A battery

Abstract

This invention relates to the field of battery technology, specifically disclosing a battery. The battery's cover plate or housing has mounting holes and a support structure, with an explosion-proof valve disposed within the mounting holes. The support structure includes two first support platforms and two support plates. Each support plate is connected to one of the first support platforms at both ends along a first direction, and the two support plates are spaced apart along a second direction. The first support platforms, support plates, and cover plate / housing form a first venting channel, which communicates with the explosion-proof valve. Therefore, after thermal runaway, the support structure can continue to support the electrode assembly, and the flow area of ​​the first venting channel meets the requirements for the flow of high-temperature, high-pressure gases. High-temperature, high-pressure gases can pass through the first venting channel and then be directionally discharged from the explosion-proof valve. The smooth flow path and high flow velocity of the high-temperature, high-pressure gases enable rapid pressure relief, resulting in good battery safety.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and more particularly to a battery. Background Technology

[0002] Lithium-ion batteries have become representative of high-performance batteries due to their advantages such as high operating voltage, high specific energy, large capacity, low self-discharge, good cycle performance, long service life, light weight, and small size. The structure of a conventional lithium-ion battery includes a cover plate, a casing, electrode assembly, and insulating components. The cover plate and casing are welded together to form a sealed space protecting the electrode assembly. An explosion-proof valve is integrated into the cover plate, which can directionally discharge high-temperature, high-pressure gas from the sealed space in the event of thermal runaway. The insulating components are located within the sealed space formed by the casing and cover plate, and are positioned between the cover plate and the electrode assembly. On one hand, the insulating components support the electrode assembly, preventing it from wobbling within the casing, thus providing good fixation; on the other hand, the insulating components prevent short circuits between the electrode assembly and the cover plate, ensuring the electrical safety of the battery.

[0003] However, insulating components are generally made of plastic materials (such as PP), which have limited strength and high-temperature resistance, and typically melt at around 150°C. When a battery experiences thermal runaway, the temperature inside the sealed space is high, causing the insulating components to melt and fail. At this point, only the still-solid electrode assembly remains in the sealed space. The gap between the electrode assembly and the cover plate increases, and due to the lack of support from the insulating components, the electrode assembly has a high degree of freedom within the casing. When high-temperature, high-pressure gas is vented through the explosion-proof valve, the electrode assembly will move with the high-temperature, high-pressure gas flow, posing a risk of blocking the explosion-proof valve's venting passage, reducing the valve's venting efficiency, and resulting in low safety performance. Summary of the Invention

[0004] The purpose of this invention is to provide a battery that can prevent the explosion-proof valve from being blocked due to the movement of the electrode assembly when the battery experiences thermal runaway. The explosion-proof valve has high venting efficiency and good safety performance.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] This invention provides a battery comprising:

[0007] The cover plate body and the housing are connected and enclosed to form a receiving cavity. At least one of the cover plate body and the housing is provided with a mounting hole and a support structure. The mounting hole is used to install an explosion-proof valve.

[0008] The support structure includes two first support platforms and two support plates. The two first support platforms are disposed on both sides of the mounting hole along the first direction. Each of the support plates is connected to one of the first support platforms at both ends along the first direction. The two support plates are spaced apart along the second direction.

[0009] The end face of each of the two first support platforms that is opposite to each other along the first direction is the first platform surface, and the end face of each of the first support platforms that is opposite to each other along the second direction is the second platform surface. The side of the second platform surface near the mounting hole has a first edge. The end face of each of the two support plates that is opposite to each other along the second direction is the first plate surface. The side of the first plate surface near the cover plate body or the shell has a second edge.

[0010] The first edge of the two first support platforms, the second edge of the support plate, and the end face of the cover plate body or the shell facing the support plate form a first exhaust channel. Two first exhaust channels are provided opposite each other along the second direction. The first platform, the second platform, and the first exhaust channel together form the peripheral side of the support structure.

[0011] Wherein, the area of ​​the peripheral side 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: 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 disposed on the cover plate body. The end face of the two first support platforms that is close to each other along the first direction is the third platform, and the side of the third platform facing away from the cover plate body has a third edge. The end face of the two support plates that is close to each other along the second direction is the second plate, and the side of the second plate facing away from the cover plate body has a fourth edge. The third edge of the two first support platforms and the fourth edge of the two support plates form a second exhaust channel.

[0015] Each of the support plates is provided with a plurality of vent holes, which are arranged at intervals along a first direction, and the plurality of vent holes constitute a third exhaust channel;

[0016] In a plane parallel to the first and second directions, the two support plates and the gap between the two support plates constitute the end face of the support structure away from the cover plate body. The area of ​​the end face of the support structure 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 condition: 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 includes a plastic component disposed on the side of the cover plate body near the receiving cavity, and the plastic component abuts against the support surface of the support plate on the side opposite to the cover plate body.

