Battery

Abstract

The invention relates to the technical field of batteries, and particularly discloses a battery, a cover plate body or a shell of the battery is provided with a mounting hole for mounting an explosion-proof valve, a first boss and a second boss are respectively arranged on two sides of the mounting hole along a first direction, and the first boss and the second boss are arranged towards a pole group. The insulating part is located between the cover plate body and the pole group, or the insulating part is located between the shell and the pole group. In the section parallel to the first direction, the total cross sectional area of the first boss and the second boss is S1, the cross sectional area of the pole group is S, and S1 / S is larger than or equal to 0.35 and smaller than or equal to 0.5. When the battery is subjected to thermal runaway, the insulating part is melted into a liquid state, and at the moment, the two sides of the pole group along the first direction can be supported through the first boss and the second boss, so that a relatively large circulation space is formed between the pole group and the cover plate body / shell, an exhaust path of the anti-explosion valve is relatively smooth, the exhaust efficiency is relatively high, and the safety of the battery is good.

Description

Technical Field

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

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

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

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

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] The present invention provides a battery, including:

[0007] A housing, which is hollow inside to form a receiving cavity, and at least one side of the housing is provided with an opening communicating with the receiving cavity, and the electrode assembly passes through the opening and is installed in the housing;

[0008] A cover body is encapsulated at the opening and connected to the housing; one of the cover body and the housing is provided with a mounting hole, a first boss and a second boss. The first boss and the second boss are respectively arranged on both sides of the mounting hole along a first direction. The mounting hole is used for mounting an explosion-proof valve. Both the first boss and the second boss face the electrode group.

[0009] Wherein, in a cross-section parallel to the first direction, the total cross-sectional area of the first boss and the second boss is S1, and the cross-sectional area of the electrode group is S. The relationship between S1 and S satisfies: 0.35 ≤ S1 / S ≤ 0.5.

[0010] Optionally, the heights of the first boss and the second boss along a second direction are equal. The heights of the first boss and the second boss along the second direction are both H, and the value range of H is 1.5 mm ≤ H ≤ 2.5 mm.

[0011] Optionally, when the battery is a ternary lithium system, the value range of H is 2.0 mm ≤ H ≤ 2.5 mm;

[0012] When the battery is a lithium iron phosphate system, the value range of H is 1.5 mm ≤ H ≤ 2.0 mm.

[0013] Optionally, the mounting hole, the first boss and the second boss are arranged on the cover body. The first boss and the second boss are symmetrically arranged about the central axis a of the cover body along a third direction.

[0014] Optionally, there are multiple first bosses. The multiple first bosses are arranged in a square array on one side of the mounting hole. The multiple first bosses are symmetrically arranged about the central axis b of the cover body along the first direction.

[0015] There are multiple second bosses. The multiple second bosses are arranged in a square array on the other side of the mounting hole. The multiple second bosses are symmetrically arranged about the central axis b of the cover body along the first direction.

[0016] Optionally, the battery includes an insulating member. The insulating member is located on the side of the cover body where the first boss and the second boss are provided. The insulating member is clamped between the cover body and the electrode group.

[0017] Optionally, the mounting hole, the first boss and the second boss are arranged on the housing. The battery includes an insulating member. The insulating member is located on the side of the housing where the first boss and the second boss are provided. The insulating member is clamped between the housing and the electrode group.

[0018] Optionally, a first avoidance groove is provided on one side of the insulating member facing the first boss, and the first boss is received in the first avoidance groove;

[0019] A second avoidance groove is provided on one side of the insulating member facing the second boss, and the second boss is received in the second avoidance groove.

[0020] Optionally, the dimension of the cover body or the housing in the first direction is L, and the sum of the dimensions of the first boss and the second boss in the first direction is L1. The relationship between L1 and L satisfies: 0.25 ≤ L1 / L ≤ 0.45.

[0021] Optionally, the dimension of the cover body or the housing in the third direction is W, and the sum of the dimensions of the first boss and the second boss in the third direction is W1. The relationship between W1 and W satisfies: 0.6 ≤ W1 / W ≤ 0.8.

