Top cover assembly and cell

Abstract

The present application discloses a top cover assembly and a single battery, the top cover assembly including a top cover sheet and a lower plastic part, the lower plastic part including a first connecting member and a second connecting member spaced apart from each other on one side of the top cover sheet, and a buffer member connected between the first connecting member and the second connecting member, the buffer member being expandable and contractible in response to a change in the distance between the first connecting member and the second connecting member. By providing a buffer member expandable and contractible in response to a change in the distance between the first connecting member and the second connecting member, the force applied by the lower plastic part to the post terminal is reduced, the post terminal is prevented from being displaced due to the expansion of the lower plastic part due to heating and contraction due to cooling, and the post terminal maintains an excellent sealing ability together with the seal ring.

Description

[Technical field]

[0001] This application claims priority to a Chinese patent application filed with the China Patent Office on September 6, 2022, bearing application number 202222372003.0 and entitled "Top cover assembly and single battery", the entire contents of which are incorporated herein by reference.

[0002] The present application relates to the technical field of energy storage devices, and in particular to a top cover assembly and a battery cell. [Background technology]

[0003] With the development of technology, power batteries are widely applied in electric vehicles as energy systems, and a typical power battery includes a top cover assembly for sealing the case, the top cover assembly includes a post, a top cover sheet, and a lower plastic part connected to the top cover sheet, both the top cover sheet and the lower plastic part are provided with post mounting holes, and the post is inserted into the post mounting hole for electrical connection between the electrode group and an external electric device. In order to achieve insulation between the post and the top cover sheet, a seal ring is fitted on the outside of the post, but when the lower plastic part expands due to heating and contracts due to cooling, the lower plastic part will move the post, causing a poor seal. Summary of the Invention [Problem to be solved by the invention]

[0004] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes a top cover assembly that prevents the post terminals from being displaced due to the expansion of the lower plastic part due to heating and the contraction of the lower plastic part due to cooling, and ensures sealing ability.

[0005] The present application also proposes a single cell using the above-mentioned top cover assembly. [Means for solving the problem]

[0006] The top cover assembly in the first embodiment of the present application includes: A top cover sheet; A lower plastic part connected to one side of the top cover sheet, the lower plastic part including a first connecting member and a second connecting member spaced apart, and a cushioning member connected between the first connecting member and the second connecting member, the cushioning member including a lower plastic part that is expandable and contractable in response to changes in the distance between the first connecting member and the second connecting member.

[0007] The battery module according to the embodiment of the present application has at least the following beneficial effects.

[0008] By providing a cushioning member that can expand and contract in response to changes in the distance between the first connecting member and the second connecting member, the force applied by the lower plastic part to the post terminal is reduced, and displacement of the post terminal due to expansion of the lower plastic part due to heating and contraction due to cooling is prevented, and the post terminal maintains excellent sealing ability together with the seal ring.

[0009] In another embodiment of the present application, the buffer member includes a curved portion that is curved in a thickness direction of the lower plastic part.

[0010] In another embodiment of the present application, the first connecting member includes a first main body portion and a first convex portion, the first main body portion is connected to the top cover sheet, and the first convex portion is provided on a side of the first main body portion away from the top cover sheet; the second connecting member includes a second main body portion and a second convex portion, the second main body portion is connected to the top cover sheet, and the second convex portion is provided on a side of the second main body portion away from the top cover sheet; both ends of the curved portion are connected to the first convex portion and the second convex portion, respectively; the curved portion is curved on the top cover sheet; and the curved portion and the top cover sheet are provided with a gap between them.

[0011] In another embodiment of the present application, the buffer member includes a curved portion that is curved in the width direction of the lower plastic component.

[0012] In another embodiment of the present application, the buffer member includes a first buffer section and a second buffer section, one end of the first buffer section and one end of the second buffer section are respectively connected to the first connecting member and the second connecting member, and the other end of the first buffer section and the other end of the second buffer section are connected to form the curved portion; or The curved portion has an arc shape.

[0013] In other embodiments of the present application, the lower plastic part includes a plurality of said cushioning members spaced apart in the width direction thereof, and / or the cushioning member includes a plurality of said curved portions connected in series in the length direction of the lower plastic part.