[0020] Optionally, the explosion-proof valve includes a fixing part and a body part. The fixing part is arranged around the circumference of the body part. The body part is provided with a groove. The portion surrounded by the groove forms an opening part. The periphery of the fixing part is attached 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 part is S5;

[0022] The condition S0 and S5 satisfy: 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 each other along a first direction, and the two arc segments are arranged opposite each other along a second direction. The two arc segments can form a complete circle.

[0024] The formula for calculating S0 is:

[0025] ;

[0026] Wherein, the distance between the two straight line segments along the first direction is W1, and the distance between the opposite endpoints of the two circular arc segments 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 a third direction, the distance between the end face of the support plate near the cover plate body and the end face of the cover plate body facing the support plate is H, and the thickness of the support plate is t;

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

[0031] The value of t ranges from 0.8mm to 2.0mm.

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

[0033] Optionally, the side of the first platform connected to the cover plate body is flush with the third plate surface of the support plate which is disposed opposite to the support plate in the first direction, and the side of the second platform connected to the cover plate body is flush with the first plate surface of the support plate.

[0034] Wherein, 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 formula for calculating S1 is:

[0036] ;

[0037] The formula for calculating S2 is:

[0038] .

[0039] Optionally, the support structure further includes two second support platforms, each of which is sandwiched between a first support platform and the mounting hole, and the side of the second support platform facing away from the cover plate body is connected to the support plate.

[0040] Optionally, the distance between the sides of two adjacent support plates along the second direction is E, the number of vent holes provided on each support plate is n, and the flow area of ​​each vent hole is S6; the width of the second support platform along the first direction is W3.

[0041] The formula for calculating S3 is:

[0042] ;

[0043] The formula for calculating S4 is:

[0044] .

[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 this invention are as follows:

[0048] This invention provides a battery, including a cover plate body and a shell. The cover plate body or shell has mounting holes and a support structure, and an explosion-proof valve is disposed in the mounting holes. The support structure includes two first support platforms and two support plates. Each support plate is connected to one of the first support platforms at both ends along a first direction, and the two support plates are spaced apart along a second direction. The first support platforms, support plates, and cover plate body / shell form a first exhaust channel, which is connected to the explosion-proof valve. After the battery experiences thermal runaway, the support structure can continue to support the electrode assembly. High-temperature, high-pressure gases can pass through the first exhaust channel and then be directionally discharged from the explosion-proof valve. The flow path of high-temperature, high-pressure gases is smooth and the flow speed is fast, which can achieve rapid pressure relief and ensure good battery safety. Furthermore, the flow area of ​​the first exhaust channel is sufficient to meet the needs of rapid flow of high-temperature, high-pressure gases, avoiding excessive pressure in the containment cavity that could lead to an explosion, thus ensuring high safety. At the same time, the support structure has high mechanical strength and is not prone to deformation. Attached Figure Description

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

[0050] Figure 2 This is an exploded view of the cover plate body and plastic part provided in Embodiment 1 of the present invention;

[0051] Figure 3 This is a schematic diagram of the structure of the cover plate body provided in Embodiment 1 of the present invention;

[0052] Figure 4 This is a top view of the cover plate body provided in Embodiment 1 of the present invention;

[0053] Figure 5 This is a top view of the cover plate body (without the support plate) provided in Embodiment 1 of the present invention;

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

[0055] Figure 7 This is a side view of the cover plate body provided in Embodiment 1 of the present invention;

[0056] Figure 8 for Figure 7 A magnified view of a section at point I;

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

[0058] In the picture:

[0059] 100. Cover plate body; 110. Mounting hole; 111. Limiting flange; 120. First support platform; 121. First platform surface; 122. Second platform surface; 1221. First edge; 123. Third platform 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 1422, Second exhaust channel; 143, Third plate surface; 144, Support surface; 1441, Vent hole; 200, Housing; 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 segment; 420, Body part; 421, Score groove; 430, Opening part; 500, Electrode group. Detailed Implementation

[0060] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0061] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions. Furthermore, "above," "on top of," and "over" the first feature in relation to the second feature includes the first feature directly above and diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "under," and "below" the first feature in relation to the second feature includes the first feature directly below and diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0062] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0063] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0064] Example 1

[0065] like Figures 1-4 As shown, this embodiment provides a battery, which includes a cover plate body 100 and a housing 200. At least one end of the housing 200 is provided with an opening 201. The cover plate body 100 is connected to the end of the housing 200 with the opening 201 and together with the housing 200 forms a receiving cavity for placing the electrode assembly 500.

