Battery

Abstract

The invention relates to the technical field of batteries, and particularly discloses a battery, a cover plate body or a shell of the battery is provided with a mounting hole and a supporting structure, and an anti-explosion valve is arranged in the mounting hole. The supporting structure comprises two first supporting tables and two supporting plates, the two ends, in the first direction, of each supporting plate are connected to the corresponding first supporting table, and the two supporting plates are arranged in the second direction in a spaced mode. A first exhaust channel is defined by the first supporting table, the supporting plate and the cover plate body / shell, and the first exhaust channel communicates with the anti-explosion valve. Therefore, after thermal runaway of the battery occurs, the supporting structure can continue to support the pole group, the circulation area of the first exhaust channel meets the circulation requirement of high-temperature and high-pressure gas, the high-temperature and high-pressure gas can penetrate through the first exhaust channel and then is directionally discharged from the anti-explosion valve, the circulation path of the high-temperature and high-pressure gas is smooth, and the flowing speed is high; and rapid pressure relief can be realized, and the safety of the battery is good.

Description

Technical Field

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

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

[0003] However, insulating components are generally made of plastic materials (e.g., PP), which have limited strength and high-temperature resistance and typically melt at around 150°C. When a battery experiences thermal runaway, the temperature within the enclosed space is high, causing the insulating components to melt and fail. Only the solid electrode assembly remains within the enclosed space, increasing the gap between the electrode assembly and the cover plate. Furthermore, due to the lack of support provided by the insulating components, the electrode assembly has a high degree of freedom within the housing. When high-temperature, high-pressure gas is exhausted through the explosion-proof valve, the electrode assembly moves with the high-temperature, high-pressure gas flow, posing a risk of blocking the valve's exhaust passage, reducing the valve's exhaust efficiency and resulting in low safety performance. Summary of the Invention

[0004] An object of the present invention is to provide a battery that can prevent an explosion-proof valve from being blocked due to movement of a pole group when the battery experiences 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] a cover body and a shell, wherein the cover body is connected to the shell and encloses a receiving cavity, and at least one of the cover body and the shell is provided with a mounting hole and a supporting structure, wherein the mounting hole is used for mounting the explosion-proof valve;

[0008] The support structure includes two first support platforms and two support plates, the two first support platforms are arranged on both sides of the mounting hole along the first direction, both ends of each support plate along the first direction are respectively connected to one of the first support platforms, and the two support plates are spaced apart along the second direction;

[0009] The end surfaces of the two first support platforms facing away from each other along the first direction are first surfaces, the end surfaces of each first support platform facing away from each other along the second direction are second surfaces, and the second surfaces have a first edge on a side close to the mounting hole; the end surfaces of the two support plates facing away from each other along the second direction are first plate surfaces, and the first plate surfaces have a second edge on a side close to the cover body or the shell;

[0010] A first exhaust channel is formed between the first edges of the two first support platforms, the second edge of the support plate, and the end surface of the cover body or the shell facing the support plate. Two first exhaust channels are provided opposite to each other along the second direction. The first table surface, the second table surface, and the first exhaust channels together form a peripheral side surface of the support structure.

[0011] The area of the peripheral side surface of the support structure is S1, the sum of the flow areas of the two first exhaust channels is S2, and S1 and S2 satisfy the following relationship: 0.70≤S2 / S1≤0.85;

[0012] The value range of S1 is: 800mm 2 ≤S1≤1400mm 2 ;

[0013] The value range of S2 is: 500mm 2 ≤S2≤1000mm 2 .

[0014] Optionally, the support structure and the mounting hole are arranged on the cover body, the end surfaces of the two first support platforms that are close to each other along the first direction are third platform surfaces, and the side of the third platform surfaces facing away from the cover body has a third edge; the end surfaces of the two support plates that are close to each other along the second direction are second plate surfaces, and the side of the second plate surfaces facing away from the cover body has a fourth edge; the third edges of the two first support platforms and the fourth edges of the two support plates form a second exhaust channel;

[0015] Each of the support plates is provided with a plurality of vent holes, the plurality of vent holes are spaced apart along the first direction, and the plurality of vent holes form a third exhaust channel;

[0016] In a plane parallel to the first direction and the second direction, the two support plates and the gap between the two support plates constitute an end surface of the support structure facing away from the cover plate body. The area of the end surface of the support structure facing away from the cover plate body is S3. The sum of the flow areas of the second exhaust channel and the third exhaust channel is S4. S3 and S4 satisfy the following relationship: 0.40≤S4 / S3≤0.55.

[0017] The value range of S3 is: 2500mm 2 ≤S3≤11000mm 2 ;

[0018] The value range of S4 is: 1200mm 2 ≤S4≤6000mm 2 .

[0019] Optionally, the battery further comprises a plastic component, which is arranged on a side of the cover body close to the accommodating cavity, and the plastic component abuts against a supporting surface of the support plate on a side facing away from the cover body.

[0020] Optionally, the explosion-proof valve includes a fixing portion and a main body portion, the fixing portion is arranged around the circumference of the main body portion, the main body portion is provided with a notch groove, the portion surrounded by the notch groove forms an opening portion, and the circumference of the fixing portion is affixed to and welded to the inner wall of the mounting hole;

[0021] The total area of the explosion-proof valve is S0, and the area of the opening portion is S5;

[0022] Between S0 and S5, the following condition is satisfied: 0.80≤S5 / S0≤0.90.

[0023] Optionally, the circumferential outer edge of the explosion-proof valve includes two arc segments and two straight segments, the two straight segments are arranged opposite to each other along the first direction, the two arc segments are arranged opposite to each other along the second direction, and the two arc segments can form a full circle;

[0024] The calculation formula for S0 is:

[0025]

[0026] The distance between the two straight line segments along the first direction is W1, and the distance between the endpoints of the two arc segments that are separated from each other along the second direction is L1;

[0027] The value range of W1 is: 15mm≤W1≤40mm;

[0028] The value range of L1 is: 25mm≤L1≤65mm.

