Battery cell assembly and battery pack

Abstract

According to the battery cell assembly and the battery pack provided by the utility model, the first pole pieces are provided with the bending parts extending along the second direction of the shell, the bending parts are attached to the heat-conducting insulating sheet, and the bending parts of at least two adjacent first pole pieces are connected, so that the contact area of the first pole pieces and the heat-conducting insulating sheet is increased, the heat dissipation effect is improved, and the battery cell assembly is convenient to assemble and disassemble. Therefore, the technical problem that the temperature is high in the charging and discharging process of the cell assembly is solved. The utility model further provides a battery pack, the battery cell assembly is installed in the battery pack, and the use safety of the battery pack can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and in particular to a battery core assembly and a battery pack. Background Art

[0002] In the related art, the temperature inside the core pack rises seriously during high-power charging and discharging of the battery. Excessive temperature will have an adverse effect on the chemical reaction of the battery, which will not only reduce the performance of the battery, affect the battery life, but also increase the safety risks of the battery. Utility Model Content

[0003] The embodiments of the utility model provide a battery cell assembly and a battery, which can improve the technical problem of high temperature during the charging and discharging process of the existing battery cell assembly.

[0004] In a first aspect, an embodiment of the present invention provides a battery cell assembly.

[0005] The battery cell components include:

[0006] A shell having a chamber therein, wherein the shell comprises a shell bottom wall;

[0007] A heat-conducting insulating sheet is arranged on a side of the bottom wall of the shell facing the chamber;

[0008] A battery cell body is arranged in the chamber, the battery cell body includes a first pole piece and a second pole piece which are staggered and stacked, the battery cell body also includes a diaphragm arranged between the first pole piece and the second pole piece, each of the first pole pieces includes a main body portion and a bending portion which are connected to each other, the main body portion extends along a first direction of the shell, the bending portion extends along a second direction of the shell, the first direction intersects with the second direction, the bending portion is attached to the thermally conductive insulating sheet, and the bending portions of at least two adjacent first pole pieces are connected.

[0009] In one embodiment, the bent portion of each first pole piece is at least partially connected to the bent portion of another first pole piece.

[0010] In one embodiment, the bent portions of any two adjacent first pole pieces are at least partially connected and form a plane as a whole.

[0011] In one embodiment, among two adjacent first pole pieces, the bent portion of one first pole piece at least partially overlaps the bent portion of the other first pole piece.

[0012] In one embodiment, the battery cell body includes a first lamination unit, a second lamination unit and a third lamination unit arranged in sequence, the bending portion of the second lamination unit is at least partially overlapped with the bending portion of the first lamination unit, and the bending portion of the third lamination unit is at least partially overlapped with the bending portion of the second lamination unit.

[0013] In one embodiment, the battery cell body includes a first lamination unit, a second lamination unit and a third lamination unit arranged in sequence, the bending portion of the second lamination unit is at least partially overlapped with the bending portion of the first lamination unit, the bending portion of the third lamination unit is overlapped with the bending portion of the second lamination unit, and at least partially overlapped with the bending portion of the first lamination unit.

[0014] In one embodiment, the housing includes two housing side walls arranged opposite to each other in the second direction of the housing, and the bent portion of each first pole piece extends toward the same housing side wall of the housing. In one embodiment, the second pole piece includes an end facing the thermally conductive insulating sheet, the end is spaced apart from the bent portion, and one end of the diaphragm facing the thermally conductive insulating sheet is arranged between the bent portion and the end to isolate the second pole piece from the bent portion.

[0015] In one embodiment, the diaphragm includes a first barrier segment and a second barrier segment, the first barrier segment extends in a first direction of the shell, the second barrier segment is connected to the first barrier segment and extends in a second direction of the shell, and the second barrier segment is arranged between the end and the bending portion; and / or

[0016] The diaphragm and the second pole piece are arranged along the first direction of the shell, the second pole piece is sandwiched between the two diaphragms, and along the first direction of the shell, the distance from the end to the bottom wall of the shell is greater than the distance from the diaphragm to the bottom wall of the shell.

[0017] In one embodiment, the main body includes a first part and a second part, the first part is provided with a conductive coating, the second part is connected to an end of the first part close to the bottom wall of the shell, and the bending portion is connected to an end of the second part close to the bottom wall of the shell.

