Top cover structure and lithium battery

Abstract

The utility model relates to a top cover structure and a lithium battery. The top cover structure comprises an anti-explosion valve provided with a nick, and the nick is of a non-closed structure; the cover plate is provided with a through hole which is formed in a penetrating mode, the cover plate can cover the explosion-proof valve so that at least the nick can be exposed out of the cover plate through the through hole, and the cover plate can adjust the length, exposed out of the through hole, of the nick. The explosion value of the explosion-proof valve can be adjusted by adjusting the relative position of the cover plate and the explosion-proof valve to adjust the length of the nick exposed out of the through hole, so that different types of lithium batteries can be produced by adopting the cover plate and the explosion-proof valve of the same type, the explosion-proof valve does not need to be subjected to mold opening production again, the production cost can be reduced, and the production efficiency is improved. And the assembly requirements of different types of lithium batteries are met.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a top cover structure and a lithium battery. Background Art

[0002] Currently, in the lithium battery industry, a welded explosion-proof valve and cover plate structure is commonly used to achieve lithium battery explosion. During the explosion-proof valve design process, notches are usually used to achieve the explosion of the explosion-proof valve. To prevent the bursting disc from splashing after the explosion, the explosion-proof valve is fully notched to create a connecting area between the bursting disc and the main body of the explosion-proof valve.

[0003] During the lithium battery process or over-discharge explosion process, due to the generation of excessive gas, the explosion-proof valve as a whole is subjected to an upward force. The main area of ​​the explosion-proof valve is welded to the cover plate. Under normal circumstances, due to the obstruction of the cover plate, it is slightly deformed by the force (unless the cover plate is deformed). The bursting disc in the middle is very thin and will deform before the main body of the explosion-proof valve. During the deformation process, due to the presence of notches, the aluminum at the notches will be subjected to tension from the bursting disc. At the same time, the aluminum at the notches will also be subjected to a thrust toward the cover plate. When the combined force of the tension and thrust is greater than a certain value, the bursting disc will break, thereby achieving the explosion of the explosion-proof valve.

[0004] Typically, the explosion-proof valve and cover plate are assembled to achieve a fixed range of explosion values. The explosion value between the explosion-proof valve and the cover plate cannot be adjusted, making it impossible to achieve explosions within a wide range of explosion values. Changing the explosion value of the explosion-proof valve requires re-molding and re-production, which increases lithium battery production costs and is inconvenient for the production of different lithium battery models. Utility Model Content

[0005] Based on this, it is necessary to provide a top cover structure and a lithium battery to address the problem that the explosion value between the explosion-proof valve and the cover plate in the current lithium battery cannot be adjusted. The top cover structure and the lithium battery can use the same type of explosion-proof valve to produce different types of lithium batteries without the need to re-open the mold for the explosion-proof valve, which can reduce production costs and meet the assembly requirements of different types of lithium batteries.

[0006] A roof structure, comprising:

[0007] An explosion-proof valve, the explosion-proof valve having a notch, the notch being a non-closed structure; and

[0008] The cover plate has a through hole provided therethrough. The cover plate can be covered on the explosion-proof valve so that at least the notch is exposed from the cover plate through the through hole. Moreover, the cover plate can adjust the length of the notch exposed from the through hole.

[0009] In one embodiment of the present application, the notch is in the shape of an arc, a straight line, or a combination of a straight line and an arc;

[0010] And / or, the explosion-proof valve has a circular sheet structure;

[0011] And / or, the cross-sectional area of ​​the through hole is 1 / 3 to 2 / 3 of the cross-sectional area of ​​the explosion-proof valve.

[0012] In one embodiment of the present application, the through hole is a semicircular hole, the notch is a semicircular arc, and the radius of the through hole is adapted to the radius of the notch.

[0013] In one embodiment of the present application, the cover plate includes a cover plate body and a shielding plate, the cover plate body has a mounting hole, the shielding plate is arranged in the mounting hole and has the through hole, and the shielding plate can partially shield the explosion-proof valve.

[0014] In one embodiment of the present application, the shielding plate includes a first shielding body and a second shielding body, and the first shielding body and the second shielding body are arranged in the mounting hole and surround the through hole;

[0015] And / or, the shielding plate is recessed in the surface of the cover plate body facing the explosion-proof valve to form a mounting groove, and the mounting groove is used for mounting the explosion-proof valve.

