A type of battery

Abstract

This invention relates to the field of battery technology, specifically disclosing a battery comprising an explosion-proof valve, a cover plate body, a shell, and a plastic component. At least one of the cover plate body and the shell has a mounting hole and a support structure. The explosion-proof valve is disposed within the mounting hole. The support structure includes multiple support platforms arranged circumferentially around the mounting hole, spaced apart from the mounting hole, with an exhaust channel formed between adjacent support platforms. The plastic component is disposed on the side of the cover plate body or shell near the receiving cavity. The ends of the support platforms facing away from the cover plate body or shell abut against the plastic component, thus insulating the cover plate body / shell from the electrode assembly. In the event of thermal runaway and melting of the plastic component, the multiple support platforms on the cover plate body or shell continue to support the electrode assembly, preventing the electrode assembly from blocking the mounting hole on the cover plate body or shell, ensuring smooth exhaust from the explosion-proof valve, enabling rapid pressure relief, and ensuring 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] Explosion-proof valve;

[0008] The cover plate body and the housing are connected and enclosed to form an accommodating 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 the explosion-proof valve. The support structure includes multiple support platforms, which are all arranged around the mounting hole. Each support platform is spaced apart from the mounting hole, and an exhaust channel is formed between two adjacent support platforms.

[0009] A plastic part is disposed on the side of the cover plate body or the housing near the receiving cavity, and the end of the support platform away from the cover plate body or the housing abuts against the plastic part;

[0010] Wherein, the perimeter of the mounting hole is S1, the sum of the lengths of all the support platforms is S2, and S1 and S2 satisfy the following condition: 0.65≤S2 / S1≤1.1.

[0011] Optionally, the mounting holes and the support structure are provided on the cover plate body, the length of each support platform is S21, the number of support platforms is n, and S2 and S21 satisfy: S2 = S21·n;

[0012] The value range of S21 is: 10mm≤S21≤16mm.

[0013] Optionally, the width of the support platform is W, and the value of W is in the range of 5mm≤W≤8mm.

[0014] Optionally, along the width direction of the cover plate body, the distance between the side of the support platform away from the mounting hole and the adjacent side of the cover plate body is A, and the size of the cover plate body is F;

[0015] The relationship between A and F satisfies: 0.12 ≤ A / F ≤ 0.2;

[0016] The range of values ​​for A is: 5mm ≤ A ≤ 10mm;

[0017] The value range of F is: 25mm≤F≤75mm.

[0018] Optionally, the distance between the side of the support platform closest to the mounting hole and the adjacent side of the mounting hole is D, and the value of D is in the range of 4mm≤D≤6mm.

[0019] Optionally, the height of the support platform is H in a direction perpendicular to the end face of the cover plate body or the housing, and the value of H is in the range of 3mm≤H≤5mm.

[0020] Optionally, when the battery is a ternary lithium system, the relationship between S1 and S2 satisfies: 0.85≤S2 / S1≤1.1;

[0021] When the battery is a lithium iron phosphate system, the relationship between S1 and S2 satisfies: 0.65≤S2 / S1≤0.8.

[0022] Optionally, the plastic part is provided with a plurality of vent holes, which are arranged at intervals on the plastic part. Along a direction perpendicular to the end face of the cover plate body or the housing, the projection of the plurality of vent holes on the cover plate body or the housing at least partially coincides with the projection of the mounting hole on the cover plate body or the housing.

[0023] Optionally, the plastic part has a clearance groove on the side facing the cover plate body or the housing, and the support platform is embedded in the clearance groove.

[0024] The beneficial effects of this invention are as follows:

[0025] This invention provides a battery comprising an explosion-proof valve, a cover body, a housing, and a plastic component. The cover body is connected to the housing and together with the housing forms a cavity for housing an electrode assembly. At least one of the cover body and the housing has a mounting hole and a support structure. The explosion-proof valve is disposed within the mounting hole. The support structure includes multiple support platforms, all disposed circumferentially around the mounting hole. Each support platform is spaced apart from the mounting hole, and adjacent support platforms are also spaced apart to form an exhaust channel between adjacent support platforms. The plastic component is disposed on the side of the cover body or housing near the cavity. The ends of the support platforms facing away from the cover body or housing abut against the plastic component, thereby insulating the cover body from the electrode assembly through the plastic component.