[0014] In another embodiment of the present application, the cushioning member includes a deformation portion having a width less than the width of other portions of the lower plastic part and / or a thickness less than the thickness of other portions of the lower plastic part.

[0015] In another embodiment of the present application, the cushioning member includes a deformation portion, a first connection portion, and a second connection portion, one end of the deformation portion is connected to the first connection member via the first connection portion and the other end of the deformation portion is connected to the second connection member via the second connection portion, and the width of the deformation portion is less than the widths of the first connection portion and the second connection portion, and / or the thickness of the deformation portion is less than the thicknesses of the first connection portion and the second connection portion.

[0016] In other embodiments of the present application, the lower plastic part includes a plurality of the cushioning members spaced apart in its width direction and / or a plurality of the deformation portions connected in series in its length direction.

[0017] The cell according to the second embodiment of the present application is A battery case; the top cover assembly provided over the battery case; and an electrode group located within the battery case.

[0018] Additional aspects and advantages of the present application will be set forth in part in the description that follows, and in part will be obvious from the description, or may be learned by practice of the present application. The present application will now be further described with reference to the drawings and examples. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is an exploded schematic view of a top cover assembly in the related art. [Diagram 2] 2 is a cross-sectional view of the top cover assembly in FIG. 1. [Diagram 3] FIG. 3 is an enlarged schematic view of part A in FIG. 2. [Figure 4] FIG. 2 is a schematic perspective view of a top cover assembly according to one embodiment of the present application. [Diagram 5] FIG. 5 is an exploded schematic view of the top cover assembly in FIG. 4. [Figure 6] FIG. 5 is a cross-sectional view of the top cover assembly in FIG. 4. [Figure 7] FIG. 7 is an enlarged schematic view of part B in FIG. [Figure 8] FIG. 2 is a schematic perspective view of a top cover assembly according to another embodiment of the present application. [Figure 9] FIG. 9 is an enlarged schematic view of part C in FIG. [Figure 10] FIG. 13 is a schematic perspective view of a top cover assembly according to a further embodiment of the present application. [Figure 11] FIG. 13 is a schematic perspective view of a top cover assembly according to a further embodiment of the present application. [Figure 12] 12 is an enlarged schematic view of part D in FIG. 11. [Figure 13] FIG. 13 is an enlarged schematic view of a top cover assembly in a further embodiment of the present application. [Figure 14]FIG. 13 is an enlarged schematic view of a top cover assembly in a further embodiment of the present application. [Figure 15] FIG. 13 is a cross-sectional view of a top cover assembly in a further embodiment of the present application. [Figure 16] FIG. 16 is an enlarged schematic view of a part E in FIG. [Figure 17] FIG. 2 is a schematic disassembled view of a single cell according to an embodiment of the present application. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] In the following, the embodiments of the present application shown in the drawings will be described in detail, in which the same or similar reference numerals throughout the drawings indicate the same or similar elements, or elements having the same or similar functions. The embodiments described below with reference to the drawings are illustrative and are only used to explain the present application, and are not to be understood as limiting the present specification.

[0021] In addition, in the description of this application, orientations or positional relationships indicated by up, down, front, rear, left, right, etc. are based on orientations or positional relationships shown in the drawings, and are merely for the purpose of facilitating and simplifying the description of this application, and are not intended to indicate or imply that the indicated devices or elements have a specific orientation or must be configured and operate in a specific orientation, and therefore are not to be understood as limiting this application.

[0022] In the description of this application, "several" means one or more, "plurality" means two or more, "greater than," "smaller than," "more than," etc. are understood to be exclusive of the number, and "greater than," "less than," "within," etc. are understood to be inclusive of the number. "First," "second," etc. are merely intended to distinguish technical features and should not be understood to indicate or imply relative importance, or to imply the number of the indicated technical features, or to imply the context of the indicated technical features.

[0023] In the description of this application, unless otherwise expressly limited, the terms "provide", "attach", "connect" and the like should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application by referring to the specific content of the technical solutions.

