Cover plate assembly, battery cell and battery

Abstract

The utility model provides a cover plate assembly, a battery cell and a battery, and relates to the technical field of batteries. The cover plate assembly comprises a cover plate, a lower plastic part, a pole and a tab insulating film; the lower plastic part is connected with the cover plate, and the lower plastic part is provided with a post terminal abdicating hole; the pole is fixedly arranged on the cover plate and penetrates through the pole abdicating hole; the pole column is provided with a pole lug connecting groove; and the tab insulating film is arranged on one side, deviating from the cover plate, of the lower plastic part and is configured to insulate and isolate the tab of the battery cell from the shell of the battery cell. According to the present invention, the tab connection groove is formed in the pole, such that the conductive connection sheet can be omitted so as to use the original space for arranging the conductive connection sheet for arranging the pole piece, and the tab and the pole can share a part of the height space so as to use the original part of the space for arranging the tab for arranging the pole piece. Therefore, the internal space utilization rate of the battery cell can be improved, so that the energy density of the battery cell can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a cover plate assembly, a battery cell and a battery. BACKGROUND

[0002] At present, higher energy demands are put forward for power batteries in all-scene use environments. To meet this demand, the space utilization rate of the battery cell is mainly improved to increase the space for accommodating the pole piece in the battery cell, thereby increasing the energy density of the battery cell.

[0003] In the related art, the battery cell includes a shell, an electrode assembly arranged in the shell, and a cover plate assembly for closing an opening of the shell. The cover plate assembly includes a cover plate and a positive pole and a negative pole penetrating the cover plate. The electrode assembly includes a positive pole piece, a separator and a negative pole piece arranged in sequence. The pole piece is connected to the corresponding pole by a conductive connecting piece. Due to the arrangement of the conductive connecting piece, there is a height difference between the pole piece and the pole to form a space for arranging the conductive connecting piece. Thus, the internal space utilization rate of the battery cell is low, which has an adverse effect on the energy density of the battery cell. UTILITY MODEL CONTENT

[0004] Embodiments of the present application provide a cover plate assembly, a battery cell and a battery, which can improve the internal space utilization rate of the battery cell.

[0005] In a first aspect, embodiments of the present application provide a cover plate assembly applied to a battery cell, which includes a cover plate, a lower plastic part, a pole and a tab insulating film. The lower plastic part is connected to the cover plate, and the lower plastic part is provided with a pole accommodation hole. The pole is fixed to the cover plate and penetrates the pole accommodation hole. An end of the pole close to the lower plastic part is provided with a tab connecting groove. The tab insulating film is arranged on a side of the lower plastic part away from the cover plate and is configured to insulate and isolate the tab of the battery cell from the shell of the battery cell.

[0006] In an embodiment, the peripheral side wall of the pole is provided with a flange, the flange is arranged adjacent to the slot opening of the tab connecting groove, and the flange is overlapped with the side of the lower plastic part away from the cover plate.

[0007] In an embodiment, the side of the lower plastic part away from the cover plate is provided with a sunken platform, the sunken platform is arranged around the periphery of the pole accommodation hole, and the flange is overlapped with the bottom wall of the sunken platform.

[0008] In an embodiment, the depth dimension of the sunken platform is consistent with the thickness dimension of the flange.

[0009] In an embodiment, the distance between the flange and the outer edge adjacent to the lower plastic part is X, which satisfies: 3mm≤X.

[0010] In an embodiment, the tab insulation film comprises a connecting portion connected with the lower plastic part and an isolation portion extending away from the cover plate, and the isolation portion is configured to insulate the tab of the battery cell from the shell of the battery cell.

[0011] In an embodiment, the distance between the end surface of the isolation portion away from the cover plate and the lower plastic part is H1, and H1 satisfies: H1≥20mm; or, the distance between the end surface of the isolation portion away from the cover plate and the lower plastic part is H1, and the height of the battery cell is H, and 0.2H≤H1≤0.8H is satisfied.

[0012] In an embodiment, the tab insulation film is hot-melt connected with the lower plastic part.

