Cover plate structure and applicable power battery thereof

Abstract

The utility model provides a cover plate structure and a power battery with the same, and the cover plate structure comprises a pole which comprises a positive pole and a negative pole; the welding rings comprise a positive electrode welding ring and a negative electrode welding ring, and each welding ring comprises an upper convex ring, a first annular plane and a first boss; the sealing ring comprises a positive electrode sealing ring and a negative electrode sealing ring, the sealing ring is provided with a first side and a second side which are opposite to each other along the cross section of the sealing ring, the sealing ring is provided with a first sealing part on the first side and a second sealing part on the second side, and the first sealing part and the second sealing part are symmetrical along the cross section; the positive sealing ring is located in the first cavity of the positive welding ring and tightly surrounds the positive pole, and the negative sealing ring is located in the first cavity of the negative welding ring and tightly surrounds the negative pole. According to the cover plate structure and the applicable power battery provided by the invention, the working efficiency can be improved, the battery packaging is convenient, and the sealing performance of the cover plate is improved.

Description

Technical Field

[0001] This application mainly relates to the technical field of batteries, and particularly relates to a cover plate structure and a power battery to which it is applicable. Background Art

[0002] The hard shell structural parts of lithium battery cells can be divided into cylindrical and square structural parts, mainly including a housing, a cover plate, a connecting row, etc. Among them, the cover plate plays an important role in the battery, but the structure is relatively complex. Generally, the cover plate is composed of about ten structural parts. Among them, the structural parts have functions of fixing / sealing, current conduction, pressure relief, fuse protection, and reducing electrocorrosion. The structural parts include a sealing ring. The sealing ring in the existing structure is an asymmetric structure, so there is a front and back side for the sealing ring. Since the height of the sealing ring is only about 1.1 mm, it is very easy to install it backwards during the assembly process. Once installed backwards, the head of the sealing ring may interfere with the boss of the welding ring, resulting in a change in the compression amount of the sealing ring. The main function of the sealing ring is to achieve a sealing effect, and the sealing effect mainly depends on the compression amount of the sealing ring. Once the compression amount of the sealing ring changes, there may be a situation of liquid leakage. Further, at present in the field, the support plate and the cover piece are connected by bonding, which easily leads to the situation of the support plate falling off, thus resulting in insulation problems. Summary of the Utility Model

[0003] The technical problem to be solved by this application is to provide a cover plate structure and a power battery to which it is applicable, which can improve work efficiency, facilitate battery packaging, and improve the sealing performance of the cover plate.

[0004] To solve the above technical problem, this application provides a cover plate structure applicable to a power battery. The cover plate structure includes: pole columns, including a positive pole column and a negative pole column; welding rings, including a positive welding ring and a negative welding ring. The welding ring includes an upper convex ring, a first annular plane, and a first boss. The upper convex ring is connected to the first boss from the inner edge, the upper convex ring is connected to the first annular plane from the outer edge, and a first cavity is formed between the inner edge of the upper convex ring and the first boss. Among them, the first cavity of the positive welding ring is adapted to accommodate the positive pole column, and the first cavity of the negative welding ring is adapted to accommodate the negative pole column; and sealing rings, including a positive sealing ring and a negative sealing ring. The sealing ring has opposite first side and second side along the cross-section of the sealing ring. The sealing ring has a first sealing portion on the first side and a second sealing portion on the second side. The first sealing portion and the second sealing portion are symmetric along the cross-section. Among them, the positive sealing ring is located in the first cavity of the positive welding ring and tightly surrounds the positive pole column, and the negative sealing ring is located in the first cavity of the negative welding ring and tightly surrounds the negative pole column.

[0005] Optionally, the welding ring further includes a lower convex ring and one or more card slots. The upper convex ring is connected to the lower convex ring from the inner edge, and the card slots are provided on the side of the lower convex ring away from the upper convex ring.

