in defective battery products.

[0082] A support platform 120 is provided on the cover body 100 of sample 12 and sample 13, but the A / F value thereof is too large, which is larger than the maximum value of the size range of 0.12≤A / F≤0.2. After the battery has thermal runaway and the plastic part 200 is melted, the support platform 120 has poor support effect on the electrode group, and part of the explosion-proof valve is blocked by the electrode group, resulting in low exhaust efficiency, low safety, and a defective battery product.

[0083] A support platform 120 is provided on the cover body 100 of Sample 14 and Sample 15, but the A / F value thereof is relatively small, which is smaller than the minimum value of the size range of 0.12≤A / F≤0.2. After the battery thermally runs away and the plastic part 200 is melted, the support platform 120 blocks the high-temperature and high-pressure gas flowing along the first direction, resulting in poor gas circulation and the explosion-proof valve failing to open in time, posing a certain risk of explosion, low safety, and a defective battery product.

[0084] In summary, it can be seen that the size design and position arrangement of the support platform 120 have a great influence on the supporting effect of the electrode group and the exhaust effect of the explosion-proof valve. When the size design specified in this embodiment is adopted, it can ensure that the support platform 120 has a good supporting effect on the electrode group, and at the same time the exhaust of the explosion-proof valve is not affected, which greatly improves the pass rate of the battery thermal runaway test and has high safety performance of the battery.

[0085] Embodiment 2

[0086] This embodiment further provides a battery, which is different from the battery in the first embodiment in that the mounting hole 110 and the plurality of support platforms 120 in this embodiment are disposed on one of the side walls of the housing 300 .

[0087] 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 first direction ( Figure 5 Openings 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.

[0088] The housing 300 includes two first side walls 310 disposed opposite to each other along the third direction, and a first side wall 310 disposed along the second 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 platform 120 are arranged on the first side wall 310 for illustration. The plastic part 200 is arranged on the side of the first side wall 310 close to the accommodating cavity, and the side of the support platform 120 away from the first side wall 310 along the third direction is abutted against the plastic part 200, and the pole group is insulated from the shell 300 by the plastic part 200.

[0089] The plurality of support platforms 120 are disposed on both sides of the mounting hole 110 along the first direction, and the plurality of support platforms 120 are spaced apart along the first direction, and all support platforms 120 extend along the second direction. Along the first direction, the sum of the dimensions of all support platforms 120 is L1, the length of the first side wall 310 of the housing 300 is L2, and the relationship between L1 and L2 satisfies: 0.2≤L1 / L2≤0.4. The value range of L1 is: 15mm≤L1≤80mm, and the value range of L2 is: 90mm≤L2≤200mm.

[0090] By controlling the value of L1 / L2 within the above range, it is possible to ensure that the exhaust space formed between the housing 300 and the pole group is large, and at the same time, the support platform 120 can provide a good support effect on the pole group. When the battery has thermal runaway and the plastic part 200 melts and fails, the pole group moves toward the first side wall 310 of the housing 300 under the impact of high-temperature and high-pressure gas. The multiple support platforms 120 arranged at intervals on the first side wall 310 can effectively block the pole group, preventing the mounting hole 110 on the housing 300 from being blocked, affecting the exhaust efficiency of the explosion-proof valve, and greatly improving the safety performance of the battery.

[0091] Optionally, 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 third 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 hole 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, and at this time, the high-temperature and high-pressure gas in the accommodating cavity can be discharged to the explosion-proof valve through the vent holes 211, so that the explosion-proof valve opens and releases pressure.

[0092] Furthermore, a side of the plastic part 200 facing the first side wall 310 of the housing 300 is provided with an escape groove 231, and the support platform 120 is embedded in the escape groove 231. By providing the escape groove 231, it is possible to avoid wasting space in the accommodating cavity, reduce the occupied space, increase the volume of the electrode group, and help improve the energy density of the battery.

[0093] 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.

[0094] 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 body and a shell, wherein the cover body and the shell are connected and enclose a receiving cavity, one of the cover body and the shell is provided with a mounting hole and a plurality of support platforms, the explosion-proof valve is arranged in the mounting hole, the plurality of support platforms are arranged on both sides of the mounting hole along a first direction, the plurality of support platforms are arranged at intervals along the first direction, and all the support platforms extend along a second direction; A plastic part, wherein the plastic part is arranged on a side of the cover body or the shell close to the accommodating cavity, and an end of the support platform away from the cover body or the shell along the third direction abuts against the plastic part; Along the first direction, the sum of the dimensions of all the support platforms is L1, the length of the cover body or the shell is L2, and the relationship between L1 and L2 satisfies: 0.2≤L1 / L2≤0.4; Among them, the value range of L1 is: 15mm≤L1≤80mm; The value range of L2 is: 90mm≤L2≤200mm.

2. The battery according to claim 1, characterized in that The plurality of support platforms are symmetrically arranged on both sides of the mounting hole along the first direction, the sizes of the plurality of support platforms along the first direction are equal, the size of each support platform is L11, and the number of the support platforms is n; The calculation formula for the sum of the dimensions of all the support platforms, L1, is: L1 = n·L11; The value range of L11 is: 5mm≤L11≤10mm.

3. The battery according to claim 1, characterized in that The cover body is provided with the mounting holes and a plurality of the support platforms, and along the second direction, the distance between the end of the support platform in the length direction and the adjacent side of the cover body is A, and the width of the cover body is F; A and F satisfy: 0.12≤A / F≤0.2; The value range of A is: 5mm≤A≤10mm; The value range of F is: 25mm≤F≤75mm.

4. The battery according to claim 3, characterized in that Along the second direction, the size of the support platform is E, the size of the mounting hole is G, and E and G satisfy: 1.5≤E / G≤2.0; The value range of E is: 15mm≤E≤60mm; The value range of G is: 8mm≤G≤30mm.

5. The battery according to claim 1, characterized in that Along the first direction, a distance between a side of the support platform adjacent to the mounting hole close to the mounting hole and an adjacent side edge of the mounting hole is C, and a value range of C is: 8mm≤C≤15mm.

6. The battery according to claim 1, characterized in that Along the first direction, the distance between the sides of two adjacent support platforms that are close to each other is B, and the value range of B is: 8mm≤B≤15mm.

7. The battery according to claim 1, characterized in that Along the first direction, the distance between the support platform adjacent to the side edge of the cover body or the shell and the side edge is D; The value range of D is: 8mm≤D≤25mm.

8. The battery according to claim 1, characterized in that Along the third direction, the height of the support platform is H, and the value range of H is 3mm≤H≤5mm.

9. The battery according to claim 1, characterized in that The plastic part is provided with a plurality of vent holes, which are arranged at intervals on the plastic part; along the third direction, the projections of the plurality of vent 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.

Images