[0022] The beneficial effects of the present invention are as follows:

[0023] The present invention provides a battery, in which an installation hole, a first boss and a second boss are provided on the cover body or the housing. The first boss and the second boss are respectively arranged on both sides of the installation hole along the first direction. The installation hole is used for installing an explosion-proof valve, and both the first boss and the second boss face the electrode group. The insulating member is located on the side of the cover body provided with the first boss and the second boss, or on the side of the housing provided with the first boss and the second boss. The insulating member can support the electrode group during normal use of the battery, avoiding the shaking of the electrode group in the housing. When the battery undergoes thermal runaway, the insulating member is melted into a liquid state and flows together with the electrolyte. At this time, the first boss and the second boss can support both sides of the electrode group along the first direction, thereby forming a relatively large flow space between the electrode group and the cover body / housing. The exhaust path of the explosion-proof valve is relatively smooth, the exhaust efficiency is relatively high, and the safety of the battery is good.

[0024] Furthermore, in a cross-section parallel to the first direction, the total cross-sectional area of the first boss and the second boss is S1, and the cross-sectional area of the electrode group is S. The relationship between S1 and S satisfies: 0.35 ≤ S1 / S ≤ 0.5. By controlling the value of S1 / S within the above range, it can be ensured that the contact area between the first boss, the second boss and the electrode group is relatively large, ensuring a better support effect on the electrode group. At the same time, a relatively large flow space is formed between the cover body and the electrode group, avoiding the first boss and the second boss from blocking the flow of high-temperature and high-pressure gas along the first direction, meeting the flow requirements of high-temperature and high-pressure gas, being conducive to realizing the rapid exhaust of the explosion-proof valve, and improving the safety performance of the battery. Description of the Drawings

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments of the present invention. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the content of the embodiments of the present invention and these drawings.

[0026] Figure 1 It is a schematic structural diagram of the cover body provided in the first embodiment of the present invention;

[0027] Figure 2 It is a top view of the cover body provided in the first embodiment of the present invention.

[0028] In the figure:

[0029] 100, cover body; 110, mounting hole; 111, limiting step; 120, first boss; 130, second boss. Detailed implementation manners

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0031] Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0032] It should be noted that: similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0033] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the inventive product is usually placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the present invention. In addition, the terms "first", "second", "third", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0034] In the description of the present invention, it should also be noted that unless otherwise clearly defined and limited, the terms "set" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] In the present invention, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the first feature has a higher horizontal height than the second feature. The first feature being "below", "under" and "beneath" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the first feature has a lower horizontal height than the second feature.

[0036] The embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation on the present invention.

[0037] Embodiment 1

[0038] As Figure 1 and Figure 2As shown in the figure, this embodiment provides a battery, which includes a housing, a cover body 100, a pole group, and an explosion-proof valve. The interior of the housing is hollow to form a receiving cavity. An opening communicating with the receiving cavity is provided on one side of the housing. The pole group passes through the opening and is installed in the housing. The cover body 100 is sealed at the opening and connected to the housing, and the receiving cavity of the housing is closed through the cover body 100. The cover body 100 is provided with a mounting hole 110, a first boss 120, and a second boss 130. The first boss 120 and the second boss 130 are respectively arranged on both sides of the mounting hole 110 along a first direction. The mounting hole 110 is used to install the explosion-proof valve, and both the first boss 120 and the second boss 130 face the pole group. Wherein, the first direction refers to the length direction of the cover body 100, that is, Figure 1 the X-axis direction shown in the figure. Optionally, the first boss 120 and the second boss 130 can be formed by stamping on the cover body 100 using a jig.

[0039] The battery further includes an insulating member. The insulating member is located on the side of the cover body 100 where the first boss 120 and the second boss 130 are provided. The insulating member is clamped between the cover body 100 and the pole group. The insulating member can support the pole group during normal use of the battery, prevent the pole group from shaking in the housing, and insulate the pole group from the cover body 100 at the same time. Exemplarily, the insulating member can be made of PP material. When the battery undergoes thermal runaway, since the temperature inside the housing rises sharply and far exceeds the melting point of the insulating member, the insulating member is melted into a liquid and flows together with the electrolyte. At this time, the first boss 120 and the second boss 130 on the cover body 100 can support both sides of the pole group along the first direction, thereby forming a relatively large flow space between the pole group and the cover body 100. The high-temperature and high-pressure gas can flow from the mounting hole 110 along both sides of the first direction to the explosion-proof valve. The exhaust path of the explosion-proof valve is relatively smooth, the exhaust efficiency is high, and the safety of the battery is good.