[0013] In an embodiment, in the direction away from the pole, the hot-melt connection part between the tab insulation film and the lower plastic part has a length L1, and L1 satisfies: L1≥3mm.

[0014] In an embodiment, the thickness of the tab insulation film is d, and 0.05mm≤d≤0.5mm is satisfied.

[0015] In an embodiment, the battery cell is a square shell battery cell, the isolation portion has two, and the two isolation portions are respectively located at the two ends of the connecting portion in the width direction of the square shell battery cell, and the isolation portion is connected with the edge adjacent to the connecting portion.

[0016] In an embodiment, the cover plate assembly further comprises a compression ring, an upper plastic part and a sealing ring, the compression ring is sleeved on the pole and is arranged away from the slot opening of the tab connecting groove, the upper plastic part is sleeved on the pole and is located between the compression ring and the cover plate, and the sealing ring is sleeved on the pole and seals the fitting part between the pole and the cover plate.

[0017] In a second aspect, an embodiment of the present application provides a battery cell, which comprises a shell, an electrode assembly, a tab and the aforementioned cover plate assembly; the shell has a receiving cavity; the electrode assembly is arranged in the receiving cavity; one end of the tab is connected with the electrode assembly; the cover plate is covered with the shell, the tab of the electrode assembly is located in the tab connecting groove and is connected with the inner wall of the tab connecting groove; the other end of the tab is located in the tab connecting groove and is connected with the inner wall of the tab connecting groove, and part of the tab insulation film is located between the tab and the shell.

[0018] In a third aspect, an embodiment of the present application provides a battery, which comprises a box assembly and the aforementioned battery cell; the box assembly has a mounting cavity; the battery cell has a plurality of, and the plurality of battery cells are connected in series and / or in parallel.

[0019] The beneficial effects of the embodiments of the present application are as follows:

[0020] In the embodiments of the present application, by arranging the tab connecting groove on the pole column, not only the conductive connecting piece can be saved, the space originally used for arranging the conductive connecting piece can be used for arranging the pole piece, but also the tab and the pole column can share a part of height space, so that the part of space originally used for arranging the tab can be used for arranging the pole piece. In this way, the internal space utilization rate of the battery cell can be improved, so that the energy density of the battery cell can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort.

[0022] Figure 1 is a structural schematic view of a cover plate assembly provided by an embodiment of the present application;

[0023] Figure 2 is a position schematic view of a tab insulating film provided by an embodiment of the present application;

[0024] Figure 3 is a structural schematic view of a pole column provided by an embodiment of the present application;

[0025] Figure 4 is Figure 1 is an enlarged view of A in FIG. 8;

[0026] Figure 5 is a top view of a tab insulating film provided by an embodiment of the present application;

[0027] Figure 6 is a structural schematic view of a tab insulating film provided by an embodiment of the present application;

[0028] Figure 7 is a structural schematic view of a battery cell provided by an embodiment of the present application;

[0029] Figure 8 is a structural schematic view of a battery provided by an embodiment of the present application.

[0030] BRIEF DESCRIPTION OF DRAWINGS

[0031] 1-cover plate assembly;

[0032] 11-cover plate; 111-first surface;

[0033] 12-lower plastic part; 121-pole column accommodation hole; 122-sink;

[0034] 13-pole column; 131-tab connecting groove; 132-flange;

[0035] 14-pole lug insulation film; 141-connection part; 142-isolation part; 143-pole post avoiding hole; 144-exhaust avoiding hole; 145-positioning hole; 146-liquid injection avoiding hole;

[0036] 15-hot melt connection part;

[0037] 16-pressing ring; 17-upper plastic part; 18-sealing ring;

[0038] 2-cell; 21-housing; 211- accommodating cavity; 22-electrode assembly; 23-pole lug;

[0039] 3-battery; 31-box assembly; 32-mounting cavity. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0041] In addition, it should be understood that the specific embodiments described herein are merely used to illustrate and explain the present application, and are not used to limit the present application. In the present application, the terms "first", "second" are used for description purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0042] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0043] The term "including", "containing" or any other variant thereof is intended to cover non-exclusive inclusion, so that the product including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or includes elements inherent to such product.

