Cylindrical battery cell, battery pack and electric equipment

Abstract

The embodiment of the utility model provides a cylindrical battery cell, a battery pack and electric equipment, a first insulating part, a collector plate and an electrode assembly are arranged in an accommodating space of a cylindrical battery cell shell, the shell comprises a side wall, the side wall comprises a concave part, and the concave part is sunken towards the axis of the cylindrical battery cell. The first insulating part comprises a first part and a second part, at least part of the first part is arranged between the concave part and the electrode assembly in the axial direction of the cylindrical battery cell, at least part of the second part is arranged between the concave part and the electrode assembly, the projection of the first part is overlapped with the projection of the current collecting disc, and the projection of the second part is separated from the projection of the current collecting disc; the thickness of the first part is delta 1, the thickness of the second part is delta 2, and delta 2 is larger than delta 1. The thickness of the second part is larger than that of the first part, the area, not covered by the current collecting disc, of the electrode assembly is filled, and uniform stress of the electrode assembly is facilitated.

Description

Technical Field

[0001] The present application relates to the field of energy storage technology, and in particular to a cylindrical battery cell, a battery pack and an electrical device. Background Art

[0002] The collector plate is an important component of the battery cell, which is connected to the electrode assembly to provide a current path. With the development of electrical equipment, large-size and large-capacity battery cells are becoming more and more popular.

[0003] In large-sized cells, the collector plate covers part of the end surface of the electrode assembly. When the cell is transported or dropped, the electrode assembly may move. At this time, the collector plate and the electrode assembly will be squeezed against each other. At this time, the area of ​​the electrode assembly covered by the collector plate and the area not covered by the collector plate are subjected to uneven force, which affects the service life of the cell. Utility Model Content

[0004] The purpose of the embodiments of the present application is to provide a cylindrical battery cell, a battery pack and an electrical device to increase their service life.

[0005] In the first aspect, the present application provides a cylindrical battery cell, comprising: a shell having a storage space; the storage space is provided with a first insulating member, a current collecting plate and an electrode assembly; the shell comprises a side wall, the side wall comprises a recess, and the recess is recessed toward the axis of the cylindrical battery cell; the first insulating member comprises a first part and a second part, along the axial direction of the cylindrical battery cell, at least part of the first part is arranged between the recess and the electrode assembly, at least part of the second part is arranged between the recess and the electrode assembly, the projection of the first part overlaps with the projection of the current collecting plate, the projection of the second part is separated from the projection of the current collecting plate, the thickness of the first part is δ1, the thickness of the second part is δ2, δ2>δ1. The excess thickness of the second part relative to the thickness of the first part "fills" the area not covered by the current collecting plate of the electrode assembly, so that the electrode assembly is subjected to a more uniform force, reducing the risk of short circuit caused by uneven force, which is conducive to improving the service life of the cylindrical battery cell.

[0006] In one or more embodiments, along the axial direction, the projection of the recess, the projection of the first part, the projection of the collector plate, and the projection of the electrode assembly overlap. When the electrode assembly moves or has a tendency to move, the recess applies pressure to the electrode assembly in the axial direction, and the first part and the collector plate serve as buffer elements in the axial direction, which is conducive to suppressing the movement of the electrode assembly and improving the stability of the first insulating member in the cylindrical battery cell accommodation space.

[0007] In one or more embodiments, 0.2 mm ≤ δ1 ≤ 1 mm; and / or, 0.3 mm ≤ δ2 ≤ 1.3 mm; and / or, 0.15 mm ≤ δ2-δ1 ≤ 0.3 mm. This is beneficial to improving the insulation performance and buffering performance of the first insulating member.

[0008] In one or more embodiments, the second portion exceeds the first portion in the axial direction. In the axial direction, the portion of the second portion that exceeds the first portion can "fill" the area not covered by the current collecting plate of the electrode assembly, which is beneficial to improve the uniformity of the force applied to the electrode assembly during movement.

[0009] In one or more embodiments, the first insulating member is an annular structure, the second part includes an annular segment, the annular segment includes a first arc away from the axis, the center angle corresponding to the first arc is α, and satisfies: 45°≤α≤135°. This is conducive to filling the area not covered by the current collector on the electrode assembly and improving the uniformity of the force on the electrode assembly when it moves.

[0010] In one or more embodiments, the material of the first insulating member includes one or more of polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyethylene terephthalate or polybutylene terephthalate. The above materials are conducive to providing insulation and buffering properties.

[0011] In one or more embodiments, it further includes: a second insulating member, including a third portion extending in the axial direction and a fourth portion extending in the radial direction of the cylindrical battery core; the third portion is arranged between the side wall and the electrode assembly; the fourth portion includes a first section and a second section, and along the axial direction, the first section is arranged between the first section and the collector disk, and the second section is arranged between the second section and the electrode assembly. The second insulating member includes a portion extending in the axial direction and the radial direction of the cylindrical battery core, which is conducive to improving the insulation performance of the electrode assembly and the collector disk and the shell, and reducing the probability of risks such as short circuits.