[0006] Optionally, the cover plate structure further includes a cover piece adapted to be welded to the welding ring. The cover piece is provided with a positive electrode hole and a negative electrode hole. The positive electrode hole is adapted to be welded to the positive electrode welding ring, and the negative electrode hole is adapted to be welded to the negative electrode welding ring. The cover piece further includes a positive electrode groove and a negative electrode groove. The positive electrode groove is connected to the positive electrode hole from below the positive electrode hole, and the negative electrode groove is connected to the negative electrode hole from below the negative electrode hole.

[0007] Optionally, the cover plate structure further includes a support plate located below the cover piece. The support plate includes a positive electrode card hole and a negative electrode card hole. The positive electrode card hole corresponds to the positive electrode hole in terms of spatial position, and the negative electrode card hole corresponds to the negative electrode hole in terms of spatial position. Both the positive electrode card hole and the negative electrode card hole include one or more buckles, and the buckles correspond to the card slots in terms of spatial position. The buckles are engaged with the card slots to fix the welding ring and the support plate.

[0008] Optionally, at least part of the buckles are provided with guiding grooves. When the buckles are engaged with the card slots, the guiding grooves guide the card slots into the buckles for engagement.

[0009] Optionally, the cover plate structure further includes an explosion-proof valve and an explosion-proof valve protection piece. The cover piece is further provided with an explosion-proof valve installation hole. The explosion-proof valve is welded to the cover piece at the position of the explosion-proof valve installation hole, and the explosion-proof valve protection piece is assembled above the explosion-proof valve through the explosion-proof valve installation hole.

[0010] Optionally, the cover plate structure further includes avoidance grooves, including a positive electrode avoidance groove and a negative electrode avoidance groove. The welding ring further includes a lower convex ring. The lower convex ring is connected to the first annular plane from below the first annular plane. The outer diameter of the first annular plane is greater than the outer diameter of the lower convex ring, so that a first groove is formed between the lower convex ring and the first annular plane. The first groove of the positive electrode welding ring and the positive electrode groove cooperate to form the positive electrode avoidance groove, and the first groove of the negative electrode welding ring and the negative electrode groove cooperate to form the negative electrode avoidance groove.

[0011] Optionally, the cover plate structure further includes upper fixing parts, including a positive electrode upper fixing part and a negative electrode upper fixing part. The positive electrode upper fixing part surrounds the upper part of the positive electrode pole from above the positive electrode pole, and the negative electrode upper fixing part surrounds the upper part of the negative electrode pole from above the negative electrode pole.

[0012] Optionally, the cover plate structure further includes an adapter piece, which is adapted to connect the tab of the power battery to the pole column so that the tab is electrically connected to the pole column.

[0013] To solve the above technical problems, the present application provides a power battery, including: the cover plate structure as described above; a housing connected to the cover plate structure; and battery cells located inside the housing.

[0014] Compared with the prior art, through the symmetric structure design of the sealing ring in the present application, the sealing ring can be used without distinguishing the front and back sides, which is convenient for the battery packaging, thereby improving the working efficiency and the sealing performance of the cover plate. On the other hand, by providing a slot on the welding ring and a buckle on the support plate, and connecting the welding ring and the support plate by a snap-fit fixing method, it can effectively prevent the support plate from falling off, avoid the problem of insulation, and by providing a guiding groove on the buckle, it is convenient for the slot and the buckle to be snap-fitted and fixed, which can further improve the insulation performance of the battery. Further, an avoidance groove is also provided in the cover plate structure of the present application, and the avoidance groove can accommodate the welding mark between the welding ring and the cover piece, so that the welding mark between the welding ring and the cover piece does not protrude, thereby ensuring the flatness of the battery cell cover plate. Description of the Drawings

[0015] The drawings are included to provide a further understanding of the present application, and they are incorporated into and constitute a part of this application. The drawings illustrate embodiments of the present application and, together with this specification, serve to explain the principles of the present application. In the drawings:

[0016] Figure 1 is an exploded view of the structure of a cover plate structure in an embodiment of the present application;