[0024] In the present description, references to the terms "one embodiment," "some embodiments," "exemplary embodiments," "example," "specific example," or "some examples" mean that the particular feature, structure, material, or characteristic described with reference to the embodiment or example is included in at least one embodiment or example of the present application. In this specification, generalized expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0025] In the related technology, the post and the top cover sheet are insulated via a seal ring. Specifically, as shown in Figures 1 to 3, a first through hole 111 and a second through hole 112 are provided in the top cover sheet 110, a lower plastic part 120 is connected to one side of the top cover sheet 110 (e.g., the lower side in the figure), and a third through hole 1211 and a fourth through hole 1221 are provided corresponding to the first through hole 111 and the second through hole 112, respectively. In other words, the first through hole 111 and the third through hole 1211 are provided corresponding to each other and are connected to each other, and the second through hole 112 and the fourth through hole 1221 are provided corresponding to each other and are connected to each other. The top cover assembly of the single cell further includes a first post terminal 130 and a second post terminal 140, the first post terminal 130 being inserted into the first through hole 111 and the third through hole 1211 and fixedly connected to the top cover sheet 110 via an upper plastic part, the second post terminal 140 being inserted into the second through hole 112 and the fourth through hole 1221 and fixedly connected to the top cover sheet 110 via an upper plastic part, and a seal ring 150 being fitted on the outside of both the first post terminal 130 and the second post terminal 140. In a normal state, the post terminals are connected to the top cover sheet 110 in the normal position shown in the figure, and the seal ring 150 normally performs its sealing function, but when the lower plastic part 120 is exposed to a high-temperature environment and expands due to heating, the lower plastic part 120 applies a leftward acting force to the first post terminal 130, as shown in Fig. 3 for example, and when it is exposed to a low-temperature environment and contracts due to cooling, the lower plastic part 120 applies a leftward acting force to the first post terminal 130. Either of the above two situations may cause the first post terminal 130 to become misaligned, resulting in poor sealing of the seal ring 150.

[0026] Based on the above, the embodiment of the present application proposes a top cover assembly that solves the problem of poor sealing caused by the expansion of the lower plastic part due to heating and contraction due to cooling by dividing the lower plastic part into two parts and providing a buffer member between the two parts to absorb deformation. Hereinafter, the present invention will be described in detail with reference to the drawings.

[0027] As shown in FIGS. 4 to 7, the top cover assembly 100 of this embodiment includes a top cover sheet 110 and a lower plastic part 120, and the top cover sheet 110 is provided with a first through hole 111 and a second through hole 112. The lower plastic part 120 is connected to one side (e.g., the lower side in the figure) of the top cover sheet 110 and includes a first connecting member 121 and a second connecting member 122 arranged at a distance from each other, the first connecting member 121 has a third through hole 1211 and the second connecting member 122 has a fourth through hole 1221, the first through hole 111 is arranged corresponding to the third through hole 1211 of the first connecting member 121, the second through hole 112 is arranged corresponding to the fourth through hole 1221 of the second connecting member 122, the first post terminal 130 is inserted through the first through hole 111 and the third through hole 1211, and the second post terminal 140 is inserted through the second through hole 112 and the fourth through hole 1221.

[0028] The lower plastic part 120 further includes a buffer member 123 connected between the first connecting member 121 and the second connecting member 122, and the buffer member 123 may be connected to the first connecting member 121 and the second connecting member 122 to form an integral structure. The buffer member 123 has elasticity, and when the lower plastic part 120 expands due to heating or contracts due to cooling, the buffer member 123 can expand and contract in response to the change in the distance between the first connecting member 121 and the second connecting member 122. Specifically, when the lower plastic part 120 expands due to heating, the distance between the first connecting member 121 and the second connecting member 122 becomes smaller, and the buffer member 123 is in a contracted state, and when the lower plastic part 120 contracts due to cooling, the distance between the first connecting member 121 and the second connecting member 122 becomes larger, and the buffer member 123 is in an extended state. In this way, the force applied by the lower plastic part 120 to the post terminal is reduced, and the post terminal is prevented from shifting due to the expansion of the lower plastic part due to heating and contraction due to cooling, allowing the post terminal to maintain excellent sealing ability together with the seal ring 150.