[0018] In one embodiment, the battery cell assembly further includes an insulating film, the battery cell body includes a body bottom wall and a body side wall surrounding the body bottom wall, and the insulating film is coated on the body side wall and on the periphery of the body bottom wall.

[0019] In one embodiment, the bottom wall of the body includes a middle area and a peripheral area, the peripheral area surrounds the middle area, the insulating film includes a ring edge covering the peripheral area, the ring edge is arranged around the middle area, and the width of the ring edge is between 1mm-20mm; and / or

[0020] The insulating film is a PET film or a PI film. In a second aspect, an embodiment of the utility model provides a battery pack, the battery pack comprising the battery cell assembly as described above.

[0021] Beneficial effects of the embodiments of the utility model:

[0022] In an embodiment of the utility model, each first pole piece includes a main body and a bent portion connected to each other, the main body extending along the first direction of the shell, the bent portion extending along the second direction of the shell, the bent portion attached to the thermally conductive insulating sheet, and the bent portions of two adjacent first pole pieces are connected to increase the contact area between the first pole piece and the thermally conductive insulating sheet, improve the heat dissipation effect, and thus improve the technical problem of high temperature during the charging and discharging process of the battery cell assembly. The present application also provides a battery pack, the aforementioned battery cell assembly is installed in the battery pack, which can avoid excessive temperature of the battery pack and improve the safety of the battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 It is a structural schematic diagram of a battery core assembly provided in an embodiment of the utility model.

[0025] Figure 2 yes Figure 1 The structural schematic diagram of the battery cell body is shown.

[0026] Figure 3 yes Figure 1 A first cross-sectional schematic diagram of a battery cell assembly is shown.

[0027] Figure 4 yes Figure 1 A cross-sectional schematic diagram of a second type of battery cell assembly is shown.

[0028] Figure 5 yes Figure 1 A third cross-sectional schematic diagram of a battery cell assembly is shown.

[0029] Figure 6 yes Figure 1 A schematic cross-sectional view of a fourth type of battery cell assembly is shown.

[0030] Figure 7 yes Figure 1 A fifth cross-sectional schematic diagram of a battery cell assembly is shown.

[0031] Figure 8 yes Figure 1 A sixth cross-sectional schematic diagram of a battery cell assembly is shown.

[0032] Fig. 9 yes Figure 1 A schematic structural diagram of the first pole piece is shown.

[0033] Fig.10 yes Figure 1 Another structural schematic diagram of the battery cell body is shown.

[0034] Reference numerals

[0035] 100. Battery cell assembly;

[0036] 10. Shell; 11. Shell bottom wall; 12. Shell side wall;

[0037] 20. Thermally conductive insulating sheet;

[0038] 30, battery cell body; 301, body bottom wall; 302, body side wall; 31, first pole piece; 311, main body; 3111, first part; 3112, second part; 312, bending part; 32, second pole piece; 33, diaphragm; 331, first barrier section; 332, second barrier section;

[0039] 40. Insulating film; 41. Ring edge;

[0040] 50. Tab; 51. Tab foil;

[0041] 60. Connecting piece;

[0042] 70. End cap. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the utility model, and are not used to limit the utility model. In the utility model, unless otherwise stated, the directional words used, such as "upper" and "lower", generally refer to the upper and lower parts of the device in actual use or working state, specifically the drawing direction in the accompanying drawings; while "inside" and "outside" refer to the outline of the device.

[0044] In the related art, since the temperature inside the core pack rises seriously during high-power charging and discharging of the battery, the excessively high temperature will have an adverse effect on the chemical reaction of the battery, which will not only reduce the performance of the battery and affect the battery life, but also increase the safety risks of the battery.

[0045] Please refer to Figure 1 , Figure 1It is a schematic diagram of the structure of the battery cell assembly provided by an embodiment of the utility model. The present application provides a battery cell assembly 100, which includes a shell 10, a thermally conductive insulating sheet 20 and a battery cell body 30. A chamber is provided in the shell 10, and the battery cell body 30 is provided in the chamber. The battery cell body 30 can be a flat winding structure, that is, a structure with a straight middle and arc transitions at both ends formed by stacking the positive electrode sheet, the diaphragm and the negative electrode sheet first and then bending and winding. It can also be a laminated structure, that is, a structure formed by stacking the positive electrode sheet, the diaphragm and the negative electrode sheet, which is not limited in the present application. The shell 10 includes a shell bottom wall 11, and the thermally conductive insulating sheet 20 is arranged on the side of the shell bottom wall 11 facing the chamber. The thermally conductive insulating sheet 20 can be an insulating material with good thermal conductivity. The thermally conductive insulating sheet 20 is pressed and tightly attached to the shell bottom wall 11 during installation, and is used to transfer the heat of the battery cell body 30 to the shell 10.

