Cover plate assembly of secondary battery and battery cell

Abstract

The utility model discloses a cover plate assembly of a secondary battery and a battery cell, the cover plate assembly comprises: a cover plate which is provided with a pole mounting hole and has a first side and a second side which are oppositely arranged along a first direction, and the first direction is the thickness direction of the cover plate; the lower insulating plate is positioned on the first side of the cover plate and is provided with a through hole corresponding to the pole mounting hole; the pole column penetrates through the through hole and the pole column mounting hole; wherein in the second direction perpendicular to the first direction, one of the pole and the lower insulating plate comprises a convex part, the other one of the pole and the lower insulating plate comprises a concave part matched with the convex part, the pole further comprises a body part, and in the second direction, the convex part is formed by the body part in a convex mode or the concave part is formed by the body part in a concave mode. According to the technical scheme, at least the lower insulating plate can be prevented from twisting relative to the cover plate.

Description

Technical Field

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

[0002] Rechargeable batteries are widely used in electronic devices such as mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools. Common rechargeable batteries include nickel-cadmium batteries, nickel-metal hydride batteries, lithium-ion batteries, and rechargeable alkaline zinc-manganese batteries. Among these, lithium-ion batteries have become the mainstream power battery for new energy vehicles due to their advantages such as high specific energy, high specific power, long lifespan, and low cost.

[0003] The cover assembly of the secondary battery includes a lower insulating plate, which is used to electrically insulate the electrode assembly from the cover. If the lower insulating plate is twisted or unstable relative to the cover, it will also affect the sealing performance of the electrode post. Therefore, it is particularly important to fix the position of the lower insulating plate. Utility Model Content

[0004] To address the above issues, this application proposes a cover plate assembly and a battery cell for a secondary battery, which can at least prevent the lower insulating plate from twisting relative to the cover plate.

[0005] The technical solution of this application is implemented as follows:

[0006] According to one aspect of this application, a cover plate assembly for a secondary battery is provided. The cover plate assembly includes: a cover plate having a terminal mounting hole and having a first side and a second side disposed opposite to each other along a first direction, the first direction being 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 terminal mounting hole; and a terminal post passing through the through hole and the terminal mounting hole; wherein, in a second direction perpendicular to the first direction, one of the terminal post and the lower insulating plate includes a protrusion, and the other of the terminal post and the lower insulating plate includes a recess that cooperates with the protrusion. The terminal post also includes a body portion, in which the protrusion is formed by the body portion or the recess is formed by the body portion in the second direction.

[0007] In some embodiments, the projection of the protrusion toward the cover plate in a 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 protrusion toward the cover plate in a first direction is an arc edge.

[0010] In some embodiments, the number of protrusions is two to four.

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

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

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

[0014] In some embodiments, the cover plate assembly further includes an electrical adapter disposed on the side of the lower insulating plate opposite to the cover plate and electrically connecting the electrode post to the electrode assembly, wherein, in a first direction, the receiving portion of the lower insulating plate is at least partially embedded in the electrical adapter in a form-fitting manner.

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

[0016] In some embodiments, the cover plate assembly further includes an electrical adapter disposed on the side of the lower insulating plate opposite to the cover plate and electrically connecting the electrode post to the electrode assembly, wherein the electrical adapter is embedded on the side of the electrode post opposite to the cover plate in a first direction.

[0017] In some embodiments, the portion of the electrode post embedded in the electrical adapter is projected as a circle in the cover plate.

[0018] In some embodiments, the portion of the electrode embedded in the electrical adapter coincides with the projection of the electrode body and protrusion or the electrode body and recess.

[0019] In some embodiments, the electrode mounting hole includes a first electrode mounting hole and a second electrode mounting hole; the through hole includes a first through hole corresponding to the first electrode mounting hole and a second through hole corresponding to the second electrode mounting hole; the electrode includes a first electrode and a second electrode with opposite polarities, the first electrode passing through the first through hole and the first electrode mounting hole, and the second electrode passing through the second through hole and the second electrode mounting hole; wherein, in a second direction perpendicular to the first direction, the first electrode includes a first protrusion, and the lower insulating plate includes a first recess that cooperates with the first protrusion; the second electrode includes a second recess, and the lower insulating plate includes a second protrusion that cooperates with the second recess.

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

[0021] According to another aspect of this application, a battery cell is also provided, comprising: a housing having an opening; an electrode assembly disposed within the housing; and the aforementioned cover assembly covering the opening of the housing, the cover assembly including a lower insulating plate located on a first side of the cover plate near the electrode assembly.

