Battery cell assembly, battery monomer, battery and power utilization device

Abstract

The invention discloses a battery cell assembly, a battery monomer, a battery and a power utilization device, the battery cell assembly comprises a pole piece, the pole piece comprises a main body part and a plurality of tabs connected with the main body part, the pole piece is wound, a through hole is formed in a part of the tabs close to the winding center of the pole piece, and the through hole penetrates through the tabs along the thickness direction of the tabs; and no through hole is formed in the tab on the outermost circle in the plurality of tabs. The through hole is formed in the part of the tab close to the winding center of the pole piece, so that electrolyte can rapidly permeate to the main body part from the through hole, and the efficiency of a liquid injection procedure in the manufacturing process of the battery core assembly and the battery is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a battery core assembly, a battery cell, a battery and an electrical device. Background Art

[0002] In the related art, in order to reduce the internal resistance of the battery and reduce the heat during the charging and discharging process, cylindrical batteries usually adopt a multi-electrode or full-electrode structure. However, the positive and negative electrodes of the battery with this structure have a large number of stacked poles, which makes it difficult for the electrolyte to enter the battery cell assembly during the injection process, which can easily lead to insufficient electrolyte infiltration or prolonged infiltration time. Summary of the invention

[0003] The present invention provides a battery core assembly, a battery cell, a battery and an electric device, and is at least used to solve the problem of difficulty in injecting liquid into a battery with a multi-electrode structure.

[0004] In the first aspect, the present invention proposes a battery cell assembly, which includes a pole piece, the pole piece includes a main body and a plurality of pole ears connected to the main body, the pole piece is wound, and some pole ears among the plurality of pole ears close to the winding center of the pole piece are formed with through holes, the through holes penetrate the pole ears along the thickness direction of the pole ears, and the outermost pole ears among the plurality of pole ears are not provided with through holes.

[0005] In the battery cell assembly of the embodiment of the present application, a through hole is formed in the part of the pole ear near the winding center of the pole piece, so that the electrolyte can quickly penetrate into the main body from the through hole, thereby improving the efficiency of the injection process in the battery cell assembly and battery manufacturing process. At the same time, the outermost pole ear is not provided with a through hole, which ensures the welding strength between the outermost pole ear and the external components, making the battery cell assembly more reliable. In addition, in the case of battery formation or thermal runaway, the through hole on the pole ear can also allow the gas generated inside the battery to pass quickly, accelerate the battery exhaust, and improve the safety performance of the battery.

[0006] In some embodiments, the two ends of the main body in the flattened state in the length direction are respectively the core end and the tail end, the core end is the starting end of the winding of the pole piece when the pole piece is wound, and the tail end is the ending end of the winding of the pole piece when the pole piece is wound, the pole ear is arranged on one side in the width direction of the main body, and the plurality of pole ears are spaced apart along the winding direction, the pole ear close to the tail end is the first pole ear, and the pole ear close to the core end is the second pole ear, the number of the second pole ears is greater than the number of the first pole ears, and through holes are formed on the second pole ears.

[0007] In this way, through holes are formed on the second pole ear, and the number of the second pole ears is greater than the number of the first pole ears, so as to form as many channels as possible for the electrolyte to pass through. The first pole ear is located on the outer ring when the pole piece is wound, and is used for welding with the external power connection structure. The first pole ear is not provided with a through hole and has a complete surface, which improves the adhesion rate and welding strength of the pole ear, and is conducive to widening the current channel, reducing the internal resistance of the battery cell or battery pack, and improving the charging and discharging performance.

[0008] In some embodiments, at least one first electrode tab is disposed on a side of the second electrode tab away from the main body.

[0009] In this way, the complete surface of the second electrode tab is retained at both the positive and negative electrodes of the battery cell assembly to enhance the welding strength of the electrode tab.

[0010] In some embodiments, the through holes formed on the plurality of second electrode tabs are at least partially opposite to and connected to each other.

[0011] In this way, the through holes are at least partially opposite and connected, thereby forming a channel for the electrolyte to pass through, further promoting the electrolyte to penetrate into the battery cell assembly along the axial direction of the battery cell assembly.

[0012] In some embodiments, the through holes formed on the plurality of second electrode tabs are aligned and connected along the winding axis.

[0013] In this way, the through holes formed on the plurality of second pole ears are directly opposite and connected along the winding axis, thereby improving the injection efficiency of the electrolyte and enhancing the wetting effect of the pole piece.