[0029] 6 and 7, in some embodiments, the buffer member 123 includes a curved portion 1231 having both ends connected to the first connecting member 121 and the second connecting member 122. The curved portion 1231 is curved in the thickness direction of the lower plastic part 120, and when the lower plastic part 120 expands due to heating, the curved angle of the curved portion 1231 becomes smaller and the buffer member 123 enters a contracted state, and when the lower plastic part 120 contracts due to cooling, the curved angle of the curved portion 1231 becomes larger and the buffer member 123 enters an extended state.

[0030] 7, in one specific embodiment of the buffer member 123 in the above embodiment, the first connecting member 121 includes a first main body portion 1212 and a first convex portion 1213, the first main body portion 1212 is connected to the top cover sheet 110 in which the first through hole 111 is provided, and the first convex portion 1213 is provided on the side of the first main body portion 1212 away from the top cover sheet 110 (for example, the lower side in the figure). Specifically, the first main body portion 1212 may have a plate-like structure, the first convex portion 1213 may be a boss or a plate-like structure perpendicular to the first main body portion 1212 in the figure, and the first main body portion 1212 and the first convex portion 1213 may be connected to form an integral structure. Similarly, the second connecting member 122 includes a second main body portion 1222 and a second convex portion 1223, the second main body portion 1222 is connected to the top cover sheet 110 in which the second through hole 112 is provided, and the second convex portion 1223 is provided on the side of the second main body portion 1222 away from the top cover sheet 110 (for example, the lower side in the figure), that is, the first convex portion 1213 and the second convex portion 1223 are provided on the same side, and both are provided away from the top cover sheet 110.

[0031] In order to make the curved portion 1231 easier to stretch, the curved portion 1231 needs to have a certain degree of curvature, so that its height is usually greater than the thickness of a conventional lower plastic part. Also, the height of the curved portion 1231 changes when it stretches, and in order to prevent the curved portion 1231 from stretching and pushing against other structures, the highest point of the curved portion 1231 must be below the upper end of the lower plastic part 120 and the lowest point must be above the lower end of the lower plastic part 120; however, doing so increases the overall thickness of the lower plastic part 120, reducing the capacity of the electrode group and lowering the energy density of the battery. Based on the above, both ends of the curved portion 1231 are connected to the first convex portion 1213 and the second convex portion 1223, respectively. Specifically, the curved portion 1231 is connected to the bottom ends of the first convex portion 1213 and the second convex portion 1223. The curved portion 1231 is curved and provided on the top cover sheet 110. The curved portion 1231 and the top cover sheet 110 are provided with a gap therebetween. As a result, when the lower plastic part 120 expands due to heating, the curved portion 1231 moves to the top cover sheet 110. However, assuming that the curved portion 1231 moves to the highest point, Even if the curved portion 1231 is extended, the curved portion 1231 does not contact the top cover sheet 110, and the curved portion 1231 is provided curved on the top cover sheet 110, so that the lowest point of the curved portion 1231 does not become lower than the lowest points of the first convex portion 1213 and the second convex portion 1223. In other words, the change in height of the curved portion 1231 is limited to between the first convex portion 1213 and the second convex portion 1223, and the curved portion 1231 is prevented from pressing the components below it. Furthermore, the thickness of the first main body portion 1212 and the second main body portion 1222 can be reduced to reduce the space occupied by the lower plastic component 120 in the case.

[0032] As shown in Figs. 8 to 10, in some other embodiments, the cushioning member 123 also includes a curved portion 1231, and both ends of the curved portion 1231 are connected to the first connecting member 121 and the second connecting member 122, respectively. In comparison with the embodiments of Figs. 6 and 7, in these embodiments, the curved portion 1231 is provided curved in the width direction of the lower plastic part 120. When the lower plastic part 120 expands due to heating, the curved angle of the curved portion 1231 becomes smaller, and the cushioning member 123 enters a contracted state, and when the lower plastic part 120 contracts due to cooling, the curved angle of the curved portion 1231 increases, and the cushioning member 123 enters an extended state, thus fulfilling the role of cushioning.