[0022] The beneficial technical effects of this utility model include:

[0023] By configuring the main body of the electrode post to have a recess or protrusion in a direction perpendicular to the thickness direction of the cover plate, and the lower insulating plate including a protrusion or recess that cooperates with the recess or protrusion of the electrode post, the relative position of the cover plate and the lower insulating plate is fixed, preventing the lower insulating plate from twisting relative to the cover plate. Secondly, by preventing the lower insulating plate from twisting, the situation where the electrode post is twisted due to the twisting of the lower insulating plate is avoided, which can improve the sealing stability between the electrode post and the cover plate, thereby improving the overall safety and airtightness of the battery. Furthermore, since the position of the lower insulating plate is fixed, it is convenient to use the insulating film (such as...) for the insulating shell and electrode assembly during the assembly process. The positioning of the Mylar (polyester film) and the lower insulating plate facilitates the fixing of the insulating components onto the lower insulating plate. Furthermore, during the cell insertion process, the fixed position of the lower insulating plate relative to the cover plate prevents interference between the lower insulating plate and the casing, thus improving assembly efficiency. It also prevents the insulating components fixed to the lower insulating plate from rubbing against the casing, improving the insulation effect between the insulating components and the casing. In addition, during production, transportation, supply chain delivery, and use, it prevents the relative position of the lower insulating plate from shifting, which could easily trap particles from inside the cell, thereby reducing the risk of cell corrosion caused by particles and improving battery safety. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is an exploded view of an existing cover plate assembly.

[0026] Figure 2A This is an exploded view of a cover plate assembly according to an embodiment of this application.

[0027] Figure 2B This is a bottom plan view of a cover plate assembly according to an embodiment of this application.

[0028] Figure 2C This is a front view of a cover plate assembly and an electrode assembly according to an embodiment of this application.

[0029] Figure 3A This is a bottom view of a pole according to an embodiment of this application.

[0030] Figure 3B This is an isometric side view of a pole according to an embodiment of this application.

[0031] Figure 3C This is a front view of a pole according to an embodiment of this application.

[0032] Figure 4A This is a bottom plan view of the lower insulating plate according to an embodiment of this application.

[0033] Figure 4B The image in the middle is an isometric side view of the lower insulating plate according to an embodiment of this application.

[0034] Figure 5A This is a bottom plan view of the second insulating plate portion according to an embodiment of this application.

[0035] Figure 5B The image in the middle is an isometric side view of the second insulating plate portion according to an embodiment of this application.

[0036] Figure 6A This is an exploded view of a cover plate assembly according to another embodiment of this application.

[0037] Figure 6B This is an isometric side view of a cover plate assembly according to another embodiment of this application.

[0038] Figure 6C This is a bottom plan view of the lower insulating layer and pole of the cover plate assembly according to another embodiment of this application.

[0039] Figure 6D This is an isometric side view of the lower insulating layer and the pole of a cover plate assembly according to an embodiment of this application.

[0040] Figure 7A An isometric side view of oppositely polarized poles of a cover plate assembly according to another embodiment is shown.

[0041] Figure 7B A bottom plan view of the first insulating plate portion and the second insulating plate portion of the cover plate assembly according to another embodiment is shown.

[0042] Figure 8A This is an isometric side view of the electrical adapter of a cover plate assembly according to another embodiment of this application.

[0043] Figure 8B This is an isometric side view of the pole of a cover plate assembly according to another embodiment of this application.

[0044] Figure 9This is an isometric side view of the pole of the cover plate assembly according to other embodiments of this application. Detailed Implementation

[0045] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0046] The following disclosure provides numerous different embodiments or instances for implementing various features of the provided subject matter. Specific examples of elements and arrangements will be described below to simplify the present invention. These are merely examples and are not intended to limit the present invention. For example, in the following description, forming a first component above or on a second component may include embodiments where the first and second components are in direct contact, or embodiments where an additional component is formed between the first and second components such that the first and second components are not in direct contact. Furthermore, reference numerals and / or letters may be repeated in various instances of the present invention. Such repetition is merely for brevity and clarity and does not in itself indicate a relationship between the various embodiments and / or configurations discussed.

[0047] Furthermore, where there is no conflict, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0048] Figure 1 This is an exploded view of an existing cover plate assembly. For example... Figure 1 As shown, the lower insulating plate 12 of a typical battery cell generally includes a split first insulating plate portion 12A and a second insulating plate portion 12B. The opposite ends of the first insulating plate portion 12A and the second insulating plate portion 12B in the longitudinal direction (direction X) of the cover plate are fixed to the lower side of the cover plate 20 by corresponding poles 14A and 14B and are heat-fused with Mylar. During the assembly process of the first insulating plate portion 12A and the second insulating plate portion 12B with the poles 14A and 14B, the first insulating plate portion 12A and the second insulating plate portion 12B are prone to twisting around the corresponding poles 14A and 14B. This may cause the long side of the first insulating plate portion 12A or the second insulating plate portion 12B to twist to a certain extent, resulting in interference when the battery cell is inserted into the casing, instability in the position of the Mylar and the lower plastic heat-fused parts, twisting of the lower insulating plate 12, and unstable position. It may also affect the sealing performance of the poles, and these problems are more obvious when the battery cell is long.

[0049] Figure 2A This is an exploded view of a cover plate assembly according to an embodiment of this application. Figure 2BThis is a bottom plan view of a cover plate assembly according to an embodiment of this application. Figure 2C This is a front view of a cover plate assembly and electrode assembly 900 according to an embodiment of this application. See also... Figures 2A to 2B As shown, the cover plate assembly 100 may include a cover plate 110, which has a first side 110S1 and a second side 110S2 disposed opposite to each other along direction Z (which may be referred to as 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 has a pole mounting hole 112A (which can be referred to as the first pole mounting hole) and a pole mounting hole 112B (which can be referred to as the second pole mounting hole). The pole mounting holes 112A and 112B extend from the first side 110S1 of the cover plate 110 to the second side 110S2.