[0046] Please refer to Figure 2 , Figure 3 , Figure 2 yes Figure 1 The schematic diagram of the structure of the battery cell body is shown in FIG. Figure 3 yes Figure 1 The first cross-sectional schematic diagram of the battery cell assembly is shown. The battery cell body 30 includes a plurality of first pole pieces 31 and a plurality of second pole pieces 32 that are staggered and stacked, and the battery cell body 30 also includes a diaphragm 33 disposed between adjacent first pole pieces 31 and second pole pieces 32, and the diaphragm 33 is used to isolate the first pole piece 31 and the second pole piece 32. The battery cell body 30 includes two interconnected battery cell monomers, that is, each battery cell monomer includes a plurality of first pole pieces 31, a second pole piece 32, and a diaphragm 33 isolated between the first pole piece 31 and the second pole piece 32, and the diaphragm 33 is used to reduce the risk of short circuit between the positive pole piece and the negative pole piece, and the material of the diaphragm 33 can be polyethylene, polypropylene, etc., and the present application does not limit the material of the diaphragm 33.

[0047] It can be understood that, in some embodiments, the first pole piece 31 is a positive pole piece, and the second pole piece 32 is a negative pole piece; in other embodiments, the first pole piece 31 is a negative pole piece, and the second pole piece 32 is a positive pole piece.

[0048] The first pole piece 31 includes a main body portion 311 and a bending portion 312 which are connected to each other. The main body portion 311 is extended along the first direction of the shell 10, and the bending portion 312 is extended along the second direction of the shell 10. The first direction intersects with the second direction, and the bending portion 312 is attached to the thermally conductive insulating sheet 20, and the bending portions 312 of at least two adjacent first pole pieces 31 are connected. Specifically, the first direction is the length direction of the battery cell body 30, and the second direction is the width direction of the battery cell body 30. In some embodiments, the first direction is perpendicular to the second direction, and the bonding area of ​​the bending portion 312 is the largest. In some other embodiments, the first direction may not be perpendicular to the second direction, such as when the angle between the first direction and the second direction is between 80° and 100°.

[0049] Each first pole piece 31 includes a first pole tab foil 51, the first pole tab foil 51 is connected to one end of the main body 311 away from the bottom wall 11 of the housing, and the bent portion 312 is connected to the other end of the main body 311. The housing 10 also includes an end cover 70, on which a pole is provided, and a plurality of first pole tab foils 51 are connected to form a first pole tab 50, and connected to the pole through a connecting sheet 60, which is a common structure of a battery and will not be described in detail here.

[0050] The bending portion 312 can be flattened to fit the bending portion 312 and the thermally conductive insulating sheet 20. Flattening refers to deforming the bottom edge of the pole piece by extrusion to form a plane, so as to change the extension direction of the bending portion 312 relative to the main body 311. Flattening can eliminate the deformation of the pole piece caused by temperature, strength and other aspects during use, so that the battery cell can operate in a more stable state. Compared with the related art, by fitting the bending portion 312 and the thermally conductive insulating sheet 20, the contact area between the bending portion 312 and the thermally conductive insulating sheet 20 can be increased, thereby increasing the heat dissipation effect. The bending portions 312 of two adjacent first pole pieces 31 are connected to ensure the continuity of the fitting surface and further improve the heat dissipation effect.

[0051] In some embodiments, the thickness of the thermally conductive insulating sheet 20 is between 0.1 mm and 2.0 mm. If the thermally conductive insulating sheet 20 is too thin, it may affect the reliability of insulation, while if it is too thick, it will waste the internal space of the battery and cause the energy density of the battery to decrease. Specifically, the thickness of the thermally conductive insulating sheet 20 can be 0.2 mm, 0.4 mm, 0.6 mm, 0.8 mm, 1.0 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, 2.0 mm, etc., and the present application does not limit the specific value here.