[0017] Figure 2 is a top view of a welding ring in a cover plate structure in an embodiment of the present application;

[0018] Figure 3 is a side view of a welding ring in a cover plate structure in an embodiment of the present application;

[0019] Figure 4 is a top view of a sealing ring in a cover plate structure in an embodiment of the present application;

[0020] Figure 5 is a side view of a sealing ring in a cover plate structure in an embodiment of the present application;

[0021] Figure 6 is a schematic structural view of a cover piece in a cover plate structure in an embodiment of the present application;

[0022] Figure 7 is a top view of a support plate in a cover plate structure in an embodiment of the present application;

[0023] Figure 8 It is a side view of a support plate in a cover plate structure in an embodiment of the present application;

[0024] Figure 9 As shown in Figure 8 It is a schematic diagram of the partial A structure of a support plate in a cover plate structure in the embodiment shown;

[0025] Figure 10 It is a top view of a cover plate structure in an embodiment of the present application;

[0026] Figure 11 It is a side view of a cover plate structure in an embodiment of the present application;

[0027] Figure 12 As shown in Figure 11 It is a schematic diagram of the structure of partial B of a cover plate structure in the embodiment shown;

[0028] Figure 13 As shown in Figure 11 It is a schematic diagram of the structure of partial C of a cover plate structure in the embodiment shown. Detailed implementation manners

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the accompanying drawings required for the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some examples or embodiments of the present application. For those of ordinary skill in the art, without creative efforts, the present application can also be applied to other similar scenarios based on these drawings. Unless obvious from the language context or otherwise stated, the same reference numerals in the drawings represent the same structure or operation.

[0030] As shown in the present application and the claims, unless the context clearly indicates an exceptional situation, words such as "a", "an", "one" and / or "the" are not specifically singular and may also include plural. Generally speaking, the terms "include" and "comprise" only indicate the inclusion of the clearly identified steps and elements, and these steps and elements do not constitute an exclusive list. The method or device may also include other steps or elements.

[0031] Unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for the sake of convenience in description, the dimensions of the various parts shown in the drawings are not drawn in actual proportional relationship. Technologies, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the said technologies, methods, and devices should be regarded as part of the authorization specification. In all the examples shown and discussed here, any specific values should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0032] In the description of the present application, it should be understood that the orientation or positional relationship indicated by orientation terms such as "front, rear, upper, lower, left, right", "lateral, vertical, perpendicular, horizontal", and "top, bottom", etc. is usually based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description. Without contrary description, these orientation terms do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and thus should not be construed as limiting the protection scope of the present application; the orientation terms "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0033] For the convenience of description, spatial relative terms such as "above...", "over...", "on the upper surface of...", "above", etc. can be used here to describe the spatial positional relationship between a device or feature shown in the drawings and other devices or features. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation described in the drawings for the device. For example, if the device in the drawing is inverted, the device described as "above other devices or structures" or "over other devices or structures" will then be positioned "below other devices or structures" or "under other devices or structures". Thus, the exemplary term "above..." can include both the orientations of "above..." and "below...". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the corresponding explanations should be made for the spatial relative descriptions used here.

[0034] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Without additional statements, these terms have no special meanings, so they should not be construed as limiting the protection scope of this application. In addition, although the terms used in this application are selected from well-known and commonly used terms, some terms mentioned in the specification of this application may be selected by the applicant according to his or her judgment, and their detailed meanings are described in the relevant parts of this description. In addition, it is required to understand this application not only through the actual terms used, but also through the meanings implied by each term.

[0035] This application refers to Figure 1 and proposes a cover plate structure 10. Figure 1 Fig. shows an exploded view of the cover plate structure 10. The cover plate structure mainly includes a pole column 101, a welding ring 102 and a sealing ring 103. Among them, the pole column 101 includes a positive pole column 1011 and a negative pole column 1012; the welding ring 102 includes a positive welding ring 1021 and a negative welding ring 1022; the sealing ring 103 includes a positive sealing ring 1031 and a negative sealing ring 1032. The cover plate structure 10 further includes an upper fixing member 112, and the upper fixing member 112 includes a positive upper fixing member 1121 and a negative upper fixing member 1122. Exemplarily, the upper fixing member 112 can be upper plastic.

