Cover plate assembly and cell of secondary battery

Abstract

The present invention provides a cover plate assembly and cell for a secondary battery that can prevent the lower insulating plate from twisting relative to the cover plate. [Solution] The cover plate assembly and cell of the secondary battery of the present invention include a cover plate having pole pole mounting holes, having a first side and a second side arranged opposite to each other along a first direction which is the thickness direction of the cover plate, a lower insulating plate located on the first side of the cover plate and having a through hole corresponding to the pole pole mounting hole, and a pole pole passing through the through hole and the pole pole mounting hole, wherein in a second direction perpendicular to the first direction, one of the pole pole and the lower insulating plate includes a convex portion, and the other of the pole pole and the lower insulating plate includes a concave portion that engages with the convex portion, and the pole pole further includes a main body portion, wherein in the second direction, the convex portion is formed by protruding from the main body portion, or the concave portion is formed by recessing from the main body portion.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to the cover plate assembly and cell of a secondary battery.

Background Art

[0002] Secondary batteries are widely used in electronic devices, such as mobile phones, notebook computers, electric bicycles, electric vehicles, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, electric tools, etc. Currently, common secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, lithium-ion batteries, secondary alkaline zinc-manganese batteries, etc. Among these, lithium-ion batteries have advantages such as high specific energy, high specific efficiency, long life, and low cost, and thus have become the mainstream power batteries for new energy vehicles.

[0003] The cover plate assembly of a secondary battery includes a lower insulating plate for electrically insulating the electrode assembly and the cover plate. If the lower insulating plate twists or becomes unstable with respect to the cover plate, it will also affect the sealing performance of the pole post. Therefore, it is particularly important to fix the position of the lower insulating plate.

Summary of the Invention

Problems to be Solved by the Invention

[0004] In view of the above problems, this application provides a cover plate assembly and cell of a secondary battery that can at least prevent the lower insulating plate from twisting with respect to the cover plate.

Means for Solving the Problems

[0005] The technical solution of this application is realized as follows.

[0006] According to one aspect of the present invention, a cover plate assembly for a secondary battery is provided, the cover plate assembly comprising: a cover plate having pole pole mounting holes, having a first side and a second side arranged opposite to each other along a first direction which is the thickness direction of the cover plate; a lower insulating plate located on the first side of the cover plate and having a through hole corresponding to the pole pole mounting hole; and a pole pole passing through the through hole and the pole pole mounting hole, wherein in a second direction perpendicular to the first direction, one of the pole pole and the lower insulating plate includes a convex portion, and the other of the pole pole and the lower insulating plate includes a recess that engages with the convex portion, and the pole pole further includes a main body portion, wherein in the second direction, the convex portion is formed by protruding from the main body portion, or the recess is formed by recessing from the main body portion.

[0007] In some embodiments, the projection of the convex cover plate in the first direction includes at least one edge.

[0008] In some embodiments, the number of protrusions is one.

[0009] In some embodiments, the projection of the convex cover plate in the first direction is an arc.

[0010] In some embodiments, the number of protrusions is 2 to 4.

[0011] In some embodiments, the length of the convex portion in the second direction is 1 / 15 to 1 / 8 of the length of the pole column in the second direction.

[0012] In some embodiments, the length range of the protrusion in the second direction is 1.8 to 3.0 mm.

[0013] In some embodiments, the lower insulating plate protrudes toward the side opposite to the cover plate to form a housing portion, and at least a portion of the main body portion and the protrusion is located within the housing portion, or at least a portion of the main body portion and the recess is located within the housing portion, and in a plane perpendicular to the first direction, the housing portion has a shape that engages with the main body portion and the protrusion, or has a shape that engages with the main body portion and the recess.

[0014] In some embodiments, the cover plate assembly further includes an electrical connection component positioned on the side of the lower insulating plate facing the cover plate and electrically connecting the poles and the electrode assembly, wherein in a first direction, the housing of the lower insulating plate engages with the electrical connection component at least partially by shape.

[0015] In some embodiments, the shape of the main body is at least one of a triangle, a rhombus, or an ellipse.

[0016] In some embodiments, the cover plate assembly further includes an electrical connection component positioned on the side of the lower insulating plate facing away from the cover plate and electrically connecting the pole and the electrode assembly, wherein in a first direction, the side of the pole facing away from the cover plate engages with the electrical connection component.

[0017] In some embodiments, the projection of the portion of the pole that engages with the electrical connection component onto the cover plate is circular.

[0018] In some embodiments, the portion of the pole that engages with the electrical connection component has a projection that overlaps with the main body and protrusions of the pole, or with the main body and recesses of the pole.

[0019] In some embodiments, the pole mounting holes include a first pole mounting hole and a second pole mounting hole, the through holes include a first through hole corresponding to the first pole mounting hole and a second through hole corresponding to the second pole mounting hole, the poles include a first pole and a second pole with opposite polarities, the first pole penetrates the first through hole and the first pole mounting hole, the second pole penetrates the second through hole and the second pole mounting hole, in a second direction perpendicular to the first direction, the first pole includes a first protrusion, the lower insulating plate includes a first recess that engages with the first protrusion, the second pole includes a second recess, and the lower insulating plate includes a second protrusion that engages with the second recess.

[0020] In some embodiments, the length of the cover plate ranges from 100 to 350 mm.