[0052] It is understandable that the entire bent portion 312 is attached to the thermally conductive insulating sheet 20 to better ensure the attachment area. However, in some embodiments, most of the bent portion 312 is attached to the thermally conductive insulating sheet 20, and a small portion extends away from the thermally conductive insulating sheet 20 and connects to the bent portion 312 of another adjacent pole piece.

[0053] Please continue to refer to Figure 3 In some embodiments, some adjacent two bending portions 312 are connected, and other adjacent two bending portions 312 are not connected. For example, the battery cell body includes a plurality of lamination units, such as a first lamination unit, a second lamination unit, and a third lamination unit, which are arranged in sequence. Each lamination unit includes a first pole piece 31, a diaphragm 33, and a second pole piece 32. The bending portions 312 of the first lamination unit and the second lamination unit are connected, and the bending portions 312 of the third lamination unit and the fourth lamination unit are not connected to other bending portions 312. There may also be five or six lamination units, and the number of bending portions 312 increases accordingly. The application does not limit the specific number here.

[0054] Please refer to Figure 4 , Figure 4 yes Figure 1 The cross-sectional schematic diagram of the second type of battery cell assembly shown. In some embodiments, the bend portion 312 of each first pole piece 31 is at least partially connected to the bend portion 312 of another first pole piece 31. For example, the battery cell body 30 includes a plurality of laminate units, such as a first laminate unit, a second laminate unit, and a third laminate unit, which are arranged in sequence. Each laminate unit includes a first pole piece 31, a diaphragm 33, and a second pole piece 32. The bend portions 312 of the first laminate unit and the second laminate unit are connected, the bend portion 312 of the third laminate unit is not connected to the bend portions 312 of the first laminate unit and the second laminate unit, and the bend portion 312 of the fourth laminate unit is at least partially connected to the bend portions 312 of the first laminate unit, the second laminate unit, and the third laminate unit. Specifically, the bending portion 312 of the fourth lamination unit is partially connected to the bending portion 312 of the third lamination unit, and is not connected to the bending portion 312 of the second lamination unit and the first lamination unit; the bending portion 312 of the fourth lamination unit is stacked on the bending portion 312 of the third lamination unit, and is partially connected to the bending portion 312 of the second lamination unit; the bending portion 312 of the fourth lamination unit is stacked on the bending portions 312 of the third lamination unit and the second lamination unit, and is partially connected to the bending portion 312 of the first lamination unit. The number of lamination units can also be five, six, etc., and the number of bending portions 312 increases accordingly. The present application does not limit the specific number here.

[0055] Please refer to Figure 5 , Figure 5 yes Figure 1The third cross-sectional schematic diagram of the battery cell assembly shown. In some embodiments, the bending portions 312 of any two adjacent first pole pieces 31 are at least partially connected, and the whole forms a plane. For example, the battery cell body 30 includes a plurality of lamination units, such as a first lamination unit, a second lamination unit, and a third lamination unit, arranged in sequence, each lamination unit includes a first pole piece 31, a diaphragm 33, and a second pole piece 32. The bending portions 312 of the first lamination unit and the second lamination unit are connected, and the bending portion 312 of the third lamination unit is connected to the bending portion 312 of the second lamination unit to form a continuous plane. In this scheme, the plane area formed by the multiple bending portions 312 is the largest, and the heat dissipation effect is the best. There can also be four, five, six, etc. lamination units, and the number of bending portions 312 increases accordingly. The present application does not limit the specific number here.

[0056] In some embodiments, among two adjacent first pole pieces 31 , the bending portion 312 of one first pole piece 31 is at least partially overlapped on the bending portion 312 of the other first pole piece 31 , and the overlapping can further ensure the connection effect between the bending portions 312 .

[0057] Specifically, please refer to Figure 6-Figure 7 , Figure 6 yes Figure 1 A fourth cross-sectional schematic diagram of a battery cell assembly is shown. In some embodiments, the battery cell body 30 includes a plurality of laminate units, such as a first laminate unit, a second laminate unit, and a third laminate unit, which are arranged in sequence. Each laminate unit includes a first pole piece 31, a diaphragm 33, and a second pole piece 32. The bending portion 312 of the second laminate unit is at least partially overlapped with the bending portion 312 of the first laminate unit. The bending portion of the third laminate unit is at least partially overlapped with the bending portion 312 of the second laminate unit, and is not overlapped with the bending portion 312 of the first laminate unit. There may also be four, five, six, etc. laminate units, and the number of the bending portions 312 increases accordingly. The present application does not limit the specific number here.

