Battery cover plate and battery

Abstract

The invention relates to the technical field of batteries, and particularly discloses a battery cover plate and a battery, the battery cover plate comprises a cover plate body, an anti-explosion valve protection sheet and an anti-explosion valve, an annular boss is arranged in the circumferential direction of a first mounting hole in the cover plate body, and the end face of the side, away from a pole group, of the annular boss is higher than the end face of the side, away from the pole group, of the cover plate body; a second mounting hole is formed in the center of the annular boss and communicated with the first mounting hole. The anti-explosion valve protection sheet is connected to the side, away from the pole group, of the annular boss, and the anti-explosion valve is connected to the side, close to the pole group, of the annular boss. And through the arrangement of the annular boss, the mounting position of the anti-explosion valve protection sheet is raised, so that the electrolyte overflowing during liquid injection is prevented from flowing to the anti-explosion valve, and a good protection effect on the anti-explosion valve is achieved. Meanwhile, due to the arrangement of the annular boss, the structural strength around the installation position of the anti-explosion valve is improved, the anti-explosion valve is not prone to being pressed and deformed, and reliability is high. The invention also provides a battery which comprises the battery cover plate.

Description

Technical Field

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

[0002] As lithium-ion battery technology becomes increasingly mature, lithium-ion batteries are widely used as power batteries in electric vehicles and energy storage fields. The traditional lithium battery structure includes a cover plate, a shell and a pole group. The cover plate and the shell are welded and sealed to encapsulate the pole group inside. The cover plate is provided with an injection hole and an explosion-proof valve, and the electrolyte is injected into the shell through the injection hole. The explosion-proof valve is set on one side of the injection hole to relieve pressure in the event of thermal runaway. An explosion-proof valve protection sheet is provided above the explosion-proof valve to protect the explosion-proof valve from direct mechanical impact. A notch is provided on the explosion-proof valve protection sheet to ensure the accuracy of helium detection.

[0003] However, there is a phenomenon of electrolyte bubbling during the injection process, which causes a certain probability that the electrolyte will flow from the gap of the explosion-proof valve protection plate to the explosion-proof valve, which may cause the explosion-proof valve to corrode and fail in the air, and it is also difficult to clean the electrolyte on the explosion-proof valve. Summary of the invention

[0004] The object of the present invention is to provide a battery cover and a battery, wherein the explosion-proof valve protection sheet can prevent the explosion-proof valve from being corroded by electrolyte, plays a good protective role for the explosion-proof valve, and ensures the accuracy of helium detection at the same time.

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

[0006] In one aspect, the present invention provides a battery cover, comprising:

[0007] A cover plate body is arranged on one side of the pole group, a first mounting hole is arranged on the cover plate body, an annular boss is arranged on the end surface of the cover plate body away from the pole group, the annular boss is located in the circumference of the first mounting hole, the end surface of the annular boss away from the pole group is higher than the end surface of the cover plate body away from the pole group, a second mounting hole is formed at the center of the annular boss, and the second mounting hole is connected with the first mounting hole; a first liquid injection hole is arranged on the cover plate body, and the first liquid injection hole is arranged on one side of the annular boss along the first direction;

[0008] An explosion-proof valve protection sheet connected to a side of the annular boss away from the pole group, the explosion-proof valve protection sheet being provided with a notch, the notch connecting the second mounting hole with a space on a side of the cover plate body away from the pole group;

[0009] An explosion-proof valve connected to a side of the annular boss close to the pole group, wherein a pressure relief channel is formed when the explosion-proof valve is opened, and the pressure relief channel is communicated with the first mounting hole;

[0010] Wherein, along the second direction, the distance between the end face of the annular boss on the side away from the electrode group and the end face of the cover plate body on the side away from the electrode group is f;

[0011] The value range of f is 0.3mm ≤ f ≤ 10mm.

[0012] Optionally, along the second direction, the thickness of the cover plate body is e;

[0013] The value range of e is 1mm ≤ e ≤ 10mm.

[0014] Optionally, along the third direction, the distance between the outer peripheral wall of the annular boss and the adjacent side wall of the cover plate body along the third direction is a, and the value range of a is: 1mm ≤ a ≤ 100mm.

[0015] Optionally, a first sunk platform for installing the explosion-proof valve is provided on the side of the annular boss facing the electrode group. The first sunk platform includes a platform bottom wall and a platform side wall. The explosion-proof valve includes a fixing part. The end face of the fixing part on the side away from the electrode group abuts against the platform bottom wall, and the peripheral side wall of the fixing part is spaced from the platform side wall;

[0016] Along the third direction, the distance between the platform side wall and the inner wall of the first mounting hole is b;

[0017] The value range of b is: 0.3mm ≤ b ≤ 100mm.

[0018] Optionally, along the second direction, the distance between the end face of the annular boss on the side facing the electrode group and the end face of the annular boss on the side away from the electrode group is h1;

[0019] b and h1 satisfy: 0.03 ≤ b / h1 ≤ 25;

[0020] The value range of h1 is: 0.5mm ≤ h1 ≤ 10mm.