[0014] In some embodiments, the through holes formed on the plurality of second electrode tabs are opposed to and connected along the axial direction of the winding, and are staggered along the radial direction of the winding.

[0015] In this way, the through holes formed on the multiple second pole ears are opposite and interconnected along the axial direction of the battery cell assembly, so that the electrolyte can penetrate into the battery cell assembly along the direction in which two adjacent through holes are opposite and connected, thereby accelerating the infiltration speed.

[0016] In some embodiments, a through hole is formed on each of the plurality of second electrode tabs.

[0017] This helps the electrolyte to penetrate the multi-layer stacked tabs as quickly as possible.

[0018] In some embodiments, among the plurality of second electrode tabs, some of the second electrode tabs are formed with through holes, and the second electrode tabs formed with through holes are arranged at intervals along the winding axial direction.

[0019] In this way, the second pole ears with through holes are arranged at intervals along the winding axis, which maintains the overall strength and stability of the pole ears to a certain extent and reduces the risk of the pole ears being broken or deformed due to stress concentration during battery cycling.

[0020] In some embodiments, the main body includes a current collector and an active material layer, the active material layer is disposed on at least one surface of the current collector, the electrode tab is disposed on one side in the width direction of the current collector and is electrically connected to the current collector, and the distance between the edge of the active material layer close to the electrode tab along the width direction of the current collector and the electrode tab is greater than or equal to 0.5 mm.

[0021] In this way, the electrolyte quickly penetrates into the main body through the through hole, and fully infiltrates the active material on the active material layer in a relatively short time, thereby improving the electrolyte infiltration effect, which is beneficial to improving the charge and discharge performance of the battery cell assembly.

[0022] In a second aspect, the present invention provides a battery cell, which includes a shell and a battery cell assembly of any one of the above embodiments, wherein the shell is used to accommodate the battery cell assembly, and the electrode sheet is a positive electrode sheet and / or a negative electrode sheet.

[0023] Since the battery cell of the embodiment of the present application includes the battery cell assembly of the above embodiment, it has all the beneficial effects of the battery cell assembly provided by the embodiment of the present application.

[0024] In a third aspect, the present invention provides a battery pack, which includes the battery cell of the above embodiment.

[0025] In a fourth aspect, the present invention provides an electrical device, which includes a battery cell or a battery pack according to the above embodiment.

[0026] The electrical device of the embodiment of the present application includes the battery cell or battery pack of the above-mentioned embodiment. By providing a pole ear with a through hole in the battery cell assembly of the battery cell, the infiltration speed of the electrolyte is accelerated, and the manufacturing efficiency of the battery cell and the battery pack is improved. At the same time, it helps to accelerate the exhaust of the battery (including the battery pack and the battery cell), thereby improving the safety performance of the electrical device.

[0027] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0029] Figure 1 An axial cross-sectional view of a battery cell according to an embodiment of the present invention;

[0030] Figure 2 for Figure 1 A schematic diagram of the structure of a battery cell in the illustrated embodiment when viewed from above;

[0031] Figure 3It is a schematic structural diagram of a pole piece in a flattened state according to an embodiment of the present invention;

[0032] Figure 4 It is a schematic structural diagram of a pole piece in a flattened state according to another embodiment of the present invention;

[0033] Figure 5 It is a schematic structural diagram of a pole piece in a flattened state according to another embodiment of the present invention;

[0034] Figure 6 It is a schematic diagram of the stacking structure of the tabs at one end of the battery cell assembly according to an embodiment of the present invention;

[0035] Figure 7 It is a schematic diagram of the stacking structure of the tabs at one end of the battery cell assembly according to another embodiment of the present invention;

[0036] Figure 8 This is a schematic diagram of the stacking structure of the tabs at one end of a battery cell assembly according to yet another embodiment of the present invention.