[0016] In one embodiment of the present application, the explosion-proof valve includes an explosion-proof body and a bursting disc, the explosion-proof body is disposed around the bursting disc, the notch is disposed between the explosion-proof body and the bursting disc, and the explosion-proof body is directly connected to the bursting disc at a location where the notch is not disposed.

[0017] The bursting disc is partially covered by the cover plate and partially exposed through the through hole.

[0018] In one embodiment of the present application, the surface of the explosion-proof valve facing the cover plate has a first mating portion, the first mating portion is arranged on the outer peripheral side of the notch, and the surface of the cover plate facing the explosion-proof valve has a second mating portion, the first mating portion and the second mating portion are arranged correspondingly and matingly connected;

[0019] The first matching portion and the second matching portion are matching structures of a protrusion and a groove.

[0020] In one embodiment of the present application, there are multiple second matching parts, and the multiple second matching parts are spaced apart around the outer circumference of the notch, and there is at least one first matching part.

[0021] In one embodiment of the present application, there are a plurality of first matching portions, which are spaced apart on the explosion-proof valve around the outer circumference of the notch, and there is at least one second matching portion.

[0022] A lithium battery comprising a battery housing, a battery cell, and a top cover structure as described in any one of the above technical features, wherein the top cover structure is disposed on the battery housing and encloses an installation space with the battery housing;

[0023] The battery cell is installed in the installation space.

[0024] After adopting the above technical solution, this application has at least the following technical effects:

[0025] The top cover structure and lithium battery of the present application are such that, in the top cover structure, the cover plate is arranged behind the explosion-proof valve, and at least part of the notch of the explosion-proof valve can be exposed through the through hole, and when the cover plate and the explosion-proof valve are assembled, the length of the cover notch exposed through the through hole can be adjusted. When the length of the notch exposed through the through hole is different, the explosion-proof valve can have different ranges of bursting values, thereby enabling the explosion of the explosion-proof valve with multiple bursting values. By adjusting the relative position of the cover plate and the explosion-proof valve to adjust the length of the notch exposed through the through hole, the bursting value of the explosion-proof valve can be adjusted. In this way, different types of lithium batteries can be produced using the same type of cover plate and explosion-proof valve, without the need to re-open the mold for the explosion-proof valve, which can reduce production costs and meet the assembly requirements of different types of lithium batteries. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic exploded view of a top cover structure according to an embodiment of the present application viewed from one angle.

[0027] Figure 2 for Figure 1 The top cover structure shown is a schematic diagram viewed from another angle.

[0028] Figure 3 for Figure 1 Schematic diagram of the cover plate in the top cover structure shown.

[0029] Figure 4 for Figure 1 Schematic diagram of the explosion-proof valve in the top cover structure shown.

[0030] Figure 5 for Figure 1 A partial schematic diagram of an embodiment of a top cover structure is shown.

[0031] Figure 6 for Figure 1 A schematic diagram of another embodiment of the top cover structure is shown.

[0032] Figure 7 for Figure 1 A schematic diagram of another embodiment of a top cover structure is shown.

[0033] Among them: 100, top cover structure; 110, explosion-proof valve; 111, notch; 112, explosion-proof body; 113, bursting disc; 114, first matching part; 120, cover plate; 121, through hole; 122, cover plate body; 123, shielding plate; 1231, first shielding body; 1232, second shielding body; 124, mounting groove; 125, electrode hole; 126, injection hole; 127, second matching part. DETAILED DESCRIPTION

[0034] To make the above-mentioned objects, features, and advantages of the present application more clearly understood, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0035] In the description of this application, it should be understood that if the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. appear, the orientation or position relationship indicated by these terms is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0036] In addition, if the terms "first" or "second" appear, these terms are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of this application, if the term "plurality" appears, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0037] In this application, unless otherwise specified or limited, the terms "mounted," "connected," "connected," "fixed," etc., should be interpreted broadly. For example, these terms may refer to fixed connections, removable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediary; and internal communication between two components or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0038] In this application, unless otherwise expressly specified or limited, if a first feature is described as being "above" or "below" a second feature, or similar descriptions appear, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above," "above," and "above" the second feature may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. The first feature being "below," "below," and "below" the second feature may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0039] It should be noted that if an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. If an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element. If any, the terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in this application are for illustrative purposes only and do not represent the only embodiment.