[0029] Optionally, along the third direction, a distance between an end surface of the support plate close to the cover plate body and an end surface of the cover plate body facing the support plate is H, and a thickness of the support plate is t;

[0030] The value range of H is: 1.7mm≤H≤4.0mm;

[0031] The value range of t is 0.8mm≤t≤2.0mm;

[0032] The relationship between H and t is: 2.5mm≤H+t≤6.0mm.

[0033] Optionally, a side of the first table surface connected to the cover body is flush with a third plate surface of the support plate arranged opposite to the third plate surface in the first direction, and a side of the second table surface connected to the cover body is flush with the first plate surface of the support plate;

[0034] The length of the support plate along the first direction is B, the width of the first support platform along the first direction is W2, and the length of the first support platform along the second direction is L2.

[0035] The calculation formula for S1 is:

[0036] S1=(L2+B)*H;

[0037] The calculation formula for S2 is:

[0038] S2=2*(B-2*W2)*H.

[0039] 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 the second support platform is connected to the support plate at a side facing away from the cover plate body.

[0040] Optionally, the distance between the sides of two adjacent support plates along the second direction that are close to each other is E, the number of the vents provided on each support plate is n, and the flow area of each vent is S6; the width of the second support platform along the first direction is W3;

[0041] The calculation formula for S3 is:

[0042] S3 = B*L2;

[0043] The calculation formula for S4 is:

[0044] S4=E*(B-2*W2-2*W3)+n*S6.

[0045] Optionally, the length of the second support platform along the second direction is L3;

[0046] The relationship between L2 and L3 satisfies: L2>L3, and 5mm≤L2-L3≤10mm.

[0047] The beneficial effects of the present invention are:

[0048] The present invention provides a battery comprising a cover body and a housing. The cover body or the housing is provided with a mounting hole and a support structure, and an explosion-proof valve is disposed within the mounting hole. The support structure comprises two first support platforms and two support plates, each of which is connected to a first support platform at both ends along a first direction, and the two support plates are spaced apart along a second direction. A first exhaust channel is formed between the first support platforms, the support plates, and the cover body / housing, and is connected to the explosion-proof valve. After thermal runaway of the battery occurs, the support structure can continue to support the electrode assembly, allowing high-temperature, high-pressure gas to pass through the first exhaust channel and then be discharged from the explosion-proof valve in a targeted manner. The high-temperature, high-pressure gas has a smooth flow path and a high flow rate, enabling rapid pressure relief and ensuring good battery safety. Furthermore, the first exhaust channel has a sufficient flow area to meet the needs of rapid circulation of high-temperature, high-pressure gas, preventing explosions caused by excessive pressure within the chamber, thereby enhancing safety. Furthermore, the support structure has high mechanical strength and is less susceptible to deformation. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 This is a schematic structural diagram of a battery provided in Example 1 of the present invention;

[0050] Figure 2 This is an exploded view of the cover body and the plastic part provided in the first embodiment of the present invention;

[0051] Figure 3 This is a structural diagram of the cover body provided in the first embodiment of the present invention;

[0052] Figure 4 A top view of the cover body provided in the first embodiment of the present invention;

[0053] Figure 5 This is a top view of the cover plate body (without the support plate) provided in the first embodiment of the present invention;

[0054] Figure 6 This is a schematic structural diagram of the explosion-proof valve provided in Example 1 of the present invention;

[0055] Figure 7 This is a side view of the cover body provided in the first embodiment of the present invention;

[0056] Figure 8 for Figure 7 A partial enlarged view of the center Ι;

[0057] Figure 9 This is a schematic structural diagram of a battery provided in Example 2 of the present invention.

[0058] In the picture:

[0059] 100, cover body; 110, mounting hole; 111, limiting flange; 120, first support platform; 121, first table surface; 122, second table surface; 1221, first edge; 123, third table surface; 1231, third edge; 130, second support platform; 140, support plate; 141, first plate surface; 1411, second edge; 1412, first exhaust channel; 142, second plate surface; 1421, fourth edge Edge; 1422, second exhaust channel; 143, third plate surface; 144, support surface; 1441, vent; 200, shell; 201, opening; 210, first side wall; 220, second side wall; 300, plastic part; 301, exhaust hole; 400, explosion-proof valve; 410, fixing part; 411, arc segment; 412, straight line segment; 420, main body; 421, notched groove; 430, opening part; 500, pole group. DETAILED DESCRIPTION

[0060] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0061] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions, and the first feature being "above", "above" and "above" the second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature includes the first feature being directly below and obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0062] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0063] The following describes embodiments of the present invention in detail. Examples of the embodiments 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 intended only to explain the present invention and are not to be construed as limiting the present invention.

[0064] Example 1

[0065] like Figure 1-Figure 4 As shown, this embodiment provides a battery, which includes a cover body 100 and a shell 200, at least one end of the shell 200 is provided with an opening 201, the cover body 100 is connected to the end of the shell 200 with the opening 201 and together with the shell 200 forms a accommodating cavity for placing the electrode group 500.

[0066] 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 two support plates 140. The two first support platforms 120 are arranged on both sides of the mounting hole 110 along the first direction, and the two first support platforms 120 are symmetrically arranged about the axis of the mounting hole 110 along the second direction. Each support plate 140 is connected to a first support platform 120 at both ends along the first direction, and the two support plates 140 are spaced apart along the second direction. The above-mentioned first direction is Figure 1 The X-axis direction shown in the second direction is Figure 1 The Y-axis direction shown in .