[0021] According to another aspect of the present invention, a cell is further provided, comprising a housing having an opening, an electrode assembly disposed within the housing, and the cover plate assembly, wherein the cover plate assembly seals the opening of the housing, and the cover plate assembly includes a lower insulating plate, the lower insulating plate located on the first side of the cover plate closer to the electrode assembly. [Effects of the Invention]

[0022] The beneficial technical effects of this invention are as follows:

[0023] The main body of the electrode post has a recess or protrusion perpendicular to the thickness direction of the cover plate, and the lower insulating plate includes a protrusion or recess that engages with the recess or protrusion of the electrode post, thereby fixing the relative positions of the cover plate and the lower insulating plate and preventing the lower insulating plate from twisting relative to the cover plate. Next, by preventing the twisting of the lower insulating plate, the occurrence of a situation in which the electrode post twists due to the twisting of the lower insulating plate can be avoided, improving the sealing stability between the electrode post and the cover plate, and consequently improving the safety and airtightness performance of the entire battery. Furthermore, since the position of the lower insulating plate is fixed, it becomes easier to position the insulating film (e.g., Mylar (polyester film)) used for insulating the housing and electrode assembly and the lower insulating plate during the assembly process, and to fix the insulating member to the lower insulating plate. In addition, since the position of the lower insulating plate is fixed relative to the cover plate during the process of inserting the cell into the housing, interference between the lower insulating plate and the housing can be avoided, improving assembly efficiency, and friction between the insulating member fixed to the lower insulating plate and the housing can be avoided, improving the insulation effect between the insulating member and the housing. Furthermore, during production, transportation, supply chain supply, and use, the design prevents particle contamination inside the cell due to movement of the lower insulating plate relative to each other, reducing the risk of cell corrosion by particles and improving the safety performance of the battery. [Brief explanation of the drawing]

[0024] To more clearly illustrate the embodiments of the present application or the technical solutions of the prior art, the drawings used in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can obtain other drawings based on these drawings without creative efforts.

[0025] [Figure 1] It is an exploded view of a conventional cover plate assembly. [Figure 2A] It is an exploded view of a cover plate assembly according to an embodiment of the present application. [Figure 2B] It is a bottom view of a cover plate assembly according to an embodiment of the present application. [Figure 2C] It is a front view of a cover plate assembly and an electrode assembly according to an embodiment of the present application. [Figure 3A] It is a bottom view of a terminal post according to an embodiment of the present application. [Figure 3B] It is an isometric side view of a terminal post according to an embodiment of the present application. [Figure 3C] It is a front view of a terminal post according to an embodiment of the present application. [Figure 4A] It is a bottom view of a lower insulating plate according to an embodiment of the present application. [Figure 4B] It is an isometric side view of a lower insulating plate according to an embodiment of the present application. [Figure 5A] It is a bottom view of a second insulating plate portion according to an embodiment of the present application. [Figure 5B] It is an isometric side view of a second insulating plate portion according to an embodiment of the present application. [Figure 6A] It is an exploded view of a cover plate assembly according to another embodiment of the present application. [Figure 6B] It is an isometric side view of a cover plate assembly according to another embodiment of the present application. [Figure 6C] It is a bottom view of the lower insulating layer and the terminal post of a cover plate assembly according to another embodiment of the present application. [Figure 6D] It is an isometric side view of the lower insulating layer and the terminal post of a cover plate assembly according to an embodiment of the present application. [Figure 7A]This is an isometric side view of pole columns with opposite polarities in a cover plate assembly according to another embodiment. [Figure 7B] This is a bottom view of the first insulating plate portion and the second insulating plate portion of a cover plate assembly according to another embodiment. [Figure 8A] This is an isometric side view of the electrical connection component of a cover plate assembly according to another embodiment of the present application. [Figure 8B] An isometric side view of the pole column of a cover plate assembly according to another embodiment of the present application. [Figure 9] An isometric side view of the pole column of a cover plate assembly according to another embodiment of the present application. [Modes for carrying out the invention]

[0026] The technical inventions in the embodiments of this application will be described clearly and completely below with reference to the drawings of the embodiments. Clearly, the embodiments described are only some, and not all, embodiments of this application. All other embodiments that a person skilled in the art can obtain based on the embodiments of this application are within the scope of protection of this application.

[0027] The following disclosure provides many different embodiments or examples for realizing different features of the subject matter provided. Hereinafter, specific examples of elements and arrangements are described for the sake of brevity of the invention. Naturally, these are merely examples and are not intended to limit the invention. For example, in the following description, forming the first member above or on top of the second member may include embodiments in which the first and second members are in direct contact, and also include embodiments in which an additional member is formed between the first and second members, and the first and second members are not in direct contact. Furthermore, the invention may repeat reference numbers and / or letters in various examples. This repetition is for conciseness and clarity only and does not indicate relationships between the embodiments and / or configurations discussed.

[0028] Furthermore, where there are no contradictions, the embodiments and features of the present application can be interoperated. The present application will be described in detail below by combining embodiments with reference to the drawings.

[0029] Figure 1 is an exploded view of a conventional cover plate assembly. As shown in Figure 1, the lower insulating plate 12 of a cell generally includes a separate first insulating plate portion 12A and a second insulating plate portion 12B. The first insulating plate portion 12A and the second insulating plate portion 12B are fixed to the underside of the cover plate 20 at their opposing ends in the longitudinal direction (direction X) of the cover plate via corresponding pole posts 14A and 14B, and are heat-welded to the Mylar. Furthermore, during the process of assembling the first insulating plate portion 12A and the second insulating plate portion 12B with the pole posts 14A and 14B, the first insulating plate portion 12A and the second insulating plate portion 12B tend to twist around the corresponding pole posts 14A and 14B as axes, causing a certain degree of twisting on the long side of the first insulating plate portion 12A or the second insulating plate portion 12B, leading to a series of problems such as interference when the cell is inserted into the housing, instability in the heat-welding position between the Mylar and the lower plastic, twisting of the lower insulating plate 12, instability in position, and impact on the sealing performance of the pole posts. The aforementioned problems become particularly pronounced when the cell length is long.