[0036] Furthermore, the positive welding ring 1021 and the negative welding ring 1022 have the same structure. Taking the positive welding ring 1021 as an example, refer to Figure 2 and Figure 3 , Figure 2 Fig. shows a top view of the positive welding ring 1021. Figure 3 Fig. shows a side view of the positive welding ring 1021. As can be seen from the figure, the positive welding ring 1021 includes an upper convex ring 104, a first annular plane 105 and a first boss 106. The upper convex ring 104 is connected to the first boss 106 from the inner edge, the upper convex ring 104 is connected to the first annular plane 105 from the outer edge, and a first cavity S1 is formed between the inner edge of the upper convex ring 104 and the first boss 106. The positive welding ring 1021 further includes a lower convex ring 109 and four card slots 110. The upper convex ring 104 is connected to the lower convex ring 109 from the inner edge, and card slots 110 are provided on the side of the lower convex ring 109 away from the upper convex ring 104.

[0037] Preferably, the lower convex ring 109 on the welding ring 102 is connected to the first annular plane 105 from below the first annular plane 105, and the outer diameter of the first annular plane 105 is greater than the outer diameter of the lower convex ring 109, so that a first groove 600 is formed between the lower convex ring 109 and the first annular plane 105.

[0038] In this embodiment, since the negative welding ring 1022 has the same structure as the positive welding ring 1021, the reference numerals of the respective structures in the positive welding ring 1021 are used for the respective structures inside the negative welding ring 1022. Among them, the first cavity S1 of the positive welding ring 1021 is adapted to accommodate the positive pole column 1011, and the first cavity S1 of the negative welding ring 1022 is adapted to accommodate the negative pole column 1012.

[0039] On the other hand, the positive sealing ring 1031 and the negative sealing ring 1032 have the same structure. Taking the positive sealing ring 1031 as an example, referring to Figure 4 and Figure 5 , Figure 4 shows a top view of the positive sealing ring 1031, Figure 5 shows a side view of the positive sealing ring 1031. As can be seen from the figure, the positive sealing ring 1031 has opposite first side A1 and second side A2 along the cross-section A. The positive sealing ring 1031 has a first sealing portion 107 on the first side A1 and a second sealing portion 108 on the second side A2. The first sealing portion 107 and the second sealing portion 108 are symmetric along the cross-section A and have the same structure. Since the positive sealing ring 1031 and the negative sealing ring 1032 have the same structure, the reference numerals of the respective structures in the positive sealing ring 1031 are used for the respective structures inside the negative sealing ring 1032.

[0040] In this embodiment, due to the symmetric structure of the sealing ring 103, the sealing ring 103 can be installed without distinguishing between the front and back sides. That is, whether the first mounting portion 107 is placed upwards or the second mounting portion 108 is placed upwards, it will not affect the compression amount of the sealing ring 103, ensuring the sealing performance of the sealing ring 103. Moreover, when the staff packages the sealing ring 103, there is no need to spend time distinguishing the front and back sides of the sealing ring 103, which can save the installation time and improve the installation efficiency.

[0041] Referring to Figure 6 , the cover structure 10 further includes a cover sheet 111. Figure 6 shows a schematic structural view of the cover sheet 111 in the cover structure 10. The cover sheet 111 is adapted to be welded to the welding ring 102. The cover sheet 111 is provided with a positive hole 1111 and a negative hole 1112. The positive hole 1111 is adapted to be welded to the positive welding ring 1021, and the negative hole 1112 is adapted to be welded to the negative welding ring 1022. The cover sheet 111 further includes a positive groove 1113 and a negative groove 1114. The positive groove 1113 is connected to the positive hole 1111 from below the positive hole 1111, and the negative groove 1114 is connected to the negative hole 1112 from below the negative hole 1112. Exemplarily, the cover sheet 111 can be a light aluminum sheet.