[0050] The cover plate 110 extends longitudinally in the X direction. The terminal mounting holes 112A and 112B can be arranged opposite each other in the X direction. The cover plate 110 may also include an explosion-proof valve structure 114, which can be located between the terminal mounting holes 112A and 112B. In the event of thermal runaway in the battery cell, the explosion-proof valve structure 114 can directionally release pressure, allowing heat and ejected materials to be discharged to the outside of the battery cell, reducing the internal pressure and preventing an explosion caused by high internal pressure.

[0051] The cover plate assembly 100 also includes a lower insulating plate 150, which is located on the first side 110S1 of the cover plate and has through holes 151A (which can be referred to as the first through hole) and 151B (which can be referred to as the second through hole) corresponding to the pole mounting holes 112A and 112B. The lower insulating plate 150 extends longitudinally in the X direction, and the through holes 151A and 151B can be arranged opposite to each other in the X direction.

[0052] 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 the X direction may be greater than the length of the second insulating plate portion 154. Through holes 151A and 151B are respectively provided in the first insulating plate portion 152 and the second insulating plate portion 154. The lower insulating plate 150 may also include a plurality of holes 156 corresponding to the explosion-proof valve structure 114 for providing exhaust channels.

[0053] The cover plate assembly 100 also includes poles 220A (which may be referred to as the first pole) and 220B (which may be referred to as the second pole) with opposite polarities. In some embodiments, pole 220A is the positive pole and pole 220B is the negative pole. Alternatively, pole 220A can be the negative pole and pole 220B can be the positive pole.

[0054] The first electrode post 220A passes through the through hole 151A and the electrode post mounting hole 112A, and the second electrode post 220B passes through the through hole 151B and the electrode post mounting hole 112B. Additionally, upper insulating members 322A and 322B, as well as electrode terminals 224A and 224B, may be provided above the cover plate 110. The electrode posts 220A and 220B may also pass through the corresponding upper insulating members 322A and 322B and be connected to the corresponding electrode terminals 224A and 224B.

[0055] The lower insulating plate 150 includes a first side 150S1 and a second side 150S2 opposite each other in the X direction. The first side 150S1 faces away from the cover plate 110 and towards the electrode assembly 900, while the second side 150S2 faces the cover plate 110. The cover plate assembly 100 may also include electrical adapters 250A and 250B, which are disposed on the first side 150S1 of the lower insulating plate 150. Electrical adapter 250A electrically connects the terminal 220A to the electrode assembly 900, for example, by connecting a corresponding tab (e.g., a positive tab) of the electrode assembly 900. Electrical adapter 250B electrically connects the terminal 220B to the electrode assembly 900, for example, by connecting a corresponding tab (e.g., a negative tab) of the electrode assembly 900.

[0056] Figure 3A This is a bottom view of a pole according to an embodiment of this application. Figure 3B This is an isometric side view of a pole according to an embodiment of this application. Figure 3C This is a front view of a pole post according to an embodiment of this application. See also: Figures 3A to 3C As shown, the pole post 220A includes a body portion 225 and a columnar portion 227 connected to the body portion 225. The columnar portion passes through the through hole 151A and the pole post mounting hole 112A. The body portion 225 is located between the lower insulating plate 150 and the electrical adapter 250A.

[0057] In this embodiment, the body portion 225 includes a recessed portion 225R. The recessed portion 225R is recessed by the body portion 225 in a direction perpendicular to the Z direction. In some embodiments, the structure of the pole post 220B may be the same as that of the pole post 220A.

[0058] Figure 4A This is a bottom plan view of the lower insulating plate 150 according to an embodiment of this application. Figure 4B The image in the middle is an isometric side view of the lower insulating plate 150 according to an embodiment of this application. Figure 4A and Figure 4B The first side 150S1 of the lower insulating plate 150 facing the electrode assembly 900 is shown.

[0059] See Figure 4A and Figure 4BAs shown, the lower insulating plate 150 includes protrusions 150P. Each protrusion 150P protrudes in a direction perpendicular to the Z direction. The recess 225R of the pole piece engages with the corresponding protrusion 150P of the lower insulating plate 150.

[0060] By configuring the main body 225 of the pole posts 220A and 220B to have a recessed portion 225R that is recessed in a direction perpendicular to the Z direction, and the lower insulating plate 150 including a protrusion 150P that cooperates with the recessed portion 225R, the relative position of the cover plate 110 and the lower insulating plate 150 (e.g., relative position in the XY plane) is fixed, and the lower insulating plate 150 is prevented from twisting relative to the cover plate 110. Specifically, by preventing the lower insulating plate 150 from twisting, and avoiding the situation where the twisting of the lower insulating plate 150 causes the twisting of the terminals 220A and 220B, the sealing stability between the terminals 220A and 220B and the cover plate 110 can be improved, thereby enhancing the overall safety and airtightness of the battery. Furthermore, since the lower insulating plate 150 is fixed in position, it is convenient to position the insulating film (such as Mylar) used for the insulating shell and electrode assembly with the lower insulating plate 150 during the assembly process, and it is also convenient to fix the insulating components on the lower insulating plate 150. In addition, during the process of inserting the battery cell into the shell, the fixed position of the lower insulating plate 150 relative to the cover plate 110 can avoid interference between the lower insulating plate 150 and the shell, thereby improving assembly efficiency. At the same time, it also avoids the insulating components fixed to the lower insulating plate 150 from rubbing against the shell, improving the insulation effect between the insulating components and the shell. Furthermore, during production, transportation, supply chain delivery, and use, the relative position of the lower insulation plate 150 is kept in place to prevent the accumulation of particles from the battery cell, thereby reducing the risk of cell corrosion caused by particles and improving the battery's safety performance.