[0040] Understandably, the current explosion-proof valve and cover assembly process can only achieve a fixed range of explosion values. The explosion value between the explosion-proof valve and the cover cannot be adjusted, and it cannot achieve explosions with a variety of explosion values. If the explosion value of the explosion-proof valve is changed, the explosion-proof valve needs to be re-molded and produced, which increases the production cost of lithium batteries and is inconvenient for the production of different types of lithium batteries.

[0041] See also Figure 1 and Figure 2 To this end, the present application provides a new top cover structure 100. Figure 1 This is a schematic exploded view of the top cover structure 100 according to one embodiment of the present application, viewed from one angle. Figure 2 for Figure 1The top cover structure 100 is shown as a schematic diagram from another angle. This top cover structure 100 is used in a lithium battery (not shown) and is installed on top of the battery housing (not shown). These lithium batteries come in different models to meet the power requirements of different types of electrical devices. Optionally, the lithium battery is a prismatic battery.

[0042] The top cover structure 100 can adjust the burst value of the explosion-proof valve 110 so that the explosion-proof valve 110 has a burst value within different ranges. In this way, the same type of explosion-proof valve 110 can be used to produce different types of lithium batteries without having to re-mold the explosion-proof valve 110, which can reduce production costs and meet the assembly requirements of different types of lithium batteries. The following describes the specific structure of the top cover structure 100 in one embodiment.

[0043] See also Figures 1 to 4 In one embodiment, the top cover structure 100 includes an explosion-proof valve 110 and a cover plate 120. The explosion-proof valve 110 has a notch 111, which is a non-enclosed structure. The cover plate 120 has a through hole 121 extending therethrough. The cover plate 120 can be mounted on the explosion-proof valve 110 so that at least the notch 111 is exposed through the through hole 121. The cover plate 120 can also adjust the length of the notch 111 exposed through the through hole 121. Figure 3 for Figure 1 The schematic diagram of the cover plate 120 in the top cover structure 100 is shown. Figure 4 for Figure 1 A schematic diagram of the explosion-proof valve 110 in the top cover structure 100 is shown.

[0044] The cover plate 120 is the mounting base for the top cover structure 100. The cover plate 120 can be placed on top of the battery casing of a lithium battery. Thus, the cover plate 120 and the battery casing can enclose an installation space (not shown) for mounting the lithium battery cells (not shown). Optionally, the cover plate 120 is square. Furthermore, the cover plate 120 is rectangular.

[0045] The explosion-proof valve 110 is a safety component for lithium batteries. When pressure inside a lithium battery rises due to overcharging, over-discharging, a short circuit, or other reasons, the explosion-proof valve 110 senses this pressure change and automatically explodes when the pressure reaches a predetermined explosion value, releasing the gas inside the lithium battery. This quickly reduces the pressure inside the lithium battery, preventing the lithium battery from exploding and ensuring its safety.

[0046] The explosion-proof valve 110 has a notch 111 recessed into the surface of the explosion-proof valve 110 facing the cover plate 120. This notch 111 is a weak point in the explosion-proof valve 110. When the explosion-proof valve 110 explodes, the force applied to the notch 111 reaches the bursting value, causing the notch 111 to break first, thus causing the explosion of the explosion-proof valve 110.

[0047] Furthermore, the notch 111 on explosion-proof valve 110 is a non-closed structure. That is, rather than being a circle around the valve 110, notch 111 has an opening, connecting the portion of the valve 110 outside the notch 111 with the portion inside the notch 111. This connected portion prevents splashing when the valve 110 explodes, ensuring safety.

[0048] The cover plate 120 has a through hole 121 extending therethrough. When the cover plate 120 is placed over the explosion-proof valve 110, at least a portion of the notch 111 of the explosion-proof valve 110 is exposed through the through hole 121 of the cover plate 120. When the explosion-proof valve 110 is disconnected at the notch 111, the gas inside the lithium battery can be discharged through the explosion-proof valve 110 and the through hole 121, thereby depressurizing the lithium battery and ensuring its safety.