[0037] Reference numerals:

[0038] Cell assembly 100, winding center 101, center hole 103, outer peripheral surface 105, pole piece 10, main body 11, current collector 111, active material layer 112, pole ear 12, through hole 120, first pole ear 121, second pole ear 122, positive pole ear 123, negative pole ear 124, positive pole sheet 13, negative pole sheet 14, winding core end 15, winding tail end 16;

[0039] The battery cell 200 and the housing 210 . DETAILED DESCRIPTION

[0040] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0041] In the description of the present invention, it should be understood that the terms "center", "length", "width", "thickness", "upper", "lower", "front", "back", "bottom", "inner", "outer", "axial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0042] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0043] See also Figure 1-Figure 3 In a first aspect, the present invention provides a battery cell assembly 100, which includes a pole piece 10. The pole piece 10 includes a main body 11 and a plurality of pole ears 12 connected to the main body 11. The pole piece 10 is wound, and a portion of the pole ears 12 close to the winding center 101 of the pole piece 10 among the plurality of pole ears 12 is formed with a through hole 120. The through hole 120 penetrates the pole ear 12 along the thickness direction of the pole ear 12, and the outermost pole ear 12 among the plurality of pole ears 12 is not provided with a through hole 120.

[0044] Specifically, the electrode sheet 10 includes a positive electrode sheet 13 and a negative electrode sheet 14, and the battery cell assembly 100 is mainly formed by winding or stacking the positive electrode sheet 10 and the negative electrode sheet 10, and the parts of the positive electrode sheet 10 and the negative electrode sheet 10 with active materials constitute the main body 11 of the battery cell assembly 100, and the parts of the positive electrode sheet 10 and the negative electrode sheet 10 without active materials each constitute the pole ear 12. Usually, a diaphragm is provided between the positive electrode sheet 13 and the negative electrode sheet 14. The positive pole ear 123 and the negative pole ear 124 can be located at one end of the main body 11 or at both ends of the main body 11 respectively. During the charge and discharge process of the battery, the positive active material and the negative active material react with the electrolyte, and the metal ions move between the positive electrode sheet 13 and the negative electrode sheet 14, and the pole ear 12 is connected to the external power connection structure to form a current loop. The external structure can be but is not limited to an electrode, a terminal, a collector plate lead, etc.

[0045] The pole ear 12 can be formed by a cutting and stacking process or a flattening process. The pole ear 12 can be formed into a parallelogram, a rhombus, a rectangle or an ellipse, etc., and this application does not limit this. The shape of the through hole 120 includes but is not limited to a circle, an ellipse, a rhombus, etc. The aperture size of the through hole 120, the position of the through hole 120 on the pole ear 12, the number of the through holes 120, etc. are matched and designed according to the type and number of the pole piece 10.

[0046] The pole piece 10 is wound along the length direction of the main body 11 in a flattened state, and can be wound to form a shape approximating a cylinder, a cuboid, a flat body, etc. The winding center 101 of the pole piece 10 points to the two ends of the battery cell assembly 100. For the convenience of explanation, in the following description, the axial direction of the winding center 101 is defined as the winding axial direction. The pole piece 10 is stacked at both ends of the main body 11 along the winding axial direction, and the stacking direction of the pole ear 12 can be parallel to the winding axial direction. The through hole 120 on the pole ear 12 faces the end surface of the main body 11 and the battery cell assembly 100 along the winding axial direction. When the electrolyte is injected into the battery cell assembly 100, it can quickly penetrate into the main body 11 through the through hole 120.

[0047] When the pole piece 10 is flattened, the pole tabs 12 extend outward from the main body 11 along the width direction of the main body 11, and a plurality of rhombus-shaped pole tabs 12 are arranged along the length direction of the main body 11. The pole piece 10 forms a multi-layer electrode stacking structure in the wound state, and the pole tabs 12 are also folded or flattened at the ends of the pole piece 10 along the winding axis toward the winding center 101 to align and fix with each layer of the multi-layer electrode.

[0048] The outermost pole lug 12 among the multiple pole lugs 12 is not provided with a through hole 120, that is, the surface of the outermost pole lug 12 away from the main body 11 along the stacking direction of the pole lugs 12 is a complete surface, and the outermost pole lug 12 is not provided with a through hole 120 and other holes, grooves, notches, etc., especially the surface of the above-mentioned pole lug 12 facing the outside of the battery cell assembly 100 is relatively smooth and complete, so as to be welded with the external power connection structure to avoid the phenomenon of cold welding, ensure the welding strength of the pole lug 12, and thereby improve the stability and reliability of the current loop formed by the battery cell assembly 100.