[0030] Figure 2A is an exploded view of a cover plate assembly according to one embodiment of the present application. Figure 2B is a bottom view of a cover plate assembly according to one embodiment of the present application. Figure 2C is a front view of the cover plate assembly and electrode assembly 900 according to one embodiment of the present application. As shown in Figures 2A to 2B, the cover plate assembly 100 includes a cover plate 110, the cover plate 110 having a first side 110S1 and a second side 110S2 arranged opposite to each other along direction Z (also called the first direction). Direction Z is the thickness direction of the cover plate 110. The first side 110S1 is the side of the cover plate 110 facing the electrode assembly 900 (see Figure 2C). The cover plate 110 includes pole mounting holes 112A (also called the first pole mounting hole) and pole mounting holes 112B (also called the second pole mounting hole). The pole mounting holes 112A and 112B extend from the first side 110S1 to the second side 110S2 of the cover plate 110.

[0031] The cover plate 110 extends vertically in direction X. The pole post mounting holes 112A and 112B can be positioned opposite each other along direction X. The cover plate 110 may further include an explosion-proof valve structure 114, which can be located between the pole post mounting holes 112A and 112B. If the cell experiences thermal runaway, the explosion-proof valve structure 114 can provide directional pressure relief, allowing heat and ejecta to be discharged to the outside of the cell through the explosion-proof valve structure 114, reducing the pressure inside the cell and preventing an explosion due to high pressure inside the cell.

[0032] The cover plate assembly 100 further includes a lower insulating plate 150, which is located on the first side 110S1 of the cover plate and has through holes 151A (also called the first through hole) and 151B (also called the second through hole) corresponding to pole mounting holes 112A and 112B. The lower insulating plate 150 extends vertically in direction X, and the through holes 151A and 151B can be arranged opposite each other along direction X.

[0033] In this embodiment, the lower insulating plate 150 specifically includes a first insulating plate portion 152 and a second insulating plate portion 154 connected to the first insulating plate portion 152. The length of the first insulating plate portion 152 in direction X may be greater than the length of the second insulating plate portion 154. Through holes 151A and 151B are provided in the first insulating plate portion 152 and the second insulating plate portion 154, respectively. The lower insulating plate 150 may further include a plurality of holes 156 corresponding to the explosion-proof valve structure 114, which are used to provide exhaust passages.

[0034] The cover plate assembly 100 further includes poles 220A (also called the first pole) and 220B (also called the second pole) with opposite polarities. In some embodiments, pole 220A is a positive pole and pole 220B is a negative pole. Alternatively, pole 220A may be a negative pole and pole 220B may be a positive pole.

[0035] The pole post 220A passes through the through hole 151A and the pole post mounting hole 112A, and the second pole post 220B passes through the through hole 151B and the pole post mounting hole 112B. Furthermore, upper insulating members 322A, 322B and electrode terminals 224A, 224B can be provided above the cover plate 110. The pole posts 220A, 220B can pass through the corresponding upper insulating members 322A, 322B and be connected to the corresponding electrode terminals 224A, 224B.

[0036] The lower insulating plate 150 includes a first side 150S1 and a second side 150S2 that are opposite each other in direction X, with the first side 150S1 facing away from the cover plate 110 and toward the electrode assembly 900, and the second side 150S2 facing toward the cover plate 110. The cover plate assembly 100 further includes electrical connection components 250A and 250B, which are located on the first side 150S1 of the lower insulating plate 150. Electrical connection component 250A electrically connects the pole 220A to the electrode assembly 900, for example, to the corresponding tab of the electrode assembly 900 (e.g., the positive electrode tab). Electrical connection component 250B electrically connects the pole 220B to the electrode assembly 900, for example, to the corresponding tab of the electrode assembly 900 (e.g., the negative electrode tab).

[0037] Figure 3A is a bottom view of a pole column according to one embodiment of the present application. Figure 3B is an isometric side view of a pole column according to one embodiment of the present application. Figure 3C is a front view of a pole column according to one embodiment of the present application. As shown in Figures 3A to 3C, the pole column 220A includes a main body portion 225 and a columnar portion 227 connected to the main body portion 225. The columnar portion passes through a through hole 151A and a pole column mounting hole 112A. The main body portion 225 is located between the lower insulating plate 150 and the electrical connection component 250A.

[0038] In this embodiment, the main body portion 225 includes a recess 225R. The recess 225R is recessed from the main body portion 225 in a direction perpendicular to direction Z. In some embodiments, the structure of the pole column 220B may be the same as that of the pole column 220A.

[0039] Figure 4A is a bottom view of the lower insulating plate 150 according to one embodiment of the present application. Figure 4B is an isometric side view of the lower insulating plate 150 according to one embodiment of the present application. Figures 4A and 4B show the first side 150S1 of the lower insulating plate 150 facing the electrode assembly 900.

[0040] As shown in Figures 4A and 4B, the lower insulating plate 150 includes protrusions 150P. Each protrusion 150P projects in a direction perpendicular to direction Z. The recesses 225R of the pole columns engage with the corresponding protrusions 150P of the lower insulating plate 150.