[0012] In one or more embodiments, the present invention further comprises: an end cap assembly; a current collecting plate comprising a bottom layer and at least one laminated layer, the bottom layer is connected to the electrode assembly, and the at least one laminated layer is connected to the end cap assembly. The current collecting plate comprising a bottom layer and at least one laminated layer is conducive to welding the end cap assembly and the electrode assembly with the current collecting plate, and a current path is formed through the current collecting plate, which facilitates the assembly of the end cap assembly and the housing.

[0013] In one or more embodiments, the thickness of the bottom layer is δ3, 0mm≤(δ2-δ1)-δ3≤0.1mm, which is beneficial to further improve the uniformity of the pressure on the electrode assembly.

[0014] In one or more embodiments, the end cap assembly includes an end cap, an explosion-proof disc, an orifice plate, an explosion-proof disc insulating member and an end cap insulating member; the end cap, the explosion-proof disc and the orifice plate are arranged in sequence in the axial direction of the cylindrical battery cell, and the explosion-proof disc insulating member is arranged between the edge of the orifice plate and the explosion-proof disc; the explosion-proof disc includes a valve plate, the orifice plate includes a current separation plate, the valve plate and the current separation plate are connected, and the outer periphery of the explosion-proof disc wraps the outer peripheral edge of the end cap; the end cap insulating member wraps the outer peripheral edge of the explosion-proof disc; the port of the shell is provided with an inwardly bent edge, and the end cap insulating member is pressed between the folded edge and the recess; at least one layer of the laminate is electrically connected to the orifice plate. When severe working conditions such as short circuit occur, the temperature inside the cylindrical battery cell rises, and the gas production of the electrolyte increases, causing the air pressure inside the shell to rise. When the air pressure in the shell reaches a first threshold, the explosion-proof disk flips in the direction away from the orifice plate, and the valve plate of the explosion-proof disk drives the current separation plate to move, so that the current separation plate is separated from the orifice plate. When the air pressure in the shell continues to increase and reaches a second threshold, the valve plate of the explosion-proof disk can be opened to release pressure, which is beneficial to improve the safety of the cylindrical battery cell.

[0015] In a second aspect, the present application provides a battery pack, comprising: the above-mentioned cylindrical battery cell.

[0016] In a third aspect, the present application provides an electrical device, including: the above-mentioned battery pack or the above-mentioned cylindrical battery cell.

[0017] The cylindrical battery cell, battery pack and electrical equipment provided by the embodiment of the present application are provided with a first insulating member, a current collecting disk and an electrode assembly in the accommodation space of the cylindrical battery cell shell, and the shell includes a side wall, and the side wall includes a recessed portion, and the recessed portion is recessed toward the axis of the cylindrical battery cell. The first insulating member includes a first part and a second part. Along the axial direction of the cylindrical battery cell, at least part of the first part is arranged between the recessed portion and the electrode assembly, and at least part of the second part is arranged between the recessed portion and the electrode assembly. The projection of the first part overlaps with the projection of the current collecting disk, and the projection of the second part is separated from the projection of the current collecting disk. The thickness of the first part is δ1, and the thickness of the second part is δ2, and δ2>δ1. The part of the thickness of the second part that is more than the thickness of the first part "fills" the area not covered by the current collecting disk of the electrode assembly, which is conducive to making the force of the electrode assembly uniform and improving the service life of the cylindrical battery cell, battery pack and electrical equipment.

[0018] Of course, any product implementing the present application does not necessarily need to achieve all of the above advantages at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application, and a person of ordinary skill in the art can also obtain other drawings based on these drawings.

[0020] Figure 1 is a schematic diagram of the structure of a cylindrical battery cell provided in an embodiment of the present application;

[0021] Figure 2 is a schematic diagram of a partial cross-sectional structure of a cylindrical battery cell provided in an embodiment of the present application;

[0022] Figure 3 is a schematic structural diagram of a first insulating member provided in an embodiment of the present application;

[0023] Figure 4 is a schematic diagram of a top view of the structure of a first insulating member provided in an embodiment of the present application;

[0024] Figure 5 is a schematic structural diagram of a second insulating member provided in an embodiment of the present application;

[0025] Figure 6 It is a schematic diagram of the internal top view structure of a cylindrical battery cell provided in an embodiment of the present application;

[0026] Figure 7 It is a schematic diagram of a top view of the structure in which a current collecting disk provided in an embodiment of the present application is arranged on the end surface of an electrode assembly;

[0027] Figure 8 is a schematic diagram of the structure of the current collecting plate after it is unfolded according to an embodiment of the present application;

[0028] Fig. 9 is a schematic diagram of the structure of a battery pack provided in an embodiment of the present application;

[0029] Fig.10 It is a structural schematic diagram of the first type of electrical equipment provided in the embodiment of the present application;

[0030] Fig.11 It is a structural schematic diagram of the second type of electrical equipment provided in an embodiment of the present application.