[0042] Furthermore, the cover structure 10 further includes an explosion-proof valve (not shown in the figure) and an explosion-proof valve protection sheet 400 (refer toFigure 1 ), an explosion-proof valve installation hole 1115 is also formed on the cover plate 111. The explosion-proof valve is welded to the cover plate 111 at the position of the explosion-proof valve installation hole 1115, and the explosion-proof valve protection piece 400 is assembled above the explosion-proof valve through the explosion-proof valve installation hole 1115.

[0043] Refer to Figures 7 - 9 , the cover plate structure 10 further includes a support plate 200, Figure 7 The top view of the support plate 200 is shown, Figure 8 The side view of the support plate 200 is shown, Figure 9 Shown is Figure 8 The specific structural schematic diagram of the buckle 203 in the area A in Figure 12 ). Specifically, the support plate 200 includes a positive card hole 201 and a negative card hole 202. The positive card hole 201 corresponds to the positive hole 1111 in the spatial position, and the negative card hole 202 corresponds to the negative hole 1112 in the spatial position. Both the positive card hole 201 and the negative card hole 202 include four buckles 203. The buckles 203 correspond to the slots 110 on the welding ring 102 in the spatial position one by one. The buckles 203 are snap-fitted with the slots 110 to fix the welding ring 102 and the support plate 200. Exemplarily, the support plate 200 can be lower plastic. Further, a guiding groove 204 is provided on the buckle 203. The guiding groove 204 has a first plane S2 and a first inclined plane S3. When the buckle 203 is snap-fitted with the slot 110, the guiding groove 204 guides the slot 110 into the buckle 203 for snap-fitting (after snap-fitting, refer to

[0044] In this embodiment, by providing the slot 110 on the welding ring 102 and the buckle 203 on the support plate 200, the welding ring 102 and the support plate 200 are connected by a snap-fitting fixing method, which can effectively prevent the support plate 200 from falling off, avoid the problem of insulation, and by providing the guiding groove 204 on the buckle 203, it is convenient for the buckle 203 and the slot 110 to be snap-fitted, and can further improve the insulation performance of the battery.

[0045] Refer to Figures 10 - 13 , Figure 10 The top view of the cover plate structure 10 after the cover plate structure 10 is assembled is shown, Figure 11 The side view of the cover plate structure 10 after the cover plate structure 10 is assembled is shown, Figure 12 Shown is Figure 11 The structural schematic diagram of the partial B in Figure 13 Shown is Figure 11Schematic diagram of the structure of local C

[0046] For a clearer reference Figure 12 Taking the negative electrode structure as an example, after the cover plate structure 10 is assembled, the fixing member 1122 on the negative electrode surrounds the upper part of the negative electrode terminal 1012 from above the negative electrode terminal 1012. Among them, the negative electrode sealing ring 1032 is located in the first cavity S1 of the negative electrode welding ring 1022 and tightly surrounds the negative electrode terminal 1011. The buckle 203 on the support plate 200 is engaged with the slot 110 on the welding ring 102 to fix the welding ring 102 and the support plate 200.

[0047] Preferably in this embodiment, with reference to Figure 13 Taking the negative electrode welding ring 1022 as an example, the first groove 600 of the negative electrode welding ring 1022 cooperates with the negative electrode groove 1114 on the cover piece 111 to form a negative electrode avoidance groove 500. Through the design of the avoidance groove 500, the weld mark formed when the negative electrode welding ring 1022 and the cover piece 111 are laser welded can be located in the negative electrode avoidance groove, which is convenient for preventing the weld mark from protruding, thereby improving the flatness of the cell cover plate structure 10. A positive electrode avoidance groove will also be formed between the positive electrode welding ring 1021 and the positive electrode groove 1113 of the cover piece 111, and its structural function is the same as that of the positive electrode avoidance groove 500. For details, please refer to the above description and will not be elaborated here.