[0041] The main body portions 225 of the pole posts 220A and 220B have recesses 225R that are recessed in a direction perpendicular to direction Z, and the lower insulating plate 150 includes protrusions 150P that engage with the recesses 225R. This fixes the relative positions of the cover plate 110 and the lower insulating plate 150 (for example, relative positions in the XY plane), preventing the lower insulating plate 150 from twisting relative to the cover plate 110. By preventing the twisting of the lower insulating plate 150, the occurrence of a situation in which the pole posts 220A and 220B twist due to the twisting of the lower insulating plate 150 is avoided, improving the sealing stability between the pole posts 220A and 220B and the cover plate 110, and ultimately improving the safety and airtightness performance of the entire battery. Furthermore, since the position of the lower insulating plate 150 is fixed, it becomes easier to position the insulating film (e.g., Mylar) used for insulating the housing and electrode assembly during the assembly process and the lower insulating plate 150, making it easier to fix the insulating member to the lower insulating plate 150. Furthermore, during the process of inserting the cell into the housing, the lower insulating plate 150 is fixed in position relative to the cover plate 110, thereby avoiding interference between the lower insulating plate 150 and the housing, improving assembly efficiency, and also avoiding friction between the insulating material fixed to the lower insulating plate 150 and the housing, thereby improving the insulation effect between the insulating material and the housing. In addition, during production, transportation, supply chain supply, and use, the vibration of the relative positions of the lower insulating plate 150 prevents particle contamination inside the cell, reducing the risk of cell corrosion by particles and improving the safety performance of the battery.

[0042] In some embodiments, the length range of the cover plate 110 in direction X is 100 to 350 mm. In this case, the cover plate becomes longer due to the longer cell design, and it becomes necessary to fix multiple lower plastics to the cover plate 110 to achieve insulation between the cover plate 110 and the electrode assembly. In this case, fixing the position of the lower insulating plate becomes more important. According to the embodiments of the present invention, the poles 220A and 220B have recesses 225R, and the lower insulating plate 150 includes protrusions 150P that engage with the recesses 225R. This fixes the position of the long cover plate 110 and the lower insulating plate 150, prevents the lower insulating plate 150 from twisting relative to the long cover plate 110, and thereby effectively improves the battery's safety and airtightness, assembly efficiency, the insulating effect of the insulating material, and the safety of the battery.

[0043] In some embodiments, as shown in Figures 3A to 3C, the projection of the recess 225R of the main body 225 of the pole column 220B in direction Z, corresponding to the protrusion 150P, includes at least an arc. The arc-shaped recess 225R has the advantage of being easy to process. The number of recesses 225R may be 2 to 4 (Figures 3A and 3B show the case with 4). If there are too few arc-shaped recesses, it may not be sufficient to prevent the lower insulating plate from twisting relative to the cover plate, and if there are too many, the processing difficulty becomes too great. By setting the number of arc-shaped recesses 225R to 2 to 4, it is possible to prevent the lower insulating plate from twisting relative to the cover plate without increasing the processing difficulty.

[0044] Specifically, the first insulating plate portion 152 and the second insulating plate portion 154 can each include a protrusion 150P. The protrusion 150P of the first insulating plate portion 152 engages with the recess 225R of the pole column 220A, and the protrusion 150P of the second insulating plate portion 154 engages with the recess 225R of the pole column 220B. Hereinafter, embodiments of the present invention will be described mainly by the engagement between the protrusion 150P of the second insulating plate portion 154 and the recess 225R of the pole column 220B.

[0045] Figure 5A is a bottom view of the second insulating plate portion 154 according to one embodiment of the present application. Figure 5B is an isometric side view of the second insulating plate portion 154 according to one embodiment of the present application. As shown in Figures 5A and 5B, in this embodiment, the projection of the convex portion 150P in direction Z is an arc. Such an arc-shaped convex portion 150P has the advantage of being easy to process.

[0046] In some embodiments, the number of protrusions 150P on the second insulating plate portion 154 is 2 to 4. In the embodiments shown in Figures 5A and 5B, the number of protrusions 150P on the second insulating plate portion 154 is 4. If there are too few arc-shaped protrusions 150P, it may not be sufficient to prevent the lower insulating plate from twisting relative to the cover plate, and if there are too many, the manufacturing difficulty becomes too great. By setting the number of arc-shaped protrusions 150P to 2 to 4, it is possible to prevent the lower insulating plate from twisting relative to the cover plate while reducing the manufacturing difficulty.

[0047] In some other embodiments, the projection of the recess 225R of the pole posts 220A and 220B in direction Z may include at least one edge portion. Correspondingly, the projection of the protrusion 150P of the lower insulating plate 150 in direction Z may include at least one edge portion. Compared to arc-shaped protrusions and recesses, edge-shaped protrusions and recesses can provide a better anti-torsion effect. In one embodiment, the number of edge-shaped recesses 225R and protrusions 150P may each be one. Because the anti-torsion effect of edge-shaped protrusions and recesses is superior, the difficulty of processing can be further reduced by setting one protrusion and one recess that engage with each other.

[0048] In some embodiments, the length of the recess 225R of pole posts 220A and 220B in direction X is 1 / 15 to 1 / 8 of the length of pole post 220A in direction X. Note that the length of pole post 220A refers to the maximum length of pole post 220A. In embodiments where the pole post is circular, the length of pole post 220A is the diameter. In some embodiments, the maximum length of pole post 220A is the maximum length of its main body 225. If the above length ratio is too small, the length of the recess 225R may be too small, and it may not be possible to effectively prevent the lower insulating plate from twisting relative to the cover plate. If the ratio is too large, the length of the recess 225R may be too large, making processing difficult and costly. The length ratio range of 1 / 15 to 1 / 8 allows for preventing the lower insulating plate from twisting relative to the cover plate while also being easy to process and costly.