[0031] The reference numerals are as follows:

[0032] Shell 10, accommodating space 101, side wall 11, recess 111, folded edge 12, first insulating member 20, first portion 21, second portion 22, annular segment 221, first arc 222, second arc 223, current collecting plate 30, bottom layer 31, stack 32, folded portion 33, electrode assembly 40, end surface 40a, first outer edge arc 41, second outer edge arc 42, second insulating member 50, third portion 51, fourth portion 52, first section 521, second section 522, end cap assembly 60, end cap 61, explosion-proof disk 62, valve plate 621, orifice plate 63, current separator plate 631, explosion-proof disk insulating member 64, end cap insulating member 65;

[0033] Cylindrical battery cell 100, battery pack 200, battery pack housing 201, and electrical equipment 300;

[0034] First area A, second area B, axis L, axial direction X, radial direction Y. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with 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 of the embodiments.

[0036] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0037] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0038] Reference to "embodiment" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. The various embodiments in the present application may be combined with each other in the absence of conflict.

[0039] It should be noted that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary and should not constitute any limitation to the present application.

[0040] In cylindrical cells, the collector plate is the current-passing component of the electrode assembly and is usually directly connected to the electrode assembly. As the diameter of the cylindrical cell increases, in some models of cylindrical cells, the collector plate covers part of the end face of the electrode assembly. Under conditions such as transportation, the electrode assembly may move, and the electrode assembly and the collector plate may squeeze each other. The area on the end face of the electrode assembly that is not covered by the collector plate and the area that is covered by the collector plate will be unevenly stressed, which can easily affect the service life of the cell.

[0041] Figure 1 is a schematic diagram of the structure of a cylindrical battery cell provided in an embodiment of the present application, Figure 2 is a schematic diagram of a partial cross-sectional structure of a cylindrical battery cell provided in an embodiment of the present application, such as Figure 1 and Figure 2 As shown, in the first aspect, the present application provides a cylindrical battery cell 100, comprising: a housing 10, a first insulating member 20, a current collecting plate 30 and an electrode assembly 40. The current collecting plate 30 and the electrode assembly 40 are electrically connected, and the first insulating member 20 is connected to the current collecting plate 30.

[0042] In some embodiments, the housing 10 has a receiving space 101. The first insulating member 20, the current collecting plate 30 and the electrode assembly 40 are disposed in the receiving space 101. The housing 10 includes a side wall 11, and the side wall 11 includes a recess 111, which is recessed toward the axis L of the cylindrical battery cell 100.

[0043] In some embodiments, the first insulating member 20 includes a first part 21 and a second part 22. Along the axial direction X of the cylindrical battery cell 100, at least a portion of the first part 21 is disposed between the recess 111 and the electrode assembly 40, and at least a portion of the second part 22 is disposed between the recess 111 and the electrode assembly 40. The projection of the first part 21 overlaps with the projection of the current collecting disk 30, and the projection of the second part 22 is separated from the projection of the current collecting disk 30. The thickness of the first part 21 is δ1, and the thickness of the second part 22 is δ2, and δ2>δ1.

[0044] In the cylindrical battery cell 100 provided in the embodiment of the present application, at least part of the first portion 21 of the first insulating member 20 is disposed between the recess 111 and the electrode assembly 40 to achieve insulation isolation between the recess 111 and the electrode assembly 40, and at least part of the second portion 22 of the first insulating member 20 is disposed between the recess 111 and the electrode assembly 40 to achieve insulation isolation between the recess 111 and the electrode assembly 40. The recess 111 presses the electrode assembly 40 through the first insulating member 20, which helps to reduce the risk of the electrode assembly 40 moving.

[0045] In some embodiments, the entire first portion 21 is disposed between the recess 111 and the electrode assembly 40. In some embodiments, a portion of the first portion 21 is disposed between the recess 111 and the electrode assembly 40.

[0046] In some embodiments, the entirety of the second portion 22 is disposed between the recess 111 and the electrode assembly 40. In some embodiments, a portion of the second portion 21 is disposed between the recess 111 and the electrode assembly 40.

[0047] like Figure 2 and Figure 7 As shown, the current collecting disk 30 and the electrode assembly 40 are electrically connected to provide a current flow path. The current collecting disk 30 is arranged on the end face 40a of the electrode assembly 40, and the end face 40a of the electrode assembly 40 includes an area A covered by the current collecting disk 30 and an area B not covered by the current collecting disk 30. Along the axial direction X of the cylindrical battery 100, the projection of the first part 21 and the projection of the current collecting disk 30 overlap, the projection of the second part 22 and the projection of the current collecting disk are separated, the thickness δ2 of the second part 22 is greater than the thickness δ1 of the first part 21, and the recess 111 is pressed against the electrode assembly 40 through the first part 21 and the second part 22. When the electrode assembly 40 moves or has a tendency to move, the excess thickness of the second part 22 relative to the thickness of the first part 21 can "fill" the area B not covered by the current collecting disk on the end face 40a of the electrode assembly, thereby facilitating the uniform force on the end face 40a of the electrode assembly as a whole and improving the service life of the cylindrical battery 100.