[0044] In the description of the embodiments of the present application, the words "example" or "for example" or like terms are used to mean illustrative, exemplary, or to provide an example or design solution. Any embodiment or design solution described as "example" or "for example" in the present application is not to be interpreted as being more preferred than another embodiment or design solution. The use of words such as "example" or "for example" is intended to present clearly relative concepts in a clear manner.

[0045] Please refer to Figure 1 , Figure 1 is a structural schematic diagram of a cover plate assembly 1 provided by an embodiment of the present application. The embodiment of the present application provides a cover plate assembly 1 applied to a battery cell. The cover plate assembly 1 comprises a cover plate 11, a lower plastic part 12, a pole 13, and a tab insulation film 14. The lower plastic part 12 is connected with the cover plate 11. The lower plastic part 12 is provided with a pole accommodating hole 121. The pole 13 is fixedly arranged on the cover plate 11 and penetrates through the pole accommodating hole 121. An end of the pole 13 close to the lower plastic part 12 is provided with a tab connecting groove 131. The tab insulation film 14 is arranged on a side of the lower plastic part 12 away from the cover plate 11 and is configured to insulate and isolate the tab of the battery cell from the shell 21 of the battery cell, as shown in Figure 2 , Figure 2 is a position schematic diagram of the tab insulation film 14 provided by an embodiment of the present application.

[0046] Specifically, the cover plate 11 has a first surface 111. The lower plastic part 12 is connected with the first surface 111.

[0047] The tab insulation film 14 can be glued with the lower plastic part 12, or can be hot-melt connected with the tab insulation film 14. The tab insulation film 14 can also be connected with the cover plate 11.

[0048] In addition, the tab of the battery cell is at least partially located in the tab connecting groove 131 and is welded with the inner wall of the tab connecting groove 131. Optionally, the tab is welded with the groove bottom of the tab connecting groove 131.

[0049] In the present embodiment, by arranging the tab connecting groove 131 on the pole 13, not only the conductive connecting piece can be saved, so that the space originally used for arranging the conductive connecting piece is used for arranging the pole piece, but also a part of the height space shared with the pole 13 can be used to arrange the tab piece. In this way, the internal space utilization rate of the battery cell can be improved, so that the energy density of the battery cell can be improved.

[0050] In addition, in some application environments, the battery cell needs to have more tabs, and correspondingly, the size of the tab post 13 needs to be larger. When there are more tabs, the size of the tab stack will be larger. In order to reduce the space occupied by the tabs, the tabs need to be bent and arranged. The radius of the tab bending increases as the size of the tab stack increases. When the radius of the tab bending is larger, the spacing between the outermost tab and the shell of the battery cell is smaller. In this way, the risk of short circuit caused by the contact between the tab and the shell is higher.

[0051] Based on this, in the embodiment, by arranging the tab insulating film 14, the insulation between the tab and the shell can be improved, thereby reducing the risk of short circuit caused by the contact between the tab and the shell, and further improving the reliability of the battery cell.

[0052] In addition, in the embodiment, part of the tab insulating film 14 is connected with the lower plastic part 12 or the cover plate 11, which plays a role in fixing the tab insulating film 14, and the other part is arranged between the tab and the shell of the battery cell, which plays a role in insulating and isolating the tab and the shell of the battery cell. In this way, the tab insulating film 14 has a simple structure, thereby effectively avoiding material waste and controlling the material cost of the battery cell.

[0053] Please refer to Figure 3 and Figure 4 , Figure 3 is a structural schematic diagram of the tab post 13 provided by the embodiment of the present application, Figure 4 is Figure 1 In an embodiment, the circumferential wall of the tab post 13 is provided with a flange 132. The flange 132 is arranged adjacent to the slot of the tab connecting groove 131. The flange 132 is overlapped with the side of the lower plastic part 12 away from the cover plate 11.