[0049] In some embodiments, the length range of the recess 225R of pole posts 220A and 220B in direction X is 1.8 to 3.0 mm. This length range further facilitates the machining of the recess 225R and provides a good anti-torsion effect.

[0050] In some embodiments, the second insulating plate portion 154 protrudes toward the first side 150S1 to form a housing portion 158. At least a portion of the main body portion 225 and recess 225R of the pole column 220B is located within the housing portion 158. The sides of the main body portion 225 and recess 225R facing the cover plate 110 are located within the housing portion 158. In the XY plane, the housing portion 158 has a shape that engages with the main body portion 225 and recess 225R. By providing a housing portion 158 that engages with the main body portion 225 and recess 225R in this way, the second insulating plate portion 154 not only engages with the recess 225R but also with the shape of the main body portion 225, further enhancing the anti-twist effect.

[0051] In some other embodiments, the main body portion 225 of the pole poles 220A and 220B may have other applicable shapes. In some other embodiments, the shape of the main body portion 225 may be polygonal, for example, triangular or hexagonal (see Figure 9), or the shape of the main body portion 225 may be elliptical. These shapes of the main body portion 225 have the advantages of being easy to manufacture and having good anti-twist effect.

[0052] Referring to Figures 3A to 3C and Figures 5A and 5B, the pole posts 220A and 220B are fitted into the corresponding electrical connection components 250 in direction Z to realize an electrical connection between the pole posts and the electrical connection components. In some embodiments, the pole posts 220A and 220B may further include a defining portion 229 (see Figure 3C) connected to the main body 225, the defining portion 229 being connected to the side of the main body 225 relative to the columnar portion 227. The defining portion 229 refers to the fact that, while the main body 225 has an irregular projection shape on the cover plate 110 along direction Z, the projection of the defining portion 229 on the cover plate 110 along direction Z has a regular geometric shape (e.g., a circle). In some embodiments, the nominal portions 229 of the pole posts 220A and 220B fit into the corresponding electrical connectors 250 in direction Z, and the pole posts and electrical connectors overlap at least partially in the thickness direction (direction Z), thereby reducing the space occupied by the pole posts and electrical connectors within the cell and improving the overall energy density of the cell. In some embodiments, the projection of the nominal portion 229 onto the cover plate 110 in direction Z is circular. The circular nominal portion 229 is easy to machine, convenient for fitting the nominal portion 229 onto the electrical connectors 250, and can improve assembly efficiency.

[0053] Referring to Figure 2A, electrical connectors 250A and 250B may include grooves 251A and 251B, respectively, on the side facing the lower insulating plate 150. The shapes of grooves 251A and 251B engage with the shapes of the defining portions 229 of pole posts 220A and 220B. In some embodiments, the projection of grooves 251A and 251B in direction Z is circular. The defining portions 229 of pole posts 220A and 220B may be located within the corresponding grooves 251A and 251B.

[0054] Furthermore, the first insulating plate portion 152 and the second insulating plate portion 154 each have a protrusion 159 in direction Z. The protrusion 159 can extend along the surface edge of the first side 150S1 of the corresponding first insulating plate portion 152 and second insulating plate portion 154 to form a closed ring shape. The closed ring shape formed by the protrusion 159 engages with the shape of the surface facing the lower insulating plate 150 of the corresponding electrical connection components 250A and 250B (the surface on which grooves 251A and 251B are formed) and fits into the electrical connection components 250A and 250B. In addition, the center of the closed ring shape is open, and the poles 220A and 220B pass through the corresponding openings and fit into the electrical connection components 250A and 250B, respectively. The protrusions 159 of the lower insulating plate 150 engage with the electrical connection components 250A and 250B by their shape, thereby fixing the relative positions of the poles 220A and 220B, the lower insulating plate 150, the electrical connection components 250A and 250B, preventing the lower insulating plate from twisting relative to the electrical connection components, and further improving the battery's airtightness, assembly efficiency, the insulating effect of the insulating material, and the overall safety of the battery.

[0055] In some other embodiments, the first insulating plate portion 152 and the second insulating plate portion 154 do not fit onto the electrical connectors 250A and 250B, and the poles 220A and 220B directly penetrate the opening and fit onto the electrical connectors 250A and 250B. Such a structure reduces the difficulty of processing and saves on processing costs.

[0056] Figure 6A is an exploded view of the cover plate assembly 200 according to another embodiment of the present application. Figure 6B is an isometric side view of the cover plate assembly 200 according to another embodiment of the present application.

[0057] Figure 6C is a bottom view of the lower insulating layer and pole column of a cover plate assembly 200 according to another embodiment of the present application. Figure 6D is an isometric side view of the lower insulating layer and pole column of a cover plate assembly 200 according to one embodiment of the present application. Multiple embodiments of the cover plate assembly 200 shown in Figures 6A to 6D may be identical to the cover plate assembly 100 described in Figures 2A to 5B above, and the differences of the cover plate assembly 200 will be described below.

[0058] As shown in Figures 6A to 6D, pole post 220A includes a protrusion 225P, and the corresponding first insulating plate portion 152 includes an engaging recess 150R. Pole post 220B includes a recess 225R, and the corresponding second insulating plate portion 154 includes an engaging protrusion 150P. Protrusions 225P and 150P each project in a direction perpendicular to direction Z (e.g., direction X). Recesses 150R and 225R each recess in a direction perpendicular to direction Z (e.g., direction X).