[0058] Figure 7 yes Figure 1 A fifth cross-sectional schematic diagram of a battery cell assembly is shown. In some embodiments, if the battery cell body 30 includes a plurality of laminated units such as a first laminated unit, a second laminated unit, and a third laminated unit arranged in sequence, the bending portion 312 of the second laminated unit is at least partially stacked on the bending portion 312 of the first laminated unit, and the bending portion 312 of the third laminated unit is stacked on the bending portion 312 of the second laminated unit, and at least partially stacked on the bending portion 312 of the first laminated unit. The number of laminated units can also be four, five, six, etc., and the number of the bending portions 312 increases accordingly, and the present application does not limit the specific number here.

[0059] In some embodiments, the housing 10 includes two housing side walls 12 arranged opposite to each other in the second direction of the housing 10, and the bent portion 312 of each first pole piece 31 extends toward the same housing side wall 12 of the housing 10. The bent portions 312 extending in the same direction can ensure consistency and orderliness of the fit with the housing bottom wall 11, thereby increasing the heat dissipation area.

[0060] In some embodiments, the bent portion 312 of a portion of the first pole piece 31 extends toward the same shell side wall 12 , and the bent portion 312 of a portion of the first pole piece 31 extends toward another shell side wall 12 .

[0061] In some embodiments, the shell side wall 12 includes a left side wall and a right side wall, the first pole piece 31 is arranged on the side close to the left side wall, and the second pole piece 32 is arranged on the side close to the right side wall. In order to avoid the extension length exceeding the left side wall, multiple bending portions 312 all extend toward the right side wall; in other embodiments, the first pole piece 31 is arranged on the side close to the right side wall. In order to avoid the extension length exceeding the right side wall, the bending portions 312 of multiple first pole pieces 31 all extend toward the left side wall.

[0062] In some embodiments, the second pole piece 32 includes an end facing the heat-conducting insulating sheet 20, and the end is spaced apart from the bending portion 312. Since the contact between the first pole piece 31 and the second pole piece 32 during the bending of the bending portion 312 may cause a short circuit, the diaphragm 33 is disposed between the bending portion 312 and the end with one end facing the heat-conducting insulating sheet 20 to isolate the second pole piece 32 from the bending portion 312.

[0063] Please refer to Figure 8 , Figure 8 yes Figure 1 The sixth cross-sectional schematic diagram of the battery cell assembly shown. In some embodiments, the diaphragm 33 includes a first barrier segment 331 and a second barrier segment 332, the first barrier segment 331 extends in a first direction toward the housing 10, and the second barrier segment 332 is connected to the first barrier segment 331 and extends in a second direction along the housing 10, and the extension direction is the same as the extension direction of the bending portion 312. The second barrier segment 332 is disposed between the end and the bending portion 312 to prevent the first pole piece 31 from contacting the bending portion 312, and the length of the second barrier segment 332 can be adjusted according to the length of the bending portion 312.

[0064] In some embodiments, the diaphragm 33 is not bent, and the diaphragm 33 and the second pole piece 32 are arranged along the first direction of the shell 10. When the first pole piece 31, the diaphragm 33 and the second pole piece 32 are pressed tightly, the second pole piece 32 is clamped between two adjacent diaphragms 33, and along the first direction of the shell 10, the distance from the end of the second pole piece 32 to the bottom wall 11 of the shell is greater than the distance from the diaphragm 33 to the bottom wall 11 of the shell, so as to avoid the second pole piece 32 protruding from the diaphragm 33 and contacting the bent portion 312.

[0065] Please refer to Fig. 9 , Fig. 9 yes Figure 1 The schematic diagram of the structure of the first pole piece is shown. In some embodiments, the main body 311 includes a first part 3111 and a second part 3112, the first part 3111 is provided with a conductive coating, the second part 3112 is connected to one end of the first part 3111 close to the bottom wall 11 of the shell, and the bending part 312 is connected to one end of the second part 3112 close to the bottom wall 11 of the shell. The second part 3112 and the bending part 312 are not coated with a conductive coating. If the first pole piece 31 is completely coated with a conductive coating, the conductive coating of the bending part 312 will fall off during the bending and flattening process, and the powder loss will cause structural deformation, short circuit and other faults inside the battery cell, thereby causing safety hazards.