[0067] The end surfaces of the two first support platforms 120 that are away from each other along the first direction are the first platform 121, and the end surfaces of each first support platform 120 that are away from each other along the second direction are the second platform 122. The second platform 122 has a first edge 1221 ( Figure 8(shown in the figure). The end surfaces of the two support plates 140 facing away from each other along the second direction are first plate surfaces 141. The first plate surface 141 has a second edge 1411 on the side of the cover plate body 100 that is close to the first edge 1221 of the two first support platforms 120, the second edge 1411 of the support plate 140, and the end surface of the cover plate body 100 facing the support plate 140 define a first exhaust channel 1412. Two first exhaust channels 1412 are provided opposite each other along the second direction. The first exhaust channels 1412 connect the pressure relief channel of the explosion-proof valve 400 with the accommodating chamber.

[0068] Through the above-mentioned arrangement, after thermal runaway occurs in the battery, the support structure provided on the cover body 100 can continue to support the electrode group 500, preventing the electrode group 500 from randomly flowing with the high-temperature and high-pressure gas, causing the mounting hole 110 on the cover body 100 to be blocked by the electrode group 500. The high-temperature and high-pressure gas can pass through the first exhaust channel 1412, and then flow to the mounting hole 110 and be directionally discharged through the explosion-proof valve 400 provided in the mounting hole 110. The flow path of the high-temperature and high-pressure gas is smooth and the flow speed 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.

[0069] Furthermore, this embodiment defines that the first table 121, the second table 122 and the first exhaust channel 1412 together form the peripheral side surface of the support structure, the area of the peripheral side surface of the support structure is S1, the sum of the flow areas of the two first exhaust channels 1412 is S2, and S1 and S2 satisfy: 0.70≤S2 / S1≤0.85. For example, in some embodiments, the value of S2 / S1 can be 0.70, 0.72, 0.75, 0.78, 0.80, 0.82 or 0.85, etc. In this way, the flow area of the first exhaust channel 1412 is ensured to be large, which meets the needs of rapid circulation of high-temperature and high-pressure gas, avoids explosion caused by excessive pressure in the accommodating cavity, and has higher safety. At the same time, the mechanical strength of the support structure is higher and deformation problems are not easy to occur. Optionally, the value range of S1 is: 800mm 2 ≤S1≤1400mm 2 , the value range of S2 is: 500mm 2 ≤S2≤1000mm 2 For example, the value of S1 is 800mm 2 When S2 is 560 mm 2 , 600mm 2 、650mm 2 or 680mm 2 Etc. For example, the value of S1 is 1400mm 2 When S2 is 980 mm 2 or 1000mm 2 wait.

[0070] Continue to see Figure 2-Figure 4 The battery further includes a plastic part 300, which is disposed on a side of the cover body 100 close to the accommodating cavity. The plastic part 300 abuts against a support surface 144 of the support plate 140 on a side facing away from the cover body 100. The plastic part 300 can insulate the cover body 100 from the electrode group 500.

[0071] Furthermore, in this embodiment, the end surfaces of the two first support platforms 120 that are close to each other along the first direction are the third table surface 123, and the third table surface 123 has a third edge 1231 on the side facing away from the cover body 100. The end surfaces of the two support plates 140 that are close to each other along the second direction are the second plate surface 142, and the second plate surface 142 has a fourth edge 1421 on the side facing away from the cover body 100. A second exhaust channel 1422 is formed between the third edges 1231 of the two first support platforms 120 and the fourth edges 1421 of the two support plates 140. Each support plate 140 is provided with a plurality of ventilation holes 1441 that pass through the support plate 140 along the third direction, and the plurality of ventilation holes 1441 are arranged at intervals along the first direction, and the plurality of ventilation holes 1441 constitute a third exhaust channel. The above-mentioned third direction, namely Figure 2 The Z-axis direction shown in .

[0072] In a plane parallel to the first direction and the second direction, the two support plates 140 and the gap between the two support plates 140 constitute the end surface of the support structure away from the cover body 100. Optionally, the area of the end surface of the support structure away from the cover body 100 is S3, and the sum of the flow areas of the second exhaust channel 1422 and the third exhaust channel is S4, and S3 and S4 satisfy: 0.40≤S4 / S3≤0.55. For example, in some embodiments, the value of S4 / S3 can be 0.40, 0.42, 0.45, 0.48, 0.50, 0.52 or 0.55, etc. Thus, the area where high-temperature and high-pressure gas can circulate is increased, the flow area of the second exhaust channel 1422 and the third exhaust channel is sufficient, and the high-temperature and high-pressure gas can circulate quickly along the third direction, with high exhaust efficiency and high safety. In addition, an exhaust hole 301 is provided at the position corresponding to the mounting hole 110 on the plastic part 300, along the thickness direction of the cover body 100 (i.e. Figure 1 (Z-axis direction shown in FIG), vent hole 301 is directly opposite explosion-proof valve 400, allowing high-temperature, high-pressure gas to directly act on explosion-proof valve 400 before plastic part 300 is melted. This allows explosion-proof valve 400 to respond promptly and open quickly, ensuring battery safety. Furthermore, second exhaust channel 1422 is also directly opposite explosion-proof valve 400, allowing high-temperature, high-pressure gas to directly act on explosion-proof valve 400 after plastic part 300 is melted, thereby achieving rapid pressure relief.

[0073] Optionally, the value range of S3 is: 2500mm 2 ≤S3≤11000mm 2 , the value range of S4 is: 1200mm 2 ≤S4≤6000mm 2 For example, the value of S3 is 2500mm 2 When the value of S4 can be 1200mm 2 , 1250mm 2 , 1300mm 2 or 1350mm 2 Etc. For example, the value of S3 is 11000mm 2 When the value of S4 can be 4400mm 2 , 5000mm 2 , or 6000mm 2 wait.