[0059] The pole posts 220A, 220B and their corresponding first and second insulating plate portions 152 and 154 have convex and concave portions that interlock in a direction perpendicular to direction Z, thereby fixing the relative positions of the cover plate 110 and the lower insulating plate 150 (for example, relative positions in the XY plane), and preventing the lower insulating plate 150 from twisting relative to the cover plate 110. This avoids situations where the pole posts 220A, 220B twist due to the twisting of the lower insulating plate 150, improving the sealing stability between the pole posts 220A, 220B and the cover plate 110, and ultimately improving the safety and airtightness of the entire battery. Furthermore, because the position of the lower insulating plate 150 is fixed, the positioning of the insulating film (e.g., Mylar) used for insulating the housing and electrode assembly during the assembly process and the lower insulating plate 150 becomes easier, and it becomes easier to fix the insulating member to the lower insulating plate 150. Furthermore, during the process of inserting the cell into the housing, the lower insulating plate 150 is fixed in position relative to the cover plate 110, thereby avoiding interference between the lower insulating plate 150 and the housing and improving assembly efficiency. It also avoids friction between the insulating material fixed to the lower insulating plate 150 and the housing, improving the insulation effect between the insulating material and the housing. Moreover, during production, transportation, supply chain supply, and use, it prevents particle contamination inside the cell due to movement of the relative positions of the lower insulating plate 150, reducing the risk of cell corrosion by particles and improving the safety performance of the battery.

[0060] More specifically, Figure 7A shows an isometric side view of poles with opposite polarities in a cover plate assembly according to another embodiment. Figure 7B shows a bottom view of the first insulating plate portion and the second insulating plate portion of the cover plate assembly according to another embodiment.

[0061] Referring to Figure 7A, pole columns 220A and 220B each include a main body 225 and a columnar portion 227 connected to the main body 225. The shape of the main body 225 is a rounded rhombus, specifically a square.

[0062] Regarding the pole column 220A, the main body portion 225 of the pole column 220A includes a protrusion 225P. In this embodiment, the protrusion 225P protrudes from the main body portion 225 in direction X. The shape of the main body portion 225 is a rounded rhombus (the specific shape may be a square). The projection of the protrusion 225P in direction Z includes at least one edge portion. In this embodiment, the projection of the protrusion 225P in direction Z includes three edge portions, and the three edge portions are sequentially connected by rounded corners. This edge-shaped structure including the edge portion of the protrusion 225P has an excellent anti-twist effect and is easy to manufacture.

[0063] In this embodiment, the number of protrusions 225P and corresponding recesses 150R of the main body 225 is one each. Setting the number of protrusions 225P and recesses 150R to one each has the advantage of being easy to process and cost-effective. In this embodiment, the number of recesses 225R and corresponding protrusions 150P of the pole column 220B is one each, and because the shape of the protrusions 225P on the edge has an excellent effect in preventing twisting, setting only one protrusion further reduces the difficulty of processing.

[0064] In some embodiments, the length of the protrusion 225P in direction X is 1 / 15 to 1 / 8 of the length of the pole column 220A in direction X. Here, the length of the pole column 220A refers to the maximum length of the pole column 220A. In embodiments where the pole column is circular, the length of the pole column 220A is the diameter. In some embodiments, the maximum length of the pole column 220A is the maximum length of its main body 225. If the above length ratio is too small, the length of the protrusion 225P may be too small, and the lower insulating plate may not be able to effectively prevent twisting relative to the cover plate. If the ratio is too large, the length of the protrusion 225P may be too large, making processing difficult and costly. The length ratio range of 1 / 15 to 1 / 8 allows for preventing twisting of the lower insulating plate relative to the cover plate, while also being easy to process and costly.

[0065] In some embodiments, the length range of the cover plate 110 in direction X is 100 to 350 mm. As described above, when the cover plate becomes longer due to the longer cell design, the embodiment of the present invention fixes the position of the long cover plate 110 and the lower insulating plate 150, thereby preventing the lower insulating plate 150 from twisting relative to the long cover plate 110, and effectively improving the battery's safety airtightness, assembly efficiency, insulating effect of insulating material, and battery safety.

[0066] In some embodiments, the length range of the protrusion 225P in direction X is 1.8 to 3.0 mm. This length range facilitates the machining of the protrusion 225P and provides a good anti-twist effect.

[0067] Regarding the pole column 220B, the main body portion 225 of the pole column 220B includes a recess 255R. In this embodiment, the recess 255R is recessed from the main body portion 225 in direction X. The projection of the recess 255R in direction Z includes at least one edge portion. In this embodiment, the recess 255R includes three edge portions, and the three edge portions are sequentially connected by rounded corners. This edge-shaped structure of the recess 255R has the advantages of being easy to process, low cost, and having a good anti-twist effect.

[0068] In some other embodiments, the main body portion 225 of the pole poles 220A and 220B may have other applicable shapes. For example, the shape of the main body portion 225 may be polygonal, such as a triangle or a hexagon (see Figure 9), or the main body portion 225 may be elliptical. These shapes of the main body portion 225 have the advantages of being easy to manufacture and having a good anti-twist effect.