[0026] With the above configuration, even after thermal runaway and melting of the plastic parts, the multiple support platforms on the cover plate or shell can continue to support the electrode assembly, preventing the electrode assembly from flowing randomly with the high-temperature and high-pressure gas and causing the mounting holes on the cover plate to be blocked by the electrode assembly. The high-temperature and high-pressure gas can pass through the exhaust channel between two adjacent support platforms on the cover plate, and then flow to the mounting hole and be discharged in a directional manner through the explosion-proof valve installed in the mounting hole. The flow path of the high-temperature and high-pressure gas is smooth and the flow speed is fast. The explosion-proof valve has a good exhaust effect and can achieve rapid pressure relief, thus ensuring the safety of the battery. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of the present invention and these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the structure of the cover plate body provided in Embodiment 1 of the present invention;

[0029] Figure 2 for Figure 1 A magnified view of a section at point A in the middle;

[0030] Figure 3 This is a top view of the cover plate body provided in Embodiment 1 of the present invention;

[0031] Figure 4 This is a schematic diagram of the battery structure provided in Embodiment 2 of the present invention;

[0032] Figure 5 This is a partial enlarged view of the battery provided in Embodiment 2 of the present invention.

[0033] In the picture:

[0034] 100, Cover plate body; 110, Mounting hole; 111, Limiting flange; 120, Support platform; 120a, First boss; 120b, Second boss; 121, Exhaust channel; 200, Housing; 210, First side wall; 220, Second side wall. Detailed Implementation

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] Example 1

[0040] like Figures 1-3 As shown, this embodiment provides a battery including an explosion-proof valve, a cover body 100, a housing 200, and a plastic part. The cover body 100 is connected to the housing 200 and together with the housing 200 forms a cavity for placing the electrode assembly. The cover body 100 is provided with a mounting hole 110 and a support structure. The explosion-proof valve is disposed in the mounting hole 110. The support structure includes multiple support platforms 120, all of which are disposed around the mounting hole 110. In this embodiment, the mounting hole 110 is racetrack-shaped, and the multiple support platforms 120 form a quasi-annular structure. This quasi-annular structure has the same shape as the mounting hole 110 and is concentric with the mounting hole 110. Each support platform 120 is spaced apart from the mounting hole 110, and adjacent support platforms 120 are also spaced apart to form an exhaust channel 121 between adjacent support platforms 120. The plastic part is disposed on the side of the cover plate body 100 near the receiving cavity, and the end of the support platform 120 away from the cover plate body 100 abuts against the plastic part, thereby insulating the cover plate body 100 from the pole group through the plastic part.

[0041] With the above configuration, even after thermal runaway and melting of the plastic parts, the multiple support platforms 120 on the cover body 100 can continue to support the electrode assembly, preventing the electrode assembly from randomly flowing with the high-temperature, high-pressure gas and causing the mounting holes 110 on the cover body 100 to be blocked by the electrode assembly. The high-temperature, high-pressure gas can pass through the exhaust channel 121 between two adjacent support platforms 120 on the cover body 100, and then flow to the mounting hole 110, where it is directionally discharged through the explosion-proof valve. The flow path of the high-temperature, high-pressure gas is smooth and the flow speed is fast, resulting in good venting effect of the explosion-proof valve and rapid pressure relief, thus ensuring good battery safety. It should be noted that the explosion-proof valve is in the open state at this time.

[0042] Furthermore, the perimeter of the mounting hole 110 is S1, and the sum of the lengths of all support platforms 120 is S2. S1 and S2 satisfy the condition: 0.65 ≤ S2 / S1 ≤ 1.1. For example, the value of S2 / S1 can be 0.65, 0.75, 0.80, 0.85, 0.90, or 1.1. By controlling the value of S2 / S1 within the above range, it is ensured that the exhaust channel 121 formed between two adjacent support platforms 120 is relatively large. This satisfies the need for high-temperature, high-pressure gas flow when the battery experiences thermal runaway and the plastic parts melt and fail. Simultaneously, the large contact area between the support platform 120 and the electrode assembly provides excellent support for the electrode assembly, maintaining the formation of the exhaust channel 121 and preventing the electrode assembly from shifting towards the cover plate body 100 under the impact of high-temperature, high-pressure gas, thus preventing the mounting hole 110 on the cover plate body 100 from being blocked. This ensures high exhaust efficiency of the explosion-proof valve and significantly improves the battery's safety performance.