[0054] In the embodiment, by arranging the flange 132, on the one hand, when the tab is inserted into the tab connecting groove 131 and welded with the tab post 13, the flange 132 can support the part of the tab outside the tab connecting groove 131, so as to reduce the deformation of the tab during welding, thereby effectively ensuring the flatness of the contact part between the tab and the tab post 13, and further improving the welding reliability between the tab and the tab post 13. On the other hand, the cover plate 11 can clamp and fix the lower plastic part 12 in combination with the flange 132, thereby improving the positional stability of the lower plastic part 12, and further improving the structural reliability of the cover plate assembly 1.

[0055] Please refer to Figure 4In an embodiment, the lower plastic part 12 is provided with a sunken portion 122 on the side away from the cover plate 11. The sunken portion 122 is arranged around the periphery of the pole receiving hole 121, and the flange 132 overlaps the bottom wall of the sunken portion 122. In this way, the fitting structure between the pole 13 and the lower plastic part 12 can be increased, thereby improving the fitting between the lower plastic part 12 and the pole 13, and improving the structural reliability of the cover plate assembly 1.

[0056] In addition, by arranging the flange 132 in the sunken portion 122, the thickness of the part of the lower plastic part 12 where the sunken portion 122 is arranged can be increased. In this way, the thickness of other parts of the lower plastic part 12 can be controlled to control the amount of material and weight of the lower plastic part 12, and the thickness of the part of the lower plastic part 12 that fits with the pole 13 can be increased to reduce the thermal influence of the pole 13 on the lower plastic part 12 when the pole 13 is welded with the conductive member such as the tab or terminal.

[0057] Referring to Figure 4 In an embodiment, the depth of the sunken portion 122 is the same as the thickness of the flange 132. In this way, the part of the lower plastic part 12 adjacent to the sunken portion 122 is flush with the end face of the pole 13 where the tab connecting groove 131 is arranged, so that when the tab is inserted into the tab connecting groove 131 and welded with the pole 13, the part of the tab outside the tab connecting groove 131 can be supported by the part of the lower plastic part 12 adjacent to the sunken portion 122, so as to reduce the deformation of the tab during welding, thereby effectively ensuring the flatness of the contact part between the tab and the pole 13. In this way, the welding reliability between the tab and the pole 13 can be improved.

[0058] Referring to Figure 1 In an embodiment, the distance X between the flange 132 and the edge of the lower plastic part 12 adjacent to the flange 132 satisfies: 3mm≤X.

[0059] It can be understood that the arrangement of the flange 132 reduces the distance between the pole 13 and the shell 21. Therefore, in order to ensure the insulation distance between the pole 13 and the shell 21, the distance X between the flange 132 and the edge of the lower plastic part 12 adjacent to the flange 132 is limited to avoid the risk of short circuit caused by too small distance X, thereby improving the circuit reliability of the battery cell.

[0060] Referring to Figure 1 In an embodiment, the tab insulating film 14 includes a connecting part 141 and an isolation part 142 connected to each other. The connecting part 141 is connected to the lower plastic part 12. The isolation part 142 is arranged to extend away from the cover plate 11. The isolation part 142 is configured to insulate and isolate the tab of the battery cell from the shell 21 of the battery cell, as shown in Figure 2 In this way, the structure of the tab insulating film is simple, easy to manufacture, and can control the material cost.

[0061] Referring toFigure 1 In an embodiment, the distance between the end surface of the isolation portion 142 facing away from the cover plate 11 and the lower plastic member 12 is H1, and H1≥20mm is satisfied. Alternatively, the distance between the end surface of the isolation portion 142 facing away from the cover plate 11 and the lower plastic member 12 is H1, and the height dimension of the battery cell is H, and 0.2H≤H1≤0.8H is satisfied.

[0062] It can be understood that when H1≥20mm, the maximum value of H1 is basically required not to interfere with the bottom wall of the shell.

[0063] Here, the distance H1 between the end surface of the isolation portion 142 facing away from the cover plate 11 and the lower plastic member 12 specifically refers to the distance between the end surface of the isolation portion 142 facing away from the cover plate 11 and the part where the lower plastic member 12 is connected to the tab insulation film 14.

[0064] In the present embodiment, by limiting H1, the tab insulation film 14 can have an isolation portion 142 with sufficient length to improve the insulation between the tab and the shell.

