Explosion protection valve, battery cover plate and battery

Abstract

Explosion protection valve, wherein the explosion protection valve (1) is provided with an annular groove (12), wherein the annular groove (12) divides the explosion protection valve (1) into a fracture section (13) and a fastening section (14), wherein one side of the fracture section (13) is provided with a concave arcuate pressure-receiving groove (15), wherein a bottom side of the pressure-receiving groove (15) is located inside the annular groove (12).

Description

Technical field

[0001] The present application relates to the technical field of batteries, for example an explosion protection valve, a battery cover plate and a battery. State of the art

[0002] With the increasing maturity of lithium-ion battery technology, lithium-ion batteries are widely used as energy storage devices in electric vehicles. The production of gas during battery overcharging causes an increase in the battery's internal pressure. To prevent a battery explosion, it is necessary to install an explosion-proof valve, which is typically mounted on the underside of the battery's cover plate or on the bottom of the battery casing.

[0003] However, if a large amount of gas is generated due to battery overcharging, causing an increase in internal pressure, one side of the explosion protection valve facing the inside of the battery will be subject to the same gas pressure, making it difficult to predict the rupture position of the explosion protection valve, and the situation will be uncontrollable in the event of the explosion protection valve rupturing, easily leading to danger. Disclosure of the invention

[0004] An explosion protection valve, a battery cover plate, and a battery are provided in the present application. This allows the rupture position of the explosion protection valve to be controlled under gas pressure, thereby improving safety.

[0005] In the first aspect, the present application provides an explosion protection valve which is provided with an annular groove, wherein the annular groove divides the explosion protection valve into a break section and a fastening section, wherein one side of the break section is provided with a concave arcuate pressure-receiving groove, wherein a bottom side of the pressure-receiving groove is located inside the annular groove.

[0006] In one embodiment, the explosion protection valve is provided with a liquid filling hole.

[0007] In one embodiment, the explosion protection valve is provided with a blocking groove, and the liquid filling hole is provided on the underside of the blocking groove.

[0008] In one embodiment, the underside of the annular groove is provided with a notch.

[0009] In one embodiment, the width of the notch gradually decreases in a direction from a groove opening of the annular groove to the underside of the annular groove.

[0010] In one embodiment, the notch extends along a circumferential direction of the annular groove.

[0011] In one embodiment, the explosion protection valve is made of a metallic material.

[0012] A battery cover plate is provided. The battery cover plate includes the explosion protection valve and a top cover on which the explosion protection valve is mounted.

[0013] In one embodiment, the cover plate of a battery further comprises a first insulating element which is detachably connected to the upper cover and is located between the upper cover and a housing of the battery.

[0014] In one embodiment, one of the first insulating element and the upper cover is provided with a first positioning column, and the other is provided with a first positioning hole into which the first positioning column is inserted.

[0015] In the second aspect, the present embodiment of the present application provides a battery. The battery comprises the above-mentioned battery cover plate and the battery housing. The battery housing is provided with a mounting hole, and the battery cover plate is closed against the battery housing to close the mounting hole.

[0016] This application has beneficial effects:

[0017] The present application provides an explosion protection valve, a battery cover plate, and a battery. The explosion protection valve is provided with an annular groove, which reduces its inherent strength. Because the thickness of the explosion protection valve is smaller at the annular groove, the valve is more likely to fracture at the groove and release pressure when subjected to gas breakthrough. Meanwhile, the pressure-absorbing groove of the fracture section is located on a side of the fracture section facing the inside of the battery.If the gas inside the battery breaches the explosion protection valve, more gas collects at the pressure-receiving groove. Since the curved surface of the pressure-receiving groove has a larger area than a flat surface, the pressure-receiving groove is subjected to the greater and more concentrated gas pressure. This results in the fracture section being subjected to greater pressure than the mounting section, and consequently, the explosion protection valve is more likely to breach at the annular groove. The explosion protection valve can break at the annular groove when subjected to the gas pressure, and the fracture location is controllable, thus improving safety. Short description of the characters Fig. Figure 1 shows an exploded view of a cover plate of a battery according to embodiments of the present application; Fig. 2 shows a cross-sectional view of a cover plate of a battery according to embodiments of the present application; Fig. Figure 3 shows a schematic structural view of an explosion protection valve according to embodiments of the present application; Fig. Figure 4 shows a cross-sectional view of an explosion protection valve according to embodiments of the present application. Reference symbol:

[0018] 1, Explosion protection valve; 2, Top cover; 3, Pole; 4, Current collector disc; 5, First insulating element; 6, Sealing ring; 7, Terminal; 8, Second insulating element;

[0019] 11, Liquid filling hole; 12, Ring groove; 13, Break section; 14, Mounting section; 15, Pressure receiving groove; 16, Locking groove; 51, First positioning column; 81, Second positioning column;

[0020] 121, notch. Specific embodiments

[0021] In the description of this application, the terms "center", "top", "bottom", "left", "right", "vertical", "horizontal", "inside", "outside", etc., are used in each case in relation to the directional or positional relationship shown in the respective figure. They serve only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the device or element in question must have a particular orientation, be constructed and operated in a particular direction; therefore, they should not be construed as limiting the present application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying any relative significance. The terms "first position" and "second position" refer to two distinct positions.

[0022] The terms "attach," "connected," "linked," and "fasten" should be interpreted in the broadest sense unless expressly stated otherwise or limited. For example, they can refer to a permanent or detachable connection, as well as a mechanical or electrical connection. Furthermore, they can refer to a direct connection, an indirect connection via an intermediate piece, an internal connection between two elements, or an interaction between two elements. As experts in this field, they can use the facts as a basis to determine the intended meaning of these terms according to the present utility model.

[0023] A phrase stating that a first feature is "above" or "below" a second feature implies that the first feature is in direct contact with the second feature, or it may also include the first feature not being in direct contact with the second feature, but rather being connected to the second feature through additional features between them, unless explicitly stated and limited otherwise. Furthermore, a phrase stating that the first feature is "at," "above," or "on" the second feature implies that the first feature is directly above or diagonally above the second feature, or it simply indicates that the first feature is higher than the second feature in horizontal height.And the formulation that the first feature is located “below”, “below”, and “underneath” the second feature implies that the first feature is located directly below or diagonally below the second feature, or it merely indicates that the first feature is lower in horizontal height than the second feature.

[0024] The technical solution of the present application is explained in more detail with reference to specific embodiments in conjunction with the attached figures.

[0025] The embodiment provides a battery. The battery is a lithium-ion battery and comprises a positive electrode, a negative electrode, a separator, and electrolyte. The separator is configured to separate the positive electrode from the negative electrode and to prevent a short circuit. The separator is permeable to lithium ions. The manufacturing process for the lithium-ion battery typically employs a winding method, meaning a winding structure is formed by stacking and winding the positive electrode, separator, and negative electrode one after the other. Once the winding process is complete, the winding structure is placed in the battery casing, and the electrolyte is added to form a complete battery.

[0026] The battery comprises a casing and a cover plate. The battery casing has a mounting hole, and the cover plate is attached to the casing to seal this hole. The removable cover plate makes it easier for an operator to insert the positive electrode, negative electrode, separator, electrolyte, and other components into the battery casing through the mounting hole. This facilitates disassembly and recycling of the battery at a later date, thus reducing battery costs over the entire battery lifecycle.

[0027] For example, how in Fig. As shown in Figure 1, the cover plate of a battery includes a top cover 2 which is configured to close onto the battery housing to form a locking structure.

[0028] For example, how in Fig. 1 and Fig. As shown in Figure 2, the cover plate of a battery includes a terminal 3. One end of terminal 3 is attached to the upper cover 2, and a second end of terminal 3 extends through and out of the upper cover 2. Terminal 3 is connected to the positive electrode of the battery, and the battery casing is connected to the negative electrode of the battery. Thus, the positive and negative electrodes of the battery can be connected to an external circuit.