[0066] The cover plate body 100 is provided with mounting holes 110 and a support structure, and the explosion-proof valve 400 is disposed in the mounting holes 110. The support structure includes two first support platforms 120 and two support plates 140. The two first support platforms 120 are disposed on both sides of the mounting holes 110 along a first direction, and the two first support platforms 120 are symmetrically arranged about the axis of the mounting holes 110 along a second direction. Each support plate 140 is connected to one of the first support platforms 120 at both ends along the first direction, and the two support plates 140 are spaced apart along the second direction. The aforementioned first direction is... Figure 1 The X-axis direction shown, the second direction is... Figure 1 The Y-axis direction is shown in the figure.

[0067] The end face of each of the two first support platforms 120 that is opposite to each other along the first direction is the first platform 121, and the end face of each of the first support platforms 120 that is opposite to each other along the second direction is the second platform 122. The side of the second platform 122 closest to the mounting hole 110 has a first edge 1221. Figure 8(As shown in the diagram). The end faces of the two support plates 140 that are opposite to each other along the second direction are the first plate face 141. The side of the first plate face 141 near the cover plate body 100 has a second edge 1411. The first edge 1221 of the two first support platforms 120, the second edge 1411 of the support plate 140, and the end face of the cover plate body 100 facing the support plate 140 form 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 to the accommodating cavity.

[0068] With the above settings, after the battery experiences thermal runaway, the support structure on the cover body 100 can continue to support the electrode assembly 500, preventing the electrode assembly 500 from flowing randomly with the high-temperature and high-pressure gas, which would cause the mounting hole 110 on the cover body 100 to be blocked by the electrode assembly 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 discharged in a directional manner through the explosion-proof valve 400 set 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, which can achieve rapid pressure relief and ensure the safety of the battery.

[0069] Furthermore, in this embodiment, the first platform 121, the second platform 122, and the first exhaust channel 1412 together form the peripheral surface of the support structure. The area of ​​the peripheral surface of the support structure is S1, and the sum of the flow areas of the two first exhaust channels 1412 is S2. S1 and S2 satisfy the condition: 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. This ensures that the flow area of ​​the first exhaust channel 1412 is large, meeting the need for rapid flow of high-temperature, high-pressure gases, avoiding excessive pressure within the containment cavity that could lead to an explosion, thus ensuring high safety. Simultaneously, the support structure has high mechanical strength and is less prone to deformation. Optionally, the value range of S1 is 800 mm. 2 ≤S1≤1400mm 2 The value range of S2 is 500mm. 2 ≤S2≤1000mm 2 For example, the value of S1 is 800mm. 2 At that time, the value of S2 can be 560mm. 2 600mm 2 650mm 2 Or 680mm 2 For example, the value of S1 is 1400mm. 2 At that time, the value of S2 can be 980mm. 2 Or 1000mm 2 wait.

[0070] See also Figures 2-4 The battery also includes a plastic part 300, which is disposed on the side of the cover body 100 near the accommodating cavity. The plastic part 300 abuts against the support surface 144 of the support plate 140 on the side away from the cover body 100. The plastic part 300 can insulate the cover body 100 from the electrode group 500.

[0071] Further, in this embodiment, the end faces of the two first support platforms 120 that are close to each other along the first direction are designated as third platform faces 123, and the side of the third platform face 123 facing away from the cover plate body 100 has a third edge 1231. The end faces of the two support plates 140 that are close to each other along the second direction are designated as second plate faces 142, and the side of the second plate face 142 facing away from the cover plate body 100 has a fourth edge 1421. The third edges 1231 of the two first support platforms 120 and the fourth edges 1421 of the two support plates 140 form a second exhaust channel 1422. Each support plate 140 is provided with a plurality of vent holes 1441 that penetrate the support plate 140 along a third direction. The plurality of vent holes 1441 are arranged at intervals along the first direction, and the plurality of vent holes 1441 constitute the third exhaust channel. The aforementioned third direction is... Figure 2 The Z-axis direction is shown in the figure.

