Battery cell component, battery cell and electrical apparatus

Abstract

A battery cell component (100), a battery cell (200), and an electrical apparatus. The battery cell component (100) comprises electrode sheets (10); the electrode sheets (10) each comprise a main body part (11) and a plurality of tabs (12) connected thereto; the electrode sheets (10) are wound; through holes (120) are formed in some of the plurality of tabs (12) close to the winding center of the electrode sheets (10); the through holes (120) pass through the tabs (12) in the thickness direction of the tabs (12); the outermost tabs (12) among the plurality of tabs (12) are not provided with through holes (120).

Description

Battery cell assembly, battery cell and electric device

[0001] Priority information

[0002] The present application claims priority to and the benefit of the filing date of Chinese Patent Application No. 202410866618X, filed on June 28, 2024, and which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present application relates to the technical field of batteries, and in particular to a battery cell assembly, a battery cell and an electric device. BACKGROUND

[0004] In the related art, in order to reduce the internal resistance of the battery and reduce the heat during charging and discharging, a cylindrical battery usually adopts a multi-tab or full-tab structure. However, the battery with such a structure has a large number of tabs stacked on both the positive and negative electrodes, which makes it difficult for the electrolyte to enter the inside of the battery cell assembly during the liquid injection process, and is prone to cause insufficient electrolyte immersion or prolonged immersion time. SUMMARY

[0005] The present application provides a battery cell assembly, a battery cell and an electric device, and at least solves the problem of liquid injection difficulty of the battery with a multi-tab structure.

[0006] In a first aspect, the present application provides a battery cell assembly, which comprises a tab sheet, the tab sheet comprising a main body portion and a plurality of tabs connected to the main body portion, the tab sheet being wound, and a portion of the tabs close to the winding center of the tab sheet being formed with a through hole, the through hole penetrating the tab along the thickness direction of the tab, and the outermost tabs of the plurality of tabs not being provided with a through hole.

[0007] In the battery cell assembly of the present application, the portion of the tabs close to the winding center of the tab sheet is formed with a through hole, so that the electrolyte can quickly penetrate from the through hole to the main body portion, thereby improving the efficiency of the liquid injection process during the manufacture of the battery cell assembly and the battery. At the same time, the outermost tabs are not provided with a through hole, which ensures the welding strength of the outermost tabs with external elements, so that the reliability of the battery cell assembly is high. In addition, in the case of battery formation or thermal runaway, the through hole on the tab can also make the gas generated inside the battery pass quickly, accelerate the battery exhaust, and improve the safety performance of the battery.

[0008] In some embodiments, the main body portion has two ends in the length direction in the flattened state, which are a winding core end and a winding tail end, the winding core end is the winding starting end of the tab sheet in the wound state of the tab sheet, the winding tail end is the winding ending end of the tab sheet in the wound state of the tab sheet, the tabs are arranged on one side of the main body portion in the width direction, the plurality of tabs are distributed in the winding direction, the tabs close to the winding tail end are first tabs, the tabs close to the winding core end are second tabs, the number of the second tabs is greater than the number of the first tabs, and the second tabs are formed with a through hole.

[0009] Thus, the second tab is formed with a through hole, and the number of the second tabs is greater than the number of the first tabs, so as to form as many channels as possible for the electrolyte to pass through. The first tab is located at the outer circle in the winding state of the pole piece and is used for welding with the external power connection structure. The first tab is not provided with a through hole and has a complete surface, thereby improving the adhesion rate and welding strength of the tab, and further facilitating the widening of the current channel, reducing the internal resistance of the battery monomer or battery pack, and improving the charge and discharge performance.

[0010] In some embodiments, the at least one first tab is arranged on a side of the second tab away from the main body part.

[0011] Thus, the complete surface of the second tab is reserved on the positive and negative electrodes of the battery cell assembly to strengthen the welding strength of the tab.

[0012] In some embodiments, the through holes formed on the plurality of second tabs are at least partially opposite and connected.

[0013] Thus, the through holes are at least partially opposite and connected, thereby forming a channel for the electrolyte to pass through, and further promoting the penetration of the electrolyte along the axial direction of the battery cell assembly to the inside of the battery cell assembly

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

[0015] Thus, the through holes formed on the plurality of second tabs are opposite and connected along the winding axial direction, thereby improving the electrolyte injection efficiency and enhancing the immersion effect of the pole piece.

[0016] In some embodiments, the through holes formed on the plurality of second tabs are partially opposite and connected along the winding axial direction and are arranged staggered along the winding radial direction.

[0017] Thus, the through holes formed on the plurality of second tabs are opposite and connected to each other along the axial direction of the battery cell assembly, so that the electrolyte can penetrate into the inside of the battery cell assembly along the direction of the opposite and connected two through holes, thereby accelerating the immersion speed.

[0018] In some embodiments, the through holes are formed on the plurality of second tabs.

[0019] Thus, it is beneficial for the electrolyte to penetrate the plurality of stacked tabs as quickly as possible.

[0020] In some embodiments, among the plurality of second tabs, part of the second tabs are formed with a through hole, and the second tabs formed with a through hole are arranged spaced apart along the winding axial direction.

[0021] In this way, the second tab with the through hole is arranged at intervals along the winding axis, which to some extent maintains the overall strength and stability of the tab and reduces the risk of the tab being broken or deformed due to stress concentration during the cycle use of the battery.

[0022] In some embodiments, the body part 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 tab is arranged on one side of the current collector 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 tab and the tab in the width direction of the current collector is greater than or equal to 0.5 mm.

[0023] In this way, the electrolyte quickly penetrates into the body part through the through hole, realizes sufficient soaking of the active material on the active material layer in a short time, thereby improving the electrolyte soaking effect and being beneficial to improving the charge and discharge performance of the battery cell assembly.