[0021] Optionally, along the third direction, the distance between the outer peripheral wall of the annular boss and the inner wall of the first mounting hole is d;

[0022] Along the second direction, the distance between the end face of the annular boss on the side facing the electrode group and the end face of the cover plate body on the side facing the electrode group is h2, and d and h2 satisfy: 0.2 ≤ h2 / d ≤ 10;

[0023] And h1 and h2 satisfy: 0.2 ≤ h2 / h1 ≤ 20;

[0024] The value range of d is: 0.3mm ≤ d ≤ 10mm;

[0025] The value range of h2 is: 0mm<h2≤10mm.

[0026] Optionally, along the second direction, a distance between an end surface of the annular boss away from the pole group and the bottom wall of the boss is c, and a value range of c is: 0.3 mm ≤ c ≤ 10 mm.

[0027] Optionally, along the second direction, the thickness of the fixing portion is z;

[0028] The relationship between h1, c and z satisfies: 0.1≤z / (h1-c)≤8;

[0029] The value range of z is: 0.5mm≤z≤2mm.

[0030] Optionally, along the third direction, the distance between the peripheral side wall of the fixing portion and the side wall of the platform is g;

[0031] The value range of g is: 0.05mm≤g≤1mm.

[0032] On the other hand, the present invention provides a battery, comprising the battery cover plate in any of the above schemes.

[0033] The beneficial effects of the present invention are:

[0034] The present invention provides a battery cover, comprising a cover body, an explosion-proof valve protection sheet and an explosion-proof valve. The cover body is arranged on one side of the pole group, a first mounting hole is arranged on the cover body, an annular boss is arranged on the end surface of the cover body away from the pole group, the annular boss is located in the circumference of the first mounting hole, the end surface of the annular boss away from the pole group is higher than the end surface of the cover body away from the pole group, a second mounting hole is formed at the center of the annular boss, and the second mounting hole is connected to the first mounting hole. The explosion-proof valve protection sheet is connected to the side of the annular boss away from the pole group, and the explosion-proof valve is connected to the side of the annular boss close to the pole group. Further, a first injection hole is arranged on the cover body on one side of the annular boss, and the installation position of the explosion-proof valve protection sheet is raised by the setting of the annular boss, so that the explosion-proof valve protection sheet is higher than the end surface of the cover body away from the pole group, thereby preventing the overflowing electrolyte from flowing to the explosion-proof valve through the notch on the explosion-proof valve protection sheet when injecting liquid through the first injection hole, thereby playing a good protective role for the explosion-proof valve. At the same time, due to the setting of the annular boss, the structural strength around the installation position of the explosion-proof valve is improved, the explosion-proof valve is not easily deformed by pressure, the valve opening pressure is accurate, and the reliability is high.

[0035] The present invention also provides a battery, comprising the battery cover. By adopting the battery cover, it is ensured that the explosion-proof valve will not be corroded by the electrolyte when the battery is filled with liquid, which plays a good protective role on the explosion-proof valve. At the same time, the fixing structure of the explosion-proof valve on the cover body is stable and not easy to deform. The valve opening pressure is accurate and the reliability is high. Brief Description of the Drawings

[0036] Figure 1 It is a schematic structural diagram of the battery cover plate provided in the embodiment of the present invention;

[0037] Figure 2 It is an exploded view of the battery cover plate provided in the embodiment of the present invention;

[0038] Figure 3 It is a top view of the battery cover plate provided in the embodiment of the present invention;

[0039] Figure 4 It is Figure 3 a sectional view of the A-A section in;

[0040] Figure 5 It is Figure 3 a sectional view of the B-B section in;

[0041] Figure 6 It is Figure 5 a partial enlarged view of the E position in.

[0042] In the figure:

[0043] 100, cover plate body; 110, first mounting hole; 120, first liquid injection hole; 200, annular boss; 210, second mounting hole; 220, first sunk platform; 221, bottom wall of the platform; 222, side wall of the platform; 300, explosion-proof valve protection piece; 310, notch; 400, explosion-proof valve; 410, fixing part; 420, body part; 421, scoring groove; 500, plastic part; 510, air hole; 520, second liquid injection hole. Detailed Embodiments

[0044] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0045] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. 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 to the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions. 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 simply 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 simply indicating that the first feature has a lower horizontal height than the second feature.

[0046] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "mounted", "connected" and "coupled" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. 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.

[0047] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, in which 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 drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation to the present invention.

[0048] As Figures 1 - 4 shown, this embodiment provides a battery cover plate, which is welded and connected to the side of the housing with an opening. A receiving cavity is formed jointly by the battery cover plate and the housing, and the electrode group is arranged in the receiving cavity.