[0072] In a plane parallel to the first and second directions, the two support plates 140 and the gap between them constitute the end face of the support structure facing away from the cover plate body 100. Optionally, the area of ​​the end face 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, where S3 and S4 satisfy the condition: 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. This increases the area where high-temperature and high-pressure gases can flow, and the flow areas of the second exhaust channel 1422 and the third exhaust channel are sufficient, allowing high-temperature and high-pressure gases to flow rapidly along the third direction, resulting in higher exhaust efficiency and safety. Furthermore, an exhaust hole 301 is provided on the plastic part 300 at the position corresponding to the mounting hole 110, along the thickness direction of the cover plate body 100 (i.e., Figure 1 As shown in the Z-axis direction, the vent 301 is directly opposite the explosion-proof valve 400, allowing the high-temperature, high-pressure gas before the plastic part 300 is melted to directly act on the explosion-proof valve 400, enabling the explosion-proof valve 400 to respond promptly and open quickly, ensuring battery safety. Furthermore, the second vent channel 1422 is also directly opposite the explosion-proof valve 400, allowing the high-temperature, high-pressure gas after the plastic part 300 is melted to directly act on the explosion-proof valve 400, 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 At that time, the value of S4 can be 1200mm. 2 1250mm 2 1300mm 2 Or 1350mm 2 For example, the value of S3 is 11000mm. 2 At that time, the value of S4 can be 4400mm 2 5000mm 2 or 6000mm 2 wait.

[0074] See Figure 5 and Figure 6 In this embodiment, the cover plate body 100 has a mounting hole 110 at its center 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 inserted into the mounting hole 110 from the side of the cover plate body 100 facing the plastic part 300 and abut against the limiting flange 111 on the inner wall of the mounting hole 110. At this time, it indicates that the explosion-proof valve 400 is installed in place, and the explosion-proof valve 400 can be welded to the cover plate body 100. The setting of the limiting flange 111 ensures accurate positioning between the explosion-proof valve 400 and the cover plate body 100, and the assembly precision is high. In addition, the limiting flange 111 can also temporarily fix the explosion-proof valve 400, which facilitates the welding of the explosion-proof valve 400 to the cover plate body 100.

[0075] Optionally, the explosion-proof valve 400 includes a fixing part 410 and a body part 420. The fixing part 410 is arranged around the circumference of the body part 420. The body part 420 is provided with a groove 421, which is C-shaped or annular. The portion enclosed by the groove 421 forms an opening part 430. When the explosion-proof valve 400 is inserted into the mounting hole 110 from the side of the cover plate body 100 facing the plastic part 300, the end face of the fixing part 410 facing the cover plate body 100 abuts against the limiting flange 111. The periphery of the fixing part 410 is attached to and welded to the inner wall of the mounting hole 110. When the pressure inside the battery's accommodating cavity is too high, it will break through the groove 421 on the body part 420, forming a pressure relief channel at the opening part 430. High-temperature and high-pressure gas can be discharged from the battery's accommodating cavity through the pressure relief channel, 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 part 430 is S5, which means the flow area of ​​the pressure relief channel is S5. 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, etc. This ensures sufficient flow area in the pressure relief channel, smooth exhaust of high-temperature and high-pressure gases, and sufficient mechanical strength of the fixing part 410, resulting in a high connection strength between the fixing part 410 and the cover plate body 100. Otherwise, if the value of S5 / S0 is too large, the area of ​​the fixing part 410 will be small, leading to lower welding strength between the fixing part 410 and the cover plate body 100, and insufficient connection strength between the explosion-proof valve 400 and the cover plate body 100. Of course, the value of S5 / S0 should not be too small either; otherwise, insufficient flow area in the pressure relief channel may lead to untimely pressure relief, resulting in safety risks.

[0077] See also Figure 5 and Figure 6 In this embodiment, the explosion-proof valve 400 is waist-shaped. The circumferential outer edge of the explosion-proof valve 400 includes two arc segments 411 and two straight segments 412. The two straight segments 412 are arranged opposite each other along a first direction, and the two arc segments 411 are arranged opposite each other along a second direction. The two arc segments 411 can form a complete circle. Since the fixing part 410 is located at the outermost edge of the explosion-proof valve 400, that is, the circumferential outer edge of the fixing part 410 includes the aforementioned two arc segments 411 and two straight segments 412.

[0078] Therefore, the formula for calculating 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 opposite endpoints of the two arc segments 411 along the second direction is L1. Since the outer edge of the fixing part 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] For example, 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 plate body 100 along the first direction is A, and W1 < A. The dimension of the cover plate body 100 along the second direction is C, and L1 < C. Therefore, a portion of installation space is reserved on the side of the cover plate body 100 in the length direction and the side of the cover plate body 100 in the width direction to facilitate the welding operation between the cover plate body 100 and the housing 200, and to avoid the heat generated during the welding of the cover plate body 100 and the housing 200 causing deformation or cracking of the explosion-proof valve 400, which would affect the accuracy of the opening pressure of the explosion-proof valve 400.