[0049] In a specific example, the pole piece 10 is wound in a cylindrical shape, and the pole lugs 12 are stacked at both ends of the battery cell assembly 100 in the axial direction, one end of which is the positive pole lug 123, and the other end is the negative pole lug 124. The edge of the pole lug 12 in the width direction of the pole piece 10 is cut into a rhombus, and one side of the rhombus is connected to the edge of the main body 11. Then it is folded toward the winding center 101 as the pole piece 10 is wound, and is flattened at both ends of the battery cell assembly 100. Several layers of pole lugs 12 close to the winding center 101 are provided with a through hole 120 at the geometric center, and the two outermost layers of pole lugs 12 along the winding axis form a complete surface and are welded to the external power connection structure. Multiple pole lugs 12 are stacked along the winding axis and the edges are aligned, so that the through holes 120 on the multiple layers of pole lugs 12 are connected up and down to achieve rapid liquid seepage.

[0050] In the battery cell assembly 100 of the embodiment of the present application, a portion of the pole lugs 12 near the winding center 101 of the pole piece 10 forms a through hole 120, so that the electrolyte can quickly penetrate from the through hole 120 to the main body 11, thereby improving the efficiency of the battery cell assembly 100 and the injection process in the battery manufacturing process. At the same time, the outermost pole lug 12 of the multiple pole lugs 12 is not provided with a through hole 120, which ensures the welding strength between the outermost pole lug 12 and the external components, making the battery cell assembly 100 more reliable. In addition, in the case of battery formation or thermal runaway, the through hole 120 on the pole lug 12 can also allow the gas generated inside the battery to pass quickly, accelerate the battery exhaust, and improve the safety performance of the battery.

[0051] See also Figure 1 and Figure 3 In some embodiments, the two ends of the main body 11 in the flattened state in the length direction are respectively a core end 15 and a tail end 16, the core end 15 is the starting end of the winding of the pole piece 10 when the pole piece 10 is in the wound state, and the tail end 16 is the ending end of the winding of the pole piece 10 when the pole piece 10 is in the wound state, and a plurality of pole ears 12 are spaced apart along the winding direction, the pole ear 12 close to the tail end 16 is a first pole ear 121, and the pole ear 12 close to the core end 15 is a second pole ear 122, the number of the second pole ears 122 is greater than the number of the first pole ears 121, and a through hole 120 is formed on the second pole ear 122.

[0052] Specifically, taking the pole piece 10 in a rectangular shape in a flattened state as an example, the core end 15 and the tail end 16 are respectively located at the two opposite wide sides of the pole piece 10 along the length direction. The pole piece 10 is wound along its own length direction and can be wound into a cylindrical shape. The winding center 101 forms a center hole 103. The end where the winding starts is the core end 15, and the end where the winding ends is the tail end 16. After the winding is completed, the core end 15 is located in the innermost layer of the battery cell assembly 100 in the radial direction and can form the inner wall surface of the center hole 103; the tail end 16 is located in the outermost layer of the battery cell assembly 100 in the radial direction and covers the outer peripheral surface 105 of the battery cell assembly 100. The width direction of the main body 11 in the flattened state is also the winding axis. The winding direction of the pole piece 12 in the wound state can be clockwise or counterclockwise, and the winding direction of the pole piece 12 in the wound state is defined as a winding radial direction, and the winding radial direction can point to the same direction as the circumferential direction of the center hole 103 .

[0053] The pole tabs 12 are distributed at the ends of the pole piece 10 in the width direction, and the positive pole tab 123 and the negative pole tab 124 are respectively located at the two ends of the battery cell assembly 100 in the axial direction. The first pole tab 121 is close to the roll tail end 16 when the pole piece 10 is flattened. In the stacked positive pole tabs 123 and negative pole tabs 124, the first pole tabs 121 are both located on the side away from the main body 11 along the winding axis, and at least cover the two end surfaces of the battery cell assembly 100 in the axial direction. The second pole tab 122 is close to the roll core end 15 when the pole piece 10 is flattened. In the stacked positive pole tabs 123 and negative pole tabs 124, they are both located on the side close to the main body 11 along the winding axis.

[0054] The number of the second pole lugs 122 is greater than the number of the first pole lugs 121, and through holes 120 are formed on the second pole lugs 122 to form as many channels as possible for electrolyte to pass through. The first pole lugs 121 are located in the outer circle among the multiple pole lugs 12 when the pole piece 10 is wound, and are used for welding with the external power connection structure, and the number of the first pole lugs 121 welded with the external power connection structure is less than the total number of the first pole lugs 121. The first pole lug 121 is not provided with a through hole, and the surface of the first pole lug 121 is a complete surface, which improves the adhesion rate and welding strength of the pole lug 12, thereby facilitating the widening of the current channel, reducing the internal resistance of the battery cell 200 or the battery pack, and improving the charging and discharging performance.