[0043] See also Figure 3 In this embodiment, some support platforms 120 extend along the length direction of the cover plate body 100, and some support platforms 120 extend along the width direction of the cover plate body 100. For ease of explanation, the support platform 120 extending along the length direction of the cover plate body 100 is designated as the first boss 120a, and the support platform 120 extending along the width direction of the cover plate body 100 is designated as the second boss 120b. The length direction of the cover plate body 100 is... Figure 3 The X-axis direction shown is denoted as the first direction here, and the width direction of the cover plate body 100 is... Figure 3 The Y-axis direction shown is denoted as the second direction. The total number of support platforms 120 is n, meaning the sum of the number of the first boss 120a and the second boss 120b is n. The length of both the first boss 120a and the second boss 120b is S21. S2 and S21 satisfy the following relationship: S2 = S21·n. The value range of S21 is: 10mm ≤ S21 ≤ 16mm. For example, the value of S21 can be 10mm, 12mm, 14mm, or 16mm, etc.

[0044] In this embodiment, two first protrusions 120a and six second protrusions 120b are provided as an example. The two first protrusions 120a are symmetrically arranged on opposite sides of the mounting hole 110 along the second direction. The six second protrusions 120b are divided into two groups, each group consisting of three protrusions 120b, spaced apart along the second direction. The first protrusions 120a and second protrusions 120b are also spaced apart. Thus, exhaust channels 121 are formed between the first protrusions 120a and second protrusions 120b, and between adjacent second protrusions 120b, allowing high-temperature, high-pressure gas to flow. This reduces the resistance to the flow of high-temperature, high-pressure gas along the first direction, allowing it to be discharged to the mounting hole 110, ensuring smooth opening of the explosion-proof valve and relatively unobstructed exhaust. Here, S2 and S21 satisfy the following condition: S2 = S21·8.

[0045] Furthermore, the width of the support platform 120 is W, that is, the dimension of the first boss 120a along the second direction is W, and the dimension of the second boss 120b along the first direction is W. The dimensions of the first boss 120a along the second direction and the dimensions of the second boss 120b along the first direction are equal. The value range of W is: 5mm ≤ W ≤ 8mm. For example, the value of W can be 5mm, 6mm, 7mm, or 8mm, etc. By limiting the value of W within the above range, the contact area between each support platform 120 (including the first boss 120a and the second boss 120b) and the electrode assembly is larger, ensuring that the support platform 120 provides good support for the electrode assembly, and the support platform 120 is not too sharp, making it easy to stamp. Otherwise, if the value of W is too small, the support effect of the support platform 120 on the electrode assembly will decrease, and there is a risk that the electrode assembly will block the mounting hole 110 on the cover plate body 100, resulting in poor ventilation of the explosion-proof valve. In addition, the support platform 120 is not easy to stamp on the cover plate body 100, resulting in a low processing yield.

[0046] Furthermore, multiple support platforms 120 are formed on the cover plate body 100 by stamping. The distance between the side of the support platform 120 near the mounting hole 110 and the adjacent side of the mounting hole 110 is D, and the value of D is in the range of 4mm≤D≤6mm. Specifically, along the second direction, the distance between the side of the first boss 120a near the mounting hole 110 and the mounting hole 110 is D. Along the first direction, the distance between the side of the second boss 120b near the mounting hole 110 and the mounting hole 110 is also D, and the distance between the first boss 120a and the mounting hole 110 is equal to the distance between the second boss 120b and the mounting hole 110.