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

[0083] See Figure 7 and Figure 8 Along the third direction, the distance H between the end face of the support plate 140 near the cover plate body 100 and the end face of the cover plate body 100 facing the support plate 140 is also the height H of the first support platform 120 along the third direction. The value of H is in the range of 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 of t is in the range of 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 the condition: 2.5mm ≤ H + t ≤ 6.0mm, where 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. Consequently, when the plastic part 300 is melted and the support plate 140 on the cover plate body 100 abuts against the electrode group 500, the exhaust space between the cover plate body 100 and the electrode group 500 is larger, which is beneficial to improving the exhaust efficiency of the explosion-proof valve 400 and ensuring high safety.

[0084] See also Figure 4 and Figure 7In this embodiment, the side of the first platform 121 connected to the cover plate body 100 is flush with the third plate surface 143 of the support plate 140, which is disposed opposite to the support plate 140 along the first direction. The side of the second platform 122 connected to the cover plate body 100 is flush with the first plate surface 141 of the support plate 140. That is, the two support plates 140 and the two first support platforms 120 form a frame similar to a square. 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, which is the distance between the opposite sides of the two support plates 140 (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 formula for calculating S1 is:

[0086] .

[0087] The formula for calculating S2 is:

[0088] .

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

[0090] Optionally, the value of W2 is in the range of 15mm ≤ W2 ≤ 20mm. In some embodiments, the value of W2 can be 15mm, 18mm, or 20mm, etc. By limiting the value of W2 to 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 stamp and form, and the contact area between the first support platform 120 and the support plate 140 is large, resulting in a better support effect for the support plate 140. Otherwise, if the value of W2 is too small, the manufacturing yield of the first support platform 120 will be low, the cover plate body 100 will be easily broken during stamping, and the support effect of the first support platform 120 on the support plate 140 after manufacturing will be poor, thus affecting the support effect of the support plate 140 on the electrode assembly 500. Of course, the value of W2 should not be too large either, 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 of L2 is in the range of 25mm ≤ L2 ≤ 65mm. For example, the value of L2 can be 25mm, 35mm, 45mm, 55mm, or 65mm, etc. It should be noted that the value of L2 is greater than twice the width of the support plate 140 along the second direction, so as to ensure that a gap is formed between two adjacent support plates 140 to facilitate venting.

[0092] See also Figure 4 and Figure 5 The support structure in this embodiment also includes two second support platforms 130. Each second support platform 130 is sandwiched between a first support platform 120 and a mounting hole 110. The side of the second support platform 130 facing away from the cover plate body 100 is connected to the support plate 140. The second support platforms 130 provide better support for the support plate 140, ensuring the structural stability of the support plate 140. This allows it to resist the impact of the electrode assembly 500 on the support plate 140, prevents the explosion-proof valve 400 and the mounting hole 110 from being blocked, and makes the support plate 140 less prone to deformation.

[0093] The distance between the sides of two adjacent support plates 140 along the second direction is E. That is, the distance between the fourth edges 1421 of the second surfaces 142 of the two support plates 140 along the second direction is E. The number of vent holes 1441 provided on each support plate 140 is n. The shape of the vent holes 1441 can be circular, square, oblong, etc., and is not limited here. The flow area of ​​each vent hole 1441 is S6. The width of the second support platform 130 along the first direction is W3.

[0094] The formula for calculating S3 is:

[0095] .

[0096] The formula for calculating S4 is:

[0097] .

[0098] It should be noted that, considering that the second support platform 130 partially obstructs the second exhaust channel 1422, the calculation formula for S4 above includes " One item.

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

[0100] .

[0101] Optionally, the value of E ranges from 9mm to 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 either, 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 decrease, and the support plate 140 may deform, resulting in poor support for the pole group 500 or the plastic part 300.

[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 smooth flow of high-temperature, high-pressure gas along the length direction (first direction) of the cover plate body 100, preventing the first support platform 120 or the second support platform 130 from obstructing the flow of high-temperature, high-pressure gas along the length direction of the cover plate body 100, thus avoiding a decrease in flow velocity and 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 25mm, the value of L2 can be 25mm, and the value of L3 can be 20mm. In some embodiments, when the value of L1 is 30mm, the value of L2 can be 30mm, and the value of L3 can be 25mm, 20mm, etc. In some embodiments, when the value of L1 is 65mm, the value of L2 can be 65mm, and the value of L3 can be 60mm, 55mm, etc., and so on.