[0033] As shown in Figures 6 to 9, in some specific embodiments, the buffer member 123 includes a first buffer section 1232 and a second buffer section 1233, and the first buffer section 1232 and the second buffer section 1233 are both inclined, one end of the first buffer section 1232 is connected to the first connecting member 121, one end of the second buffer section 1233 is connected to the second connecting member 122, and the other end of the first buffer section 1232 and the other end of the second buffer section 1233 are connected to each other to form the above-mentioned curved portion 1231.

[0034] As shown in FIG. 10, in some other specific embodiments, the curved portion 1231 is in the shape of an arc.

[0035] As shown in Figures 5-9, in some embodiments, the lower plastic part 120 includes a plurality of buffer members 123 spaced apart across its width, which improves the connection strength between the first connecting member 121 and the second connecting member 122.

[0036] In some other embodiments, the cushioning member 123 includes multiple curved sections 1231 connected in series along the length of the lower plastic part 120, and each curved section 1231 can expand and contract synchronously, thereby reducing the amount of expansion and contraction of a single curved section 1231 and avoiding excessive deformation of the curved sections 1231.

[0037] It should be noted that the above embodiments may be used in combination, i.e. the lower plastic part 120 includes a plurality of cushioning members 123 spaced apart in its width direction, and each cushioning member 123 includes a plurality of curved portions 1231 connected in sequence in the length direction of the lower plastic part 120, thereby improving the connection strength and reducing the amount of expansion and contraction of each curved portion 1231.

[0038] The present application also proposes other ways to realize the expansion and contraction of the cushioning member 123, for example, as shown in Figures 11 to 14, the cushioning member 123 includes a deformation portion 1234, and the width of the deformation portion 1234 is less than the width of other parts of the lower plastic part 120, or as shown in Figures 15 and 16, the thickness of the deformation portion 1234 is less than the thickness of other parts of the lower plastic part 120, so that the deformation portion 1234 becomes a weak part of the cushioning member 123 and is deformed when a certain force is applied. Compared with the above embodiments, in these embodiments, the cushioning member 123 of the present embodiment is curved only when the lower plastic part 120 expands due to heating and contracts due to cooling.

[0039] It should be noted that the above embodiments may be used in combination, that is, the width and thickness of the deformation 1234 are both less than the width and thickness of other portions of the lower plastic part 120 .

[0040] As shown in Figures 13 and 16, in one specific embodiment of the buffer member 123, the buffer member 123 is, as a whole, a flat plate structure that is flush with the first connecting member 121 and the second connecting member 122, and includes a deforming portion 1234, a first connecting portion 1235, and a second connecting portion 1236, one end of the deforming portion 1234 is connected to the first connecting member 121 via the first connecting portion 1235, and the other end of the deforming portion 1234 is connected to the second connecting member 122 via the second connecting portion 1236, the thicknesses of the first connecting portion 1235 and the first connecting member 121 may be equal, and the second connecting portion 1236 and the second connecting member 122 may be equal. Here, in Figure 13, the width of deformed portion 1234 is less than the width of first connecting portion 1235 and second connecting portion 1236, and when lower plastic part 120 expands due to heating and contracts due to cooling, deformed portion 1234 bends in the width direction, causing cushioning member 123 to expand and contract, and in Figure 16, the thickness of deformed portion 1234 is less than the thickness of first connecting portion 1235 and second connecting portion 1236, and when lower plastic part 120 expands due to heating and contracts due to cooling, deformed portion 1234 bends in the thickness direction, causing cushioning member 123 to expand and contract.

[0041] As shown in Figures 11-16, in some embodiments, the lower plastic part 120 includes a plurality of buffer members 123 spaced apart across its width, thereby improving the connection strength between the first connecting member 121 and the second connecting member 122.

[0042] In some other embodiments, the lower plastic part 120 includes multiple deformation sections 1234 connected in series along its length, and each deformation section 1234 can expand and contract synchronously, thereby reducing the amount of expansion and contraction of any one deformation section 1234 and avoiding excessive deformation of the deformation sections 1234.

[0043] In addition, the above embodiments may be used in combination, that is, the lower plastic part 120 includes a plurality of cushioning members 123 spaced apart in its width direction, and one cushioning member 123 includes a plurality of deformable portions 1234 connected in sequence in the length direction of the lower plastic part 120, thereby improving the connection strength and reducing the amount of expansion and contraction of one deformable portion 1234.