[0049] Furthermore, when the cover plate 120 and explosion-proof valve 110 are assembled, their relative positions can be adjusted, thereby adjusting the length of the notch 111 exposed through the through-hole 121, thereby adjusting the bursting value of the explosion-proof valve 110. This allows the explosion-proof valve 110 to have different bursting values. When producing different lithium battery models, the explosion-proof valve 110 and cover plate 120, produced using the same mold, can be used together, eliminating the need to re-mold the explosion-proof valve 110.

[0050] See also Figures 5 to 7 The explosion-proof valve 110 moves relative to the cover plate 120 to adjust the length of the notch 111 that exposes the through hole 121. Figure 5 for Figure 1 The partial schematic diagram of an embodiment of the top cover structure 100 shown in FIG. Figure 6 for Figure 1 The schematic diagram of another embodiment of the top cover structure 100 is shown. Figure 7 for Figure 1 FIG. 1 is a schematic diagram of another embodiment of a top cover structure 100 .

[0051] exist Figure 5 In the example, after cover plate 120 is placed over explosion-proof valve 110, notch 111 completely exposes through-hole 121. This leaves the vulnerable area of ​​explosion-proof valve 110 completely exposed and unobstructed by cover plate 120. Under the pressure of the gas inside the lithium battery, explosion-proof valve 110 deforms significantly, which reduces the pressure required to open the valve, resulting in a lower burst value for explosion-proof valve 110.

[0052] exist Figure 6 middle, Figure 6 for Figure 5The cover plate 120 is shown rotated 45° clockwise. At this time, 3 / 4 of the notch 111 is exposed to the through hole 121, and 1 / 4 of the notch 111 is hidden in the cover plate 120. Figure 7 middle, Figure 7 for Figure 5 The cover plate 120 is shown rotated 60° clockwise. At this time, 2 / 3 of the notches 111 are exposed to the through hole 121 , and 1 / 3 of the notches 111 are hidden in the cover plate 120 .

[0053] When the length of the notch 111 exposed from the through-hole 121 shortens, the vulnerable area of ​​the explosion-proof valve 110 is reduced, and a portion of the vulnerable area is shielded by the cover plate 120. Under the gas pressure inside the lithium battery, the deformation of the explosion-proof valve 110 is small, and the required opening pressure of the explosion-proof valve 110 is greater, that is, the burst value of the explosion-proof valve 110 is larger.

[0054] Furthermore, the shorter the length of the notch 111 exposed from the through hole 121, the greater the explosion value of the explosion-proof valve 110. Figure 5 The explosion value of the explosion-proof valve 110 shown is> Figure 6 The explosion value of the explosion-proof valve 110 shown is> Figure 7 The explosion value of the explosion-proof valve 110 is shown. In this way, the explosion value of the explosion-proof valve 110 can be adjusted according to the length of the explosion-proof valve 110 exposed through the through hole 121 to adapt to different types of lithium batteries.

[0055] It is worth noting that the above only lists several lengths of the notches 111 exposed through the through hole 121 to illustrate the explosion value of the explosion-proof valve 110. The length of the notches 111 exposed through the through hole 121 can also be other, which will not be shown in this application.

[0056] The top cover structure 100 of the above embodiment can adjust the bursting value of the explosion-proof valve 110 by adjusting the relative position of the cover plate 120 and the explosion-proof valve 110 to adjust the length of the notch 111 exposing the through hole 121. In this way, different types of lithium batteries can be produced using the same type of cover plate 120 and explosion-proof valve 110 without having to re-open the mold for production of the explosion-proof valve 110, which can reduce production costs and meet the assembly requirements of different types of lithium batteries.

[0057] It is worth noting that the shape of the notch 111 is not limited in principle, as long as the notch 111 is located on the surface of the explosion-proof valve 110 facing the cover plate 120 to form a weak area on the explosion-proof valve 110. In one embodiment, the notch 111 is arc-shaped. This facilitates the formation of the notch 111 while also placing it close to the edge of the explosion-proof valve 110, facilitating the explosion of the explosion-proof valve 110.