[0040] In some embodiments, a limiting step 111 is provided on the inner wall of the mounting hole 110. The explosion-proof valve can be installed in the mounting hole 110 from the side of the cover body 100 close to the insulating member. The circumferential edge of the explosion-proof valve overlaps on the limiting step 111, and the circumferential edge of the explosion-proof valve is welded to the cover body 100 to realize the installation and fixation of the explosion-proof valve on the cover body 100. When the pressure in the receiving cavity of the housing exceeds the opening pressure of the explosion-proof valve, the explosion-proof valve is opened, and an exhaust channel for the high-temperature and high-pressure gas to flow through is formed on the explosion-proof valve, thereby realizing pressure relief and ensuring the safety of the battery.

[0041] Of course, in other embodiments, openings communicating with the receiving cavity can also be provided on both opposite sides of the housing. At this time, two cover bodies 100 are also correspondingly provided, and each cover body 100 is used to seal one opening of the housing.

[0042] Further, in a cross-section parallel to the first direction, the total cross-sectional area of the first boss 120 and the second boss 130 is S1, and the cross-sectional area of the electrode group is S. The relationship between S1 and S satisfies: 0.35 ≤ S1 / S ≤ 0.5. Exemplarily, the value of S1 / S can be 0.35, 0.4, 0.45, 0.5, etc. Optionally, the value range of S1 is 1000 mm 2 ≤ S1 ≤ 4000 mm 2 , and the value range of S is 3000 mm 2 ≤ S ≤ 8000 mm 2 . For example, when the value of S is 3000 mm 2 , the value of S1 can be 1050 mm 2 , 1200 mm 2 , 1350 mm 2 or 1500 mm 2 etc. When the value of S is 5000 mm 2 , the value of S1 can be 1750 mm 2 , 2000 mm 2 , 2250 mm 2 or 2500 mm 2 etc. When the value of S is 8000 mm 2 , the value of S1 can be 2800 mm 2 , 3200 mm 2 , 3600 mm 2 or 4000 mm 2 etc.

[0043] By controlling the value of S1 / S within the above range, it can ensure a large contact area between the first boss 120, the second boss 130 and the electrode group, guarantee a good supporting effect on the electrode group, and at the same time form a large flow space between the cover body 100 and the electrode group, avoiding the first boss 120 and the second boss 130 from blocking the flow of high-temperature and high-pressure gas in the first direction, meeting the flow requirements of high-temperature and high-pressure gas, being conducive to realizing the rapid exhaust of the explosion-proof valve, and improving the safety performance of the battery. Otherwise, when the value of S1 / S is too small, the contact area between the first boss 120, the second boss 130 and the electrode group is small, and the supporting effect on the electrode group is not good, and there may be a situation where the electrode group shields the explosion-proof valve, resulting in poor exhaust; when the value of S1 / S is too large, when the cross-sectional area of the first boss 120 and the second boss 130 is large, it may block the flow of high-temperature and high-pressure gas in the first direction, and the exhaust speed decreases, which is not conducive to battery safety.

[0044] Continue to refer to Figure 1, in this embodiment, the heights of the first boss 120 and the second boss 130 in the second direction are equal. The heights of the first boss 120 and the second boss 130 in the second direction are both H, and the value range of H is 1.5 mm ≤ H ≤ 2.5 mm. Herein, the second direction refers to the height direction of the cover body 100, that is, Figure 1 the Z-axis direction shown in

[0045] By controlling the value of H within the above range, it can be ensured that the flow space between the cover body 100 and the electrode group is relatively large, meeting the exhaust requirements, and the high-temperature and high-pressure gas can be exhausted smoothly. Otherwise, when the value of H is too small, the gap between the cover body 100 and the electrode group is small, the flow space between the cover body 100 and the electrode group is insufficient, the high-temperature and high-pressure gas cannot be exhausted smoothly, and the exhaust efficiency of the explosion-proof valve is low; when the value of H is too large, the heights of the first boss 120 and the second boss 130 in the second direction are large, resulting in waste of the space inside the battery in the second direction, and the volumetric energy density of the battery decreases.