[0061] In some embodiments, the length of the cover plate 110 in the X direction ranges from 100mm to 350mm. In this case, the longer cell design results in a longer cover plate, necessitating multi-segment lower plastic to fix the cover plate 110, thereby achieving insulation between the cover plate 110 and the electrode assembly. In this situation, fixing the position of the lower insulating plate is more important. According to embodiments of this application, by configuring the electrode posts 220A and 220B with recesses 225R, and the lower insulating plate 150 including protrusions 150P that cooperate with the recesses 225R, the position of the longer cover plate 110 and the lower insulating plate 150 is fixed, preventing the lower insulating plate 150 from twisting relative to the longer cover plate 110, thereby effectively improving the battery's safety and airtightness, assembly efficiency, insulation effect of the insulating components, and battery safety.

[0062] In some embodiments, see Figures 3A to 3CAs shown, corresponding to the protrusion 150P, the projection of the recess 225R of the main body 225 of the pole post 220B in the Z direction includes at least an arc edge. The arc-shaped recess 225R has the advantage of being easy to process. The number of recesses 225R can be two to four. Figure 3A and Figure 3B (As shown in the example of four), if the number of the arc-shaped recesses is too small, it may be insufficient to prevent the lower insulating plate from twisting relative to the cover plate; if the number is too large, it will cause too much processing difficulty. By setting the number of arc-shaped recesses 225R to two to four, it is possible to ensure that the lower insulating plate is prevented from twisting relative to the cover plate while ensuring that the processing difficulty is not too great.

[0063] Specifically, the first insulating plate portion 152 and the second insulating plate portion 154 may each include a protrusion 150P. The protrusion 150P of the first insulating plate portion 152 mates with the recess 225R of the pole post 220A, and the protrusion 150P of the second insulating plate portion 154 mates with the recess 225R of the pole post 220B. The embodiments of this application will be described below mainly with reference to the mate between the protrusion 150P of the second insulating plate portion 154 and the recess 225R of the pole post 220B.

[0064] Figure 5A This is a bottom plan view of the second insulating plate portion 154 according to an embodiment of this application. Figure 5B The image shown is an isometric side view of the second insulating plate portion 154 according to an embodiment of this application. See also... Figure 5A and Figure 5B As shown, in this embodiment, the projection of the protrusion 150P in the Z direction is an arc edge. This arc-shaped protrusion 150P has the advantage of being easy to manufacture.

[0065] In some embodiments, the number of protrusions 150P in the second insulating plate portion 154 is two to four. Figure 5A and Figure 5B In the illustrated embodiment, the second insulating plate portion 154 has four protrusions 150P. If the number of these arc-shaped protrusions 150P is too small, it may be insufficient to prevent the lower insulating plate from twisting relative to the cover plate; if the number is too large, it will make processing too difficult. By setting the number of arc-shaped protrusions 150P to two to four, the processing difficulty can be reduced while ensuring that the lower insulating plate is prevented from twisting relative to the cover plate.

[0066] In other embodiments, the projection of the recess 225R of the poles 220A and 220B in the Z direction may include at least one edge. Correspondingly, the projection of the protrusion 150P of the lower insulating plate 150 in the Z direction may include at least one edge. Compared to protrusions and recesses with curved edges, protrusions and recesses with angular shapes provide better anti-torsion performance. In one embodiment, the number of edge-shaped recesses 225R and protrusions 150P may each be one. Since edge-shaped protrusions and recesses have better anti-torsion performance, one protrusion and one recess can be provided to cooperate with each other, which can further reduce the manufacturing difficulty.

[0067] In some embodiments, the length of the recess 225R of the poles 220A and 220B in the X direction is 1 / 15 to 1 / 8 of the length of the pole 220A in the X direction. Here, the length of the pole 220A refers to its maximum length. In embodiments where the pole is circular, the length of the pole 220A is its diameter. In some embodiments, the maximum length of the pole 220A is the maximum length of its body portion 225. If the above length ratio is too small, the length of the recess 225R will be too small, which may not effectively prevent the lower insulating plate from twisting relative to the cover plate. If the above length ratio is too large, the length of the recess 225R will be too large, resulting in excessive processing difficulty and high cost. A length ratio range of 1 / 15 to 1 / 8 ensures that the lower insulating plate can be prevented from twisting relative to the cover plate, while also being easy to process and low in cost.

[0068] In some embodiments, the length of the recess 225R of the poles 220A and 220B in the X direction ranges from 1.8 mm to 3.0 mm. This length range makes it easier to process the recess 225R and also provides good anti-torsion effect.