[0055] See also Figure 1 and Figure 6 , Figure 6 1 is a schematic diagram of the stacking structure of the tabs 12 at one of the two ends of the battery cell assembly 100 in the axial direction. In some embodiments, at least one first tab 121 is disposed on a side of the second tab 122 away from the main body 11 .

[0056] Specifically, the winding axis is defined as the up-down direction, and the first pole tab 121 is stacked above the second pole tab 122 along the winding axis, with the position of the main body 11 as the bottom, and the second pole tab 122 close to the main body 11 is lower than the second pole tab 122. At least one first pole tab 121 is provided at each of the two ends of the battery cell assembly 100 along the winding axis, that is, the positive and negative electrodes of the battery cell assembly 100.

[0057] In this way, the complete surface of the second electrode tab 122 is retained at both the positive and negative electrodes of the battery cell assembly 100 to enhance the welding strength of the electrode tab 12 .

[0058] See also Figure 6 and Figure 7 In some embodiments, the through holes 120 formed on the plurality of second electrode tabs 122 are at least partially opposite to and connected to each other.

[0059] Specifically, since the tabs 12 are compactly stacked, when the electrolyte penetrates from the through holes 120 into the interior of the battery cell assembly 100, it also flows and infiltrates along the surface of the tabs 12 where the through holes 120 are located, which may slow down the speed at which the electrolyte penetrates into the interior of the battery cell assembly 100. Therefore, the plurality of through holes 120 are opposite to each other along the stacking direction of the tabs 12, that is, the winding axis and at least partially connected to each other, reducing the obstacles to the electrolyte penetrating from the tabs 12 into the main body 11.

[0060] In this way, the through holes 120 are at least partially opposite to each other and connected, thereby forming a channel for the electrolyte to pass through, further promoting the electrolyte to penetrate into the battery cell assembly 100 along the winding axis.

[0061] See also Figure 6 In some embodiments, the through holes 120 formed on the plurality of second electrode tabs 122 are directly opposite and connected along the winding axis.

[0062] Specifically, in order to accurately align with the multi-layer electrode, the multiple pole tabs 12 have the same shape and size, and are aligned and stacked in sequence along the winding axis. The positions of the through holes 120 formed on the second pole tabs 122 are all the same. Figure 6 In the illustrated embodiment, the through hole 120 is a circular hole located at the geometric center of the square pole tab 12. The through holes 120 formed on the plurality of second pole tabs 122 are arranged linearly along the stacking direction of the pole tabs 12, that is, along the winding axis, so that the electrolyte can quickly penetrate along the arrangement direction of the through holes 120 when penetrating from the end of the battery cell assembly 100 to the inside.

[0063] Furthermore, each second pole ear 122 is formed with a through hole 120 , and a plurality of through holes 120 are opposite and connected along the winding axis, thereby forming a linear channel that is continuous along the axial direction of the battery cell assembly 100 , further promoting the penetration of the electrolyte.

[0064] In this way, the through holes 120 formed on the plurality of second pole tabs 122 are aligned and connected along the winding axis, thereby improving the injection efficiency of the electrolyte and enhancing the wetting effect of the pole piece 10 .

[0065] See also Figure 7 In some embodiments, the through holes 120 formed on the plurality of second pole tabs 122 are opposite and connected along the axial direction of the winding, and are staggered along the radial direction of the winding.

[0066] Specifically, multiple pole tabs 12 can be aligned and stacked along the winding axis, and the positions of the through holes 120 on the second pole tabs 122 can be staggered along the winding radial direction. The through holes 120 on two adjacent second pole tabs 122 can be opposite to each other obliquely upward or obliquely downward, and partially overlap in the winding radial direction.

[0067] In another example, the positions of the plurality of second pole tabs 122 in the radial direction of the battery cell assembly 100 may be staggered, so that the through holes 120 on the second pole tabs 122 are staggered along the winding radial direction. In this embodiment, the through holes 120 on two adjacent second pole tabs 122 are opposite and connected obliquely upward or obliquely downward.