[0058] In one embodiment, the cross-sectional area of ​​through-hole 121 is 1 / 3 to 2 / 3 the cross-sectional area of ​​explosion-proof valve 110. In other words, only a portion of explosion-proof valve 110 is exposed through-hole 121 of cover plate 120, while the remainder of explosion-proof valve 110 is obscured by cover plate 120. When the pressure inside the lithium battery reaches the bursting point, only the portion of explosion-proof valve 110 exposed through-hole 121 can deform and explode; the portion of explosion-proof valve 110 obscured by cover plate 120 cannot deform. This allows the explosion-proof valve 110 to adjust its bursting point.

[0059] See also Figures 1 to 4 In this embodiment, through-hole 121 is a semicircular hole, and notch 111 is a semicircular arc. The radius of through-hole 121 matches the radius of notch 111. Thus, after cover plate 120 is placed over explosion-proof valve 110, semicircular through-hole 121 can expose the semicircular explosion-proof valve 110. When explosion-proof valve 110 rotates relative to cover plate 120, the length of notch 111 exposed through-hole 121 can be adjusted.

[0060] Of course, in other embodiments of the present application, the central angle of the notch 111 can be smaller or larger than 180°. This is sufficient as long as the explosion-proof valve 110 and the cover plate 120 cooperate to adjust the burst value of the explosion-proof valve 110. Of course, in other embodiments of the present application, the through hole 121 can also be square or other shapes. Of course, in other embodiments of the present application, the notch 111 can also be straight or a combination of straight and curved shapes.

[0061] See also Figure 1 and Figure 2 In one embodiment, the explosion-proof valve 110 is in a circular sheet-like structure. This facilitates the installation of the explosion-proof valve 110 and also reduces the area of ​​the explosion-proof valve 110, thereby reducing production costs.

[0062] Optionally, the explosion-proof valve 110 is made of aluminum sheet. Aluminum sheet is heat-resistant and non-combustible. Furthermore, the explosion-proof valve 110 made of aluminum sheet can withstand certain impacts. As long as the pressure inside the lithium battery does not reach the bursting value, the explosion-proof valve 110 will not burst. Only when the pressure inside the lithium battery reaches the bursting value will the explosion-proof valve 110 made of aluminum sheet burst.

[0063] See also Figures 1 to 3 In one embodiment, the cover plate 120 includes a cover plate body 122 and a shielding plate 123. The cover plate body 122 has a mounting hole (not shown). The shielding plate 123 is arranged in the mounting hole and has a through hole 121. The shielding plate 123 can partially shield the explosion-proof valve 110.

[0064] The cover plate body 122 is the main structure of the cover plate 120. It can be placed on top of the battery housing to form a mounting space with the battery housing. The shielding plate 123 is a component that shields the explosion-proof valve 110 and exposes it. The cover plate 120 has a mounting hole extending therethrough, and the shielding plate 123 is mounted in the mounting hole. The shielding plate 123 has a through hole 121 extending therethrough.

[0065] After the cover plate 120 is placed over the explosion-proof valve 110, the position of the explosion-proof valve 110 and the shielding plate 123 are aligned. A portion of the explosion-proof valve 110 and its through-hole 121 can be exposed through the through-hole 121 of the shielding plate 123, while the shielding plate 123 can cover the remaining portion of the explosion-proof valve 110. When the pressure inside the lithium battery reaches the explosion value, the explosion-proof valve 110 corresponding to the through-hole 121 will deform, causing the explosion.

[0066] See also Figures 1 to 3 In one embodiment, the shielding plate 123 and the cover body 122 are integrally formed. This ensures the strength of the cover 120 while reducing the number of parts and facilitating assembly. Of course, in other embodiments of the present application, the shielding plate 123 and the cover body 122 may be separate components and securely connected via gluing, welding, or other methods.

[0067] See also Figure 2 Figure 3 In one embodiment, the shielding plate 123 includes a first shielding body 1231 and a second shielding body 1232. The first shielding body 1231 and the second shielding body 1232 are disposed in the mounting hole and form a through-hole 121. The outer walls of the first shielding body 1231 and the outer walls of the second shielding body 1232 are connected to the inner wall of the mounting hole, allowing the shielding plate 123 to be disposed in the mounting hole. Furthermore, the first shielding body 1231 and the second shielding body 1232 form a through-hole 121, exposing the notch 111.