[0104] It is important to note that the values ​​of L2 and L3 should not be too large. Otherwise, if the end of the first support platform 120 along the second direction is too close to the side of the cover plate body 100 along the second direction, and the end of the second support platform 130 along the second direction is too close to the side of the cover plate body 100 along the second direction, the risk of interference between the support plate 140 and the plastic part 300 will be high due to the influence of the precision of the processing equipment when the plastic part 300 is heat-fused to the cover plate body 100, resulting in decreased assembly precision. Of course, the values ​​of L2 and L3 should also not be too small. Otherwise, the support effect of the first support platform 120 and the second support platform 130 on the support plate 140 will be poor, increasing the risk of deformation of the support plate 140 after being stamped by the electrode assembly 500, which may affect venting and pose a safety risk.

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

[0106] Depending on the battery's reaction system, the amount of gas generated by electrode assembly 500 during thermal runaway varies. For example, when electrode assembly 500 is a ternary lithium system, the reaction between electrode assembly 500 and the electrolyte is more vigorous, resulting in a larger amount of gas generated during thermal runaway. Therefore, the height of the support structure along the third direction needs to be increased. 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 following tests were conducted on samples of different design sizes to verify the thermal runaway of the ternary lithium battery system and to determine whether the battery could pass the safety test. The standard for passing the safety test was that the battery's explosion-proof valve 400 could open smoothly with accurate opening pressure and no explosion occurred. The results are shown in Table 1.

[0108] Table 1

[0109]

[0110] The results above indicate that in samples 1 and 2, the values ​​of H, t, and H+t do not meet their corresponding 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 provide good support for the electrode group 500, and the electrode group 500 obstructs the mounting hole 110. Ultimately, this leads to the explosion-proof valve 400 failing to open during thermal runaway, preventing the battery from releasing pressure in time, posing a safety risk, resulting in a low safety test pass rate and defective batteries.

[0111] In samples 4 and 6, the S2 / S1 values ​​are too small, failing to meet the size limit of 0.75≤S2 / S1≤0.85. The flow area of ​​the first exhaust channel 1412 is small, affecting the flow of high-temperature and high-pressure gas to the explosion-proof valve 400. This makes it impossible to ensure smooth exhaust from the explosion-proof valve 400, and there is a possibility that the explosion-proof valve 400 may not open in time, posing a safety risk. As a result, the battery safety test pass rate is low, and the battery is defective.

[0112] In samples 5 and 6, the values ​​of S4 / S3 are small, failing to meet the size limit of 0.45≤S4 / S3≤0.55. The flow area of ​​the second exhaust channel 1422 is small, affecting the flow of high-temperature and high-pressure gas to the explosion-proof valve 400. This makes it impossible to ensure smooth exhaust from the explosion-proof valve 400, which may lead to the explosion-proof valve 400 failing to open and release pressure in time, posing a safety risk. Consequently, the battery safety test pass rate is low, and the battery is defective.

[0113] In sample 3, all parameters H, t, H+t, S2 / S1, and S4 / S3 meet their corresponding value ranges. At this time, the support structure provides significant support for 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 smoothly and exhaust smoothly with high exhaust efficiency. The battery passed all safety tests without explosion, and the battery product is in good condition.

[0114] When the electrode assembly 500 of the battery is a lithium iron phosphate system, the reaction between the electrode assembly 500 and the electrolyte is relatively slow, and the amount of gas generated during thermal runaway is smaller than that of a ternary lithium system battery. Therefore, the height of the support structure along the third direction can be appropriately reduced to decrease the space occupied by the support structure and increase the arrangement space of the electrode assembly 500. At this time, the value range of H is: 1.7mm≤H≤2.8mm, the relationship between H and t is: 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 tests were conducted on samples of different design sizes to verify the thermal runaway of the lithium iron phosphate battery system described above, and to determine whether the battery could pass the safety test. The standard for passing the safety test was that the battery's explosion-proof valve 400 could open smoothly with accurate opening pressure and no explosion occurred. The results are shown in Table 2.

[0116] Table 2

[0117]

[0118] The results above indicate that in sample 7, the values ​​of H, t, and H+t are too small and do not meet their corresponding 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 prone to deformation, resulting in poor support for the electrode group 500. The electrode group 500 obstructs the mounting hole 110, ultimately causing the explosion-proof valve 400 to fail to open during thermal runaway. The battery cannot 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.

[0119] In sample 8, the value of t is too small and does not meet its corresponding 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 does not provide good support for the electrode group 500. 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 has a low safety test pass rate and is defective.

[0120] In samples 12 and 13, the value of S2 / S1 is too small, failing to meet the size limit of 0.70≤S2 / S1≤0.80. The flow area of ​​the first exhaust channel 1412 is small, affecting the flow of high-temperature and high-pressure gas to the explosion-proof valve 400. This makes it impossible to ensure smooth exhaust from the explosion-proof valve 400, and there is a possibility that the explosion-proof valve 400 may not open in time, posing a safety risk. As a result, the battery safety test pass rate is low, and the battery is defective.