[0044] An embodiment of the present application also proposes a single battery including a battery case 200, an electrode group 300, and the top cover assembly 100 of each of the above-mentioned embodiments, as shown in FIG. 17, in which the electrode group 300 is located within the battery case 200, and the top cover assembly 100 is covered by the battery case 200.

[0045] Although the embodiments of the present application have been described in detail above with reference to the drawings, the present application is not limited to the above embodiments, and various modifications may be made within the scope of knowledge of those skilled in the art without departing from the spirit of the present application. Furthermore, the embodiments of the present application and the features of the embodiments may be combined with each other unless inconsistent. [Explanation of symbols]

[0046] Top cover assembly 100, top cover sheet 110, first through hole 111, second through hole 112, lower plastic part 120, first connecting member 121, third through hole 1211, first main body portion 1212, first convex portion 1213, second connecting member 122, fourth through hole 1221, second main body portion 1222, second convex portion 1223, cushioning member 123, curved portion 1231, first cushioning section 1232, second cushioning section 1233, deformation portion 1234, first connecting portion 1235, second connecting portion 1236, first post terminal 130, second post terminal 140, seal ring 150, battery case 200, electrode group 300.

Claims

1. A top cover sheet; A top cover assembly characterized by comprising: a lower plastic part connected to one side of the top cover sheet, the lower plastic part including a first connecting member and a second connecting member spaced apart, and a cushioning member connected between the first connecting member and the second connecting member, the cushioning member being expandable and contractable in response to changes in the distance between the first connecting member and the second connecting member.

2. The top cover assembly according to claim 1 , wherein the cushioning member includes a curved portion that is curved in a thickness direction of the lower plastic part.

3. 3. The top cover assembly of claim 2, wherein the first connecting member includes a first main body portion and a first convex portion, the first main body portion is connected to the top cover sheet, and the first convex portion is provided on a side of the first main body portion away from the top cover sheet; the second connecting member includes a second main body portion and a second convex portion, the second main body portion is connected to the top cover sheet, and the second convex portion is provided on a side of the second main body portion away from the top cover sheet; both ends of the curved portion are connected to the first convex portion and the second convex portion, respectively; the curved portion is curved on the top cover sheet, and the curved portion and the top cover sheet are provided at a distance from each other.

4. 2. The top cover assembly according to claim 1, wherein the cushioning member includes a curved portion that is curved in a width direction of the lower plastic part.

5. The buffer member includes a first buffer section and a second buffer section, one end of the first buffer section and one end of the second buffer section are connected to the first connecting member and the second connecting member, respectively, and the other end of the first buffer section and the other end of the second buffer section are connected to form the curved portion; or 5. The top cover assembly according to claim 2, wherein the curved portion is in the shape of a circular arc.

6. A top cover assembly as described in any one of claims 2 to 4, characterized in that the lower plastic part includes a plurality of the cushioning members spaced apart in its width direction, and / or the cushioning member includes a plurality of the curved portions connected in sequence in the length direction of the lower plastic part.

7. The top cover assembly of claim 1, characterized in that the cushioning member includes a deformed portion whose width is less than the width of other portions of the lower plastic part and / or whose thickness is less than the thickness of other portions of the lower plastic part.

8. The top cover assembly of claim 1, characterized in that the cushioning member includes a deformation portion, a first connecting portion, and a second connecting portion, one end of the deformation portion is connected to the first connecting member via the first connecting portion, and the other end of the deformation portion is connected to the second connecting member via the second connecting portion, and a width of the deformation portion is less than a width of the first connecting portion and the second connecting portion, and / or a thickness of the deformation portion is less than a thickness of the first connecting portion and the second connecting portion.

9. A top cover assembly as described in claim 7 or 8, characterized in that the lower plastic part includes a plurality of the cushioning members spaced apart in its width direction and / or a plurality of the deformation portions connected in series in its length direction.

10. A battery case; The top cover assembly according to any one of claims 1 to 9, which is provided on the battery case; and an electrode group located within the battery case.

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