[0068] In this embodiment, the first shielding body 1231 is semicircular, and the second shielding body 1232 is arc-shaped. The outer contours of the first shielding body 1231 and the second shielding body 1232 are arranged to form a complete circle and are installed in the installation hole. The first shielding body 1231 and the second shielding body 1232 enclose the semicircular through hole 121.

[0069] See also Figure 2 and Figure 3In one embodiment, shielding plate 123 is recessed into the surface of cover plate body 122 facing explosion-proof valve 110 to form mounting groove 124 for mounting explosion-proof valve 110. Specifically, shielding plate 123 is thinner than cover plate body 122. Mounting groove 124 thus positions explosion-proof valve 110, ensuring accurate mounting of explosion-proof valve 110 on cover plate 120, allowing notch 111 to expose through-hole 121.

[0070] Optionally, the thickness of the shielding plate 123 is consistent with that of the explosion-proof valve 110 and the thickness of the cover body 122. In this way, after the explosion-proof valve 110 is installed in the mounting hole, the explosion-proof valve 110 will not protrude from the surface of the cover body 122, thereby preventing the explosion-proof valve 110 from occupying the space inside the lithium battery.

[0071] See also Figures 1 to 3 In one embodiment, the cover plate 120 further includes two electrode holes 125, which are provided on both sides of the cover plate body 122. In a lithium battery, the electrode posts of the battery cell can extend through the two electrode holes 125 respectively, so that the lithium battery can supply power.

[0072] See also Figures 1 to 3 In one embodiment, the cover plate 120 further has an injection hole 126 that passes through the cover plate 120 and connects to the installation space of the lithium battery. Electrolyte can be injected into the installation space through the injection hole 126 to ensure the performance of the lithium battery.

[0073] See also Figure 1 、 Figure 2 and Figure 4 In one embodiment, explosion-proof valve 110 includes an explosion-proof body 112 and a bursting disc 113. Explosion-proof body 112 surrounds bursting disc 113, with notches 111 disposed between the two. The body 112 is directly connected to bursting disc 113 where no notches 111 are provided. Bursting disc 113 is partially obscured by cover plate 120 and partially exposed through through-hole 121.

[0074] The bursting disc 113 is positioned in the center of the explosion-proof body 112, with the notch 111 located at the edge of the bursting disc 113 and between the explosion-proof body 112 and the bursting disc 113. After the explosion-proof valve 110 is installed in the mounting slot 124 of the cover plate 120, the bursting disc 113 is partially obscured by the first shielding body 1231 and partially exposed through the through-hole 121. The explosion-proof body 112 corresponds to the edge of the first shielding body 1231 and the second shielding body 1232. This prevents the portion of the bursting disc 113 obscured by the shielding body 123 from deformation, while the portion of the bursting disc 113 exposed through the through-hole 121 may deform under the internal gas pressure of the lithium battery.

[0075] Furthermore, because notch 111 is a non-enclosed structure, bursting disc 113 is connected to explosion-proof body 112 through notch 111 on one side and directly connected to explosion-proof body 112 on the other side. When explosion-proof valve 110 explodes, it primarily breaks at notch 111. The direct connection between explosion-proof valve 110 and bursting disc 113 prevents splashing of explosion-proof valve 110, ensuring safety.

[0076] In one embodiment, the explosion-proof body 112 and the bursting disc 113 are integrally formed, thereby ensuring the structural strength of the explosion-proof valve 110 and facilitating the forming of the notch 111 .

[0077] See also Figures 1 to 4 In one embodiment, the surface of explosion-proof valve 110 facing cover plate 120 has a first mating portion 114, which is disposed on the outer periphery of notch 111. The surface of cover plate 120 facing explosion-proof valve 110 has a second mating portion 127, which corresponds to and is mated with the first mating portion 114 and the second mating portion 127. The first mating portion 114 and the second mating portion 127 are configured as a protrusion and a groove.

[0078] The first mating portion 114 is disposed on the explosion-proof body 112 of the explosion-proof valve 110, and the second mating portion 127 is disposed on the second shielding body 1232 of the shielding plate 123. The first mating portion 114 and the second mating portion 127 are disposed in a corresponding manner. Thus, when the explosion-proof valve 110 is installed on the cover plate 120, the mating of the first mating portion 114 and the second mating portion 127 prevents the cover plate 120 from being reversed with the explosion-proof valve 110, thereby improving assembly efficiency. Furthermore, the mating of the first mating portion 114 and the second mating portion 127 further positions the explosion-proof valve 110 relative to the cover plate 120, preventing movement of the explosion-proof valve 110 relative to the cover plate 120 and ensuring that the notch 111 accurately exposes the through-hole 121.