[0066] In some embodiments, the sum of the lengths of the second portion 3112 and the bent portion 312 is between 1 mm and 20 mm. If the lengths of the second portion 3112 and the bent portion 312 are too short, the bent portion 312 may not be flattened; if the lengths are too long, not only will the flattening be more difficult, but the increased thickness of the bend will waste the internal space of the battery, resulting in a decrease in the energy density of the battery. The sum of the lengths of the second portion 3112 and the bent portion 312 may be 1 mm, 2 mm, 4 mm, 6 mm, 8 mm, 10 mm, 12 mm, 14 mm, 16 mm, 18 mm, 20 mm, etc., and the present application does not limit the specific values.

[0067] In some embodiments, the first electrode piece 31 is a positive electrode, and the second portion 3112 and the bent portion 312 of the first electrode piece 31 are aluminum foil; in some embodiments, the first electrode piece 31 is a negative electrode, and the second portion 3112 and the bent portion 312 of the first electrode piece 31 are copper foil.

[0068] Please refer to Fig.10 , Fig.10 yes Figure 1Another structural schematic diagram of the battery body shown. In some embodiments, the battery cell assembly 100 further includes an insulating film 40, and the battery cell body 30 includes a body bottom wall 301 and a body side wall 302 surrounding the body bottom wall 301, and the insulating film 40 is coated on the body side wall 302 and the periphery of the body bottom wall 301. Among them, the insulating film 40 is used to coat the outer surface of the battery cell assembly 100 before the battery cell body 30 is loaded into the shell 10. After the coating is completed, the battery cell body 30 and the insulating film 40 are jointly loaded into the chamber inside the shell 10. On the one hand, the insulating film 40 can play a role in fixing and connecting multiple battery cell units as a whole, and on the other hand, it also plays a role in protecting the battery cell body 30. In the process of the battery cell body 30 being put into the shell, the insulating film 40 is wrapped outside the battery cell body 30, which can prevent the stacked battery cell body 30 from directly contacting the shell 10, and avoid the shell 10 from causing scratches and other damages to the battery cell body 30, so that the battery cell body 30 is damaged during the assembly process, so as to improve product safety.

[0069] In some embodiments, the body bottom wall 301 includes a middle area and a peripheral area, the peripheral area surrounds the middle area, the bending portion 312 is convexly arranged in the middle area, and the insulating film 40 includes a ring edge 41 covering the peripheral area, and the ring edge 41 is arranged around the middle area. An opening is provided in the ring edge 41, and the opening is used to avoid the bending portion 312 so that the bending portion 312 can extend to the thermally conductive insulating sheet 20.

[0070] In some embodiments, the width of the ring edge 41 is between 1mm and 20mm. If the ring edge 41 is too short, it may affect the reliability of insulation. If the ring edge 41 is too long, it will affect the heat dissipation effect on the one hand, and the lamination of the insulating film 40 will waste the internal space of the battery, resulting in a decrease in the energy density of the battery. Specifically, the width of the ring edge can be 1mm, 2mm, 4mm, 6mm, 8mm, 10mm, 12mm, 14mm, 16mm, 18mm, 20mm, etc., and the present application does not limit the specific values ​​here.

[0071] In some embodiments, the insulating film 40 is a PET (Polyethylene terephthalate) film or a PI (Polyimide Film) film. In the related art, PP (Polypropylene) is often used as an insulating material, but its thermal conductivity is low and the heat dissipation effect is poor. The present application can use PET film and PI film. Both PET film and PI film have high temperature resistance, low temperature resistance and insulation properties, and have good thermal conductivity. While sealing the phase change material, they can adapt to the environment where the temperature of the battery cell changes drastically, thereby ensuring the service life of the battery cell.

[0072] In some embodiments, the thickness of the insulating film 40 is between 0.03 mm and 0.07 mm. In order to ensure the heat dissipation effect, the insulating film 40 should not be too thick. Preferably, the thickness of the insulating film 40 can be 0.05 mm. In addition, the insulating film 40 can also be 0.04 mm, 0.03 mm, 0.06 mm, 0.07 mm, etc. This application does not limit the specific value here.