[0074] See also Figure 5 and Figure 6 In this embodiment, a mounting hole 110 is provided in the middle portion of the cover body 100 along the first direction. The mounting hole 110 can be formed by stamping or cutting. A limiting flange 111 is provided on the inner wall of the mounting hole 110. The explosion-proof valve 400 can be installed into the mounting hole 110 from the side of the cover body 100 facing the plastic part 300 and abuts against the limiting flange 111 on the inner wall of the mounting hole 110. At this point, it is indicated that the explosion-proof valve 400 is installed in place and the explosion-proof valve 400 can be welded to the cover body 100. The provision of the limiting flange 111 ensures accurate positioning between the explosion-proof valve 400 and the cover body 100, and high assembly precision. In addition, the limiting flange 111 can also temporarily fix the explosion-proof valve 400, facilitating welding of the explosion-proof valve 400 to the cover body 100.

[0075] Optionally, the explosion-proof valve 400 includes a fixing portion 410 and a main body 420. The fixing portion 410 is disposed circumferentially around the main body 420. The main body 420 is provided with a notched groove 421. The notched groove 421 is C-shaped or annular. The portion enclosed by the notched groove 421 forms an opening 430. When the explosion-proof valve 400 is installed into the mounting hole 110 from the side of the cover body 100 toward the plastic component 300, the end surface of the fixing portion 410 facing the cover body 100 abuts against the limiting flange 111, and the circumference of the fixing portion 410 is bonded and welded to the inner wall of the mounting hole 110. When the pressure in the battery's storage chamber becomes excessive, it will break through the notched groove 421 in the main body 420, forming a pressure relief channel at the opening 430. High-temperature, high-pressure gas can be discharged from the battery's storage chamber through the pressure relief channel, thereby avoiding safety risks such as explosion.

[0076] Furthermore, the total area of the explosion-proof valve 400 is S0, and the area of the opening 430 is S5, that is, the flow area of the pressure relief passage is S5, and the relationship between S0 and S5 satisfies: 0.80 ≤ S5 / S0 ≤ 0.90. For example, the value of S5 / S0 can be 0.80, 0.85, or 0.90. This ensures that the flow area of the pressure relief passage is sufficient, allowing high-temperature, high-pressure gas to be exhausted smoothly. At the same time, the mechanical strength of the fixing portion 410 is sufficient, and the connection strength between the fixing portion 410 and the cover body 100 is high. Otherwise, if the value of S5 / S0 is too large, the area of the fixing portion 410 is small, resulting in low welding strength between the fixing portion 410 and the cover body 100, and insufficient connection strength between the explosion-proof valve 400 and the cover body 100. Of course, the value of S5 / S0 should not be too small, otherwise the flow area of the pressure relief passage will be insufficient, which may lead to untimely pressure relief and cause safety risks.

[0077] Continue to see Figure 5 and Figure 6 The explosion-proof valve 400 in this embodiment is waist-shaped. Its circumferential outer edge includes two arc segments 411 and two straight segments 412. The two straight segments 412 are arranged opposite each other along a first direction, while the two arc segments 411 are arranged opposite each other along a second direction. The two arc segments 411 form a complete circle. Because the fixing portion 410 is located at the outermost side of the explosion-proof valve 400, the fixing portion 410's circumferential outer edge includes the two arc segments 411 and two straight segments 412.

[0078] Therefore, the calculation formula of S0 can be obtained as follows:

[0079]

[0080] The distance between the two straight segments 412 along the first direction is W1, and the distance between the two opposing endpoints of the arc segments 411 along the second direction is L1. Because the circumferential outer edge of the fixing portion 410 is in contact with the inner wall of the mounting hole 110, the dimension of the mounting hole 110 along the first direction is also W1, and the dimension of the mounting hole 110 along the second direction is L1.

[0081] Exemplarily, the value range of W1 is: 15mm≤W1≤40mm. For example, the value of W1 can be 15mm, 20mm, 30mm or 40mm, etc. The value range of L1 is: 25mm≤L1≤65mm. For example, the value of L1 can be 25mm, 30mm, 40mm, 50mm or 60mm, etc. It should be noted that the dimension of the cover body 100 along the first direction is A, W1<A. The dimension of the cover body 100 along the second direction is C, L1<C. Therefore, some installation space is reserved on the side of the length direction of the cover body 100 and the side of the width direction of the cover body 100, which facilitates the welding operation of the cover body 100 and the shell 200, and avoids the heat generated when the cover body 100 and the shell 200 are welded, causing the explosion-proof valve 400 to deform or crack, affecting the accuracy of the valve opening pressure of the explosion-proof valve 400.

[0082] Optionally, the value range of A is 120 mm ≤ A ≤ 200 mm. For example, in some embodiments, the value of A can be 120 mm, 150 mm, 180 mm, or 200 mm. The value range of C is 35 mm ≤ C ≤ 75 mm. For example, in some embodiments, the value of C can be 35 mm, 45 mm, 55 mm, 65 mm, or 75 mm.

[0083] See also Figure 7 and Figure 8 , along the third direction, the distance between the end surface of the support plate 140 close to the cover body 100 and the end surface of the cover body 100 facing the support plate 140 is H, that is, the height of the first support platform 120 along the third direction is H, and the value range of H is: 1.7mm≤H≤4.0mm. For example, the value of H can be 1.7mm, 2.0mm, 3.0mm or 4.0mm, etc. The thickness of the support plate 140 along the third direction is t, and the value range of t is 0.8mm≤t≤2.0mm. For example, the value of t can be 0.8mm, 1.0mm, 1.5mm or 2.0mm, etc. H and t satisfy: 2.5mm≤H+t≤6.0mm, and H+t is the height of the support structure along the third direction. By limiting the value of H within the above range, the flow area of the first exhaust channel 1412 is larger. Therefore, after the plastic part 300 is melted, when the support plate 140 on the cover body 100 abuts against the electrode group 500, the exhaust space between the cover body 100 and the electrode group 500 is larger, which is beneficial to improving the exhaust efficiency of the explosion-proof valve 400 and improving safety.