[0069] Referring to Figure 7B, the first insulating plate portion 152 protrudes toward the first side 150S1 to form a housing portion 158A. The housing portion 158A has a recess 150R. At least a portion of the main body portion 225 and the protrusion portion 225P of the pole column 220A is located within the housing portion 158. The sides of the main body portion 225 and the protrusion portion 225P of the pole column 220A facing the cover plate 110 are located within the housing portion 158A. In the XY plane, the housing portion 158A has a shape that engages with the main body portion 225 and the protrusion portion 225P. By providing a housing portion that engages with the main body portion 225 and the protrusion portion 225P, the first insulating plate portion 152 not only engages with the protrusion portion 225P but also with the shape of the main body portion 225, further enhancing the anti-twist effect.

[0070] Similarly, the second insulating plate portion 154 protrudes toward the first side 150S1 to form a housing portion 158B. The housing portion 158B has a convex portion 150P. At least a portion of the main body portion 225 and recess 255R of the pole column 220B (for example, the side facing the cover plate 110) is located within the housing portion 158B. In the XY plane, the housing portion 158B has a shape that engages with the main body portion 225 and recess 255R, and the second insulating plate portion 154 engages with either the shape of the main body portion 225 or the recess 255R, further enhancing the anti-twist effect.

[0071] In some embodiments, the first insulating plate portion 152 and the second insulating plate portion 154 each have a protrusion 159 in direction Z. The protrusion 159 can extend along the surface edge of the first side 150S1 of the corresponding first insulating plate portion 152 and second insulating plate portion 154 to form a closed ring shape. The closed ring shape formed by the protrusion 159 engages with the shape of the surface facing the lower insulating plate 150 of the corresponding electrical connectors 250A and 250B (the surface on which grooves 251A and 251B are formed) and fits into the electrical connectors 250A and 250B. The center of the closed ring shape is open, and the poles 220A and 220B pass through the corresponding openings and fit into the electrical connectors 250A and 250B, respectively. The protrusions 159 of the lower insulating plate 150 engage with the electrical connection components 250A and 250B through their shape, thereby fixing the relative positions of the poles 220A and 220B, the lower insulating plate 150, the electrical connection components 250A and 250B, preventing the lower insulating plate from twisting relative to the electrical connection components, and further improving the battery's airtightness, assembly efficiency, the insulating effect of the insulating material, and the overall safety of the battery.

[0072] In some other embodiments, the first insulating plate portion 152 and the second insulating plate portion 154 do not fit onto the electrical connectors 250A and 250B, and the poles 220A and 220B directly pass through the opening and fit onto the electrical connectors 250A and 250B. Such a structure can reduce the difficulty of manufacturing.

[0073] Figure 8A is an isometric side view of an electrical connection component 250A of a cover plate assembly 200 according to another embodiment of the present application. Figure 8B is an isometric side view of a pole column 220A of a cover plate assembly 200 according to another embodiment of the present application. Figures 8A and 8B show the electrical connection component 250A and the pole column 220A as examples, respectively. Referring to Figures 8A and 8B, in some embodiments, in direction Z, the side of the pole column 220A that is away from the cover plate fits into the electrical connection component 250A. Specifically, the nominal portion 229 of the pole column 220A can fit into the electrical connection component 250A, and the side of the main body portion 225 and the convex portion 225P of the pole column 220A that is connected to the nominal portion 229 can fit into the electrical connection component 250A. Since the main body 225 and the rectifier 229 of the pole post 220A overlap at least partially with the electrical connection component 250A in the thickness direction (direction Z), the space occupied by the pole post and the electrical connection component inside the cell can be further reduced, improving the overall energy density of the cell. In some embodiments, the projection of the rectifier 229 onto the cover plate 110 in direction Z is circular. A circular rectifier 229 is easier to manufacture, convenient to fit the rectifier 229 onto the electrical connection component 250, and can improve assembly efficiency.

[0074] In some embodiments, the portion of the pole post 220A that engages with the electrical connection component 250A has a projection that overlaps with the main body portion 225 and the protrusion 225P of the pole post 220A in direction Z. Specifically, the electrical connection component 250A may include a groove 251A on the side facing the lower insulating plate 150. The side wall of the groove 251A may have a recess 251R that engages with the shape of the main body portion 225 and the protrusion 225P of the pole post 220A, so that at least a portion of the main body portion 225 and the protrusion 225P engages with the groove 251A in direction Z. By engaging the protrusion 225P with the electrical connection component 250A, the protrusion 225P and the electrical connection component 250A engage with each other, further exhibiting a twist prevention effect and keeping the relative positions of the pole post 220A, the first insulating plate portion 152, and the electrical connection component 250A fixed. Furthermore, the design ensures that electrical connector 250A is set in place and that the angles between the two electrical connectors 250A and 250B are parallel, thereby securing design advantages.

[0075] The specific electrical connection component 250A may further include a through hole 253A located below the groove 251A. The shape of the through hole 253A can engage with the shape of the defined portion 229, so that the defined portion 229 of the pole post 220A can be fitted into the through hole 253A.

[0076] Referring to Figure 8A, in direction Z, the housing portion 158A of the first lower insulating plate 152 engages with the electrical connection component 250A, for example, the groove 251A, at least partially, through its shape. This keeps the relative positions of the pole 220A, the first insulating plate portion 152, and the electrical connection component 250A fixed.

[0077] The configuration of the electrical connection component 250A, pole 220A, and first lower insulating plate 152 has been described above with reference to Figures 8A and 8B. It should be understood that the electrical connection component 250B, pole 220B, and second lower insulating plate 154 can have a similar configuration.

[0078] Embodiments of the present invention further provide a cell comprising a housing having an opening, an electrode assembly disposed within the housing (e.g., electrode assembly 900), and a cover plate assembly sealing the opening of the housing (e.g., the cover plate assembly 100 or 200).