[0049] The battery cover plate includes a cover plate body 100, an explosion-proof valve protection piece 300, and an explosion-proof valve 400. The four peripheral edges of the cover plate body 100 are welded to the side of the housing with an opening, and the cover plate body 100 is located on one side of the electrode group. A first mounting hole 110 is provided on the cover plate body 100, and an annular boss 200 is provided on the end surface of the cover plate body 100 facing away from the electrode group. The annular boss 200 is located circumferentially around the first mounting hole 110, and the annular boss 200 extends towards the center of the first mounting hole 110 in the radial direction of the first mounting hole 110. Optionally, the cover plate body 100 and the annular boss 200 are of an integral structure. The end surface of the annular boss 200 facing away from the electrode group is higher than the end surface of the cover plate body 100 facing away from the electrode group, and a second mounting hole 210 is formed at the center of the annular boss 200. The second mounting hole 210 communicates with the first mounting hole 110. The explosion-proof valve protection piece 300 is connected to the side of the annular boss 200 facing away from the electrode group. Exemplarily, the circumferential edge of the explosion-proof valve protection piece 300 can be adhesively bonded to the end surface of the annular boss 200 facing away from the electrode group by back glue, thereby fixing the explosion-proof valve protection piece 300. The explosion-proof valve 400 is connected to the side of the annular boss 200 close to the electrode group. For example, the explosion-proof valve 400 can be connected to the side of the annular boss 200 close to the electrode group by welding, thereby fixing the explosion-proof valve 400.

[0050] When the explosion-proof valve 400 opens, a pressure relief channel is formed. The pressure relief channel communicates with the first mounting hole 110. A notch 310 is provided on the explosion-proof valve protection piece 300. The notch 310 communicates the second mounting hole 210 with the space on the side of the cover plate body 100 facing away from the electrode group. The setting of the notch 310 is beneficial to ensuring the accuracy of helium leak detection. When the battery undergoes thermal runaway, the explosion-proof valve 400 will open, and the high-temperature and high-pressure gas inside the battery enters the first mounting hole 110 and the second mounting hole 210 through the pressure relief channel of the explosion-proof valve 400, and then breaks through the explosion-proof valve protection piece 300 and is released to the space on the side of the cover plate body 100 facing away from the electrode group to achieve pressure relief.

[0051] Further, a first liquid injection hole 120 is provided on the cover plate body 100. The first liquid injection hole 120 is provided on one side of the annular boss 200 along a first direction, where the first direction is Figure 1 the X-axis direction shown in. The electrolyte can be injected into the accommodating cavity through the first liquid injection hole 120 so that the electrode group is immersed in the electrolyte, and the electrode group can react with the electrolyte for charging and discharging.

[0052] See Figure 5 and Figure 6 Along a second direction, the distance between the end surface of the annular boss 200 facing away from the electrode group and the end surface of the cover plate body 100 facing away from the electrode group is f, and the value range of f is 0.3 mm ≤ f ≤ 10 mm. The second direction is Figure 5The Z-axis direction shown in . For example, the value of f can be 0.3mm, 0.8mm, 1.0mm, 3.0mm, 5.0mm, 8.0mm or 10.0mm, etc. By setting the annular boss 200, the installation position of the explosion-proof valve protection sheet 300 is raised, so that the end face of the explosion-proof valve protection sheet 300 is higher than the end face of the cover body 100 away from the pole group, thereby preventing the overflowing electrolyte from flowing through the notch 310 on the explosion-proof valve protection sheet 300 to the explosion-proof valve 400 when injecting liquid into the accommodating cavity through the first injection hole 120, causing corrosion to the explosion-proof valve 400, and playing a good protective role for the explosion-proof valve 400. At the same time, due to the setting of the annular boss 200, the structural strength around the installation position of the explosion-proof valve 400 is improved, which is conducive to protecting the explosion-proof valve 400 from being easily deformed by pressure and the valve opening pressure is accurate.

[0053] Along the second direction, the thickness of the cover plate body 100 is e, and the value range of e is 1mm≤e≤10mm. For example, the value of e can be 1mm, 2mm, 5mm, 8mm or 10mm. Generally speaking, the thickness of a conventional cover plate is at least 1.5mm. In this embodiment, since an annular boss 200 is provided around the first mounting hole 110, the cover plate body 100 can be thinned by about 0.5mm, and the mechanical strength around the installation position of the explosion-proof valve 400 can still be guaranteed to meet the requirements.

[0054] Furthermore, along the third direction, the distance between the outer peripheral wall of the annular boss 200 and the adjacent side wall of the cover body 100 along the third direction is a. Figure 5 The Y-axis direction shown in . The value range of a is: 1mm≤a≤100mm. For example, the value of a can be 1mm, 5mm, 10mm, 50mm or 100mm, etc. By limiting the value of a within the above range, it can be ensured that the outer peripheral wall of the annular boss 200 is far away from the adjacent side wall of the cover body 100 along the third direction, so as to avoid the heat generated when the cover body 100 is welded to the shell from burning the annular boss 200 or the explosion-proof valve protection sheet 300, causing the annular boss 200 and / or the explosion-proof valve protection sheet 300 to deform. At the same time, it also ensures that sufficient installation space is reserved on both sides of the cover body 100 along the third direction, so as to facilitate the welding of the cover body 100 and the shell.