[0029] If the battery requires a high discharge rate (3C or more), the thermal effect of the current becomes significant. This can easily lead to localized heating of the battery terminals and cause battery expansion, creating a hazard. To address this problem, the battery cover plate incorporates a current collector disk 4. Terminal 3 passes through the current collector disk 4 and is electrically connected to it. The positive electrode of the winding structure extends from one end, and the negative electrode extends from the other. Both the positive and negative electrodes of the winding structure have a multilayer structure. The positive electrode of the multilayer structure is electrically connected to the current collector disk 4, and the negative electrode of the multilayer structure is electrically connected to the battery casing.The battery thus forms a full-plate structure, which significantly reduces the thermal effect of the battery during high-rate discharge and allows for heat dispersion, improving the battery's safety performance.

[0030] Since the top cover 2 is usually made of a metallic material to prevent short circuits in the battery, the cover plate of a battery also includes a first insulating element 5, which is detachably connected to the top cover 2 and is located between the top cover 2 and the battery housing. The cover plate of a battery does not allow charging, so a safety distance exists between the positive and negative electrodes to prevent short circuits. The top cover 2 must come into contact with the battery housing to be secured; therefore, a first insulating element 5 must be provided to insulate between the top cover 2 and the battery housing.

[0031] For example, how in Fig. As shown in Figure 1, the first insulating element 5 is provided with a first positioning column 51, the upper cover 2 is provided with a first positioning hole, and the first positioning column 51 is inserted into the first positioning hole. The first positioning column 51 works in conjunction with the first positioning hole so that, when the first insulating element 5 and the upper cover 2 are assembled, the upper cover 2 is prevented from making partial contact with the housing and causing a short circuit due to any deviations, thus improving battery safety. Two first positioning columns 51 and two first positioning holes are provided as an example to improve positioning accuracy.

[0032] In other embodiments, the upper cover 2 is provided with a first positioning column 51, and the first insulating element 5 is provided with a first positioning hole, so that a positioning effect can also be achieved between the upper cover 2 and the first insulating element 5.

[0033] After the batteries are grouped, a busbar must be welded to connect the electrodes of the multiple batteries in series or parallel so that the batteries can be connected to the external circuit. However, the size of terminal 3 of the battery is small, and the weld strength is not high. To solve this problem, as in Fig. 1 and Fig. As shown in Figure 2, the cover plate of a battery further comprises a terminal 7, which is rigidly connected to the upper cover 2 and electrically connected to an end of the pole 3 extending from the upper cover 2. A suitable material for the terminal 7 can be selected according to the welding performance, and a sufficiently large welding area can be designed according to the welding requirements, thereby improving the weld strength of the terminal to the busbar.

[0034] For example, the cover plate of a battery further includes a second insulating element 8, which is provided between terminal 7 and the upper cover 2. The second insulating element 8 is configured to insulate the upper cover 2 and the terminal 3. The second insulating element 8 works together with the first insulating element 5 so that the upper cover 2 is isolated from the positive and negative electrodes of the battery, respectively, thereby further improving the safety of the battery and reducing the risk of short circuits.

[0035] For example, the second insulating element 8 is provided with a second positioning column 81, the terminal 7 is provided with a second positioning hole, and the second positioning column 81 is inserted into the second positioning hole. The second positioning column 81 works in conjunction with the second positioning hole so that, when the second insulating element 8 and the terminal 7 are assembled, the terminal 2 is prevented from making partial contact with the upper cover 2 due to any deviations, thus improving battery safety. For example, two second positioning columns 81 and two second positioning holes are provided to improve positioning accuracy.

[0036] In other embodiments, the terminal 7 is provided with a second positioning column 81, and the second insulating element 8 is provided with a second positioning hole, so that the positioning effect between the terminal 7 and the second insulating element 8 can also be achieved.