[0048] Ten first measuring points at different positions of the first portion 21 are randomly selected, and thicknesses of the ten first measuring points are measured using a vernier caliper to obtain ten thicknesses, and the average value is calculated to obtain the thickness δ1 of the first portion 21 .

[0049] Ten second measuring points at different positions of the second portion 22 are randomly selected, and thicknesses of the ten second measuring points are measured using a vernier caliper to obtain ten thicknesses, and the average value is calculated to obtain the thickness δ2 of the second portion 21 .

[0050] In some embodiments, along the axial direction X, the projection of the collecting plate 30 is separated from the projection of the recess 111, and the projection of the first portion 21 overlaps with the projection of the collecting plate 30. The recess 111 presses against the first portion 21, and the first portion 21 transfers pressure to the collecting plate 30 and the electrode assembly 40, which helps to suppress the movement of the electrode assembly 40.

[0051] In some embodiments, along the axial direction X, the projection of the recess 111, the projection of the first portion 21, the projection of the current collecting plate 30, and the projection of the electrode assembly 40 overlap, the first portion 21 of the first insulating member 20 is clamped between the current collecting plate 30 and the recess 111, and the second portion 22 of the first insulating member 20 is clamped between the battery assembly 40 and the recess 111. The recess 111 can limit both the first portion 21 and the second portion 22 of the first insulating member 20 to maintain the stability of the first insulating member 20 in the cylindrical battery cell 100.

[0052] In some embodiments, the second portion 22 exceeds the first portion 21 along the axial direction X. In some embodiments, the first insulating member 20 is flat on one side facing the recess 111 in the axial direction X, which is conducive to the recess 111 pressing against the first insulating member 20 to inhibit the movement of the electrode assembly 40. The second portion 22 exceeds the first portion 21 in the axial direction X, and can "fill" the area B on the end surface 40a of the electrode assembly 40 that is not covered by the current collecting plate 30, which is conducive to uniform force on the end surface 40a of the electrode assembly 40.

[0053] In some embodiments, the first portion 21 implements insulation isolation between the current collecting plate 30 and the recess 111. The first insulating member 20 may be a gasket. The thickness of the first portion 21 may be set according to the compaction degree of the end surface 40a of the electrode assembly 40 and the compression rate of the first portion 21. The thickness of the first portion 21 is δ1, satisfying: 0.2mm≤δ1≤1mm. For example, δ1 may be: 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm or a range consisting of any two values ​​therebetween.

[0054] In some embodiments, the second portion 22 is insulated and isolated between the electrode assembly 40 and the recess 111, and the thickness of the second portion 22 can be set according to the degree of compaction of the end surface 40a of the electrode assembly 40 and the compression rate of the second portion 22. The thickness of the second portion 22 is δ2, which satisfies: 0.3mm≤δ2≤1.3mm. For example, δ2 can be: 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm or a range consisting of any two values ​​therebetween.

[0055] The difference between the thickness δ2 of the second portion 22 and the thickness δ1 of the first portion 21, that is, the thickness of the second portion 22 exceeding the first portion 21, can be determined according to the thickness of the area B on the end surface 40a of the electrode assembly 40 that is not covered by the current collecting plate 30 and the compression rate of the second portion 22. The difference δ2-δ1 between the thickness δ2 of the second portion 22 and the thickness δ1 of the first portion 21 satisfies: 0.15mm≤δ2-δ1≤0.3mm. For example, the difference δ2-δ1 can be: 0.15mm, 0.16mm, 0.17mm, 0.18mm, 0.19mm, 0.2mm, 0.21mm, 0.22mm, 0.23mm, 0.24mm, 0.25mm, 0.26mm, 0.27mm, 0.28mm, 0.29mm, 0.3mm or a range consisting of any two values ​​therebetween.

[0056] Figure 3 is a schematic diagram of the structure of the first insulating member provided in an embodiment of the present application, such as Figure 2 and Figure 3 As shown, the first insulating member 20 can be an annular structure, including a first portion 21 and a second portion 22 with different thicknesses. The first portion 21 is located between the collector disk 30 and the recess 111, so that an insulating isolation is formed between the collector disk 30 and the recess 111. The second portion 22 is located between the electrode assembly 40 and the recess 111, so that an insulating isolation is formed between the electrode assembly 40 and the recess 111.