[0065] Please refer to Figure 5 , Figure 5 is a top view of the tab insulation film 14 provided by the embodiment of the present application. In an embodiment, the tab insulation film 14 is connected to the lower plastic member 12 by thermal fusion. In this way, not only is there no need to use adhesives such as glue, thereby avoiding aging or connection failure due to the passage of time, but also the thermal fusion connection makes the lower plastic member 12 and the tab insulation film 14 melt into one body by heating, so that the connection is more solid.

[0066] In an embodiment, in the direction away from the pole 13, the thermal fusion connection portion 141 between the tab insulation film 14 and the lower plastic member 12 has a length dimension L1, and L1≥3mm is satisfied. In this way, the reliability of the thermal fusion connection between the tab insulation film 14 and the lower plastic member 12 can be ensured.

[0067] It can be understood that the maximum value of the dimension L1 of the thermal fusion connection portion 141 is basically required not to interfere with other components of the cover plate assembly 1.

[0068] Please refer to Figure 1 In an embodiment, the thickness dimension of the tab insulation film 14 is d, and 0.05mm≤d≤0.5mm is satisfied.

[0069] It can be understood that the thickness dimension d of the tab insulation film 14 includes but is not limited to 0.05mm, 0.06mm, 0.8mm, 0.1mm, 0.15mm, 0.19mm, 0.2mm, 0.25mm, 0.28mm, 0.3mm, 0.36mm, 0.4mm, 0.45mm, 0.5mm.

[0070] In the embodiment, by limiting the thickness dimension d of the tab insulation film 14, on one hand, the tab insulation film 14 can have appropriate strength to meet the insulation requirement; on the other hand, the thickness of the tab insulation film 14 can be prevented from being too large to cause unnecessary cost increase.

[0071] Referring to Figure 6 , Figure 6 is a structural schematic diagram of the tab insulation film 14 assembled to the battery cell 2 provided by the embodiment of the present application. In an embodiment, the battery cell is a square cell. The isolation part 142 has two. Along the width direction of the square cell, the two isolation parts 142 are respectively located at the two ends of the connecting part 141. The isolation part 142 is connected to the edge adjacent to the connecting part 141.

[0072] It can be understood that in the square cell, the tab is parallel to the large face of the square cell before being bent, that is, the tab is perpendicular to the width direction of the square cell before being bent. When the tab is bent, the end of the tab is bent around the root of the tab towards the electrode assembly. In this way, the root of the tab is protruded along the width direction to the shell due to the bending, thereby causing the distance between the root of the tab and the shell in the width direction of the battery to be small.

[0073] Based on this, in the embodiment, by arranging the isolation part 142 along the width direction of the square cell, when the cover plate assembly 1 is applied to the square cell, not only the insulation between the tab and the shell can be effectively ensured, but also the structure of the tab insulation film 14 can be simple and easy to manufacture.

[0074] Among them, the connecting part 141 is provided with a pole 13 avoiding hole, an exhaust avoiding hole 144, a liquid injection avoiding hole 146 and a positioning hole 145. It can be understood that the pole 13 avoiding hole is used to avoid the pole 13, so as to facilitate the connection of the pole 13 and the tab. The exhaust avoiding hole 144 is used for the gas inside the battery cell 2 to pass through, so as to facilitate the battery cell to exhaust and release pressure through the explosion-proof valve. The liquid injection avoiding hole 146 facilitates the electrolyte to pass through the positioning hole 145 to cooperate with the positioning column on the lower plastic part 12, so that the tab insulation film 14 can be quickly positioned on the lower plastic part 12, so as to improve the assembly efficiency.

[0075] Referring to Figure 1 In an embodiment, the cover plate assembly 1 further includes a compression ring 16, an upper plastic part 17 and a sealing ring 18. The compression ring 16 is sleeved on the pole 13 and is arranged away from the notch of the tab connecting groove 131. The upper plastic part 17 is sleeved on the pole 13 and is located between the compression ring 16 and the cover plate 11. The sealing ring 18 is sleeved on the pole 13 and seals the cooperation part between the pole 13 and the cover plate 11.