[0055] Continue to see Figure 2 and Figure 6, in this embodiment, a first sunk platform 220 for installing the explosion-proof valve 400 is provided on the side of the annular boss 200 facing the electrode group, and the explosion-proof valve 400 is embedded in the first sunk platform 220. Optionally, the explosion-proof valve 400 includes a fixing portion 410 and a body portion 420. The fixing portion 410 is arranged on the circumference of the body portion 420, and a notch groove 421 in a ring shape or a C shape is provided on the body portion 420. The first sunk platform 220 includes a platform bottom wall 221 and a platform side wall 222. The end surface of the fixing portion 410 facing away from the electrode group abuts against the platform bottom wall 221, and a relatively small gap is provided between the circumferential side wall of the fixing portion 410 and the platform side wall 222. The circumferential side wall of the fixing portion 410 and the platform side wall 222 are welded together. Along the second direction, the projection of the notch groove 421 on the cover plate body 100 overlaps with the first mounting hole 110. Thus, when the battery undergoes thermal runaway, the high-temperature and high-pressure gas can directly act on the notch groove 421, causing the body portion 420 to tear at the notch groove 421, and further forming a pressure relief channel in the portion surrounded by the inner side of the notch groove 421 of the body portion 420 to achieve the pressure relief function of the explosion-proof valve 400.

[0056] Optionally, along the third direction, the distance between the circumferential side wall of the fixing portion 410 and the platform side wall 222 is g, and the value range of g is: 0.05 mm ≤ g ≤ 1 mm. For example, the value of g can be 0.05 mm, 0.1 mm, 0.2 mm, 0.5 mm, 0.8 mm, 1 mm, etc. By controlling the value of g within the above range, it can ensure the smooth welding of the fixing portion 410 and the annular boss 200. Otherwise, if the value of g is too small, it is not easy to assemble the explosion-proof valve 400 to the first sunk platform 220 of the annular boss 200, and the fixing portion 410 of the explosion-proof valve 400 and the platform side wall 222 of the first sunk platform 220 are interference fit. If the value of g is too large, the welding strength between the fixing portion 410 and the annular boss 200 cannot be guaranteed, the weld is prone to cracking, and there may also be problems such as inability to weld.

[0057] Along the third direction, the distance between the side wall 222 of the platform and the inner wall of the first mounting hole 110 is b, and the value range of b is: 0.3 mm ≤ b ≤ 100 mm. For example, the value of b can be 0.3 mm, 0.5 mm, 1 mm, 5 mm, 10 mm, 50 mm, 100 mm, etc. By limiting the value of b within the above range, the welding position of the explosion-proof valve 400 and the annular boss 200 is far from the cover body 100, avoiding burning the inner wall of the first mounting hole 110 on the cover body 100. Of course, the value of b should not be too large. When the value of b is too large, the size of the annular boss 200 along the third direction increases, affecting the structural strength around the installation position of the explosion-proof valve 400. Of course, the value of b should not be too small either. When the value of b is too small, it may cause insufficient weld width at the weld formed by the circumferential side wall of the fixing portion 410 and the side wall 222 of the platform, resulting in a decrease in the connection strength between the explosion-proof valve 400 and the annular boss 200. If a large weld width is ensured, it may burn the cover body 100, causing the cover body 100 to deform, affecting the welding of the cover body 100 and the housing and reducing the assembly accuracy.

[0058] Further, along the second direction, the distance between the end face of the annular boss 200 facing the electrode group and the end face of the annular boss 200 facing away from the electrode group is h1, and b and h1 satisfy: 0.03 ≤ b / h1 ≤ 25. For example, the value of b / h1 can be 0.03, 0.05, 0.1, 0.5, 1, 5, 10, 25, etc. Through the above settings, it is ensured that the support strength of the annular boss 200 for the explosion-proof valve 400 is relatively high, avoiding cracking at the welding position of the explosion-proof valve 400 and the annular boss 200 or at the position of the notch groove 421 on the explosion-proof valve 400 when the battery cover is subjected to external forces, affecting the performance of the battery cover. The value range of h1 is: 0.5 mm ≤ h1 ≤ 10 mm. For example, the value of h1 can be 0.5 mm, 1 mm, 3 mm, 5 mm, 10 mm, etc. By limiting the value of h1 within the above range, the mechanical strength of the annular boss 200 itself can be ensured to be sufficient.