[0046] Exemplarily, when the battery is a ternary lithium system, the chemical reaction between the electrode group and the electrolyte is relatively intense, and the gas generation amount is large. At this time, the value range of H is 2.0 mm ≤ H ≤ 2.5 mm. For example, the value of H can be 2.0 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm or 2.5 mm, etc. The value of H is relatively large, so as to ensure that the gap between the cover body 100 and the electrode group is large, and the flow space formed between the cover body 100 and the electrode group is sufficient to meet the exhaust requirements of the explosion-proof valve, and the exhaust efficiency is high.

[0047] Continue to refer to Figure 2 , in this embodiment, the first boss 120 and the second boss 130 are symmetrically arranged about the central axis a of the cover body 100 in the third direction, so that the forces on both sides of the electrode group in the first direction are relatively uniform, and the supporting effect is better. Herein, the third direction refers to the width direction of the cover body 100, that is, Figure 2 the Y-axis direction shown in

[0048] Furthermore, a plurality of first bosses 120 are provided. The plurality of first bosses 120 are arranged in a square array on one side of the mounting hole 110, and the plurality of first bosses 120 are symmetrically arranged about the central axis b of the cover body 100 in the first direction. A plurality of second bosses 130 are provided. The plurality of second bosses 130 are arranged in a square array on the other side of the mounting hole 110, and the plurality of second bosses 130 are symmetrically arranged about the central axis b of the cover body 100 in the first direction. This makes the forces on both sides of the electrode group in the third direction relatively uniform, and the support effect is better.

[0049] Optionally, in this embodiment, four first bosses 120 and four second bosses 130 are taken as examples for illustration. The four first bosses 120 are arranged on one side of the mounting hole 110 in the first direction of the cover body 100. Two of the first bosses 120 form a set of first support structures. The two sets of first support structures are spaced apart in the first direction. The two first bosses 120 in each set of first support structures are symmetrically arranged about the central axis b of the cover body 100 in the first direction. The four second bosses 130 are arranged on the other side of the mounting hole 110 in the first direction of the cover body 100. Two of the second bosses 130 form a set of second support structures. The two sets of second support structures are spaced apart in the first direction. The two second bosses 130 in each set of second support structures are symmetrically arranged about the central axis b of the cover body 100 in the first direction.

[0050] Optionally, a first avoidance groove is provided on the side of the insulating part facing the first boss 120, and the first boss 120 is received in the first avoidance groove. A second avoidance groove is provided on the side of the insulating part facing the second boss 130, and the second boss 130 is received in the second avoidance groove. Through the settings of the first avoidance groove and the second avoidance groove, interference between the insulating part and the first boss 120 and the second boss 130 on the cover body 100 is avoided, ensuring good assembly between the insulating part and the cover body 100. At the same time, through the settings of the first avoidance groove and the second avoidance groove, the overall dimension of the cover body 100 and the insulating part in the second direction after assembly is reduced, thereby increasing the layout space of the electrode group in the housing, which is beneficial to improving the volume energy density of the battery.

[0051] Furthermore, the dimension of the cover plate body 100 in the first direction is L, and the sum of the dimensions of the first boss 120 and the second boss 130 in the first direction is L1. The relationship between L1 and L satisfies: 0.25 ≤ L1 / L ≤ 0.45. For example, the value of L1 / L can be 0.25, 0.30, 0.40, or 0.45. Optionally, the value range of L is 80mm ≤ L ≤ 120mm. For example, the value of L can be 80mm, 90mm, 100mm, 110mm, or 120mm, etc. By controlling the value of L1 / L within the above range, there is sufficient flow space for the high-temperature and high-pressure gas in the third direction, and at the same time, it is ensured that the first boss 120 and the second boss 130 can provide good support for the electrode group, avoiding the exhaust passage of the explosion-proof valve being blocked. Otherwise, when the value of L1 / L is too small, the support effect of the first boss 120 and the second boss 130 on the electrode group is poor, and there is a situation where the exhaust passage of the explosion-proof valve is blocked; when the value of L1 / L is too large, the flow space for the high-temperature and high-pressure gas in the third direction is insufficient, affecting the exhaust effect and resulting in low exhaust efficiency.