[0084] Continue to see Figure 4 and Figure 7In this embodiment, the side of the first table 121 connected to the cover body 100 is flush with the third plate surface 143 of the support plate 140, which is arranged opposite to each other along the first direction. The side of the second table 122 connected to the cover body 100 is flush with the first plate surface 141 of the support plate 140. In other words, the two support plates 140 and the two first support platforms 120 form a square-like frame. The length of the support plate 140 along the first direction is B, and the width of the first support platform 120 along the first direction is W2. The length of the first support platform 120 along the second direction is L2, that is, the distance between the two sides of the two support plates 140 facing away from each other is L2 (the distance between the second edges 1411 of the first plate surfaces 141 of the two support plates 140 along the second direction is L2).

[0085] The calculation formula for S1 is:

[0086] S1=(L2+B)*H.

[0087] The calculation formula for S2 is:

[0088] S2=2*(B-2*W2)*H.

[0089] Optionally, the value range of B is 90 mm ≤ B ≤ 180 mm, where B < A. This ensures that there is sufficient installation space on both sides of the cover body 100 along the first direction, preventing interference between the support plate 140 and the housing 200 when the cover body 100 and the housing 200 are assembled. For example, the value of B can be 90 mm, 120 mm, 150 mm, 160 mm, or 180 mm.

[0090] Optionally, the value range of W2 is: 15mm≤W2≤20mm. In some embodiments, the value of W2 can be 15mm, 18mm or 20mm, etc. By limiting the value of W2 within the above range, it can be ensured that the width of the first support platform 120 along the first direction is large, the first support platform 120 is easy to be stamped and formed, and the contact area between the first support platform 120 and the support plate 140 is large, and the support effect on the support plate 140 is better. Otherwise, if the value of W2 is too small, the production yield of the first support platform 120 is low, the cover plate body 100 is easily broken during stamping, and the first support platform 120 after production has poor support effect on the support plate 140, thereby affecting the support effect of the support plate 140 on the electrode group 500. Of course, the value of W2 should not be too large, otherwise the flow area of the first exhaust channel 1412 will be reduced, affecting the exhaust efficiency of high-temperature and high-pressure gas.

[0091] Optionally, the length of the first support platform 120 along the second direction is L2, and the value range of L2 is: 25 mm ≤ L2 ≤ 65 mm. For example, the value of L2 can be 25 mm, 35 mm, 45 mm, 55 mm, or 65 mm. It should be noted that the value of L2 is greater than twice the width of the support plate 140 along the second direction to ensure that a gap is formed between two adjacent support plates 140 to facilitate exhaust.

[0092] Continue to see Figure 4 and Figure 5 The support structure in this embodiment further includes two second support platforms 130. Each second support platform 130 is sandwiched between a first support platform 120 and the mounting hole 110. The side of the second support platform 130 facing away from the cover body 100 is connected to the support plate 140. The provision of the second support platforms 130 provides better support for the support plate 140, ensuring the structural stability of the support plate 140, thereby being able to withstand the impact of the electrode group 500 on the support plate 140, preventing the explosion-proof valve 400 and the mounting hole 110 from being blocked, and preventing the support plate 140 from deformation.

[0093] The distance between the sides of two adjacent support plates 140 along the second direction, where they approach each other, is E. That is, the distance between the fourth edges 1421 of the second plate surfaces 142 of the two support plates 140 along the second direction is E. The number of vents 1441 provided on each support plate 140 is n. The shape of the vents 1441 can be circular, square, or waist-shaped, etc., without limitation. The flow area of each vent 1441 is S6. The width of the second support platform 130 along the first direction is W3.

[0094] The calculation formula for S3 is:

[0095] S3=B*L2.

[0096] The calculation formula for S4 is:

[0097] S4=E*(B-2*W2-2*W3)+n*S6.

[0098] It should be noted that, considering that the second support platform 130 blocks a portion of the second exhaust channel 1422 , the calculation formula of S4 includes an item “-2*W3”.

[0099] In other embodiments, if the length of the second support platform 130 along the second direction is short and does not block the second exhaust channel 1422 and the vent hole 1441, the calculation formula of S4 is:

[0100] S4=E*(B-2*W2)+n*S6.

[0101] Optionally, the value range of E is: 9mm≤E≤32mm. In some embodiments, the value of E can be 9.0mm, 12.0mm, 18mm, 20mm, 25mm, 30mm or 32mm, etc. It should be noted that the value of E should not be too small, otherwise the width of the gap formed between two adjacent support plates 140 will be small, and the exhaust efficiency will be reduced. Of course, the value of E should not be too large, otherwise the width of the support plate 140 along the second direction will be small, the contact area between the support plate 140 and the cover plate body 100 will be small, the overall strength of the support structure will be reduced, the support plate 140 may be deformed, and the support effect on the pole group 500 or the plastic part 300 will be poor.

[0102] Furthermore, the length of the second support platform 130 along the second direction is L3, and the relationship between L1, L2 and L3 satisfies: L1≥L2>L3. The value range of L3 is: 20mm≤L3≤60mm. This ensures that the high-temperature, high-pressure gas flowing along the length direction (first direction) of the cover body 100 flows smoothly, and avoids the first support platform 120 or the second support platform 130 from blocking the high-temperature, high-pressure gas flowing along the length direction of the cover body 100, causing a decrease in flow rate and reduced exhaust efficiency. Furthermore, the relationship between L2 and L3 also satisfies: 5mm≤L2-L3≤10mm. For example, the value of L2-L3 can be 5mm, 6mm, 7mm, 8mm, 9mm or 10mm, etc.

[0103] In some embodiments, when the value of L1 is 25 mm, the value of L2 may be 25 mm, and the value of L3 may be 20 mm. In some embodiments, when the value of L1 is 30 mm, the value of L2 may be 30 mm, and the value of L3 may be 25 mm, 20 mm, etc. In some embodiments, when the value of L1 is 65 mm, the value of L2 may be 65 mm, and the value of L3 may be 60 mm, 55 mm, etc., which are not listed here one by one.