[0068] In this way, the through holes 120 formed on the plurality of second pole tabs 122 are opposite and interconnected along the winding axis obliquely upward or obliquely downward, so that the electrolyte can penetrate into the battery cell assembly 100 along the direction in which two adjacent through holes 120 are opposite and connected, thereby accelerating the wetting speed.

[0069] See also Figure 3 and Figure 6 In some embodiments, a through hole 120 is formed on each of the plurality of second electrode tabs 122 .

[0070] Specifically, there are multiple second pole tabs 122 to ensure that the number of pole tabs 12 with through holes 120 is sufficient so that the electrolyte can penetrate as quickly as possible. Through holes 120 are formed on all second pole tabs 122, that is, except for a few pole tabs 12 near the roll tail end 16, each pole tab 12 near the roll core end 15 or relatively far from the roll tail end 16 has at least one through hole 120 formed on each pole tab 12.

[0071] This helps the electrolyte to penetrate the multi-layer stacked tabs 12 as quickly as possible.

[0072] See also Figure 4 and Figure 5 In some embodiments, among the plurality of second pole tabs 122 , some of the second pole tabs 122 are formed with through holes 120 , and the second pole tabs 122 formed with through holes 120 are arranged at intervals along the winding axial direction.

[0073] Specifically, Figure 8 As shown, in the flattened state of the pole piece 10, the second pole lug 122 with the through hole 120 and the second pole lug 122 without the through hole 120 are sequentially arranged at intervals along the length direction of the pole piece 10. The pole lug 12 is stacked and flattened after the pole piece 10 is wound. Among the stacked pole lugs 12, along the winding axis, that is, along the stacking direction of the pole lugs 12, the second pole lug 122 with the through hole 120 and the second pole lug 122 without the through hole 120 are sequentially arranged at intervals along the length direction of the pole piece 10, and a layer of the second pole lug 122 without the through hole 120 is spaced between every two adjacent through holes 120.

[0074] like Figure 5As shown, in the flattened state of the pole piece 10, every two second pole lugs 122 formed with through holes 120 and one second pole lug 122 without through holes 120 are sequentially arranged along the length direction of the pole piece 10. In the stacked pole lugs 12, along the stacking direction of the pole lugs 12, that is, along the winding axial direction, the second pole lugs 122 formed with through holes 120 and the second pole lugs 122 without through holes 120 are sequentially arranged alternately, and each second pole lug 122 without through holes 120 is spaced apart from two second pole lugs 122 formed with through holes 120.

[0075] The size, spacing and arrangement pattern of the through holes 120 can be adjusted according to the application scenarios and requirements of different battery cell assemblies 100 so as to be applied to various types of battery cells 200 and / or battery packs.

[0076] In this way, the second pole tabs 122 with through holes 120 are arranged at intervals along the winding axis, which maintains the overall strength and stability of the pole tabs 12 to a certain extent and reduces the risk of the pole tabs 12 being broken or deformed due to stress concentration during battery cycling.

[0077] See also Figure 8 In some embodiments, the tabs 12 are sequentially connected along their width direction or length direction, and are stacked along their thickness direction.

[0078] Taking the square tab 12 as an example, the edges of the multiple tabs 12 along their width direction are sequentially connected or joined, and are sequentially stacked along their thickness direction to form a step morphology arranged obliquely downward. During the injection process, the electrolyte penetrates obliquely downward along the edge of the tab 12, thereby accelerating the electrolyte penetration speed and improving the efficiency of the injection process.

[0079] See also Figure 1 and Figure 2 In some embodiments, the battery cell assembly 100 is wound in a cylindrical shape, and a center hole 103 is formed at the winding center 101 of the battery cell assembly 100 , and the center hole 103 passes through both ends of the battery cell assembly 100 in the axial direction.

[0080] Specifically, the battery cell assembly 100 realizes the charge and discharge function through chemical reactions between the positive and negative electrodes, and some chemical reactions easily generate gas, which increases the internal pressure and thus affects the cycle life of the battery cell assembly 100. A central hole 103 is formed at the winding center 101 of the battery cell assembly 100, and the central hole 103 runs through both ends of the circumference of the battery cell assembly 100. All gases generated on the closely stacked pole pieces 10 and the isolation membranes in the battery cell assembly 100 can flow to the central hole 103.