[0079] In this embodiment, the first mating portion 114 is a protrusion, and the second mating portion 127 is a groove. The explosion-proof valve 110 is mounted on the cover plate 120 through the mating of the protrusion and the groove. Of course, in other embodiments of the present application, the first mating portion 114 can also be a groove, and the second mating portion 127 can be a protrusion.

[0080] See also Figures 1 to 4 In one embodiment of the present application, there are multiple second matching portions 127, and the multiple second matching portions 127 are spaced apart around the outer circumference of the notch 111, and there is at least one first matching portion 114.

[0081] That is, a plurality of second mating portions 127 are provided on the surface of the second shielding body 1232 of the shielding plate 123 that faces the explosion-proof valve 110. The plurality of second mating portions 127 are spaced apart around the through hole 121. After the explosion-proof valve 110 is installed in the mounting groove 124, the plurality of second mating portions 127 are spaced apart around the outer circumference of the notch 111.

[0082] When assembling the cover 120 and explosion-proof valve 110, the first mating portion 114 is installed in the corresponding second mating portion 127. At this point, the notch 111 is exposed through the mounting hole. To adjust the length of the notch 111, rotate the explosion-proof valve 110 so that the first mating portion 114 is aligned with the other second mating portion 127.

[0083] It is understood that the distribution of the plurality of second mating portions 127 on the shielding plate 123 is not limited in principle, as long as the length of the notch 111 exposed through the through-hole 121 can be adjusted. Optionally, the plurality of second mating portions 127 are evenly distributed on the shielding plate 123. Of course, the plurality of second mating portions 127 can also be unevenly distributed on the shielding plate 123, or partially evenly and partially unevenly distributed.

[0084] In this embodiment, there is only one first mating portion 114, which is located in the middle area of ​​the outer periphery of the notch 111. One second mating portion 127 is disposed in the middle area of ​​the second shielding body 1232, and the remaining second mating portions 127 are spaced apart clockwise along the preceding second mating portion 127. Of course, in other embodiments of the present application, the first mating portion 114 and the second mating portion 127 may also be disposed at other locations on the outer periphery of the notch 111.

[0085] In another embodiment of the present application, multiple first mating portions 114 are provided, spaced apart around the periphery of the notch 111, and the explosion-proof valve 110 includes at least one second mating portion 127. The principle behind this is essentially the same as that of the embodiment with multiple second mating portions 127, and will not be further elaborated here.

[0086] See also Figures 1 to 7 After the cover 120 and explosion-proof valve 110 are assembled, part of the notch 111 and the explosion-proof valve 110 are exposed through the through-hole 121, while part of the explosion-proof valve 110 is hidden by the cover 120. Under the gas pressure inside the lithium battery, the explosion-proof valve 110 exposed through the through-hole 121 will deform. In addition, the explosion-proof valve 110 at the notch 111 is a weak area under stress and is prone to breakage.

[0087] During overcharge or over-discharge, the pressure from the internal gas of a lithium battery pushes upward on the portion of explosion-proof valve 110 exposed to through-hole 121, causing the portion to deform upward and bulge. As explosion-proof valve 110 deforms, the resulting thrust pulls on notch 111, generating tension there. As the combined force of the thrust and tension increases, notch 111 fractures, causing explosion-proof valve 110 to rupture.

[0088] When the length of notch 111 exposed through hole 121 shortens, the vulnerable area of ​​explosion-proof valve 110 decreases, and a portion of the vulnerable area is shielded by cover plate 120. Under the pressure of the gas inside the lithium battery, the deformation of explosion-proof valve 110 is reduced, and the required opening pressure of explosion-proof valve 110 is increased, resulting in a higher burst value of explosion-proof valve 110. This allows the burst value of explosion-proof valve 110 to be adjusted based on the length of explosion-proof valve 110 exposed through hole 121 to accommodate different lithium battery models.