[0121] In samples 13 and 14, the values ​​of S4 / S3 are small, failing to meet the size limit of 0.40≤S4 / S3≤0.50. The flow area of ​​the second exhaust channel 1422 is small, affecting the flow of high-temperature and high-pressure gas to the explosion-proof valve 400. This makes it impossible to ensure smooth exhaust from the explosion-proof valve 400, which may lead to the explosion-proof valve 400 failing to open and release pressure in time, posing a safety risk. Consequently, 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 meet their corresponding value ranges. At this time, the support structure provides significant support for 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 exhausts smoothly with high exhaust efficiency. The battery safety test is passed, no explosion occurs, and the battery product is in good condition.

[0123] In summary, it is evident that the size design and positional arrangement of the support structure have a significant impact on the support effect of the electrode group 500 and the venting effect of the explosion-proof valve 400. When the battery type is selected and the size design of the support structure is adopted according to the battery type, it can be ensured that the support structure provides good support for the electrode group 500, while the venting of the explosion-proof valve 400 is not affected. This significantly improves the problem of the explosion-proof valve 400 being blocked by the electrode group 500 and affecting venting during battery thermal runaway, resulting in high battery safety performance.

[0124] Example 2

[0125] This embodiment also provides a battery, which differs from the battery in Embodiment 1 in that the mounting hole 110 and the support structure in this embodiment are provided on one of the side walls of the housing 200.

[0126] See Figure 9 In this embodiment, the battery can be a blade battery, and the casing 200 is along the first direction ( Figure 9 Both ends of the cover plate 100 (in the X-axis direction shown) are formed with openings 201. There are two cover plate bodies 100. Each cover plate body 100 is connected to one opening 201 of the housing 200 and blocks the opening 201. The two cover plate bodies 100 and the housing 200 form a cavity for placing the electrode assembly 500.

[0127] Housing 200 includes a third direction (with) Figure 9 The two first sidewalls 210, which are perpendicular to each other in the X-axis and Y-axis directions shown, and the two sidewalls 210 arranged opposite each other along the second direction (where the X-axis and Y-axis directions are both perpendicular) Figure 9 Two second sidewalls 220 are arranged opposite each other (in the Y-axis direction shown in the diagram). The first sidewall 210 is connected to the second sidewall 220, and the area of ​​the first sidewall 210 is smaller than the area of ​​the second sidewall 220. In this embodiment, the mounting hole 110 and the support structure are arranged on the first sidewall 210 as an example. The plastic part 300 is arranged on the side of the first sidewall 210 near the receiving cavity, and the plastic part 300 abuts against the side of the support structure away from the first sidewall 210.

[0128] Specifically, a first exhaust channel 1412 is provided between the support structure and the first side wall 210 of the housing 200. The first exhaust channel 1412 connects the accommodating cavity and the pressure relief channel of the explosion-proof valve 400. With the above arrangement, even if the battery experiences thermal runaway and the plastic part 300 is melted, the support structure provided on the cover plate body 100 can continue to support the electrode assembly 500. High-temperature and high-pressure gas can pass through the first exhaust channel 1412, then flow to the mounting hole 110 and be discharged directionally through the explosion-proof valve 400 provided in the mounting hole 110, achieving rapid pressure relief and ensuring good battery safety.

[0129] Furthermore, the area of ​​the peripheral surface of the support structure is defined as S1, and the flow area of ​​the first exhaust channel 1412 is defined as S2. S1 and S2 satisfy the condition: 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. This ensures that the flow area of ​​the first exhaust channel 1412 is sufficient to meet the flow requirements of high-temperature, high-pressure gases, preventing excessive pressure within the accommodating cavity from causing an explosion, thus ensuring high safety. Simultaneously, the support structure has high mechanical strength and is less prone to deformation.

[0130] In this embodiment, the end face of the support structure away from the first sidewall 210 of the shell 200 has a second exhaust channel 1422 and a third exhaust channel. The area of ​​the end face of the support structure 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 condition: 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. This increases the area where high-temperature, high-pressure gas can flow. The flow areas of the first exhaust channel 1412, the second exhaust channel 1422, and the third exhaust channel are sufficient, allowing high-temperature, high-pressure gas to flow quickly, resulting in high exhaust efficiency and high safety. Furthermore, the second exhaust channel 1422 and the third exhaust channel are directly opposite the explosion-proof valve 400, so that the high temperature and high pressure gas after the plastic part 300 is melted can directly act on the explosion-proof valve 400, thereby achieving rapid pressure relief.