[0076] The compression ring 16 is welded to the pole 13 and cooperates with the flange 132 to fix the pole 13 to the cover plate 11. The sealing ring 18 is located between the flange 132 and the cover plate 11 and is in a compressed state, thereby forming a sealing surface between the contact surface of the sealing ring 18 and the cover plate 11 and between the contact surface of the sealing ring 18 and the flange 132.

[0077] Please refer to Figure 7 , Figure 7 is a structural schematic diagram of an electric core 2 provided by an embodiment of the present application. Accordingly, an embodiment of the present application provides an electric core 2. The electric core 2 comprises a shell 21, an electrode assembly 22, a tab 23, and the aforementioned cover plate assembly 1. The shell 21 has a receiving cavity 211. The electrode assembly 22 is arranged in the receiving cavity 211. One end of the tab 23 is connected to the electrode assembly 22. The cover plate 11 is covered with the shell 21. The tab 23 of the electrode assembly 22 is located in the tab connecting groove 131 and connected to the inner wall of the tab connecting groove 131. The other end of the tab 23 is located in the tab connecting groove 131 and connected to the inner wall of the tab connecting groove 131. The tab insulating film 14 is located between the tab 23 and the shell 21.

[0078] Specifically, the isolation portion 142 is located between the tab 23 and the shell 21.

[0079] It can be understood that the electrode assembly 22 comprises a positive electrode sheet, a separator, and a negative electrode sheet arranged in sequence. In the wound electrode assembly 22, the positive electrode sheet, the separator, and the negative electrode sheet are arranged in sequence and wound.

[0080] The pole 13 comprises a positive pole and a negative pole, and the tab 23 comprises a positive tab and a negative tab. The positive tab is connected to the positive electrode sheet and the positive pole, and the negative tab is connected to the negative electrode sheet and the negative pole.

[0081] Optionally, the electric core 2 is a square shell electric core. There are two electrode assemblies 22, and the two electrode assemblies 22 are arranged along the width direction of the square shell electric core. The positive tab of one electrode assembly 22 is connected to one side of the inner wall of the tab connecting groove 131 of the positive pole, and the positive tab of the other electrode assembly 22 is connected to the other side of the inner wall of the tab connecting groove 131 of the positive pole. The negative tab of one electrode assembly 22 is connected to one side of the inner wall of the tab connecting groove 131 of the negative pole, and the negative tab of the other electrode assembly 22 is connected to the other side of the inner wall of the tab connecting groove 131 of the negative pole.

[0082] In this embodiment, by adopting the cover plate assembly 1 disclosed by some embodiments of the present application, not only the conductive connecting piece can be omitted, and the space originally used for arranging the conductive connecting piece can be used for arranging the electrode sheet, but also the tab 23 and the pole 13 can share a part of the height space, and the part of the space originally used for arranging the tab 23 can be used for arranging the electrode sheet. In this way, the internal space utilization rate of the electric core 2 can be improved, and thus the energy density of the electric core 2 can be improved.

[0083] Please refer to Figure 8 , Figure 8 is a structural schematic diagram of a battery 3 provided by embodiments of the present application. Accordingly, embodiments of the present application also provide a battery 3, which comprises a box assembly 31 and the aforementioned battery cell 2. The box assembly 31 has a mounting cavity 32. The battery cell 2 is in plurality, and the plurality of battery cells 2 are connected in series and / or in parallel.

[0084] In the present embodiment, by using the battery cell 2 disclosed by some embodiments of the present application, not only the conductive connecting piece can be saved, so that the space originally used for arranging the conductive connecting piece can be used for arranging the tab, but also the tab 23 and the pole 13 can share a part of the height space, so that the space originally used for arranging the tab 23 can be used for arranging the tab. In this way, the internal space utilization rate of the battery cell 2 can be improved, so that the energy density of the battery 3 can be improved.

[0085] The above has carried out the detailed introduction to the embodiments of the present application, the principle and implementation mode of the present application have been described in this paper by applying specific examples, the above embodiment is only used for helping to understand the method of the present application and its core idea; At the same time, for those skilled in the art, according to the idea of the present application, the specific implementation mode and application range will be changed; In view of the above, the content of the specification should not be understood as the limitation of the present application.