[0073] The present application also provides a battery pack, which includes a box and a battery cell assembly 100 as described in any of the above embodiments, and the battery cell assembly 100 is assembled in the box. The box can be a rectangular parallelepiped, and a plurality of mounting cavities arranged in a matrix can be provided in the box, and a battery cell assembly 100 can be installed in each mounting cavity.

[0074] The above is a detailed introduction to the embodiments of the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for technicians in this field, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A battery cell assembly, characterized in that: include: A shell having a chamber therein, wherein the shell comprises a shell bottom wall; A heat-conducting insulating sheet is arranged on a side of the bottom wall of the shell facing the chamber; A battery cell body is arranged in the chamber, the battery cell body includes a first pole piece and a second pole piece which are staggered and stacked, the battery cell body also includes a diaphragm arranged between the first pole piece and the second pole piece, each of the first pole pieces includes a main body portion and a bending portion which are connected to each other, the main body portion extends along a first direction of the shell, the bending portion extends along a second direction of the shell, the first direction intersects with the second direction, the bending portion is attached to the thermally conductive insulating sheet, and the bending portions of at least two adjacent first pole pieces are connected.

2. The battery cell assembly according to claim 1, characterized in that: The bent portion of each first pole piece is at least partially connected to the bent portion of another first pole piece.

3. The battery cell assembly according to claim 2, characterized in that: The bent portions of any two adjacent first pole pieces are at least partially connected and form a plane as a whole.

4. The battery core assembly according to any one of claims 1 to 3, characterized in that: Among two adjacent first pole pieces, the bent portion of one first pole piece is at least partially overlapped on the bent portion of the other first pole piece.

5. The battery cell assembly according to claim 4, characterized in that: The battery cell body includes a first lamination unit, a second lamination unit and a third lamination unit arranged in sequence, the bending portion of the second lamination unit is at least partially overlapped with the bending portion of the first lamination unit, and the bending portion of the third lamination unit is at least partially overlapped with the bending portion of the second lamination unit.

6. The battery cell assembly according to claim 4, characterized in that: The battery cell body includes a first lamination unit, a second lamination unit and a third lamination unit arranged in sequence, the bending portion of the second lamination unit is at least partially overlapped with the bending portion of the first lamination unit, the bending portion of the third lamination unit is overlapped with the bending portion of the second lamination unit, and at least partially overlapped with the bending portion of the first lamination unit.

7. The battery core assembly according to any one of claims 1 to 3, characterized in that: The shell includes two shell side walls that are arranged opposite to each other in the second direction of the shell, and the bent portion of each of the first pole pieces extends toward the same shell side wall of the shell.

8. The battery core assembly according to any one of claims 1 to 3, characterized in that: The second pole piece includes an end facing the thermally conductive insulating sheet, the end is spaced apart from the bent portion, and one end of the diaphragm facing the thermally conductive insulating sheet is disposed between the bent portion and the end to isolate the second pole piece from the bent portion.

9. The battery core assembly according to claim 8, characterized in that: The diaphragm comprises a first barrier segment and a second barrier segment, the first barrier segment extends in the first direction, the second barrier segment is connected to the first barrier segment and extends in the second direction, and the second barrier segment is arranged between the end and the bending portion; and / or The diaphragm and the second pole piece are arranged along the first direction, the second pole piece is sandwiched between the two diaphragms, and along the first direction, the distance from the end to the bottom wall of the shell is greater than the distance from the diaphragm to the bottom wall of the shell.

10. The battery core assembly according to any one of claims 1 to 3, characterized in that: The main body includes a first part and a second part, the first part is provided with a conductive coating, the second part is connected to an end of the first part close to the bottom wall of the shell, and the bending part is connected to an end of the second part close to the bottom wall of the shell.

11. The battery core assembly according to any one of claims 1 to 3, characterized in that: The battery cell assembly further includes an insulating film, the battery cell body includes a body bottom wall and a body side wall surrounding the body bottom wall, and the insulating film is coated on the body side wall and on the periphery of the body bottom wall.

12. The battery core assembly according to claim 11, characterized in that: The bottom wall of the body includes a middle area and a peripheral area, the peripheral area surrounds the middle area, the insulating film includes a ring edge covering the peripheral area, the ring edge is arranged around the middle area, and the width of the ring edge is between 1mm-20mm; and / or The insulating film is a PET film or a PI film.

13. A battery pack, characterized in that: Comprising a battery core assembly as described in any one of claims 1 to 12.

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