[0104] It is important to note 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 will be too close to the side edge of the cover body 100 along the second direction, and the end of the second support platform 130 along the second direction will be too close to the side edge of the cover body 100 along the second direction. When the plastic part 300 and the cover body 100 are fixed by heat fusion, the precision of the processing equipment will affect the risk of interference between the support plate 140 and the plastic part 300, thereby reducing assembly accuracy. Of course, the values of L2 and L3 should not be too small either. Otherwise, the first support platform 120 and the second support platform 130 will not provide sufficient support for the support plate 140, and the risk of deformation of the support plate 140 after the pole group 500 is stamped will increase, which may affect exhaust and pose a safety risk.

[0105] By using the above calculation formulas for S1, S2, S3, and S4 and substituting the corresponding parameters, the specific values of S1, S2, S3, and S4 can be obtained. The S2 / S1 and S4 / S3 values are then calculated to see if they fall within the corresponding ranges, thereby determining whether the support structure can meet the exhaust requirements in the event of thermal runaway.

[0106] Depending on the battery's reaction system, the amount of gas produced by the electrode assembly 500 during thermal runaway can vary. For example, when the battery's electrode assembly 500 uses a ternary lithium system, the reaction between the electrode assembly 500 and the electrolyte is more intense, resulting in a higher amount of gas produced during thermal runaway. Therefore, the support structure needs to be raised along the third direction. In this case, the value range of H is: 2.8mm≤H≤4.0mm, the relationship between H and t satisfies: 4.0mm≤H+t≤6.0mm, the value range of t is 1.2mm≤t≤2.0mm, the value range of S2 / S1 is 0.75≤S2 / S1≤0.85, and the value range of S4 / S3 is 0.45≤S4 / S3≤0.55.

[0107] The thermal runaway of the above-mentioned ternary lithium system battery is verified using samples of different design sizes to determine whether the battery can successfully pass the safety test. The safety test passing criteria are: the battery's explosion-proof valve 400 can open smoothly, the valve opening pressure is accurate, and no explosion occurs. The results are shown in Table 1.

[0108] Table 1

[0109]

[0110] From the above results, it can be concluded that in sample 1 and sample 2, the values of H, t and H+t do not satisfy their corresponding value ranges, the values of H and t are too small, the flow area of the first exhaust channel 1412 is insufficient, and the support plate 140 is deformed. The support plate 140 does not support the electrode group 500 well, and the electrode group 500 blocks the mounting hole 110, which ultimately leads to the explosion-proof valve 400 being unable to open during thermal runaway. The battery cannot open the valve to release pressure in time, which poses a safety risk. The battery's safety test pass rate is low, and the battery is defective.

[0111] In samples 4 and 6, the value of S2 / S1 is too small and does not meet the size limitation of 0.75≤S2 / S1≤0.85. The flow area of the first exhaust channel 1412 is small, which affects the flow of high-temperature and high-pressure gas to the explosion-proof valve 400. The explosion-proof valve 400 cannot be guaranteed to exhaust smoothly. There is a situation where the explosion-proof valve 400 cannot open the valve in time, which poses a safety risk. The battery safety test pass rate is low and the battery is defective.

[0112] In samples 5 and 6, the value of S4 / S3 is small, which does not meet the size limit of 0.45≤S4 / S3≤0.55. The flow area of the second exhaust channel 1422 is small, which affects the flow of high-temperature and high-pressure gas to the explosion-proof valve 400. The explosion-proof valve 400 cannot be guaranteed to exhaust smoothly, which may cause the explosion-proof valve 400 to fail to open the valve to release pressure in time, posing a safety risk. The battery safety test pass rate is low, and the battery is defective.

[0113] In sample 3, each parameter of H, t, H+t, S2 / S1, and S4 / S3 satisfies its corresponding value range. At this time, the supporting structure has an obvious supporting effect on the electrode group 500, and the flow area of the first exhaust channel 1412 and the second exhaust channel 1422 is large. The explosion-proof valve 400 can open the valve smoothly and the explosion-proof valve 400 exhausts smoothly, the exhaust efficiency is high, the battery safety test has passed, no explosion occurred, and the battery product is good.

[0114] When the battery's electrode assembly 500 is a lithium iron phosphate system, the reaction between the electrode assembly 500 and the electrolyte is relatively slow, and the gas production during thermal runaway is lower than that of a ternary lithium system battery. Therefore, the height of the support structure along the third direction can be appropriately lowered to reduce the support structure's footprint and increase the layout space for the electrode assembly 500. In this case, the value range of H is: 1.7mm≤H≤2.8mm, the relationship between H and t satisfies: 2.5mm≤H+t≤4.0mm, the value range of t is 0.8mm≤t≤1.2mm, the value range of S2 / S1 is 0.70≤S2 / S1≤0.80, and the value range of S4 / S3 is 0.40≤S4 / S3≤0.50.

[0115] The following is a thermal runaway test of the lithium iron phosphate battery using samples of different design sizes to determine whether the battery can successfully pass the safety test. The safety test passing criteria are: the battery's explosion-proof valve 400 can open smoothly, the valve opening pressure is accurate, and no explosion occurs. The results are shown in Table 2.

[0116] Table 2

[0117]

[0118] From the above results, it can be concluded that in sample 7, the values of H, t, and H+t are too small and do not meet their corresponding value ranges. The flow area of the first exhaust channel 1412 is insufficient, and the value of t is too small. The support plate 140 is easily deformed, and the support effect on the electrode group 500 is not good. The electrode group 500 blocks the mounting hole 110, which ultimately leads to the explosion-proof valve 400 being unable to open during thermal runaway. The battery cannot open the valve to release pressure in time, which poses a safety risk. The battery's safety test pass rate is low, and the battery is defective.