[0057] In some embodiments, the recess 111 is formed on the entire circumference of the housing 10. Along the axial direction X, the projection of the recess 111 and the projection of the first insulating member 20 in an annular structure overlap on the entire circumference, which is conducive to the recess 111 to limit the entire periphery of the first insulating member 20, and form insulation isolation between the electrode assembly 40 and the recess 111.

[0058] Figure 4 is a schematic diagram of a top view of the first insulating member provided in an embodiment of the present application, see Figure 4 As shown, the second portion 22 of the first insulating member 20 includes an annular segment 221, and the annular segment 221 includes a first arc 222 away from the axis L. The size of the central angle corresponding to the first arc 222 is determined according to the size of the area B not covered by the current collecting plate 30 on the end surface 40a of the electrode assembly 40 that needs to be "filled". The central angle corresponding to the first arc 222 is α, which satisfies: 45°≤α≤135°. For example, α can be: 45°, 55°, 65°, 75°, 85°, 95°, 105°, 115°, 125°, 135° or a range consisting of any two values ​​therebetween.

[0059] In some embodiments, the annular segment 221 further includes a second arc 223 close to the axis L. The second arc 223 and the first arc 222 are arcs with the same center. The first arc 222 is the outer arc edge of the annular segment 221 , and the second arc 223 is the inner arc edge of the annular segment 221 .

[0060] In some embodiments, the material of the first insulating member 20 includes one or more of polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyethylene terephthalate, or polybutylene terephthalate.

[0061] The first insulating member 20 can adopt an integral structure, that is, the first part 21 and the second part 22 are an integral component, which can be formed in one step by molding or injection molding. The material of the first part 21 and the material of the second part 22 can be the same material, or different materials can be used. In some embodiments, according to the elasticity requirements of the first part 21 and the second part 22, the first part 21 and the second part 22 can also be prepared by selecting materials with different elasticity. In some embodiments, the elasticity of the material of the second part 22 is less than the elasticity of the material of the first part 21. Since the collecting plate 30 is made of metal, it is not easy to deform relative to the first insulating member 20 after being compressed. The elasticity of the material of the second part 22 is less than the elasticity of the material of the first part 21. When the first insulating member 20 is compressed, the elastic deformation of the second part 22 can better adapt to the elastic deformation of the first part 21.

[0062] In some embodiments, the first part 21 and the second part 22 may also be made of materials with different insulating properties according to the insulation requirements of the first part 21 and the second part 22. In some embodiments, the dielectric constant of the material of the first part 21 is smaller than the dielectric constant of the material of the second part 22, the first part 21 is thinner, the dielectric constant of the material of the first part 21 is smaller, and the insulating property is better, which is conducive to improving the insulating property of the first insulating member 20.

[0063] The first insulating member 20 adopts an integrated structure, which facilitates the one-time assembly of the first insulating member 20 into the housing 10. In some embodiments, the first insulating member 20 is not limited to an integrated structure, and the first part 21 and the second part 22 may also be separate components (not shown). During assembly, the first part 21 and the second part 22 are separate components, which facilitates the distinction between the first part 21 and the second part 22, and facilitates the observation of whether the second part 22 is completely placed on the end surface 40a of the electrode assembly 40 in the area not covered by the current collecting plate 30, and facilitates the installation of the first part 21 and the second part 22 in the corresponding positions.

[0064] In some embodiments, the electrode assembly 40 may adopt a winding structure, and the winding structure is not limited to a winding structure of a single-electrode tab and a winding structure of multiple-electrode tabs.

[0065] Taking the multi-electrode winding structure as an example, the winding structure (not shown) includes a first pole piece, a second pole piece and a diaphragm. The first pole piece, the diaphragm and the second pole piece are stacked and wound in sequence. The first pole piece includes a first current collector and a first active coating, the first current collector includes a first coating area and a first empty foil area, the first active coating is arranged in the first coating area, in the winding structure, the first empty foil area away from the first coating area forms a first flattened area, the first flattened area serves as the first electrode terminal and is welded to the current collector. The second pole piece includes a second current collector and a second active coating, the second current collector includes a second coating area and a second empty foil area, the second active coating is arranged in the second coating area, the second empty foil area away from the second coating area forms a second flattened area, and the second flattened area serves as the second electrode terminal.

[0066] In some embodiments, Figure 5 This is a schematic diagram of the structure of the second insulating member provided in the embodiment of the present application. Figure 2 and Figure 5 As shown, the cylindrical battery core 100 further includes a second insulating member 50, and the second insulating member 50 includes a third portion 51 extending in the axial direction X and a fourth portion 52 extending in the radial direction Y of the cylindrical battery core 100. The third portion 51 is disposed between the side wall 11 and the electrode assembly 40. The fourth portion 52 includes a first section 521 and a second section 522, and along the axial direction X, the first section 521 is disposed between the first portion 21 and the current collecting plate 30, and the second section 522 is disposed between the second portion 22 and the electrode assembly 40.