[0047] For example, the value of D can be 4mm, 5mm, or 6mm, etc. By controlling the value of D within the above range, it can be ensured that after the support platform 120 (including the first boss 120a and the second boss 120b) is stamped, the flatness of the surrounding area of ​​the mounting hole 110 on the cover plate body 100 is good, the assembly accuracy between the explosion-proof valve and the cover plate body 100 is high, the reliability of the explosion-proof valve is high, and it is not easy to fail. Otherwise, if the value of D is too small, the distance between the support platform 120 and the mounting hole 110 is too close, the flatness of the surrounding area of ​​the mounting hole 110 on the cover plate body 100 is poor, which affects the welding quality between the explosion-proof valve and the cover plate body 100 and poses a risk of sealing failure. Of course, the value of D should not be too large either, otherwise the distance between the support platform 120 and the mounting hole 110 will be too far, the support effect of the electrode group will decrease, and there is a risk that the electrode group will block the mounting hole 110 on the cover plate body 100.

[0048] Optionally, a limiting flange 111 is provided on the inner wall of the mounting hole 110. The explosion-proof valve can be inserted into the mounting hole 110 from one side of the cover plate body 100 and abut against the limiting flange 111 on the inner wall of the mounting hole 110. This indicates that the explosion-proof valve is installed in place, and the explosion-proof valve can be welded to the cover plate body 100. The setting of the limiting flange 111 ensures accurate positioning between the explosion-proof valve and the cover plate body 100, resulting in high assembly precision. In addition, the limiting flange 111 can also temporarily fix the explosion-proof valve, facilitating the welding operation between the explosion-proof valve and the cover plate body 100.

[0049] See also Figure 3 Along the width direction of the cover plate body 100, in this embodiment, the distance between the side of the first protrusion 120a facing away from the mounting hole 110 and the adjacent side of the cover plate body 100 is A, and the dimension of the cover plate body 100 is F. A and F satisfy the condition: 0.12 ≤ A / F ≤ 0.2. For example, the value of A / F can be 0.12, 0.14, 0.16, 0.18, or 0.20, etc. The range of A is 5mm ≤ A ≤ 10mm, and the range of F is 25mm ≤ F ≤ 75mm. That is, when the value of A is 5mm, the value of F can be 25mm, 30mm, 35mm, 40mm, or 42mm, etc. When the value of A is 10mm, the value of F can be 50mm, 60mm, 70mm, or 80mm, etc. The range of A is 5mm ≤ A ≤ 10mm, and the range of F is 25mm ≤ F ≤ 75mm. That is, when the value of A is 5mm, the value of F can be 25mm, 30mm, 35mm, 40mm, or 42mm, etc. When the value of A is 10mm, the value of F can be 50mm, 60mm, 70mm, or 75mm, etc.

[0050] By limiting the A / F value within the aforementioned range, a certain space is ensured between the first boss 120a and the side edge of the cover plate body 100 along the second direction, facilitating the assembly of the cover plate body 100 and the housing 200. This also minimizes the resistance to the flow of high-temperature, high-pressure gas along the first direction, ensuring smooth opening of the explosion-proof valve and efficient venting. It is important to note that the A / F value should not be too small; otherwise, the flow of high-temperature, high-pressure gas along the first direction will be obstructed, potentially causing the explosion-proof valve to fail to open in time, posing a safety risk. Conversely, the A / F value should not be too large; otherwise, the distance between the first boss 120a and the mounting hole 110 will be too small, resulting in poor support for the electrode assembly and a risk of the mounting hole 110 on the cover plate body 100 being blocked by the electrode assembly, hindering venting of the explosion-proof valve.

[0051] See also Figure 2 Along the direction perpendicular to the end face of the cover plate body 100 (i.e. Figure 1 The Z-axis direction shown in the diagram (here referred to as the third direction) has a height of H for the support platform 120, where H ranges from 3mm to 5mm. For example, H can be 3mm, 4mm, or 5mm. By limiting the value of H to the above range, the flow area of ​​the exhaust channel 121 formed between two adjacent support platforms 120 is increased. Consequently, when the plastic part is melted and the support platform 120 abuts against the electrode assembly, the exhaust space between the cover plate body 100 and the electrode assembly is larger, which helps to improve the exhaust efficiency of the explosion-proof valve and ensures high safety.