[0059] Along the third direction, the distance between the outer peripheral wall of the annular boss 200 and the inner wall of the first mounting hole 110 is d, and the value range of d is: 0.3 mm ≤ d ≤ 10 mm. For example, the value of d can be 0.3 mm, 0.5 mm, 1 mm, 3 mm, 5 mm, 10 mm, etc. By limiting the value of d within the above range, it can be ensured that the mechanical strength of the annular boss 200 is sufficient and it is stably connected to the cover body 100, and the annular boss 200 can provide stable support for the explosion-proof valve 400. Otherwise, when the value of d is too small, the connection strength between the annular boss 200 and the cover body 100 is relatively low, and the cover body 100 cannot support the annular boss 200 well and is prone to deformation; when the value of d is too large, it will cause an increase in the size of the cover body 100 along the third direction, which is not conducive to the miniaturization of the battery volume and wastes space.

[0060] Furthermore, the end surface of the annular boss 200 facing the pole group forms a second countersunk platform with the inner wall of the first mounting hole 110. Along the second direction, the distance between the end surface of the annular boss 200 facing the pole group and the end surface of the cover body 100 facing the pole group is h2, that is, the depth of the second countersunk platform along the second direction is h2, and d and h2 satisfy: 0.2≤h2 / d≤10. For example, the value of h2 / d can be 0.2, 0.5, 1, 5, 8 or 10, etc. And h1 and h2 satisfy: 0.2≤h2 / h1≤20. For example, the value of h2 / h1 can be 0.2, 0.5, 1, 5, 8, 10 or 20, etc. By ensuring that b / h1, h2 / d, and h2 / h1 meet the above-mentioned size restrictions at the same time, the annular boss 200 itself has a high mechanical strength, the connection strength between the annular boss 200 and the cover body 100 is high, and the cover body 100 has a high mechanical strength, which can provide good support for the annular boss 200, thereby preventing the welding position between the explosion-proof valve 400 and the annular boss 200 from cracking, or the position of the notch groove 421 on the explosion-proof valve 400 from cracking when the battery cover is subjected to external force, both of which will affect the performance of the battery cover.

[0061] Exemplarily, the value range of h2 is: 0mm<h2≤10mm. For example, the value of h2 can be 0.2mm, 0.5mm, 1mm, 3mm, 5mm or 10mm, etc. By limiting the value of h2 within the above range, the connection strength between the annular boss 200 and the cover body 100 can be ensured to be sufficient.

[0062] Continue to see Figure 6 , along the second direction, the distance between the end face of the annular boss 200 away from the pole group and the bottom wall 221 is c, and the value range of c is: 0.3mm≤c≤10mm. For example, the value of c can be 0.3mm, 0.5mm, 1mm, 3mm, 5mm or 10mm, etc. By limiting the value of c within the above range, it can be ensured that after the first sink 220 is set, the annular boss 200 of the residual thick part still has a high mechanical strength, can support the explosion-proof valve 400 and the explosion-proof valve protection sheet 300, and ensure that the explosion-proof valve 400 and the explosion-proof valve protection sheet 300 are firmly and stably fixed on the annular boss 200.

[0063] Further, along the second direction, the thickness of the fixing portion 410 of the explosion-proof valve 400 is z, and the relationship among h1, c, and z satisfies: 0.1 ≤ z / (h1 - c) ≤ 8. For example, the value of z / (h1 - c) can be 0.1, 0.2, 0.5, 1, 5, 8, etc. Wherein, the value of h1 - c is the depth of the first sunken platform 220 along the second direction, and is also the dimension of the platform side wall 222 along the second direction. By ensuring that the value of z / (h1 - c) is within the above range, the height difference between the end face of the fixing portion 410 facing the electrode group side and the end face of the annular boss 200 facing the electrode group side is small, so that the fixing portion 410 and the annular boss 200 can be welded smoothly. Otherwise, when the height difference between the end face of the fixing portion 410 facing the electrode group side and the end face of the annular boss 200 facing the electrode group side is too large, the fixing portion 410 and the annular boss 200 cannot be welded into one body, or welding defects such as hole explosion occur during the welding of the fixing portion 410 and the annular boss 200, and the connection stability and reliability between the fixing portion 410 and the annular boss 200 cannot be ensured. Optionally, the value range of z is: 0.5 mm ≤ z ≤ 2 mm. For example, the value of z can be 0.3 mm, 0.5 mm, 1 mm, 3 mm, 5 mm, 10 mm, etc.

[0064] The following uses the battery covers in some specific embodiments to verify the value ranges of the above structural parameters, and the results are shown in Table 1.

[0065] Table 1

[0066]

[0067] From the above results, it can be seen that in Embodiment 1, the value of parameter e is close to the lower limit of its dimension limit 1 mm ≤ e ≤ 10 mm, and the other parameters take normal values. At this time, the mechanical strength of the cover body 100 in the battery cover is relatively high, which can provide good support for the annular boss 200 and the explosion-proof valve 400, is not prone to deformation, the fixing structure of the explosion-proof valve 400 is stable and reliable. After the battery cover is subjected to a vibration test, the helium leak tightness test at the connection between the annular boss 200 and the explosion-proof valve 400 is qualified, the reliability of the battery cover is high, and the product is good.