[0052] Exemplarily, in this embodiment, there are two first bosses 120 provided on the cover plate body 100 in the first direction, and the dimension of each first boss 120 in the first direction is B1. There are two second bosses 130 provided on the cover plate body 100 in the first direction, and the dimension of each second boss 130 in the first direction is B2. L1 = 2 * B1 + 2 * B2.

[0053] Furthermore, the dimension of the cover plate body 100 in the third direction is W, and the sum of the dimensions of the first boss 120 and the second boss 130 in the third direction is W1. The relationship between W1 and W satisfies: 0.6 ≤ W1 / W ≤ 0.8. For example, the value of W1 / W can be 0.6, 0.7, or 0.8. Optionally, the value range of W is 20mm ≤ W ≤ 40mm. For example, the value of W can be 20mm, 25mm, 30mm, 35mm, or 40mm, etc. By controlling the value of W1 / W within the above range, there is sufficient flow space for the high-temperature and high-pressure gas in the housing in the first direction, and at the same time, it is ensured that the first boss 120 and the second boss 130 can provide good support for the electrode group, avoiding the exhaust passage of the explosion-proof valve being blocked. Otherwise, when the value of W1 / W is too small, the support effect of the first boss 120 and the second boss 130 on the electrode group is poor, and there is a situation where the exhaust passage of the explosion-proof valve is blocked; when the value of W1 / W is too large, the flow space for the high-temperature and high-pressure gas in the first direction is insufficient, affecting the exhaust effect and resulting in low exhaust efficiency.

[0054] Exemplarily, in this embodiment, four first bosses 120 and four second bosses 130 are respectively provided on both sides of the mounting hole 110 on the cover body 100 along the first direction. Since the four first bosses 120 and the four second bosses 130 are symmetrically arranged along the central axis a, and the four first bosses 120 are symmetrically arranged along the central axis b, and the four second bosses 130 are symmetrically arranged along the central axis b. Taking the four first bosses 120 provided on one side of the mounting hole 110 as an example, the dimension of each first boss 120 along the third direction is A1, and W1 = 2 * A1. Similarly, the dimension of each second boss 130 along the third direction is A2, W1 = 2 * A2, and A1 = A2.

[0055] Further, the gap between two adjacent first bosses 120 arranged along the third direction is A3, and the gap between two adjacent second bosses 130 arranged along the third direction is also A3. The dimension of the mounting hole 110 along the third direction is A4. The relationship between A3 and A4 satisfies: 0.6 ≤ A3 / A4 ≤ 0.8. By controlling the value of A3 / A4 within the above range, the flow of high-temperature and high-pressure gas along the first direction is not blocked by the first boss 120 or the second boss 130, ensuring smooth exhaust.

[0056] Exemplarily, the value range of A3 is 8mm ≤ A3 ≤ 10mm. The value range of A4 is 10mm ≤ A1 ≤ 16mm. For example, in some embodiments, the value of A3 can be 8mm and the value of A4 can be 10mm. In some embodiments, the value of A3 can be 10mm and the value of A4 can be 16mm. Of course, in other embodiments, the specific values of A3 and A4 can also be other values that satisfy the above relationship, which will not be listed one by one here.

[0057] Next, some samples with different design dimensions are used to verify the thermal runaway of the ternary lithium system battery with the above structure, and the verification results are shown in Table 1.

[0058] Table 1

[0059]

[0060] From the above results, it can be concluded that in the ternary lithium system battery, the H values of Sample 1, Sample 2, and Sample 3 are all less than the minimum value of 2.0mm ≤ H ≤ 2.5mm, and the S1 / S value satisfies its corresponding value range. At this time, the heights of the first boss 120 and the second boss 130 along the second direction are relatively small, the supporting effect on the electrode group is not obvious, the explosion-proof valve is likely to be shielded, the exhaust is not smooth, the passing rate of the battery thermal runaway test is relatively low, and the passing rate is about 0% - 60%, and the battery products are defective.