[0052] Furthermore, the plastic part is provided with multiple vent holes, which are spaced apart on the plastic part. Along a direction perpendicular to the end face of the cover plate body 100 (i.e., the third direction), the projections of the multiple vent holes on the cover plate body 100 at least partially overlap with the projections of the mounting holes 110 on the cover plate body 100. After thermal runaway of the battery, before the internal temperature of the battery rises to the melting point of the plastic part, the plastic part maintains its pre-melting shape to support the electrode assembly. At this time, the high-temperature, high-pressure gas in the accommodating cavity can be discharged to the explosion-proof valve through the vent holes, allowing the explosion-proof valve to open and release pressure. A clearance groove is provided on the side of the plastic part facing the cover plate body 100, and the support platform 120 is embedded in the clearance groove. The clearance groove avoids wasting space in the accommodating cavity, reduces the space occupied by the cover plate body 100, and helps to increase the volume of the electrode assembly and improve the energy density of the battery.

[0053] When the battery is a ternary lithium system, the relevant parameters S1 and S2 of the battery cover body 100 satisfy the following condition: 0.85≤S2 / S1≤1.1.

[0054] The thermal runaway of the ternary lithium system battery with the above structure was verified using samples of different design sizes. The battery capacity was 350Ah and the voltage was 3.5V. The verification results are shown in Table 1.

[0055] Table 1

[0056]

[0057] From the above results, it can be concluded that in samples 1 and 2, the value of D is less than the minimum value of 4mm≤D≤6mm, the value of W meets its corresponding range, and the relationship between S1 and S2 is: 0.85≤S2 / S1≤1.1. At this time, the distance between the support platform 120 and the mounting hole 110 is too close, the support platform 120 does not provide good support for the electrode group, it cannot maintain the design gap between the cover plate body 100 and the electrode group, the explosion-proof valve exhaust is not smooth, the pass rate of the battery thermal runaway test is low, and the battery product is defective.

[0058] In samples 3 and 4, the value of W is less than the minimum value of 5mm≤W≤8mm, and the values ​​of D and S2 / S1 meet their corresponding ranges. At this time, the width of the support platform 120 along its extension direction is small, the contact area with the electrode group is small, the support effect of the electrode group is not obvious, the exhaust space between the cover plate body 100 and the electrode group is small, and it is impossible to ensure smooth exhaust of the explosion-proof valve. The pass rate of the battery thermal runaway test is low, and there is a risk of explosion, resulting in defective battery products.

[0059] In samples 5 and 6, the values ​​of D, W, and S2 / S1 all meet their corresponding ranges. At this time, the support platform 120 provides significant support to the electrode assembly, the exhaust space between the cover plate body 100 and the electrode assembly is large, the explosion-proof valve exhausts smoothly and has high exhaust efficiency, the battery thermal runaway test is passed, no explosion occurs, and the battery product is in good condition.

[0060] In samples 7 and 8, the value of S2 / S1 is less than the minimum value of 0.85≤S2 / S1≤1.1, and the values ​​of D and W meet their corresponding ranges. At this time, the exhaust channel 121 formed between two adjacent support platforms 120 is small, and the exhaust space formed between the cover body 100 and the electrode group is small. It is impossible to ensure that the explosion-proof valve exhausts in time, which poses a certain risk of explosion. The pass rate of the battery thermal runaway test is low, and the battery product is defective.

[0061] When the battery is a lithium iron phosphate system, the relevant parameters S1 and S2 of the battery cover body 100 satisfy the following: 0.65≤S2 / S1≤0.8.

[0062] The thermal runaway of the lithium iron phosphate battery system with the above structure was verified using samples of different design sizes. The battery capacity was 350Ah and the voltage was 3.5V. The verification results are shown in Table 2.

[0063] Table 2

[0064]

[0065] From the above results, it can be concluded that in samples 1 and 2, the value of D is less than the minimum value of 4mm≤D≤6mm, the value of W meets its corresponding range, and the relationship between S1 and S2 is: 0.65≤S2 / S1≤0.8. At this time, the distance between the support platform 120 and the mounting hole 110 is too close, the support platform 120 does not provide good support for the electrode group, and it is impossible to maintain the design gap between the cover plate body 100 and the electrode group. The explosion-proof valve exhaust is not smooth, the pass rate of the battery thermal runaway test is low, and the battery product is defective.