[0068] In Embodiment 2, the value of parameter d is at the lower limit of its dimension limit 0.3 mm ≤ d ≤ 10 mm, and the other parameters take normal values. At this time, the connection strength between the cover body 100 and the annular boss 200 is relatively high, the mechanical strength of the annular boss 200 is sufficient, the annular boss 200 can provide good support for the explosion-proof valve 400, the structure of the battery cover is stable and reliable, is not prone to deformation. After the battery cover is subjected to a vibration test, the helium leak tightness test at the connection between the annular boss 200 and the explosion-proof valve 400 is qualified, and the product is good.

[0069] Example 3: The value of parameter b is at the lower limit of its dimensional limit of 0.3 mm ≤ b ≤ 100 mm, and the other parameters are taken as normal values. At this time, the welding joint between the explosion-proof valve 400 and the annular boss 200 is far from the cover body 100, avoiding burning the inner wall of the first mounting hole 110 on the cover body 100. At the same time, the structural strength of the installation position around the explosion-proof valve 400 is relatively high, and the cover body 100 is not easily deformed. After the battery cover is subjected to a vibration test, the helium leak tightness test at the connection between the annular boss 200 and the explosion-proof valve 400 is qualified, and the product is good.

[0070] In Example 4, the value of parameter h1 is at the lower limit of its dimensional limit, and the values of h2 and h2 / h1 are at the upper limits of their dimensional limits, and the other parameters are taken as normal values. At this time, the connection strength between the cover body 100 and the annular boss 200 is relatively high, the mechanical strength of the annular boss 200 is sufficient, and the annular boss 200 can provide good support for the explosion-proof valve 400. The structure of the battery cover is stable and reliable and is not easily deformed. After the battery cover is subjected to a vibration test, the helium leak tightness test at the connection between the annular boss 200 and the explosion-proof valve 400 is qualified, and the product is good.

[0071] In Example 5, the values of parameters b and b / h1 are at the upper limits of their dimensional limits, and the other parameters are taken as normal values. At this time, the connection strength between the cover body 100 and the annular boss 200 is relatively high, the mechanical strength of the annular boss 200 is sufficient, and the annular boss 200 can provide good support for the explosion-proof valve 400. The connection structure between the explosion-proof valve 400 and the annular boss 200 is stable and reliable. After the battery cover is subjected to a vibration test, the helium leak tightness test at the connection between the annular boss 200 and the explosion-proof valve 400 is qualified, and the product is good.

[0072] In Example 6, the value of parameter d is close to the lower limit of its dimensional limit, and the value of h2 / d is at the upper limit of its dimensional limit, and the other parameters are taken as normal values. At this time, the connection strength between the cover body 100 and the annular boss 200 is relatively high, the mechanical strength of the annular boss 200 is sufficient, and the annular boss 200 can provide good support for the explosion-proof valve 400. The connection structure between the explosion-proof valve 400 and the annular boss 200 is stable and reliable. After the battery cover is subjected to a vibration test, the helium leak tightness test at the connection between the annular boss 200 and the explosion-proof valve 400 is qualified, and the product is good.

[0073] In Example 7, the value of parameter c is at the lower limit of its dimensional limit, and the other parameters are taken as normal values. At this time, the connection strength between the cover body 100 and the annular boss 200 is relatively high, the mechanical strength of the annular boss 200 is sufficient, and the annular boss 200 can provide good support for the explosion-proof valve 400. The connection structure between the explosion-proof valve 400 and the annular boss 200 is stable and reliable. After the battery cover is subjected to a vibration test, the helium leak tightness test at the connection between the annular boss 200 and the explosion-proof valve 400 is qualified, and the product is good.

[0074] In Embodiment 8 and Embodiment 9, the values of the parameter z / (h1 - c) are respectively close to the lower limit and the upper limit of its dimensional limit, and the remaining parameters are all taken as normal values. At this time, the welding quality between the explosion-proof valve 400 and the annular boss 200 is good, the connection strength is high, the annular boss 200 can provide good support for the explosion-proof valve 400, the connection structure between the cover body 100 and the annular boss 200 is stable and reliable. After the battery cover is subjected to a vibration test, the helium leak tightness test at the connection between the annular boss 200 and the explosion-proof valve 400 is qualified, and the product is good.

[0075] Referring to Comparative Example 1, the values of the parameters h2 and h2 / h1 exceed the upper limit of their dimensional limits, and the remaining parameters are all taken as normal values. At this time, the structural strength at the connection between the cover body 100 and the annular boss 200 is insufficient, the annular boss 200 cannot provide good support for the explosion-proof valve 400, and the welding position between the explosion-proof valve 400 and the annular boss 200 is prone to deformation and cracking. After the battery cover is subjected to a vibration test, the helium leak tightness test at the connection between the annular boss 200 and the explosion-proof valve 400 is unqualified, and the product is defective.