[0089] The top cover structure 100 of the present application can adjust the bursting value of the explosion-proof valve 110 by adjusting the relative position of the cover plate 120 and the explosion-proof valve 110 to adjust the length of the notch 111 exposing the through hole 121. In this way, different types of lithium batteries can be produced using the same type of cover plate 120 and explosion-proof valve 110 without the need to re-open the mold for production of the explosion-proof valve 110, which can reduce production costs and meet the assembly requirements of different types of lithium batteries.

[0090] At the same time, the first mating portion 114 and the second mating portion 127 prevent the explosion-proof valve 110 and the cover plate 120 from being installed reversed during assembly, thereby improving assembly efficiency. Furthermore, the first mating portion 114 and the second mating portion 127 also serve as a positioning mechanism, preventing displacement of the explosion-proof valve 110 and the cover plate 120 during welding. Furthermore, the length of the notch 111 exposed through the through-hole 121 can be adjusted by using one first mating portion 114 and multiple second mating portions 127, thereby adjusting the burst value of the explosion-proof valve 110.

[0091] The present application also provides a lithium battery, comprising a battery housing, a battery cell, and a top cover structure 100 as described in any of the above embodiments. The top cover structure 100 is mounted on the battery housing and, together with the battery housing, forms an installation space. The battery cell is installed in the installation space. The lithium battery of the present application, when using the top cover structure 100 of the above embodiments, can adjust the burst value to produce different types of lithium batteries.

[0092] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0093] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A top cover structure, characterized in that: include: An explosion-proof valve, wherein the explosion-proof valve has a notch, and the notch is a non-closed structure; as well as The cover plate has a through hole provided therethrough. The cover plate can be covered on the explosion-proof valve so that at least the notch is exposed from the cover plate through the through hole. Moreover, the cover plate can adjust the length of the notch exposed from the through hole.

2. The top cover structure according to claim 1, characterized in that: The notches are in the shape of arcs, straight lines, or a combination of straight lines and arcs; And / or, the explosion-proof valve has a circular sheet structure; And / or, the cross-sectional area of ​​the through hole is 1 / 3 to 2 / 3 of the cross-sectional area of ​​the explosion-proof valve.

3. The top cover structure according to claim 1, characterized in that: The through hole is a semicircular hole, the notch is a semicircular arc, and the radius of the through hole is adapted to the radius of the notch.

4. The top cover structure according to claim 1, characterized in that: The cover plate includes a cover plate body and a shielding plate. The cover plate body has a mounting hole. The shielding plate is arranged in the mounting hole and has the through hole. The shielding plate can partially shield the explosion-proof valve.

5. The top cover structure according to claim 4, characterized in that: The shielding plate includes a first shielding body and a second shielding body, wherein the first shielding body and the second shielding body are arranged in the mounting hole and surround the through hole; And / or, the shielding plate is recessed in the surface of the cover plate body facing the explosion-proof valve to form a mounting groove, and the mounting groove is used for mounting the explosion-proof valve.

6. The top cover structure according to claim 1, characterized in that: The explosion-proof valve includes an explosion-proof body and a bursting disc, wherein the explosion-proof body is arranged around the bursting disc, the notch is arranged between the explosion-proof body and the bursting disc, and the explosion-proof body is directly connected to the bursting disc at a position where the notch is not arranged; The bursting disc is partially covered by the cover plate and partially exposed through the through hole.

7. The roof structure according to any one of claims 1 to 6, characterized in that: The surface of the explosion-proof valve facing the cover plate has a first matching portion, which is arranged on the outer peripheral side of the notch. The surface of the cover plate facing the explosion-proof valve has a second matching portion, which is arranged corresponding to the second matching portion and is matched and connected. The first matching portion and the second matching portion are matching structures of a protrusion and a groove.

8. The top cover structure according to claim 7, characterized in that: There are multiple second matching parts, and the multiple second matching parts are spaced apart around the outer circumference of the notch. There is at least one first matching part.

9. The top cover structure according to claim 7, characterized in that: There are a plurality of first matching portions, which are spaced apart and arranged on the explosion-proof valve around the outer circumference of the notch, and there is at least one second matching portion.

10. A lithium battery, characterized in that: The battery comprises a battery housing, a battery cell, and a top cover structure according to any one of claims 1 to 9, wherein the top cover structure is provided on the battery housing and forms an installation space with the battery housing; The battery cell is installed in the installation space.

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