[0067] In some embodiments, the second insulating member 50 is insulating tape, the third part 51 of the insulating tape forms an insulating isolation between the side wall 11 and the electrode assembly 40, the first section 521 of the fourth part 52 of the insulating tape forms an insulating isolation between the first part 21 and the collecting plate 30, and the second section 522 of the fourth part 52 of the insulating tape forms an insulating isolation between the second part 22 and the electrode assembly 40, which is beneficial to improving the safety of the cylindrical battery cell 100.

[0068] In some embodiments, see Figure 2 As shown, the cylindrical battery cell 100 further includes an end cap assembly 60 , which is connected to the current collecting plate 30 , and the current of the electrode assembly 40 is led out through the current collecting plate 30 and the end cap assembly 60 .

[0069] The end cap assembly 60 includes an end cap 61, an explosion-proof disc 62, an orifice plate 63, an explosion-proof disc insulating member 64 and an end cap insulating member 65. The end cap 61, the explosion-proof disc 62 and the orifice plate 63 are sequentially arranged in the axial direction X of the cylindrical battery cell 100, and the explosion-proof disc insulating member 64 is arranged between the edge of the orifice plate 63 and the explosion-proof disc 62. The explosion-proof disc 62 includes a valve plate 621 located in the central area of ​​the explosion-proof disc 62, and the orifice plate 63 includes a current separation plate 631 located in the central area of ​​the orifice plate 63. The valve plate 621 and the current separation plate 631 are connected, and the periphery of the explosion-proof disc 62 wraps the peripheral edge of the end cap 61. The end cap insulating member 65 wraps the peripheral edge of the explosion-proof disc 62. The port of the shell is provided with an inwardly bent folded edge 12, and the end cap insulating member 65 is pressed between the folded edge 12 and the recess 111. The collecting plate 30 is electrically connected to the orifice plate 63. The current of the electrode assembly 40 is led out through the current collecting plate 30 , the orifice plate 63 , the explosion-proof disc 62 , and the end cover 61 in sequence.

[0070] When the gas pressure in the shell 10 of the cylindrical battery cell 100 is too high and reaches the first threshold, the valve plate 621 of the explosion-proof disc 62 turns over to face away from the orifice plate 63, and the current separation plate 631 separates from the orifice plate 63 along with the valve plate 621, so that a short circuit occurs inside the cylindrical battery cell 100. When the gas pressure inside the shell 10 of the cylindrical battery cell 100 continues to increase and reaches the second threshold, the valve plate 621 of the explosion-proof disc 62 opens to discharge the high-pressure gas in the shell 10 of the cylindrical battery cell 100, which is conducive to reducing the risk of explosion of the cylindrical battery cell 100 and improving the safety of the cylindrical battery cell 100.

[0071] In some embodiments, the current separation plate 631 may be surrounded by a closed annular groove, and the valve plate 621 may be surrounded by a non-closed annular groove.

[0072] In some embodiments, the current collecting plate 30 may be connected to the electrode assembly 40 and the end cap assembly 60 respectively by welding during the process of being assembled into the housing 10 .

[0073] Figure 6 is a schematic diagram of the internal top view structure of a cylindrical battery cell provided in an embodiment of the present application, Figure 7 This is a schematic diagram of a top view of the structure in which the current collecting plate provided in the embodiment of the present application is arranged on the end surface of the electrode assembly, see Figure 6 and Figure 7 As shown, the electrode assembly 40 and the current collecting plate 30 are arranged in the housing 10, and the current collecting plate 30 includes a bottom layer 31 and at least one laminate 32, the bottom layer 31 is connected to the electrode assembly 40, and the at least one laminate 32 is connected to the end cap assembly 60. At least one laminate 32 is foldably arranged on the bottom layer 31. During assembly, the bottom layer 31 and the electrode assembly 40 are first welded and placed in the housing 10. Then the opened laminate 32 and the end cap assembly 60 connected thereto are folded together and covered on the electrode assembly 40, which is conducive to improving assembly efficiency.

[0074] At least one stack 32 may be connected to the orifice plate 63 of the end cap assembly 60 .

[0075] In some embodiments, the at least one laminate layer 32 and the bottom layer 31 are two components, and the at least one laminate layer 32 is welded to the bottom layer 31 .

[0076] Figure 8 is a schematic diagram of the structure of the current collecting plate after it is unfolded according to the embodiment of the present application, such as Figure 8 As shown, in some embodiments, at least one laminate 32 and the bottom layer 31 are an integral piece, and at least one laminate 32 and the bottom layer 31 are cut from metal sheets, and an edge of the bottom layer 31 extends with a folding portion 33 that can be folded by at least one layer, and the folding portion 33 is formed by bending the edge of the bottom layer 31 to form at least one laminate 32. Figure 8 In the illustration, the folded portion 33 is a two-layer laminate 32 , but this is not limited to this in some embodiments.