[0076] Referring to Comparative Example 2, the value of the parameter c exceeds the lower limit of its dimensional limit, and the remaining parameters are all taken as normal values. At this time, after the first sinking platform 220 is provided on the annular boss 200, the mechanical strength of the remaining annular boss 200 is insufficient and cannot well support the explosion-proof valve 400 and the explosion-proof valve protection piece 300. The welding position between the explosion-proof valve 400 and the annular boss 200 is prone to deformation and cracking. After the battery cover is subjected to a vibration test, the helium leak tightness test at the connection between the annular boss 200 and the explosion-proof valve 400 is unqualified, and the product is defective.

[0077] Referring to Comparative Example 3, the value of the parameter b / h1 exceeds the upper limit of its dimensional limit, and the remaining parameters are all taken as normal values. At this time, the dimension of the annular boss 200 in the third direction is too large, the structural strength at the installation position around the explosion-proof valve 400 decreases, and the welding position between the explosion-proof valve 400 and the annular boss 200 is prone to deformation and cracking when subjected to impact. After the battery cover is subjected to a vibration test, the helium leak tightness test at the connection between the annular boss 200 and the explosion-proof valve 400 is unqualified, and the product is defective.

[0078] Referring to Comparative Example 4, the value of the parameter h2 / d exceeds the upper limit of the dimensional limit, and the remaining parameters are all taken as normal values. At this time, the mechanical strength of the cover body 100 is insufficient and cannot provide good support for the annular boss 200. When the battery cover is subjected to an external force, the welding position between the explosion-proof valve 400 and the annular boss 200 is prone to cracking. After the battery cover is subjected to a vibration test, the helium leak tightness test at the connection between the annular boss 200 and the explosion-proof valve 400 is unqualified, and the product is defective.

[0079] Referring to Comparative Example 5, the value of the parameter z / (h1 - c) exceeds the lower limit of its dimensional limit, and the remaining parameters are all taken as normal values. At this time, the height difference between the end face of the fixing part 410 of the explosion-proof valve 400 facing the electrode group and the end face of the annular boss 200 facing the electrode group is relatively large, and the welding quality between the annular boss 200 and the fixing part 410 of the explosion-proof valve 400 is poor, and welding problems such as hole explosion are likely to occur. The sealing performance at the weld between the annular boss 200 and the fixing part 410 is poor. After the battery cover plate is subjected to a vibration test, the helium leak tightness test at the connection between the annular boss 200 and the explosion-proof valve 400 is unqualified, and the product is defective.

[0080] Referring to Comparative Example 6, the value of the parameter z / (h1 - c) exceeds the upper limit of its dimensional limit, and the remaining parameters are all taken as normal values. At this time, the height difference between the end face of the fixing part 410 of the explosion-proof valve 400 facing the electrode group and the end face of the annular boss 200 facing the electrode group is relatively large, and the welding quality between the annular boss 200 and the fixing part 410 of the explosion-proof valve 400 is poor, and welding problems such as hole explosion are likely to occur. The sealing performance at the weld between the annular boss 200 and the fixing part 410 is poor. After the battery cover plate is subjected to a vibration test, the helium leak tightness test at the connection between the annular boss 200 and the explosion-proof valve 400 is unqualified, and the product is defective.

[0081] In summary, the present invention defines some important parameters of the battery cover plate. It can be known that when the above parameters e, d, b, h1, h2, h2 / h1, b / h1, h2 / d, z, c, and z / (h1 - c) all meet their corresponding dimensional limits, the fixing structure of the explosion-proof valve 400 on the annular boss 200 can be ensured to be stable, the connection strength between the annular boss 200 and the cover body 100 is relatively high, and when the battery cover plate is subjected to external impact, the connection between the annular boss 200 and the explosion-proof valve 400 is not easily deformed or cracked, and the air tightness is good. At the same time, the setting of the annular boss 200 can also prevent the electrolyte from flowing from the notch 310 on the explosion-proof valve protection piece 300 to the explosion-proof valve 400, playing a good protective role for the explosion-proof valve 400. The opening pressure of the explosion-proof valve 400 is accurate, and the reliability of the battery cover plate is high.

[0082] Optionally, the battery cover plate further includes a plastic part 500. The plastic part 500 is arranged on the side of the cover plate body 100 close to the electrode group. Along the second direction, the plastic part 500 is clamped between the cover plate body 100 and the electrode group, so that the electrode group is insulated from the cover plate body 100 through the plastic part 500. Further, a plurality of air holes 510 and a second liquid injection hole 520 are provided on the plastic part 500. Along the second direction, the projection of the plurality of air holes 510 on the cover plate body 100 at least partially overlaps with the projection of the explosion-proof valve 400 on the cover plate body 100. Thus, the accommodation cavity can be communicated with the first mounting hole 110 through the air holes 510, and then the high-temperature and high-pressure gas can flow through the air holes 510, the first mounting hole 110, the explosion-proof valve 400, and the second mounting hole 210 in sequence. Along the second direction, the projection of the second liquid injection hole 520 on the cover plate body 100 at least partially overlaps with the projection of the first liquid injection hole 120 on the cover plate body 100. The second liquid injection hole 520 communicates the accommodation cavity with the first liquid injection hole 120, and thus the electrolyte can be injected into the accommodation cavity through the first liquid injection hole 120 and the second liquid injection hole 520.