[0119] In sample 8, the value of t is too small and does not meet its corresponding value range. H and H+t meet the corresponding size restrictions. The flow area of the first exhaust channel 1412 is sufficient, but the support plate 140 is easy to deform and the support effect on the electrode group 500 is not good. The electrode group 500 blocks the mounting hole 110, which eventually leads to the explosion-proof valve 400 being unable to open during thermal runaway. The battery cannot open the valve to release pressure in time, posing a safety risk. The battery's safety test pass rate is low, and the battery is defective.

[0120] In samples 12 and 13, the value of S2 / S1 is too small and does not meet the size limitation of 0.70≤S2 / S1≤0.80. The flow area of the first exhaust channel 1412 is small, which affects the flow of high-temperature and high-pressure gas to the explosion-proof valve 400, and cannot ensure smooth exhaust of the explosion-proof valve 400. There is a situation where the explosion-proof valve 400 cannot open the valve in time, which poses a safety risk. The battery safety test pass rate is low and the battery is defective.

[0121] In samples 13 and 14, the value of S4 / S3 is small, which does not meet the size limitation of 0.40≤S4 / S3≤0.50. The flow area of the second exhaust channel 1422 is small, which affects the flow of high-temperature and high-pressure gas to the explosion-proof valve 400. The explosion-proof valve 400 cannot be guaranteed to exhaust smoothly, which may cause the explosion-proof valve 400 to fail to open the valve to release pressure in time, posing a safety risk. The battery safety test pass rate is low, and the battery is defective.

[0122] In samples 9, 10, and 11, the parameters H, t, H+t, S2 / S1, and S4 / S3 all satisfy their corresponding value ranges. At this time, the supporting structure has an obvious supporting effect on the electrode group 500, and the flow areas of the first exhaust channel 1412 and the second exhaust channel 1422 are large. The explosion-proof valve 400 can open smoothly and the explosion-proof valve 400 exhausts smoothly, with a high exhaust efficiency. The battery safety tests have all passed without explosion, and the battery product is good.

[0123] In summary, it can be seen that the size design and position arrangement of the support structure have a great influence on the support effect of the electrode group 500 and the exhaust effect of the explosion-proof valve 400. After selecting the type of battery, when the size design of the support structure specified by the corresponding battery type is adopted, it can be ensured that the support structure has a good support effect on the electrode group 500, and at the same time the exhaust of the explosion-proof valve 400 is not affected, which significantly improves the problem of the explosion-proof valve 400 being blocked by the electrode group 500 and affecting the exhaust when the battery thermal runaway occurs, and the battery has high safety performance.

[0124] Example 2

[0125] This embodiment further provides a battery, which differs from the battery in the first embodiment in that the mounting hole 110 and the support structure in this embodiment are provided on one of the side walls of the housing 200 .

[0126] See also Figure 9 The battery in this embodiment can be a blade battery, and the housing 200 is arranged along the first direction ( Figure 9 Openings 201 are formed at both ends of the cover plate body 100 (in the X-axis direction shown in the figure), and two cover plate bodies 100 are provided. Each cover plate body 100 is connected to an opening 201 of the shell 200 and blocks the opening 201. The two cover plate bodies 100 and the shell 200 form a receiving cavity for placing the pole group 500.

[0127] The housing 200 includes a Figure 9 The X-axis direction and the Y-axis direction shown in the figure are perpendicular to each other) and the two first side walls 210 are arranged opposite to each other along the second direction ( Figure 9 The first sidewall 210 is connected to the second sidewall 220, and the area of the first sidewall 210 is smaller than that of the second sidewall 220. In this embodiment, the mounting hole 110 and the support structure are disposed on the first sidewall 210 as an example. The plastic component 300 is disposed on a side of the first sidewall 210 close to the accommodating cavity, and the plastic component 300 abuts against a side of the support structure facing away from the first sidewall 210.

[0128] Specifically, a first exhaust channel 1412 is defined between the support structure and the first sidewall 210 of the housing 200. This first exhaust channel 1412 connects the accommodating chamber and the pressure relief channel of the explosion-proof valve 400. This arrangement ensures that even after thermal runaway of the battery occurs and the plastic component 300 melts, the support structure provided on the cover body 100 can continue to support the electrode assembly 500. High-temperature, high-pressure gas can pass through the first exhaust channel 1412, then flow to the mounting hole 110 and be discharged in a directionally controlled manner through the explosion-proof valve 400 provided within the mounting hole 110, achieving rapid pressure relief and ensuring excellent battery safety.

[0129] Furthermore, the area of the peripheral side surface of the support structure is defined as S1, and the flow area of the first exhaust channel 1412 is defined as S2. The relationship between S1 and S2 satisfies the following: 0.70 ≤ S2 / S1 ≤ 0.85. For example, in some embodiments, the value of S2 / S1 can be 0.70, 0.72, 0.75, 0.78, 0.80, 0.82, or 0.85. This ensures that the flow area of the first exhaust channel 1412 is sufficient to meet the flow requirements of high-temperature, high-pressure gas, preventing explosions caused by excessive pressure in the chamber. This provides enhanced safety, while also providing the support structure with high mechanical strength and less prone to deformation.

[0130] In this embodiment, the end surface of the support structure facing away from the first sidewall 210 of the housing 200 includes a second exhaust channel 1422 and a third exhaust channel. The area of the end surface of the support structure facing away from the cover plate body 100 is S3, and the sum of the flow areas of the second exhaust channel 1422 and the third exhaust channel is S4. S3 and S4 satisfy the following relationship: 0.40 ≤ S4 / S3 ≤ 0.55. For example, in some embodiments, the value of S4 / S3 can be 0.40, 0.42, 0.45, 0.48, 0.50, 0.52, or 0.55. This increases the area through which high-temperature, high-pressure gas can circulate, providing sufficient flow areas for the first, second, and third exhaust channels 1412, 1422, and 1423, allowing for rapid circulation of high-temperature, high-pressure gas, resulting in high exhaust efficiency and safety. Furthermore, the second exhaust channel 1422 and the third exhaust channel are directly opposite to the explosion-proof valve 400 , so that after the plastic part 300 is melted, the high-temperature, high-pressure gas can directly act on the explosion-proof valve 400 , thereby achieving rapid pressure relief.