[0077] In this embodiment, compared with the embodiment requiring welding, no welding process is required, and it can be prepared by machining process using a metal plate. The entire process is relatively convenient and easy to produce and process.

[0078] The bottom layer 31 carries the current output by the electrode assembly 40, and the thickness of the bottom layer 31 can be set according to the maximum current required to be carried. The thickness of the bottom layer 31 is δ3, which satisfies: 0.15mm≤δ3≤0.4mm. For example, δ3 can be: 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, or a range consisting of any two values ​​therebetween.

[0079] In some embodiments, the difference δ2-δ1 between the thickness of the second portion 22 and the thickness of the first portion 21 may be equal to the thickness δ3 of the bottom layer 31 , which is beneficial for uniform force on the end surface 40 a of the electrode assembly 40 .

[0080] In some embodiments, the bottom layer 31 is made of metal material and has low elasticity. The second part 22 is made of non-metallic insulating material and has high elasticity. After being subjected to force, the second part 22 is compressed and its thickness is reduced, while the thickness of the bottom layer 31 is relatively stable, resulting in a greater force on the metal bottom layer 31. In this embodiment, in order to solve the above problem, the difference δ2-δ1 between the thickness of the second part 22 and the thickness of the first part 21 can be greater than the thickness δ3 of the bottom layer 31, which is conducive to making the second part 22 and the collecting plate 30 share the pressure more evenly.

[0081] In some embodiments, the difference δ2-δ1 between the thickness δ2 of the second portion 22 and the thickness δ1 of the first portion 21, and the difference (δ2-δ1)-δ3 between the thickness δ3 of the bottom layer 31, satisfy: 0mm<(δ2-δ1)-δ3≤0.1mm. For example, the difference (δ2-δ1)-δ3 can be: 0.01mm, 0.02mm, 0.03mm, 0.04mm, 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm or a range consisting of any two values ​​therebetween.

[0082] Combination Figure 6 and Figure 7 As shown, the end surface 40 a of the electrode assembly 40 includes a first region A and a second region B.

[0083] See also Figure 7 As shown, the bottom layer 31 of the current collecting disk 30 covers the first area A of the end surface 40a of the electrode assembly 40, and the bottom layer 31 of the current collecting disk 30 does not cover the second area B of the end surface 40a of the electrode assembly 40. The first area A has a first outer edge arc 41 away from the axis L, and the second area B has a second outer edge arc 42 away from the axis L. The first outer edge arc 41 and the second outer edge arc 42 are connected to form a circle. The center angle of the second outer edge arc 42 is β, and correspondingly, the center angle of the first outer edge arc 41 is 360°-β.

[0084] In some embodiments, the central angle α corresponding to the first arc 222 of the second portion 22 of the first insulating member 20 may be equal to the central angle β of the second outer edge arc 42 corresponding to the second region B.

[0085] In some embodiments, the center angle α corresponding to the first arc 222 is smaller than the center angle β of the second outer arc 42 corresponding to the second region B, and the angle difference β-α between the center angle β of the second outer arc 42 corresponding to the second region B and the center angle α corresponding to the first arc 222 satisfies: 1°≤β-α≤5°. For example, the difference of β-α can be: 1°, 1.5°, 2°, 2.5°, 3°, 3.5°, 4°, 4.5°, 5° or a range consisting of any two values ​​therebetween. The above design makes it easier to install the second part 22 to the second region B.

[0086] Along the axial direction X, the projection of the bottom layer 31 and the projection of the first portion 21 overlap, the projection of the stack 32 and the projection of the first portion 21 are separated, and the first portion 21 is disposed between the bottom layer 31 and the recess 111, so that the bottom layer 31 and the recess 111 are insulated and connected.

[0087] In some embodiments, the current collecting disk 30 is connected to the first flattened area of ​​the electrode assembly 40 to lead out the current of the electrode assembly 40. In some embodiments, the current collecting disk 30 is a first current collecting disk, and the cylindrical battery cell 100 further includes a second current collecting disk (not shown), which is connected to the second flattened area of ​​the electrode assembly 40 to lead out the current of the electrode assembly 40.

[0088] In some embodiments, the shell 10 is made of metal material, and the shell serves as the positive electrode or negative electrode of the cylindrical battery cell 100. The recess 111 is formed on the side wall 11 of the shell. The first part 21 of the first insulating member 20 forms an insulating isolation between the recess 111 and the collecting plate 30, and the second part 22 of the first insulating member 20 forms an insulating isolation between the recess 111 and the electrode assembly 40.

[0089] In some embodiments, the metal material is aluminum, the shell 10 is an aluminum shell, the aluminum shell is connected to the positive electrode sheet in the first and second electrode sheets of the electrode assembly 40, and the end cover 61 is connected to the negative electrode sheet in the first and second electrode sheets of the electrode assembly 40.