[0069] In some embodiments, the second insulating plate portion 154 protrudes from the first side 150S1 to form a receiving portion 158. At least a portion of the body portion 225 and the recessed portion 225R of the pole post 220B are located in the receiving portion 158. The sides of the body portion 225 and the recessed portion 225R facing the cover plate 110 are located in the receiving portion 158. In the XY plane, the receiving portion 158 has a shape that mates with the body portion 225 and the recessed portion 225R. Thus, by providing the receiving portion 158 that mates with the body portion 225 and the recessed portion 225R, the second insulating plate portion 154 not only mates with the recessed portion 225R, but also further mates with the shape of the body portion 225, which can further enhance the anti-torsion effect.

[0070] In some other embodiments, the body portion 225 of the poles 220A and 220B may also have other suitable shapes. In some other embodiments, the shape of the body portion 225 may be polymorphic, such as triangular or hexagonal (e.g., Figure 9 (as shown), or the shape of the body part 225 can be elliptical. These shapes of the body part 225 also have the advantages of being easy to process and having good anti-torsion effect.

[0071] See Figures 3A to 3C and combined Figure 5A and Figure 5B As shown, pole posts 220A and 220B have corresponding electrical adapters 250 embedded in the Z direction to achieve electrical connection between the pole posts and the electrical adapters. In some embodiments, pole posts 220A and 220B may also include regular portions 229 connected to the body portion 225 (see...). Figure 3C The regular portion 229 is connected to the side of the body portion 225 opposite to the columnar portion 227. The regular portion 229 refers to the irregular projection shape of the regular portion 229 onto the cover plate 110 along the Z direction relative to the body portion 225. The projection of the regular portion 229 onto the cover plate 110 along the Z direction has a regular graphic shape (e.g., circular). In some embodiments, the regular portions 229 of the poles 220A and 220B are embedded in the corresponding electrical adapters 250 in the Z direction. Since the poles and electrical adapters at least partially coincide in the thickness direction (Z direction), the space occupied by the poles and electrical adapters inside the cell can be reduced, thereby increasing the overall energy density of the cell. In some embodiments, the projection of the regular portion 229 onto the cover plate 110 in the Z direction is circular. The circular regular portion 229 is easier to process and facilitates embedding the regular portion 229 into the electrical adapter 250, improving assembly efficiency.

[0072] Combination Figure 2A As shown, electrical adapters 250A and 250B may each include a groove 251A and a groove 251B on the side facing downwards from the insulating plate 150, respectively. The shapes of grooves 251A and 251B can match the shapes of the regular portions 229 of the poles 220A and 220B. In some embodiments, the projections of grooves 251A and 251B in the Z direction are circular. The regular portions 229 of the poles 220A and 220B can be located in the corresponding grooves 251A and 251B.

[0073] Furthermore, the first insulating plate portion 152 and the second insulating plate portion 154 of the lower insulating plate 150 each have a protrusion 159 in the Z direction. The protrusion 159 can extend along the surface edge of the first side 150S1 of the corresponding first insulating plate portion 152 and the second insulating plate portion 154 to form a closed ring. The closed ring formed by the protrusion 159 can fit the shape of the corresponding electrical adapters 250A and 250B facing the surface of the lower insulating plate 150 (the surface where the grooves 251A and 251B are formed) and be embedded in the electrical adapters 250A and 250B. In addition, the closed ring has an opening in the middle, and the poles 220A and 220B pass through the corresponding opening and are embedded in the electrical adapters 250A and 250B, respectively. The protrusion 159 of the lower insulating plate 150 is embedded into the electrical adapter 250A and electrical adapter 250B in a shape-fitting manner. This can fix the relative positions of the terminals 220A and 220B, the lower insulating plate 150, and the electrical adapters 250A and 250B, preventing the lower insulating plate from twisting relative to the electrical adapters. This can further improve the battery's safety and airtightness, assembly efficiency, insulation effect of the insulating components, and battery safety.

[0074] In other embodiments, the first insulating plate 152 and the second insulating plate portion 154 are not embedded with electrical adapters 250A and 250B. The poles 220A and 220B directly pass through the openings and are embedded with electrical adapters 250A and 250B. This structure can reduce the difficulty of processing and save processing costs.

[0075] Figure 6A This is an exploded view of a cover plate assembly 200 according to another embodiment of this application. Figure 6B This is an isometric side view of a cover plate assembly 200 according to another embodiment of this application.

[0076] Figure 6C This is a bottom plan view of the lower insulating layer and pole of the cover plate assembly 200 according to another embodiment of this application. Figure 6D This is an isometric side view of the lower insulating layer and the pole of a cover plate assembly 200 according to an embodiment of this application. Figures 6A to 6D Several aspects of the cover plate assembly 200 of the illustrated embodiment are consistent with those described above. Figures 2A to 5B The cover assembly 100 is the same as described below; the main difference of the cover assembly 200 is described below.

[0077] See Figures 6A to 6DAs shown, pole piece 220A includes a protrusion 255P, and the corresponding first insulating plate portion 152 includes a matching recess 150R. Pole piece 220B includes a recess 225R, and the corresponding second insulating plate portion 154 includes a matching protrusion 150P. The protrusions 255P and 150P protrude in a direction perpendicular to the Z direction (e.g., direction X). The recesses 150R and 225R are recessed in a direction perpendicular to the Z direction (e.g., direction X).