[0083] This embodiment also provides a battery, including a housing, an electrode group, and the above battery cover plate. The battery cover plate is welded to the side of the housing with an opening. The battery cover plate and the housing jointly enclose an accommodation cavity, and the electrode group is arranged in the accommodation cavity. By adopting the above battery cover plate, it can be ensured that the explosion-proof valve 400 will not be corroded by the electrolyte during battery liquid injection, which plays a good protective role for the explosion-proof valve 400. At the same time, the fixing structure of the explosion-proof valve 400 on the cover plate body 100 is stable, not easy to deform, the valve opening pressure is accurate, and the reliability is high.

[0084] Obviously, the above embodiments of the present invention are merely examples for clearly explaining the present invention, rather than limiting the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all implementation manners here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A battery cover plate, characterized in that, include: A cover plate body is arranged on one side of the pole group, a first mounting hole is arranged on the cover plate body, an annular boss is arranged on the end surface of the cover plate body away from the pole group, the annular boss is located in the circumference of the first mounting hole, the end surface of the annular boss away from the pole group is higher than the end surface of the cover plate body away from the pole group, a second mounting hole is formed at the center of the annular boss, and the second mounting hole is connected with the first mounting hole; a first liquid injection hole is arranged on the cover plate body, and the first liquid injection hole is arranged on one side of the annular boss along the first direction; An explosion-proof valve protection sheet connected to a side of the annular boss away from the pole group, the explosion-proof valve protection sheet being provided with a notch, the notch connecting the second mounting hole with a space on a side of the cover plate body away from the pole group; An explosion-proof valve connected to a side of the annular boss close to the pole group, wherein a pressure relief channel is formed when the explosion-proof valve is opened, and the pressure relief channel is communicated with the first mounting hole; Wherein, along the second direction, the distance between the end surface of the annular boss facing away from the pole group and the end surface of the cover plate body facing away from the pole group is f; The value range of f is 0.3mm≤f≤10mm.

2. The battery cover plate according to claim 1, wherein Along the second direction, the thickness of the cover plate body is e, and the value range of e is 1mm≤e≤10mm.

3. The battery cover plate according to claim 1, characterized in that, Along the third direction, the distance between the outer peripheral wall of the annular boss and the adjacent side wall of the cover body along the third direction is a; The value range of a is: 1mm≤a≤100mm.

4. The battery cover plate according to claim 1, characterized in that, A first sunken platform for mounting the explosion-proof valve is provided on one side of the annular boss facing the pole group, the first sunken platform comprising a platform bottom wall and a platform side wall, the explosion-proof valve comprising a fixing portion, the end surface of the fixing portion facing away from the pole group abuts against the platform bottom wall, and the peripheral side wall of the fixing portion is spaced apart from the platform side wall; Along the third direction, the distance between the side wall of the platform and the inner wall of the first mounting hole is b; The value range of b is: 0.3mm≤b≤100mm.

5. The battery cover plate according to claim 4, characterized in that, Along the second direction, the distance between the end surface of the annular boss facing the pole group and the end surface of the annular boss facing away from the pole group is h1, and b and h1 satisfy: 0.03≤b / h1≤25; The value range of h1 is: 0.5mm≤h1≤10mm.

6. The battery cover plate according to claim 5, characterized in that, Along the third direction, the distance between the outer peripheral wall of the annular boss and the inner wall of the first mounting hole is d; Along the second direction, the distance between the end surface of the annular boss facing the pole group and the end surface of the cover plate body facing the pole group is h2; d and h2 satisfy: 0.2≤h2 / d≤10; And h1 and h2 satisfy: 0.2≤h2 / h1≤20; The value range of d is: 0.3mm≤d≤10mm; The value range of h2 is: 0mm<h2≤10mm.

7. The battery cover plate according to claim 6, wherein Along the second direction, the distance between the end surface of the annular boss facing away from the pole group and the bottom wall of the boss is c; The value range of c is: 0.3mm≤c≤10mm.

8. The battery cover plate according to claim 7, characterized in that, In the second direction, the thickness of the fixing part is z, and the relationship among h1, c and z satisfies: 0.1 ≤ z / (h1 - c) ≤ 8; The value range of z is: 0.5 mm ≤ z ≤ 2 mm.

9. The battery cover plate according to claim 4, wherein, In the third direction, the distance between the circumferential side wall of the fixing part and the side wall of the platform is g; The value range of g is: 0.05 mm ≤ g ≤ 1 mm.

10. A battery, characterized in that, It includes the battery cover plate according to any one of claims 1-9.

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