[0090] In some embodiments, the metal material is steel, the shell 10 is a steel shell, the steel shell is connected to the negative electrode sheet in the first and second electrode sheets of the electrode assembly 40, and the end cover 61 is connected to the positive electrode sheet in the first and second electrode sheets of the electrode assembly 40.

[0091] Fig. 9 This is a schematic diagram of the structure of the battery pack provided in the embodiment of the present application, see Fig. 9 As shown, in a second aspect, the present application provides a battery pack 200, including the cylindrical battery cell 100 in the above embodiment.

[0092] In some embodiments, the cylindrical battery cell 100 may be one. Fig. 9 As shown, there may be a plurality of cylindrical battery cells 100, and the plurality of cylindrical battery cells 100 are connected in series or in parallel with each other, or in a combination of series and parallel connection.

[0093] In some embodiments, Fig. 9 As shown, the battery pack 200 includes a battery pack housing 201 , and at least one cylindrical battery cell 100 is disposed in the battery pack housing 201 .

[0094] Fig.10 is a schematic diagram of the structure of the first type of electrical equipment provided in the embodiment of the present application, such as Fig.10 As shown, in a third aspect, the present application provides an electric device 300, the electric device 300 includes the battery pack 200 in the above embodiment, and the battery pack 200 includes the cylindrical battery cell 100 in the above embodiment.

[0095] Fig.11is a schematic diagram of the structure of the second type of electrical equipment provided in the embodiment of the present application, such as Fig.11 As shown, unlike the above-mentioned electric device 300 including the battery pack 200, in this embodiment, the electric device 300 includes the cylindrical battery cell 100 in the above-mentioned embodiment.

[0096] The present application does not specifically limit the electrical equipment, which can be any electrical equipment known in the prior art. For example, the electrical equipment can include but is not limited to computers, smart phones, backup power supplies, two-wheeled vehicles, drones, power tools, energy storage devices, etc.

[0097] The above description is only a preferred embodiment of the present application and is not intended to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application are included in the protection scope of the present application.

Claims

1. A cylindrical battery cell, characterized in that: include: A housing having a receiving space; The accommodation space is provided with a first insulating member, a current collecting plate and an electrode assembly; The housing comprises a side wall, the side wall comprises a recessed portion, and the recessed portion is recessed toward the axis of the cylindrical battery core; The first insulating member includes a first part and a second part. Along the axial direction of the cylindrical battery core, at least a part of the first part is arranged between the recess and the electrode assembly, and at least a part of the second part is arranged between the recess and the electrode assembly. The projection of the first part overlaps with the projection of the current collecting disk, and the projection of the second part is separated from the projection of the current collecting disk. The thickness of the first part is δ1, and the thickness of the second part is δ2, and δ2>δ1.

2. The cylindrical battery cell according to claim 1, characterized in that: Along the axial direction, a projection of the recess, a projection of the first portion, a projection of the current collecting plate, and a projection of the electrode assembly overlap.

3. The cylindrical battery cell according to claim 1 or 2, characterized in that: 0.2mm≤δ1≤1mm; and / or, 0.3mm≤δ2≤1.3mm; and / or, 0.15mm≤δ2-δ1≤0.3mm.

4. The cylindrical battery cell according to any one of claims 1 to 3, characterized in that: The second portion exceeds the first portion along the axial direction.

5. The cylindrical battery cell according to any one of claims 1 to 4, characterized in that: The first insulating member is an annular structure, the second part includes an annular segment, the annular segment includes a first circular arc away from the axis, the central angle corresponding to the first circular arc is α, and satisfies: 45°≤α≤135°.

6. The cylindrical battery cell according to any one of claims 1 to 5, characterized in that: The material of the first insulating member includes one or more of polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyethylene terephthalate or polybutylene terephthalate.

7. The cylindrical battery cell according to any one of claims 1 to 6, characterized in that: Also includes: A second insulating member, comprising a third portion extending in the axial direction and a fourth portion extending in the radial direction of the cylindrical battery core; The third portion is disposed between the side wall and the electrode assembly; The fourth portion includes a first section and a second section. Along the axial direction, the first section is disposed between the first portion and the current collecting plate, and the second section is disposed between the second portion and the electrode assembly.

8. The cylindrical battery cell according to any one of claims 1 to 7, characterized in that: Also includes: End cap assembly; The current collecting plate comprises a bottom layer and at least one laminated layer, the bottom layer is connected to the electrode assembly, and the at least one laminated layer is connected to the end cap assembly; The thickness of the bottom layer is δ3, 0mm≤(δ2-δ1)-δ3≤0.1mm.

9. A battery pack, characterized in that: include: The cylindrical battery cell according to any one of claims 1 to 8.

10. An electrical device, characterized in that: include: The battery pack according to claim 9 or the cylindrical battery cell according to any one of claims 1 to 8.

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