[0048] On the other hand, the cover plate structure 10 further includes a transition piece (not shown in the figure), and the transition piece is adapted to connect the ear (not shown in the figure) of the power battery with the terminal 101 to form an electrical connection between the ear and the terminal 101.

[0049] On the other hand, this application also proposes a power battery, including the cover plate structure proposed in any embodiment of this application, such as the above-mentioned cover plate structure 10. The power battery further includes a housing and a battery cell, the housing is connected to the cover plate structure, and the battery cell is located inside the housing.

[0050] Through the symmetric structure design of the sealing ring in this application, the sealing ring can be used regardless of the front and back, which is convenient for the battery packaging, thereby improving the working efficiency and the sealing performance of the cover plate. On the other hand, by setting a slot on the welding ring and a buckle on the support plate in this application, the welding ring and the support plate are connected by a snap-fitting fixing method, which can effectively prevent the support plate from falling off and avoid insulation problems. And by setting a guiding groove on the buckle, it is convenient for the slot and the buckle to be snap-fitted and fixed, which can further improve the insulation performance of the battery. Further, the cover plate structure of this application is also provided with an avoidance groove, which can accommodate the weld mark between the welding ring and the cover piece, so that the weld mark between the welding ring and the cover piece will not protrude, thus ensuring the flatness of the battery cell cover plate.

[0051] The basic concepts have been described above. Obviously, for those skilled in the art, the above application disclosure is only an example and does not constitute a limitation to this application. Although not explicitly stated here, those skilled in the art may make various modifications, improvements, and corrections to this application. Such modifications, improvements, and corrections are proposed in this application, so such modifications, improvements, and corrections still fall within the spirit and scope of the exemplary embodiments of this application.

[0052] Meanwhile, this application uses specific terms to describe the embodiments of this application. Such as "one embodiment", "an embodiment", and / or "some embodiments" mean a certain feature, structure, or characteristic related to at least one embodiment of this application. Therefore, it should be emphasized and noted that the "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more at different positions in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of this application can be appropriately combined.

[0053] Similarly, it should be noted that, in order to simplify the description of this application disclosure and thus help the understanding of one or more application embodiments, in the previous description of the embodiments of this application, sometimes multiple features are grouped into one embodiment, drawing, or description thereof. However, this disclosure method does not mean that the features required by the object of this application are more than those mentioned in the claims. In fact, the features of the embodiment are fewer than all the features of the single embodiment disclosed above.

[0054] In some embodiments, numbers describing the components and the quantity of attributes are used. It should be understood that such numbers used for the description of embodiments are, in some examples, modified by the modifiers "about", "approximately", or "substantially". Unless otherwise stated, "about", "approximately", or "substantially" indicate that the said numbers allow a variation of ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, and such approximate values may change according to the characteristics required by individual embodiments. In some embodiments, the numerical parameters should consider the specified significant digits and adopt the method of retaining the general number of digits. Although the numerical ranges and parameters used to confirm the breadth of the scope in some embodiments of this application are approximate values, in specific embodiments, the setting of such numerical values is as precise as possible within the feasible range.

[0055] Although this application has been described with reference to the current specific embodiments, those of ordinary skill in the art should recognize that the above embodiments are only used to illustrate this application, and various equivalent changes or substitutions can be made without departing from the spirit of this application. Therefore, as long as the changes and variations of the above embodiments are within the scope of the spirit of this application, they will fall within the scope of the claims of this application.