[0078] By configuring the pole posts 220A, 220B and the corresponding first insulating plate portion 152 and second insulating plate portion 154 to have protrusions and recesses that cooperate with each other in a direction perpendicular to the Z direction, the relative position of the cover plate 110 and the lower insulating plate 150 (e.g., relative position in the XY plane) is fixed, and the lower insulating plate 150 is prevented from twisting relative to the cover plate 110. This design avoids the possibility of the terminals 220A and 220B being twisted due to the twisting of the lower insulating plate 150, thus improving the sealing stability between the terminals 220A and 220B and the cover plate 110, and consequently enhancing the overall safety and airtightness of the battery. Furthermore, the fixed position of the lower insulating plate 150 facilitates the positioning of the insulating film (e.g., Mylar) used for the insulating shell and electrode assembly during assembly, and also facilitates the fixing of insulating components to the lower insulating plate 150. Additionally, the fixed position of the lower insulating plate 150 relative to the cover plate 110 during cell insertion prevents interference between the lower insulating plate 150 and the shell, thereby improving assembly efficiency. It also prevents the insulating components fixed to the lower insulating plate 150 from rubbing against the shell, improving the insulation effect between the insulating components and the shell. Moreover, during production, transportation, supply chain delivery, and use, the relative position of the lower insulating plate 150 prevents the accumulation of particles from the battery cell, reducing the risk of cell corrosion caused by particles and improving battery safety.

[0079] More specifically, Figure 7A An isometric side view of oppositely polarized poles of a cover plate assembly according to another embodiment is shown. Figure 7B A bottom plan view of the first insulating plate portion and the second insulating plate portion of the cover plate assembly according to another embodiment is shown.

[0080] Combination Figure 7A As shown, pole posts 220A and 220B each include a body portion 225 and a columnar portion 227 connected to the body portion 225. The body portion 225 is a rhombus shape with rounded corners, specifically a square shape.

[0081] For pole post 220A, the body portion 225 of pole post 220A includes a protrusion 255P. In this embodiment, the protrusion 255P protrudes from the body portion 225 in the X direction. The body portion 225 is rhomboid with rounded corners (specifically, it can be square). The projection of the protrusion 255P in the Z direction may include at least one edge. In this embodiment, the projection of the protrusion 255P in the Z direction includes three edges, and the three edges are connected sequentially by rounded corners. This edge-shaped structure of the protrusion 255P, including the edges, can have better anti-torsion effect and is not difficult to manufacture.

[0082] In this embodiment, the number of protrusions 255P and corresponding recesses 150R in the body portion 225 is one. Having only one protrusion 255P and one recess 150R offers advantages such as ease of processing and low cost. In this embodiment, the number of recesses 225R and corresponding protrusions 150P in the pole post 220B is also one. Since the protrusion 255P, with its angular shape, provides better anti-torsion performance, only one protrusion is provided, which further reduces processing difficulty.

[0083] In some embodiments, the length of the protrusion 255P in the X direction is 1 / 15 to 1 / 8 of the length of the pole post 220A in the X direction. The length of the pole post 220A refers to its maximum length. In embodiments where the pole post is circular, the length of the pole post 220A is its diameter. In some embodiments, the maximum length of the pole post 220A is the maximum length of its body portion 225. If the above length ratio is too small, the length of the protrusion 255P will be too small, which may not effectively prevent the lower insulating plate from twisting relative to the cover plate. If the above length ratio is too large, the length of the protrusion 255P will be too large, resulting in excessive processing difficulty and high cost. A length ratio range of 1 / 15 to 1 / 8 ensures that the lower insulating plate can be prevented from twisting relative to the cover plate, while also being easy to process and low in cost.

[0084] In some embodiments, the length of the cover plate 110 in the X direction ranges from 100 mm to 350 mm. As described above, when the cell design is long, resulting in a long cover plate, fixing the position of the long cover plate 110 and the lower insulating plate 150 according to the embodiments of this application can prevent the lower insulating plate 150 from twisting relative to the long cover plate 110, thereby effectively improving the battery's safety and airtightness, assembly efficiency, insulation effect of the insulating component, and battery safety.

[0085] In some embodiments, the length of the protrusion 255P in the X direction ranges from 1.8 mm to 3.0 mm. This length range makes it easier to process the protrusion 255P and provides good anti-torsion effect.

[0086] For pole post 220B, the body portion 225 of pole post 220B includes a recessed portion 255R. In this embodiment, the recessed portion 255R is recessed by the body portion 225 in the X direction. The projection of the recessed portion 255R in the Z direction may include at least one edge. In this embodiment, the recessed portion 255R includes three edges, and the three edges are connected sequentially by rounded corners. This edge-shaped structure of the recessed portion 255R has the advantages of low processing difficulty, low cost, and good anti-torsion effect.

[0087] In some other embodiments, the body portion 225 of the pole posts 220A and 220B may also have other applicable shapes. For example, the shape of the body portion 225 may be polymorphic, such as triangular or hexagonal (e.g., Figure 9 (as shown), or the body part 225 can be elliptical. These shapes of the body part 225 also have the advantages of being easy to process and having good anti-torsion effect.