[0081] In this way, the gas generated inside the battery cell assembly 100 can be discharged in time through the central hole 103, reducing the internal pressure and thus improving the charging and discharging safety.

[0082] See also Figure 3 In some embodiments, the main body 11 includes a current collector 111 and an active material layer 112, the active material layer 112 is disposed on at least one surface of the current collector 111, the pole tab 12 is disposed on one side of the current collector 111 in the width direction and is electrically connected to the current collector 111, and the distance d between the edge of the active material layer 112 along the width direction of the electrode sheet 10 and the pole tab 12 is greater than or equal to 0.5 mm.

[0083] Specifically, the battery cell assembly 100 infiltrates the active material layer 112 with electrolyte, so that the active particles in the active material move between the positive electrode sheet 13 and the negative electrode sheet 14, and a chemical reaction occurs to generate electrical energy. The active material layer 112 is formed by stacking or coating the active material and the main body 11. The active material layer 112 of the positive electrode sheet 13 and the active material layer 112 of the negative electrode sheet 14 use different active materials that can undergo corresponding chemical reactions.

[0084] Taking the lithium-ion battery cell 200 as an example, the positive electrode current collector 111 may be aluminum foil, the material of the main body 11 may be aluminum, and the active material layer 112 may be coated with active materials such as lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide. The negative electrode current collector 111 may be copper foil, and the active material layer 112 may be made of carbon or silicon. The isolation film is arranged between the active material layer 112 of the positive electrode sheet 13 and the negative electrode sheet 14, and the material of the isolation film may be PP (polypropylene, polypropylene) or PE (polyethylene, polyethylene) or the like.

[0085] In this way, the electrolyte quickly penetrates into the main body 11 through the through hole 120 , and fully infiltrates the active material on the active material layer 112 in a relatively short time, thereby improving the electrolyte infiltration effect, which is beneficial to improving the charge and discharge performance of the battery cell assembly 100 .

[0086] Please refer again Figure 1 and Figure 2 In a second aspect, the present invention provides a battery cell 200 , which includes a shell 210 and a battery cell assembly 100 of any of the above-mentioned embodiments. The shell 210 is used to accommodate the battery cell assembly 100 , and the electrode sheet 12 is a positive electrode sheet 13 and / or a negative electrode sheet 14 .

[0087] Specifically, the battery cell 200 may be a cylindrical battery cell 200, a prismatic battery cell 200, a soft-pack battery cell 200, or a battery cell 200 of other shapes. The prismatic battery cell 200 includes but is not limited to a square-shell battery cell 200, a blade-shaped battery cell 200, a multi-prismatic battery, and the multi-prismatic battery is, for example, a hexagonal battery. The battery cell assembly 100 is a component in the battery cell 200 where an electrochemical reaction occurs. One or more battery cell assemblies 100 may be included in the housing 210. The material of the housing 210 may include but is not limited to copper, iron, aluminum, stainless steel, aluminum alloy, plastic, and the like.

[0088] Since the battery cell 200 of the embodiment of the present application includes the battery cell assembly 100 of the above embodiment, it has all the beneficial effects of the battery cell assembly 100 provided by the embodiment of the present application.

[0089] In a third aspect, the present invention provides a battery pack (not shown), which includes a plurality of battery cells 200 according to the above-mentioned embodiments.

[0090] Specifically, a battery cell 200 is the smallest unit that makes up a battery pack. Multiple battery cells 200 in a battery pack can be connected in series, in parallel, or in mixed connection. Mixed connection means that multiple battery cells 200 are connected in series and in parallel. The battery pack can be a soft pack battery, a cylindrical battery, or a square battery. The battery pack can also include a box and a busbar. The box is used to accommodate the battery cells 200; the busbar is connected to the tabs 12 in the battery cells 200 to achieve electrical connection between multiple battery cells 200.

[0091] Each battery cell 200 in the battery pack can be a secondary battery or a primary battery. A disposable battery is also called a primary battery. After the battery is exhausted, it cannot be recharged and can only be discarded. A secondary battery is also called a rechargeable battery or a secondary battery or a storage battery. It can be recycled many times after being charged. The battery cell 200 can be a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery, and can also be a lead-acid battery, a nickel-hydrogen battery and a lithium-ion battery, but is not limited thereto.