[0131] 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.

[0132] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. A battery, characterized in that: include: a cover body and a shell, wherein the cover body is connected to the shell and encloses a receiving cavity, and at least one of the cover body and the shell is provided with a mounting hole and a supporting structure, wherein the mounting hole is used for mounting the explosion-proof valve; The support structure includes two first support platforms and two support plates, the two first support platforms are arranged on both sides of the mounting hole along the first direction, both ends of each support plate along the first direction are respectively connected to one of the first support platforms, and the two support plates are spaced apart along the second direction; The end surfaces of the two first support platforms facing away from each other along the first direction are first surfaces, the end surfaces of each first support platform facing away from each other along the second direction are second surfaces, and the second surfaces have a first edge on a side close to the mounting hole; the end surfaces of the two support plates facing away from each other along the second direction are first plate surfaces, and the first plate surfaces have a second edge on a side close to the cover body or the shell; A first exhaust channel is formed between the first edges of the two first support platforms, the second edge of the support plate, and the end surface of the cover body or the shell facing the support plate. Two first exhaust channels are provided opposite to each other along the second direction. The first table surface, the second table surface, and the first exhaust channels together form a peripheral side surface of the support structure. The area of the peripheral side surface of the support structure is S1, the sum of the flow areas of the two first exhaust channels is S2, and S1 and S2 satisfy the following relationship: 0.70≤S2 / S1≤0.85; The value range of S1 is: 800mm 2 ≤S1≤1400mm 2 ; The value range of S2 is: 500mm 2 ≤S2≤1000mm 2 .

2. The battery according to claim 1, characterized in that The support structure and the mounting hole are arranged on the cover body; the end surfaces of the two first support platforms that are close to each other along the first direction are the third platform surface, and the third platform surface has a third edge on the side facing away from the cover body; the end surfaces of the two support plates that are close to each other along the second direction are the second plate surface, and the second plate surface has a fourth edge on the side facing away from the cover body; the third edges of the two first support platforms and the fourth edges of the two support plates form a second exhaust channel; Each of the support plates is provided with a plurality of vent holes, the plurality of vent holes are spaced apart along the first direction, and the plurality of vent holes form a third exhaust channel; In a plane parallel to the first direction and the second direction, the two support plates and the gap between the two support plates constitute an end surface of the support structure facing away from the cover plate body. The area of the end surface of the support structure facing away from the cover plate body is S3, and the sum of the flow areas of the second exhaust channel and the third exhaust channel is S4. Between S3 and S4: 0.40≤S4 / S3≤0.55; The value range of S3 is: 2500mm 2 ≤S3≤11000mm 2 ; The value range of S4 is: 1200mm 2 ≤S4≤6000mm 2 .

3. The battery according to claim 2, characterized in that The battery further includes a plastic component, which is disposed on a side of the cover body close to the accommodating cavity and abuts against a support surface of the support plate on a side facing away from the cover body.

4. The battery according to claim 3, characterized in that The explosion-proof valve includes a fixing portion and a main body portion, wherein the fixing portion is arranged around the circumference of the main body portion, the main body portion is provided with a notch groove, and the portion surrounded by the notch groove forms an opening portion, and the circumference of the fixing portion is attached to and welded to the inner wall of the mounting hole; The total area of the explosion-proof valve is S0, and the area of the opening portion is S5; Between S0 and S5, the following condition is satisfied: 0.80≤S5 / S0≤0.

90.

5. The battery according to claim 4, characterized in that The circumferential outer edge of the explosion-proof valve includes two arc segments and two straight segments, the two straight segments are arranged opposite to each other along a first direction, the two arc segments are arranged opposite to each other along a second direction, and the two arc segments can form a full circle; The calculation formula for S0 is: The distance between the two straight line segments (412) along the first direction is W1, and the distance between the endpoints of the two circular arc segments that are separated from each other along the second direction is L1; The value range of W1 is: 15mm≤W1≤40mm; The value range of L1 is: 25mm≤L1≤65mm.

6. The battery according to claim 3, characterized in that Along the third direction, the distance between the end surface of the support plate close to the cover plate body and the end surface of the cover plate body facing the support plate is H, and the thickness of the support plate is t; The value range of H is: 1.7mm≤H≤4.0mm; The value range of t is 0.8mm≤t≤2.0mm; The relationship between H and t is: 2.5mm≤H+t≤6.0mm.

7. The battery according to claim 6, characterized in that The side of the first table connected to the cover body is flush with the third plate surface of the support plate arranged opposite to the third plate surface in the first direction, and the side of the second table connected to the cover body is flush with the first plate surface of the support plate; The length of the support plate along the first direction is B, the width of the first support platform along the first direction is W2, and the length of the first support platform along the second direction is L2. The calculation formula for S1 is: S1=(L2+B)*H; The calculation formula for S2 is: S2=2*(B-2*W2)*H.

8. The battery according to claim 7, 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 facing away from the cover plate body.

9. The battery according to claim 8, characterized in that The distance between the sides of two adjacent support plates along the second direction is E, the number of vents provided on each support plate is n, and the flow area of each vent is S6; the width of the second support platform along the first direction is W3; The calculation formula for S3 is: S3 = B*L2; The calculation formula for S4 is: S4=E*(B-2*W2-2*W3)+n*S6.

10. The battery according to claim 8, characterized in that The length of the second support platform along the second direction is L3; The relationship between L2 and L3 satisfies: L2>L3, and 5mm≤L2-L3≤10mm.

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