[0061] Among Samples 4 to 10, the value of H satisfies the range of 2.0 mm ≤ H ≤ 2.5 mm, and the value of S1 / S satisfies the range of 0.35 ≤ S1 / S ≤ 0.5. At this time, the supporting effect of the first boss 120 and the second boss 130 on the electrode group is obvious, and the flow space formed between the cover body 100 and the electrode group is large. The explosion-proof valve exhausts smoothly, the exhaust efficiency is high, and the passing rate of the battery thermal runaway test is as high as 100%, and the battery products are good.

[0062] In Sample 11, the value of S1 / S is greater than the maximum value of 0.35 ≤ S1 / S ≤ 0.5, and the value of H satisfies its corresponding range. At this time, the first boss 120 and the second boss 130 have resistance to the flow of high-temperature and high-pressure gas, the exhaust efficiency of the explosion-proof valve decreases, and the passing rate of the battery thermal runaway test is about 40%, and the battery products are defective.

[0063] In Samples 12 and 13, the value of S1 / S is less than the minimum value of 0.35 ≤ S1 / S ≤ 0.5, and the value of H satisfies its corresponding range. At this time, the supporting effect of the first boss 120 and the second boss 130 on the electrode group is not obvious, the explosion-proof valve is shielded, the exhaust is not smooth, the passing rate of the battery thermal runaway test is low, and the passing rate of the battery thermal runaway test is about 20%-40%, and the battery products are defective.

[0064] Next, some samples with different design dimensions are used to verify the thermal runaway of the lithium iron phosphate system battery with the above structure, and the verification results are shown in Table 2.

[0065] Table 2

[0066]

[0067] From the above results, it can be concluded that in the lithium iron phosphate system battery, the values of H in Samples 1, 2, and 3 are all less than the minimum value of 1.5 mm ≤ H ≤ 2.0 mm, and the value of S1 / S satisfies its corresponding range. At this time, the heights of the first boss 120 and the second boss 130 in the second direction are small, the supporting effect on the electrode group is not obvious, the explosion-proof valve is shielded, the exhaust is not smooth, the passing rate of the battery thermal runaway test is low, and the passing rate is about 0%-40%, and the battery products are defective.

[0068] Among Samples 4 to 9, the value of H satisfies the range of 1.5 mm ≤ H ≤ 2.0 mm, and the value of S1 / S satisfies the range of 0.35 ≤ S1 / S ≤ 0.5. At this time, the supporting effect of the first boss 120 and the second boss 130 on the electrode group is obvious, and the flow space formed between the cover body 100 and the electrode group is large. The explosion-proof valve exhausts smoothly, the exhaust efficiency is high, and the passing rate of the battery thermal runaway test is as high as 100%, and the battery products are good.

[0069] In sample 10, the value of S1 / S is greater than the maximum value of 0.35 ≤ S1 / S ≤ 0.5, and the value of H satisfies its corresponding value range. At this time, the first boss 120 and the second boss 130 have resistance to the flow of high-temperature and high-pressure gas, the exhaust efficiency of the explosion-proof valve decreases, the passing rate of the battery thermal runaway test is about 40%, and the battery product is defective.

[0070] In sample 11 and sample 12, the value of S1 / S is less than the minimum value of 0.35 ≤ S1 / S ≤ 0.5, and the value of H satisfies its corresponding value range. At this time, the supporting effect of the first boss 120 and the second boss 130 on the electrode group is not obvious, the explosion-proof valve is shielded, the exhaust is blocked, the passing rate of the battery thermal runaway test is low, the passing rate of the battery thermal runaway test is about 20%-60%, and the battery product is defective.

[0071] In summary, it can be seen that the size design and position arrangement of the first boss 120 and the second boss 130 have a great influence on the supporting effect of the electrode group and the exhaust effect of the explosion-proof valve. When the size design defined in this embodiment is adopted, it can ensure good supporting effect of the first boss 120 and the second boss 130 on the electrode group, and at the same time, the exhaust of the explosion-proof valve is not affected, greatly improving the passing rate of the battery thermal runaway test and the safety performance of the battery.