[0088] Combination Figure 7B As shown, the first insulating plate portion 152 protrudes from the first side 150S1 to form a receiving portion 158A. The receiving portion 158A has a recessed portion 150R. At least a portion of the body portion 225 and the protrusion 255P of the pole post 220A are located in the receiving portion 158A. The side of the body portion 225 and the protrusion 255P of the pole post 220A facing the cover plate 110 is located in the receiving portion 158A. In the XY plane, the receiving portion 158A has a shape that mates with the body portion 225 and the protrusion 255P. By providing a receiving portion that mates with the body portion 225 and the protrusion 255P, the first insulating plate portion 152 not only mates with the protrusion 255P, but also further mates with the shape of the body portion 225, which can further enhance the anti-torsion effect.

[0089] Similarly, the second insulating plate portion 154 protrudes from the first side 150S1 to form a receiving portion 158B. The receiving portion 158B has a protrusion 150P. At least a portion of the body portion 225 and the recessed portion 255R of the pole post 220B (e.g., the side facing the cover plate 110) is located in the receiving portion 158B. In the XY plane, the receiving portion 158B has a shape that mates with the body portion 225 and the recessed portion 255R, and the second insulating plate portion 154 also has a shape that mates with the body portion 225 and the recessed portion 255R, which can further enhance the anti-torsion effect.

[0090] In some embodiments, the first insulating plate portion 152 and the second insulating plate portion 154 each have a protrusion 159 in the Z direction. The protrusion 159 can extend along the surface edge of the first side 150S1 of the corresponding first insulating plate portion 152 and the second insulating plate portion 154 to form a closed ring. The closed ring formed by the protrusion 159 can fit the shape of the surface of the corresponding electrical adapter 250A and electrical adapter 250B facing the lower insulating plate 150 (the surface where the grooves 251A and 251B are formed) and be embedded in the electrical adapter 250A and electrical adapter 250B. In addition, the closed ring has an opening in the middle, and the poles 220A and 220B pass through the corresponding opening and are embedded in the electrical adapter 250A and electrical adapter 250B, respectively. The protrusion 159 of the lower insulating plate 150 is embedded into the electrical adapter 250A and electrical adapter 250B in a shape-fitting manner. This can fix the relative positions of the terminals 220A and 220B, the lower insulating plate 150, and the electrical adapters 250A and 250B, preventing the lower insulating plate from twisting relative to the electrical adapters. This can further improve the battery's safety and airtightness, assembly efficiency, insulation effect of the insulating components, and battery safety.

[0091] In other embodiments, the first insulating plate 152 and the second insulating plate portion 154 are not embedded with electrical adapters 250A and 250B, and the poles 220A and 220B are directly embedded with electrical adapters 250A and 250B through the openings. This structure can reduce the difficulty of processing.

[0092] Figure 8A This is an isometric side view of the electrical adapter 250A of the cover assembly 200 according to another embodiment of this application. Figure 8B This is an isometric side view of the pole post 220A of the cover plate assembly 200 according to another embodiment of this application. Figure 8A and Figure 8B The examples used are the electrical adapter 250A and the terminal 220A. Figure 8A and Figure 8BAs shown, in some embodiments, in direction Z, the side of the pole 220A facing away from the cover plate is embedded with the electrical adapter 250A. Specifically, the regular portion 229 of the pole 220A can be embedded in the electrical adapter 250A, and the body portion 225 and the protrusion 225P of the pole 220A connected to the side of the regular portion 229 can be embedded in the electrical adapter 250A. Since the body portion 225 and the regular portion 229 of the pole 220A coincide with the electrical adapter 250A at least partially in the thickness direction (direction Z), the space occupied by the pole and the electrical adapter inside the cell can be further reduced, thereby increasing the overall energy density of the cell. In some embodiments, the projection of the regular portion 229 on the cover plate 110 in direction Z is circular. The circular regular portion 229 is easier to process and facilitates embedding the regular portion 229 into the electrical adapter 250, which can improve assembly efficiency.

[0093] In some embodiments, the portion of the electrode post 220A embedded in the electrical adapter 250A coincides with the projection of the body portion 225 and the protrusion 225P of the electrode post 220A in the Z direction. Specifically, the electrical adapter 250A may include a groove 251A on the side facing the downward insulating plate 150. The sidewall of the groove 251A may have a recess 251R to mate with the shape of the body portion 225 and the protrusion 225P of the electrode post 220A, such that at least a portion of the body portion 225 and the protrusion 225P are embedded in the groove 251A in the Z direction. Embedding the protrusion 225P into the electrical adapter 250A, such that the protrusion 225P and the electrical adapter 250A cooperate with each other, can further play an anti-torsion role, ensuring that the relative positions of the electrode post 220A, the first insulating plate portion 152, and the electrical adapter 250A remain fixed. In addition, it can ensure that the electrical adapter 250A is set in a predetermined position, and that the angles between the two electrical adapters 250A and 250B are parallel, thus ensuring the superiority of the design.

[0094] The specific electrical adapter 250A may also include a through hole 253A located below the recess 251A. The shape of the through hole 253A can match the shape of the regular part 229 so that the regular part 229 of the pole post 220A can be inserted into the through hole 253A.