[0066] In samples 3 and 4, the value of W is less than the minimum value of 5mm≤W≤8mm, and the values ​​of D and S2 / S1 meet their corresponding ranges. At this time, the width of the support platform 120 along its extension direction is small, the contact area with the electrode group is small, the support effect of the electrode group is not obvious, the exhaust space between the cover plate body 100 and the electrode group is small, and it is impossible to ensure smooth exhaust of the explosion-proof valve. The pass rate of the battery thermal runaway test is low, and there is a risk of explosion, resulting in defective battery products.

[0067] In samples 5 and 6, the values ​​of D, W, and S2 / S1 all meet their corresponding ranges. At this time, the support platform 120 provides significant support to the electrode assembly, the exhaust space between the cover plate body 100 and the electrode assembly is large, the explosion-proof valve exhausts smoothly and has high exhaust efficiency, the battery thermal runaway test is passed, no explosion occurs, and the battery product is in good condition.

[0068] In samples 7 and 8, the value of S2 / S1 is less than the minimum value of 0.65≤S2 / S1≤0.8, and the values ​​of D and W meet their corresponding ranges. At this time, the exhaust channel 121 formed between two adjacent support platforms 120 is small, and the exhaust space formed between the cover body 100 and the electrode group is small. It is impossible to ensure that the explosion-proof valve exhausts in time, which poses a certain risk of explosion. The pass rate of the battery thermal runaway test is low, and the battery product is defective.

[0069] In summary, it is evident that the size design and position arrangement of the support platform 120 have a significant impact on the electrode assembly support effect and the explosion-proof valve venting effect. When the size design defined in this embodiment is adopted, it can be ensured that the support platform 120 provides good support for the electrode assembly, while the explosion-proof valve venting is not affected. This significantly improves the problem of the explosion-proof valve being blocked by the electrode assembly and affecting venting during battery thermal runaway, resulting in high battery safety performance.

[0070] Example 2

[0071] 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.

[0072] See Figure 4 and Figure 5In this embodiment, the battery can be a blade battery, and the casing 200 is along the first direction ( Figure 4 Both ends of the cover plate 100 (in the X-axis direction shown) are formed with openings. Two cover plate bodies 100 are provided, each connected to one opening of the housing 200 and sealing that opening. The two cover plate bodies 100 and the housing 200 together form a cavity for accommodating the electrode assembly. The housing 200 includes two first sidewalls 210 disposed opposite each other along a third direction, and a second sidewall 210 disposed along a second direction (in the X-axis direction shown). Figure 4 Two second sidewalls 220 are arranged opposite each other in the Y-axis direction shown in the diagram. A 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. The third direction is... Figure 4 The X-axis and Y-axis directions shown are both perpendicular. This embodiment uses the mounting hole 110 and the support structure located on the first sidewall 210 as an example for illustration.

[0073] Specifically, the support structure includes multiple support platforms 120, which are arranged circumferentially around the mounting holes 110. The support platforms 120 are spaced apart from the mounting holes 110, and adjacent support platforms 120 are also spaced apart to form an exhaust channel 121 between adjacent support platforms 120. A plastic part is disposed on the side of the first sidewall 210 near the receiving cavity. The support platform 120 abuts against the plastic part on the side of the third direction away from the first sidewall 210, thereby insulating the electrode assembly from the housing 200 through the plastic part.

[0074] Furthermore, in this embodiment, the perimeter of the mounting hole 110 is S1, and the sum of the lengths of all support platforms 120 is S2. S1 and S2 satisfy the condition: 0.65 ≤ S2 / S1 ≤ 1.1. For example, the value of S2 / S1 can be 0.65, 0.75, 0.80, 0.85, 0.90, or 1.1. By controlling the value of S2 / S1 within the above range, the exhaust channel 121 formed between two adjacent support platforms 120 is larger. This satisfies the need for high-temperature, high-pressure gas flow when the battery experiences thermal runaway and the plastic parts melt and fail. Simultaneously, the larger contact area between the support platform 120 and the electrode assembly provides excellent support for the electrode assembly, maintaining the existence of the exhaust channel 121 and preventing the electrode assembly from shifting towards the first sidewall 210 of the housing 200 under the impact of high-temperature, high-pressure gas, thus preventing the mounting hole 110 on the first sidewall 210 from being blocked. This ensures high exhaust efficiency of the explosion-proof valve and good battery safety performance.