[0079] The foregoing describes only preferred embodiments of the present application and does not limit the application; all modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present application are included within the scope of protection. [Industrial applicability]

[0080] The main body of the pole column has a recess or protrusion perpendicular to the thickness direction of the cover plate, and the lower insulating plate includes a protrusion or recess that is interlocked with the recess or protrusion of the pole column. This fixes the relative positions of the cover plate and the lower insulating plate, prevents the lower insulating plate from twisting relative to the cover plate, and improves the assembly efficiency of the cell and the safety performance of the battery. [Explanation of Symbols]

[0081] 12A, 152 First insulating plate section 12B, 154 Second insulating plate section 14A, 14B pole pillar 20, 110 Cover Plate 100, 200 Cover Plate Assembly 110S1, 150S1 First side 110S2, 150S2 second side 112A, 122B pole pole mounting holes 114 Explosion-proof valve structure 150 Lower insulating plate 150P, 159, 225P convex part 150R, 225R, 251R recess 151A, 151B, 253A through hole 156 holes 158, 158A, 158B storage area 220A, 220B pole pole 224A, 224B electrode terminal 225 Main body 227 Columnar part 229 Regulations 250A, 250B Electrical Connection Components 251A, 251B groove 322A, 322B Upper insulating member 900 electrode assembly X, Z direction

Claims

1. A cover plate having pole mounting holes, the cover plate having a first side and a second side arranged opposite to each other along a first direction which is the thickness direction of the cover plate, A lower insulating plate located on the first side of the cover plate and having a through hole corresponding to the pole pole mounting hole, A pole that penetrates the aforementioned through hole and the pole pole mounting hole, Includes, In a second direction perpendicular to the first direction, one of the pole column and the lower insulating plate includes a protrusion, and the other of the pole column and the lower insulating plate includes a recess that engages with the protrusion. The pole column further includes a main body, and in the second direction, the convex portion is formed by protruding from the main body, or the recess is formed by recessing the main body. A cover plate assembly for a secondary battery, characterized by the following features.

2. The projection of the protrusion onto the cover plate in the first direction includes at least one edge portion. The cover plate assembly for the secondary battery according to feature 1.

3. The number of the aforementioned protrusions is one. The cover plate assembly for a secondary battery according to feature 2.

4. The projection of the protrusion onto the cover plate in the first direction is an arc. The cover plate assembly for the secondary battery according to feature 1.

5. The number of the aforementioned protrusions is 2 to 4. The cover plate assembly for a secondary battery according to feature 4.

6. The length of the protrusion in the second direction is 1 / 15 to 1 / 8 of the length of the pole column in the second direction. The cover plate assembly for the secondary battery according to feature 1.

7. The length range of the protrusion in the second direction is 1.8 to 3.0 mm. The cover plate assembly for a secondary battery according to feature 6.

8. The lower insulating plate protrudes toward the side opposite to the cover plate to form a housing portion, and at least a part of the main body portion and the protrusion portion is located within the housing portion, or at least a part of the main body portion and the recess portion is located within the housing portion. In the plane perpendicular to the first direction, the housing portion has a shape that engages with the main body portion and the protrusion, or has a shape that engages with the main body portion and the recess. The cover plate assembly for the secondary battery according to feature 1.

9. The lower insulating plate is positioned on the side facing the cover plate and further includes an electrical connection component that electrically connects the pole column and the electrode assembly, In the first direction, the housing portion of the lower insulating plate engages with the electrical connection component by its shape, at least partially. The cover plate assembly for a secondary battery according to feature 8.

10. The shape of the main body is at least one of a triangle, a rhombus, or an ellipse. The cover plate assembly for a secondary battery according to feature 8.

11. The lower insulating plate is positioned on the side facing the cover plate and further includes an electrical connection component that electrically connects the pole column and the electrode assembly, In the first direction, the side of the pole column facing away from the cover plate fits into the electrical connection component. The cover plate assembly for the secondary battery according to feature 1.

12. The projection of the portion of the pole that fits into the electrical connection component onto the cover plate is circular. The cover plate assembly for a secondary battery according to feature 11.

13. The portion of the pole that fits into the electrical connection component has a projection that overlaps with the main body and protrusion of the pole, or the projection that overlaps with the main body and recess of the pole. The cover plate assembly for a secondary battery according to feature 11.

14. The pole pole mounting hole includes a first pole pole mounting hole and a second pole pole mounting hole, The through-hole includes a first through-hole corresponding to the first pole pole mounting hole and a second through-hole corresponding to the second pole pole mounting hole. The pole column includes a first pole column and a second pole column with opposite polarities, the first pole column passing through the first through hole and the first pole column mounting hole, and the second pole column passing through the second through hole and the second pole column mounting hole. In a second direction perpendicular to the first direction, the first pole column includes a first protrusion, the lower insulating plate includes a first recess that engages with the first protrusion, the second pole column includes a second recess, and the lower insulating plate includes a second protrusion that engages with the second recess. The cover plate assembly for the secondary battery according to feature 1.

15. The length range of the cover plate is 100 to 350 mm. The cover plate assembly for the secondary battery according to feature 1.

16. A housing having an opening, An electrode assembly disposed within the aforementioned housing, Includes a cover plate assembly according to any one of claims 1 to 15, The cover plate assembly seals the opening of the housing, The cover plate assembly includes a lower insulating plate, and the lower insulating plate is located on the first side of the cover plate that is closer to the electrode assembly. A cell characterized by the following features.

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