[0095] Combination Figure 8A As shown, in direction Z, the receiving portion 158A of the first lower insulating plate 152 is at least partially embedded in the electrical adapter 250A in a form-fit manner, for example, in the recess 251A. This ensures that the relative positions of the pole 220A, the first insulating plate portion 152, and the electrical adapter 250A remain fixed.

[0096] The above is for reference only. Figure 8A and Figure 8BThe configuration of electrical adapter 250A with pole 220A and first lower insulating plate 152 is described. It should be understood that electrical adapter 250B with pole 220B and second lower insulating plate 154 can have a similar configuration.

[0097] Embodiments of this application also provide a battery cell, which may include: a housing with an opening, an electrode assembly (such as electrode assembly 900) disposed within the housing, and a cover plate assembly (such as the cover plate assembly 100 or 200 described above) that seals the opening of the housing.

[0098] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A cover plate assembly for a secondary battery, characterized in that, include: The cover plate has pole mounting holes and has a first side and a second side disposed opposite to each other along a first direction, the first direction being the thickness direction of the cover plate; The lower insulating plate is located on the first side of the cover plate and has a through hole corresponding to the pole mounting hole; as well as The electrode post passes through the through hole and the electrode post mounting hole; In a second direction perpendicular to the first direction, one of the pole post and the lower insulating plate includes a protrusion, and the other of the pole post and the lower insulating plate includes a recess that cooperates with the protrusion. The pole post also includes a body portion, in which the protrusion is formed by the body portion or the recess is formed by the body portion in the second direction.

2. The cover plate assembly of the secondary battery according to claim 1, characterized in that, The projection of the protrusion toward the cover plate in a first direction includes at least one edge.

3. The cover plate assembly of the secondary battery according to claim 2, characterized in that, The number of protrusions is 1.

4. The cover plate assembly of the secondary battery according to claim 1, characterized in that, The projection of the protrusion onto the cover plate in a first direction is an arc edge.

5. The cover plate assembly of the secondary battery according to claim 4, characterized in that, The number of protrusions is two to four.

6. The cover plate assembly of the secondary battery according to claim 1, characterized in that, The length of the protrusion in the second direction is 1 / 15 to 1 / 8 of the length of the pole in the second direction.

7. The cover plate assembly of the secondary battery according to claim 6, characterized in that, The length of the protrusion in the second direction ranges from 1.8 mm to 3.0 mm.

8. The cover plate assembly of the secondary battery according to claim 1, characterized in that, The lower insulating plate protrudes on the side opposite to the cover plate to form a receiving portion, and at least a portion of the body portion and the protrusion or the body portion and the recess is located in the receiving portion. Wherein, in a plane perpendicular to the first direction, the receiving portion has a shape that mates with the body portion and the protrusion or the body portion and the recess.

9. The cover plate assembly of the secondary battery according to claim 8, characterized in that, Also includes: An electrical adapter is disposed on the side of the lower insulating plate facing away from the cover plate, and electrically connects the pole post to the electrode assembly. In the first direction, the receiving portion of the lower insulating plate is at least partially embedded in the electrical adapter in a form-fit manner.

10. The cover plate assembly of the secondary battery according to claim 8, characterized in that, The shape of the body portion is at least one of triangle, rhombus, and ellipse.

11. The cover plate assembly of the secondary battery according to claim 1, characterized in that, Also includes: An electrical adapter is disposed on the side of the lower insulating plate facing away from the cover plate, and electrically connects the pole post to the electrode assembly. In the first direction, the electrical adapter is embedded on the side of the pole facing away from the cover plate.

12. The cover plate assembly of the secondary battery according to claim 11, characterized in that, The portion of the electrode post embedded in the electrical adapter is projected in a circular shape on the cover plate.

13. The cover plate assembly of the secondary battery according to claim 11, characterized in that, The portion of the electrode post embedded in the electrical adapter coincides with the projection of the electrode post's body and protrusion or the electrode post's body and recess.

14. The cover plate assembly of the secondary battery according to any one of claims 1-13, characterized in that, The electrode mounting hole includes a first electrode mounting hole and a second electrode mounting hole; The through hole includes a first through hole corresponding to the first pole post mounting hole and a second through hole corresponding to the second pole post mounting hole; The electrode post includes a first electrode post and a second electrode post with opposite polarities. The first electrode post passes through the first through hole and the first electrode post mounting hole, and the second electrode post passes through the second through hole and the second electrode post mounting hole. In a second direction perpendicular to the first direction, the first electrode post includes a first protrusion, and the lower insulating plate includes a first recess that cooperates with the first protrusion; the second electrode post includes a second recess, and the lower insulating plate includes a second protrusion that cooperates with the second recess.

15. The cover plate assembly of the secondary battery according to any one of claims 1-13, characterized in that, The length of the cover plate ranges from 100mm to 350mm.

16. A battery cell, characterized in that, include: The shell has an opening; Electrode assembly, disposed within the housing; as well as The cover assembly as described in any one of claims 1-15, sealing the opening of the housing, the cover assembly including a lower insulating plate located on a first side of the cover near the electrode assembly.

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