[0092] The battery cell 200 with multiple tabs 12 provided in the embodiment of the present application is particularly suitable for high energy density lithium-ion battery packs in electric vehicles, energy storage systems, and high-performance mobile devices. The through holes 120 are formed by a plurality of tabs 12 in the positive and negative tabs 12 to allow the electrolyte to pass through quickly, which not only improves the manufacturing efficiency of the battery, is conducive to improving the infiltration effect of the electrolyte, but also further enhances the safety and stability of the battery pack.

[0093] In a fourth aspect, the present invention provides an electrical device (not shown), which includes the battery cell 200 or the battery pack of the above embodiment.

[0094] The electrical devices disclosed in the embodiments of the present application include electrical devices that use battery cells 200 or battery packs as power sources or various energy storage systems that use batteries as energy storage elements. The electrical devices may be, but are not limited to, mobile phones, tablets, laptops, electric toys, electric tools, battery vehicles, electric cars, ships, spacecraft, and the like. Among them, electric toys may include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and the like, and spacecraft may include airplanes, rockets, space shuttles, and spacecraft, and the like. Among them, electric cars may be pure electric cars, hybrid electric cars, or extended-range cars, and the like.

[0095] The electrical device of the embodiment of the present application includes the battery cell 200 or the battery pack of the above-mentioned embodiment. By providing a pole ear 12 with a through hole 120 in the battery cell assembly 100 of the battery cell 200, the infiltration speed of the electrolyte is accelerated, and the manufacturing efficiency of the battery cell 200 and the battery pack is improved. At the same time, it helps to accelerate the exhaust of the battery (including the battery pack and the battery cell 200), thereby improving the safety performance of the electrical device.

[0096] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0097] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A battery cell assembly, characterized in that: The battery cell assembly includes a pole piece, which includes a main body and a plurality of pole ears connected to the main body. The pole piece is wound, and a through hole is formed on a portion of the pole ears close to the winding center of the pole piece. The through hole penetrates the pole ears along the thickness direction of the pole ears, and the outermost pole ears among the plurality of pole ears are not provided with a through hole.

2. The battery cell assembly according to claim 1, characterized in that: The two ends of the main body in the flattened state in the length direction are respectively a core end and a tail end, the core end is the starting end of the winding of the pole piece in the winding state of the pole piece, and the tail end is the ending end of the winding of the pole piece in the winding state of the pole piece, the pole ear is arranged on one side in the width direction of the main body, and a plurality of the pole ears are spaced apart along the winding direction, the pole ear close to the tail end is the first pole ear, and the pole ear close to the core end is the second pole ear, the number of the second pole ears is greater than the number of the first pole ears, and the through hole is formed on the second pole ear.

3. The battery cell assembly according to claim 2, characterized in that: At least one of the first electrode tabs is disposed on a side of the second electrode tab away from the main body.

4. The battery cell assembly according to claim 2, characterized in that: The through holes formed on the plurality of second electrode tabs are at least partially opposite to and connected with each other.

5. The battery cell assembly according to claim 4, characterized in that: The through holes formed on the plurality of second pole tabs are directly opposite to and connected to each other along the winding axis.

6. The battery cell assembly according to claim 4, characterized in that: The through holes formed on the plurality of second pole tabs are opposed to and connected along the winding axial direction, and are staggered along the winding radial direction.

7. The battery cell assembly according to claim 2, characterized in that: The through holes are formed on each of the plurality of second pole tabs.

8. The battery cell assembly according to claim 2, characterized in that: Among the plurality of second pole tabs, some of the second pole tabs are formed with the through holes, and the second pole tabs formed with the through holes are arranged at intervals along the winding axial direction.

9. The battery core assembly according to claim 1, characterized in that: The main body includes a current collector and an active material layer, the active material layer is arranged on at least one surface of the current collector, the electrode tab is arranged on one side of the current collector in the width direction and is electrically connected to the current collector, and the distance between the edge of the active material layer close to the electrode tab along the width direction of the current collector and the electrode tab is greater than or equal to 0.5 mm.

10. A battery cell, characterized in that: It comprises a shell and a battery cell assembly according to any one of claims 1 to 9, wherein the shell is used to accommodate the battery cell assembly, and the electrode sheet is a positive electrode sheet and / or a negative electrode sheet.

11. A battery pack, characterized in that: The invention comprises a plurality of battery cells as claimed in claim 10.

12. An electrical device, characterized in that: Includes the battery cell according to claim 10 or the battery pack according to claim 11.

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