Claims

1. A cover plate assembly applied to an electric cell, characterized in that, The cover plate assembly comprises: a cover plate; a lower plastic part connected with the cover plate, the lower plastic part being provided with a pole post accommodating hole; a pole post fixedly arranged on the cover plate and penetrating through the pole post accommodating hole, the pole post being provided with a pole tab connecting groove at one end close to the lower plastic part; a pole tab insulating film arranged on a side of the lower plastic part away from the cover plate and configured to insulate and separate the pole tab of the battery cell from the shell of the battery cell.

2. The cover plate assembly of claim 1, wherein, The pole post is provided with a flange on a circumferential wall thereof, the flange being arranged adjacent to a slot opening of the pole tab connecting groove, and the flange is overlapped with the side of the lower plastic part away from the cover plate.

3. The cover plate assembly of claim 2, wherein, The side of the lower plastic part away from the cover plate is provided with a sunken platform, the sunken platform being arranged around a periphery of the pole post accommodating hole, and the flange is overlapped with a bottom wall of the sunken platform.

4. The cover plate assembly of claim 3, wherein, The depth dimension of the sunken platform is consistent with the thickness dimension of the flange.

5. The cover plate assembly of any one of claims 2-4, wherein, The distance between the flange and the outer edge of the lower plastic part adjacent to the flange is X, and 3mm≤X.

6. The cover plate assembly of any one of claims 1-4, wherein, The pole tab insulating film comprises a connecting portion connected with the lower plastic part and a separating portion arranged in a direction away from the cover plate, the separating portion being configured to insulate and separate the pole tab of the battery cell from the shell of the battery cell.

7. The cover plate assembly of claim 6, wherein, The distance between an end surface of the separating portion away from the cover plate and the lower plastic part is H1, and H1≥20mm. Alternatively, the distance between the end surface of the separating portion away from the cover plate and the lower plastic part is H1, and the height dimension of the battery cell is H, and 0.2H≤H1≤0.8H.

8. The cover plate assembly of claim 6, wherein, The pole tab insulating film is hot-melt connected with the lower plastic part.

9. The cover plate assembly of claim 8, wherein, In a direction away from the pole post, the hot-melt connection portion between the pole tab insulating film and the lower plastic part has a length dimension L1, and L1≥3mm.

10. The cover plate assembly of any one of claims 7-9, wherein, The thickness dimension of the pole tab insulating film is d, and 0.05nmm≤d≤0.5mm.

11. The cover plate assembly of any one of claims 7-9, wherein, The battery cell is a square shell battery cell, the separating portion has two, and the two separating portions are respectively located at two ends of the connecting portion in a width direction of the square shell battery cell, and the separating portion is connected with edges of the connecting portion adjacent to the separating portion.

12. The cover plate assembly of any one of claims 1-4, wherein, The cover plate assembly further comprises a compression ring, an upper plastic part and a sealing ring, the compression ring is sleeved on the pole post and is arranged away from the slot opening of the pole tab connecting groove, the upper plastic part is sleeved on the pole post and is located between the compression ring and the cover plate, and the sealing ring is sleeved on the pole post and seals a fitting portion between the pole post and the cover plate.

13. An electric cell characterized by The cover plate assembly comprises: a shell having a receiving cavity; an electrode assembly arranged in the receiving cavity; a pole tab having one end connected with the electrode assembly; and the cover plate assembly according to any one of claims 1-12, the cover plate being covered with the shell, the pole tab of the electrode assembly being located in the pole tab connecting groove and being connected with an inner wall of the pole tab connecting groove; wherein the other end of the pole tab is located in the pole tab connecting groove and is connected with the inner wall of the pole tab connecting groove, and part of the pole tab insulating film is located between the pole tab and the shell.

14. A battery, characterized by The cover plate assembly comprises: a box assembly having a mounting cavity; And, the battery cell as set forth in claim 13, wherein a plurality of the battery cells are provided, and the plurality of the battery cells are connected in series and / or in parallel.

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