[0037] For example, the interior of the battery casing is filled with electrolyte, and the seal between terminal 3 and the top cover 2 or between terminal 3 and the first insulating element 5 is poor. As in Fig. 1 and Fig. As shown in Figure 2, to prevent electrolyte leakage, the battery cover plate further comprises a sealing ring 6, which is encased at terminal 3 and clamped between the first insulating element 5 and the upper cover 2. The sealing ring 6 ensures a tight seal between itself and the terminal 3 through its own elasticity. The upper cover 2 clamps the sealing ring 6 onto the first insulating element 5, thus ensuring a tight seal between the sealing ring 6 and the first insulating element 5 and preventing electrolyte leakage.

[0038] To improve battery safety and prevent explosion or deflagration in the event of overcharging or shock, the battery cover plate further includes an explosion protection valve 1, which is provided on the upper cover 2. For example, the upper cover 2 is provided with a stepped opening, the stepped opening having a large diameter segment and a small diameter segment. The explosion protection valve 1 is provided at the end of the upper cover 2 with the large diameter segment and rests against a step between the large diameter segment and the small diameter segment.

[0039] As in Fig. 3 and Fig. As shown in Figure 4, the explosion protection valve 1 is provided with an annular groove 12, which divides the explosion protection valve 1 into a break section 13 and a mounting section 14. One side of the break section 13 is provided with a concave arcuate pressure-receiving groove 15. The groove of the pressure-receiving groove 15 is located on the annular groove 12. The mounting section 14 is configured to be welded or bonded to the inner wall of the stepped hole to secure the explosion protection valve 1.

[0040] The explosion protection valve 1 is provided with the annular groove 12, which reduces its inherent strength. Since the thickness of the explosion protection valve 1 is smaller at the annular groove 12, the valve is more likely to fail at this groove and release pressure when subjected to gas breakthrough. Meanwhile, the pressure-receiving groove 15 of the failure section 13 faces the inside of the battery. When gas within the battery breaches the explosion protection valve 1, more gas accumulates at the pressure-receiving groove 15. The arcuate surface of the pressure-receiving groove 15 has a larger area than the flat surface, so the pressure-receiving groove 15 is subjected to the greater and more concentrated gas pressure. This causes the failure section 13 to be subjected to a higher pressure than the fastening section 14, and consequently, the explosion protection valve 1 is more likely to fail at the annular groove 12.

[0041] The explosion protection valve 1 can break at the annular groove 12 when subjected to gas pressure, and the breaking position is controllable, thus improving safety.

[0042] For example, the explosion protection valve 1 is equipped with a liquid filling hole 11, thus integrating the function of the liquid filling hole 11 into the explosion protection valve 1. In the production process, the explosion protection valve 1 and the liquid filling hole 11 are integrally processed and produced, thereby improving production efficiency and reducing manufacturing costs. Because the explosion protection valve 1 integrates the liquid filling hole 11, the space required for the liquid filling hole 11 on the battery cover plate is significantly reduced, thereby increasing the mounting space of the explosion protection valve 1, effectively improving the pressure control capability of the explosion protection disc, and significantly enhancing the safety of the lithium battery.

[0043] For example, as in Fig. 3 and Fig.As shown in Figure 4, the explosion protection valve 1 is provided with a blocking groove 16, and the liquid filling hole 11 is located at the bottom of the blocking groove 16. After the electrolyte has been filled into the battery through the liquid filling hole 11, the operator must block the liquid filling hole 11 to prevent electrolyte leakage. Generally, the liquid filling hole 11 is blocked with an adhesive, and the blocking groove 16 provides a space for the adhesive to block the liquid filling hole 11. This increases the contact area between the adhesive and the explosion protection valve 1, thus increasing the blocking effect, and prevents protrusions from forming on the adhesive, thereby ensuring the flatness of the surface of the top cover 2.