Claims

1. A cover plate structure, suitable for a power battery, characterized in that: The cover plate structure comprises: Poles, including positive poles and negative poles; A welding ring, comprising a positive electrode welding ring and a negative electrode welding ring, wherein the welding ring comprises an upper convex ring, a first annular plane and a first boss, wherein the upper convex ring is connected to the first boss from an inner edge, and the upper convex ring is connected to the first annular plane from an outer edge, and a first cavity is formed between the inner edge of the upper convex ring and the first boss, wherein the first cavity of the positive electrode welding ring is suitable for accommodating the positive electrode column, and the first cavity of the negative electrode welding ring is suitable for accommodating the negative electrode column; and A sealing ring, comprising a positive sealing ring and a negative sealing ring, wherein the sealing ring has a first side and a second side opposite to each other along a cross section of the sealing ring, the sealing ring has a first sealing portion on the first side and a second sealing portion on the second side, and the first sealing portion and the second sealing portion are symmetrical along the cross section, wherein the positive sealing ring is located in the first cavity of the positive welding ring and tightly surrounds the positive electrode column, and the negative sealing ring is located in the first cavity of the negative welding ring and tightly surrounds the negative electrode column.

2. The cover plate structure according to claim 1, characterized in that: The welding ring further comprises a lower convex ring and one or more slots. The upper convex ring is connected to the lower convex ring from the inner edge. The slot is arranged on a side of the lower convex ring away from the upper convex ring.

3. The cover plate structure according to claim 2, characterized in that: It also includes a cover plate suitable for welding with the welding ring, and a positive electrode hole and a negative electrode hole are opened on the cover plate. The positive electrode hole is suitable for welding with the positive electrode welding ring, and the negative electrode hole is suitable for welding with the negative electrode welding ring. The cover plate also includes a positive electrode groove and a negative electrode groove. The positive electrode groove is connected to the positive electrode hole from below the positive electrode hole, and the negative electrode groove is connected to the negative electrode hole from below the negative electrode hole.

4. The cover plate structure according to claim 3, characterized in that: It also includes a support plate, which is located below the cover plate, and the support plate includes a positive electrode clamping hole and a negative electrode clamping hole, the positive electrode clamping hole corresponds to the positive electrode hole in space, and the negative electrode clamping hole corresponds to the negative electrode hole in space, and the positive electrode clamping hole and the negative electrode clamping hole each include one or more buckles, the buckles correspond to the clamping slots in space one by one, and the buckles are clamped and matched with the clamping slots to fix the welding ring and the support plate.

5. The cover plate structure according to claim 4, characterized in that: At least part of the buckles are provided with guide grooves, and when the buckle is engaged with the slot, the guide grooves guide the slot to enter the buckle for engagement.

6. The cover plate structure according to claim 3, characterized in that: It also includes an explosion-proof valve and an explosion-proof valve protection sheet. The cover sheet is also provided with an explosion-proof valve installation hole. The explosion-proof valve is welded to the cover sheet at the position of the explosion-proof valve installation hole. The explosion-proof valve protection sheet is assembled above the explosion-proof valve through the explosion-proof valve installation hole.

7. The cover plate structure according to claim 3, characterized in that: It also includes avoidance grooves, which include positive avoidance grooves and negative avoidance grooves. The welding ring also includes a lower convex ring, which is connected to the first annular plane from below the first annular plane. The outer diameter of the first annular plane is larger than the outer diameter of the lower convex ring, so that a first groove is formed between the lower convex ring and the first annular plane. The first groove of the positive welding ring cooperates with the positive groove to form the positive avoidance groove, and the first groove of the negative welding ring cooperates with the negative groove to form the negative avoidance groove.

8. The cover plate structure according to claim 1, characterized in that: It also includes an upper fixing member, which includes a positive upper fixing member and a negative upper fixing member. The positive upper fixing member surrounds the upper part of the positive pole from above the positive pole, and the negative upper fixing member surrounds the upper part of the negative pole from above the negative pole.

9. The cover plate structure according to claim 1, characterized in that: It also includes an adapter plate, which is suitable for connecting the pole ear of the power battery and the pole, so as to electrically connect the pole ear and the pole.

10. A power battery, characterized in that: include: The cover plate structure according to any one of claims 1 to 9; A shell connected to the cover structure; as well as The battery cell is located inside the shell.

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