[0072] Embodiment 2

[0073] This embodiment provides a battery, which is different from the battery in Embodiment 1 in that: in this embodiment, the mounting holes 110, the first boss 120 and the second boss 130 are arranged on the housing, the insulating member is located on the side of the housing where the first boss 120 and the second boss 130 are provided, and the insulating member is clamped between the housing and the electrode group. When the battery undergoes thermal runaway, due to the rapid increase in temperature inside the housing and far exceeding the melting point of the insulating member, the insulating member is melted into a liquid state and flows together with the electrolyte. At this time, the first boss 120 and the second boss 130 on the housing can support the electrode group to form a flow space between the electrode group and the housing, thereby ensuring that the exhaust passage of the explosion-proof valve is not blocked, the exhaust is relatively smooth, the exhaust efficiency is high, and the safety of the battery is good.

[0074] Optionally, the first boss 120 and the second boss 130 can be formed by stamping on the housing using a jig.

[0075] The rest of the structure of the battery in this embodiment is the same as that in Embodiment 1, and will not be described in detail here.

[0076] Obviously, the above are only the preferred embodiments of the present invention and the technical principles applied. Those skilled in the art will understand that the present invention is not limited to the specific embodiments here, and various obvious changes, re-adjustments and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments only. Without departing from the concept of the present invention, more other equivalent embodiments can be included, and the scope of the present invention is determined by the scope of the appended claims.

[0077] Note that in the description of this specification, the descriptions referring to the terms "some embodiments", "other embodiments", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

Claims

1. A battery, characterized in that: include: A shell, the interior of which is hollow to form a receiving cavity, at least one side of the shell is provided with an opening communicating with the receiving cavity, and the pole group is inserted into the shell through the opening; A cover body is encapsulated at the opening and connected to the shell; one of the cover body and the shell is provided with a mounting hole, a first boss and a second boss, the first boss and the second boss are respectively arranged on both sides of the mounting hole along a first direction, the mounting hole is used to install an explosion-proof valve, and the first boss and the second boss are both arranged toward the pole group; Among them, along the cross section parallel to the first direction, the total cross-sectional area of ​​the first boss and the second boss is S1, the cross-sectional area of ​​the pole group is S, and S1 and S satisfy: 0.35≤S1 / S≤0.

5.

2. The battery according to claim 1, characterized in that The first boss and the second boss have the same height along the second direction. The first boss and the second boss have the same height along the second direction. The height of H is H, and the value range of H is 1.5 mm ≤ H ≤ 2.5 mm.

3. The battery according to claim 2, characterized in that When the battery is a ternary lithium system, the value range of H is 2.0mm≤H≤2.5mm; When the battery is a lithium iron phosphate system, the value range of H is 1.5mm≤H≤2.0mm.

4. The battery according to claim 1, characterized in that The mounting hole, the first boss and the second boss are arranged on the cover body, and the first boss and the second boss are symmetrically arranged about a central axis a of the cover body along a third direction.

5. The battery according to claim 4, characterized in that There are a plurality of first bosses, and the plurality of first bosses are arranged in a square array on one side of the mounting hole, and the plurality of first bosses are symmetrically arranged about the central axis b of the cover body along the first direction; There are multiple second bosses, and the multiple second bosses are arranged in a square array on the other side of the mounting hole. The multiple second bosses are symmetrically arranged about the central axis b of the cover body along the first direction.

6. The battery according to claim 4, characterized in that The battery comprises an insulating member, the insulating member is located at a side of the cover body where the first boss and the second boss are provided, and the insulating member is sandwiched between the cover body and the electrode group.

7. The battery according to claim 1, characterized in that The mounting hole, the first boss and the second boss are arranged on the shell, and the battery includes an insulating member, which is located on a side of the shell where the first boss and the second boss are arranged, and the insulating member is sandwiched between the shell and the pole group.

8. The battery according to claim 6 or 7, characterized in that: A first avoidance groove is provided on one side of the insulating member facing the first boss, and the first boss is accommodated in the first avoidance groove; A second avoidance groove is provided on one side of the insulating member facing the second boss, and the second boss is accommodated in the second avoidance groove.

9. The battery according to claim 1, characterized in that The dimension of the cover body or the shell along the first direction is L, the sum of the dimensions of the first boss and the second boss along the first direction is L1, and L1 and L satisfy the following: 0.25≤L1 / L≤0.

45.

10. The battery according to claim 1, characterized in that The dimension of the cover body or the shell along the third direction is W, the sum of the dimensions of the first boss and the second boss along the third direction is W1, and W1 and W satisfy the following: 0.6≤W1 / W≤0.8.

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