[0075] Optionally, the plastic part is provided with multiple vent holes, which are spaced apart on the plastic part. Along a third direction, the projections of the multiple vent holes on the first sidewall 210 of the housing 200 at least partially coincide with the projections of the mounting holes 110 on the first sidewall 210 of the housing 200. After the battery experiences thermal runaway, before the internal temperature of the battery rises to the melting point of the plastic part, the plastic part maintains its pre-melting shape to support the electrode assembly. At this time, the high-temperature and high-pressure gas in the accommodating cavity can be discharged to the explosion-proof valve through the vent holes, so that the explosion-proof valve opens and releases pressure.

[0076] Furthermore, a clearance groove is provided on the side of the plastic part facing the first sidewall 210 of the housing 200, and the support platform 120 is embedded in the clearance groove. By setting the clearance groove, the waste of space in the accommodating cavity can be avoided, the space occupied can be reduced, the volume of the electrode assembly can be increased, and the energy density of the battery can be improved.

[0077] The remaining structure of the battery in this embodiment is the same as that in Embodiment 1, and will not be described again here.

[0078] 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: Explosion-proof valve; The cover plate body and the housing are connected and enclosed to form an accommodating 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 the explosion-proof valve. The support structure includes a plurality of support platforms, which are all arranged around the mounting hole. Each support platform is spaced apart from the mounting hole. An exhaust channel is formed between two adjacent support platforms along the radial direction of the mounting hole. A plastic part is disposed on the side of the cover plate body or the housing near the receiving cavity, and the end of the support platform away from the cover plate body abuts against the plastic part; Wherein, the perimeter of the mounting hole is S1, and the sum of the lengths of all the support platforms along the circumference of the mounting hole is S2, and S1 and S2 satisfy: 0.65≤S2 / S1≤1.1; The width of the support platform is W, and the value of W is in the range of 5mm≤W≤8mm; The distance between the side of the support platform closest to the mounting hole and the adjacent side of the mounting hole is D, and the value of D is in the range of 4mm≤D≤6mm.

2. The battery according to claim 1, characterized in that, The mounting holes and the support structure are provided on the cover plate body, the length of each support platform is S21, and the number of support platforms is n; S2 and S21 satisfy the following condition: S2 = S21·n; The value range of S21 is: 10mm≤S21≤16mm.

3. The battery according to claim 2, characterized in that, Along the width direction of the cover plate body, the distance between the side of the support platform away from the mounting hole and the adjacent side of the cover plate body is A, and the dimension of the cover plate body is F; A and F satisfy: 0.12≤A / F≤0.2; The range of values ​​for A is: 5mm ≤ A ≤ 10mm; The value range of F is: 25mm≤F≤75mm.

4. The battery according to claim 1, characterized in that, The height of the support platform is H in a direction perpendicular to the end face of the cover plate body or the housing. The value of H is in the range of 3mm ≤ H ≤ 5mm.

5. The battery according to claim 1, characterized in that, When the battery is a ternary lithium system, the relationship between S1 and S2 satisfies: 0.85≤S2 / S1≤1.

1.

6. The battery according to claim 1, characterized in that, When the battery is a lithium iron phosphate system, the relationship between S1 and S2 satisfies: 0.65≤S2 / S1≤0.

8.

7. The battery according to claim 1, characterized in that, The plastic part is provided with a plurality of vent holes, which are arranged at intervals on the plastic part. Along the direction perpendicular to the end face of the cover plate body or the housing, the projection of the plurality of vent holes on the cover plate body or the housing at least partially coincides with the projection of the mounting hole on the cover plate body or the housing.

8. The battery according to claim 1, characterized in that, The plastic part has a clearance groove on the side facing the cover plate body or the housing, and the support platform is embedded in the clearance groove.

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