[0131] The remaining structure of the battery in this embodiment is the same as that in Embodiment 1, and will not be described again here.

[0132] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A battery, characterized in that, include: The cover plate body and the housing are connected and enclosed to form a receiving cavity. At least one of the cover plate body and the housing is provided with a mounting hole and a support structure. The mounting hole is used to install an explosion-proof valve. The support structure includes two first support platforms and two support plates. The two first support platforms are disposed on both sides of the mounting hole along a first direction. Each support plate is connected to one of the first support platforms at both ends along the first direction. The two support plates are spaced apart along a second direction. The first direction is the length direction of the support structure, and the second direction is the width direction of the support structure. The end face of each of the two first support platforms that is opposite to each other along the first direction is the first platform surface, and the end face of each of the first support platforms that is opposite to each other along the second direction is the second platform surface. The side of the second platform surface near the mounting hole has a first edge. The end face of each of the two support plates that is opposite to each other along the second direction is the first plate surface. The side of the first plate surface near the cover plate body or the shell has a second edge. The first edge of the two first support platforms, the second edge of the support plate, and the end face of the cover plate body or the shell facing the support plate form a first exhaust channel. Two first exhaust channels are provided opposite each other along the second direction. The first platform, the second platform, and the first exhaust channel together form the peripheral side of the support structure. Wherein, the area of ​​the peripheral side 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: 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 ; The battery also includes a plastic part, which is disposed on the side of the cover plate body or the housing near the receiving cavity, and the plastic part abuts against the support surface of the support plate on the side away from the cover plate body or the housing. Along the third direction, the distance between the end face of the support plate near the cover plate body or the shell and the end face of the cover plate body or the shell facing the support plate is H, and the thickness of the support plate is t; wherein, the third direction is the height direction of the support structure; The value range of H is: 1.7mm ≤ H ≤ 4.0mm; The value of t ranges from 0.8mm to 2.0mm. The relationship between H and t satisfies: 2.5mm≤H+t≤6.0mm.

2. The battery according to claim 1, characterized in that, The support structure and the mounting holes are disposed on the cover plate body. The end face of the two first support platforms that is close to each other along the first direction is the third platform surface. The side of the third platform surface facing away from the cover plate body has a third edge. The end face of the two support plates that is close to each other along the second direction is the second plate surface. The side of the second plate surface facing away from the cover plate body has a fourth edge. The third edge of the two first support platforms and the fourth edge of the two support plates form a second exhaust channel. Each of the support plates is provided with a plurality of vent holes, which are arranged at intervals along a first direction, and the plurality of vent holes constitute a third exhaust channel; In a plane parallel to the first and second directions, the two support plates and the gap between the two support plates constitute the end face of the support structure away from the cover plate body. The area of ​​the end face of the support structure 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. The condition for S3 and S4 is: 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 1, characterized in that, The explosion-proof valve includes a fixing part and a body part. The fixing part is arranged around the circumference of the body part. The body part is provided with a groove. The portion surrounded by the groove forms an opening part. The periphery of the fixing part 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 part is S5; The condition S0 and S5 satisfy: 0.80≤S5 / S0≤0.

90.

4. The battery according to claim 3, characterized in that, The explosion-proof valve has two circular arc segments and two straight segments on its circumferential outer edge. The two straight segments are arranged opposite each other along a first direction, and the two circular arc segments are arranged opposite each other along a second direction. The two circular arc segments can form a complete circle. The formula for calculating S0 is: ； Wherein, the distance between the two straight line segments (412) along the first direction is W1, and the distance between the opposite endpoints of the two arc segments along the second direction is L1; The value range of W1 is: 15mm≤W1≤40mm; The value range of L1 is: 25mm≤L1≤65mm.

5. The battery according to claim 2, characterized in that, The side of the first platform connected to the cover plate body is flush with the third plate surface of the support plate which is disposed opposite to the support plate in the first direction; the side of the second platform connected to the cover plate body is flush with the first plate surface of the support plate. Wherein, 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 formula for calculating S1 is: ； The formula for calculating S2 is: 。 6. The battery according to claim 5, characterized in that, The support structure also includes two second support platforms, each of which is sandwiched between a first support platform and the mounting hole, and the side of the second support platform facing away from the cover plate body is connected to the support plate.

7. The battery according to claim 6, characterized in that, The distance between the sides of two adjacent support plates along the second direction is E; the number of vent holes provided on each support plate is n; the flow area of ​​each vent hole is S6; the width of the second support platform along the first direction is W3. The formula for calculating S3 is: ； The formula for calculating S4 is: 。 8. The battery according to claim 6, 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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