[0044] For example, the locking groove 16 must be positioned away from the annular groove 12; that is, the locking groove 16 may only be located within the fracture section 13 or the fastening section 14. If the locking groove 16 is located at the fastening section 14, the local strength of the fastening section 14 is weak, which can easily lead to an uncontrollable fracture location where the explosion protection valve 1 breaks. Therefore, the locking groove 16 is located within the annular groove 12. For example, the locking groove 16 is located in the center of the annular groove 12 so that the fracture section 13 can fracture uniformly along the annular groove 12 when subjected to a force.

[0045] For example, the underside of the annular groove 12 is provided with a notch 121. By providing the notch 121 on the underside of the annular groove 12, the strength of the annular groove 12 can be further reduced, and the specific size and quantity of the notch 121 can be controlled according to the design requirements of the explosion protection valve 1, so that when the gas pressure inside the battery reaches a predetermined value, the explosion protection valve 1 can break at the annular groove 12.

[0046] For example, the width of the notch 121 gradually decreases in one direction from the opening of the annular groove 12 to the underside of the annular groove. The lower end of the notch 121 is sharper, the stress concentration there is high, and thus the strength at the notch 121 can be further reduced.

[0047] For example, the notch 121 extends along the circumferential direction of the annular groove 12, so that the annular groove 12 has the same strength everywhere and can break uniformly when subjected to a force.

[0048] For example, the explosion protection valve 1 is made of a metallic material. The metal has a ductility that facilitates integral stamping, improves production efficiency, and reduces production costs. Furthermore, the metal has good weldability, and the explosion protection valve 1 can be attached to the upper cover 2 by welding, which is a simple process and highly efficient in terms of production.

[0049] For example, the explosion protection valve 1 and the upper cover 2 are made of the same metal, such as aluminum, steel and the like, to improve weld stability.

Claims

[1] Explosion protection valve, wherein the explosion protection valve (1) is provided with an annular groove (12), wherein the annular groove (12) divides the explosion protection valve (1) into a fracture section (13) and a fastening section (14), wherein one side of the fracture section (13) is provided with a concave arcuate pressure receiving groove (15), wherein a bottom side of the pressure receiving groove (15) is located within the annular groove (12). [2] Explosion protection valve according to claim 1, wherein the explosion protection valve (1) is provided with a liquid filling hole (11). [3] Explosion protection valve according to claim 2, wherein the explosion protection valve (1) is provided with a blocking groove (16), wherein the liquid filling hole (11) is provided on a bottom side of the blocking groove (16). [4] Explosion protection valve according to one of claims 1 to 3, wherein a bottom side of the annular groove (12) is provided with a notch (121). [5] The explosion protection valve according to claim 4, wherein a width of the notch (121) gradually decreases in a direction from a groove opening of the annular groove (12) to the bottom of the annular groove (12). [6] Explosion protection valve according to claim 4, wherein the notch (121) extends along a circumferential direction of the annular groove (12). [7] Explosion protection valve according to one of claims 1 to 6, wherein the explosion protection valve (1) consists of a metallic material. [8] A cover plate of a battery, comprising an explosion-proof valve according to any one of claims 1 to 7 and further comprising a top cover (2), the explosion-proof valve (1) being provided on the top cover (2). [9] A battery cover plate according to claim 8, further comprising a first insulating member (5) detachably connected to the top cover (2) and located between the top cover (2) and a casing of the battery. [10] A cover plate of a battery according to claim 9, wherein one of the first insulating member (5) and the top cover (2) is provided with a first positioning column (51) and the other is provided with a first positioning hole, the first positioning column (51) being inserted into the first positioning hole. [11] A battery cover plate according to any one of claims 8 to 10, wherein the explosion protection valve (1) and the top cover (2) are made of the same metal. [12] A battery, comprising a battery cover plate according to any one of claims 8 to 11 and further comprising a battery case, the battery case being provided with a mounting hole, the battery cover plate being closed to the battery case to close the mounting hole.

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