[0024] In a second aspect, the present application provides a battery monomer, which includes a shell and the battery cell assembly of any of the above embodiments, the shell is used to accommodate the battery cell assembly, and the tab is a positive tab and / or a negative tab.

[0025] The battery monomer of the embodiments of the present application includes the battery cell assembly of the above embodiments, and thus has all the beneficial effects of the battery cell assembly provided by the embodiments of the present application.

[0026] In a third aspect, the present application provides a power consumption device, which includes the battery monomer of the above embodiments.

[0027] The power consumption device of the embodiments of the present application includes the battery monomer of the above embodiments, by arranging the tab with the through hole in the battery cell assembly of the battery monomer, the soaking speed of the electrolyte is accelerated, the manufacturing efficiency of the battery monomer is improved, and the exhaust of the battery monomer is also accelerated, thereby improving the safety performance of the power consumption device.

[0028] Additional aspects and advantages of the present application will be made apparent from the following description of embodiments of the present application, which is given for the purpose of explanation and description, not limitation, taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0029] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description of embodiments, taken in conjunction with the accompanying drawings in which:

[0030] FIG. 1 is an axial sectional view of a battery monomer according to an embodiment of the present application;

[0031] FIG. 2 is a structural schematic diagram of the battery monomer shown in FIG. 1 in a top view;

[0032] FIG. 3 is a structural schematic diagram of a tab in a flattened state according to an embodiment of the present application;

[0033] Fig. 4 is a structural schematic view of the pole piece in a flattened state according to another embodiment of the present application;

[0034] Fig. 5 is a structural schematic view of the pole piece in a flattened state according to another embodiment of the present application;

[0035] Fig. 6 is a structural schematic view of the stacking of the tab at one end of the battery cell assembly according to an embodiment of the present application;

[0036] Fig. 7 is a structural schematic view of the stacking of the tab at one end of the battery cell assembly according to another embodiment of the present application;

[0037] Fig. 8 is a structural schematic view of the stacking of the tab at one end of the battery cell assembly according to another embodiment of the present application.

[0038] Reference numerals: battery 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, tab 12, through hole 120, first tab 121, second tab 122, positive tab 123, negative tab 124, positive pole piece 13, negative pole piece 14, winding core end 15, winding tail end 16; battery cell 200, case 210. DETAILED DESCRIPTION

[0039] Embodiments of the present application are described in detail below with reference to the attached drawings, which show by way of example, embodiments in which like numerals indicate like elements or elements having the same or similar function throughout the several views. The embodiments described below are exemplary only, and are not to be construed as limiting the present application.

[0040] In the description of the present application, it should be understood that the terms "center", "length", "width", "thickness", "upper", "lower", "front", "rear", "bottom", "inner", "outer", "axial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be construed as limiting the present application. In addition, features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise stated, the meaning of "a plurality of" is two or more.

[0041] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "linking" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be direct connection, or indirect connection through intermediate medium, or internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0042] Please refer to FIG. 1-3, the first aspect of the present application provides an electric core assembly 100, the electric core assembly 100 includes a tab 10, the tab 10 includes a main body part 11 and a plurality of tabs 12 connected with the main body part 11, the tab 10 is wound and arranged, a part of the plurality of tabs 12 close to the winding center 101 of the tab 10 is formed with a through hole 120, the through hole 120 penetrates the tab 12 along the thickness direction of the tab 12, and the outermost circle of the plurality of tabs 12 is not provided with the through hole 120.

[0043] Specifically, the tab 10 includes a positive tab 13 and a negative tab 14, the electric core assembly 100 is mainly formed by winding or stacking the positive tab 10 and the negative tab 10, and the part of the positive tab 10 and the negative tab 10 with active material constitutes the main body part 11 of the electric core assembly 100, and the part of the positive tab 10 and the negative tab 10 without active material constitutes the tab 12 respectively. A separator is usually arranged between the positive tab 13 and the negative tab 14. The positive tab 123 and the negative tab 124 can be located at one end of the main body part 11 or at two ends of the main body part 11 respectively. In the process of charging and discharging of the battery, the positive active material and the negative active material react with the electrolyte, and the metal ions move between the positive tab 13 and the negative tab 14, and the tab 12 connects the external electrical connection structure to form a current loop. The external structure can be, but is not limited to, electrode, terminal, busbar lead, etc.

[0044] The tab 12 can be made by cutting and folding process or rubbing and flattening process. The tab 12 can be shaped as parallelogram, rhombus, rectangle or ellipse, etc., which is not limited in the present application. The shape of the through hole 120 includes, but is not limited to, circle, ellipse, rhombus, etc., the aperture size of the through hole 120, the position of the through hole 120 on the tab 12, the number of the through hole 120, etc. are matched and designed according to the type and number of the tab 10.

[0045] The pole piece 10 is wound along the length direction of the body part 11 in the flattened state, and can be wound to form a shape of approximately a cylinder, a cuboid, a flat body, etc. The winding center 101 of the pole piece 10 is directed to the two ends of the battery cell assembly 100, and for the convenience of description, the axial direction of the winding center 101 is defined as the winding axial direction in the following description. The pole pieces 10 are stacked at the two ends of the body part 11 along the winding axial direction, the direction of the pole tabs 12 is parallel to the winding axial direction, the through holes 120 on the pole tabs 12 are directed outward from the end surface of the body part 11 and the battery cell assembly 100, and the electrolyte can quickly penetrate into the body part 11 through the through holes 120 when the electrolyte is injected into the battery cell assembly 100.

[0046] In the flattened state of the pole piece 10, the pole tabs 12 extend outward from the body part 11 along the width direction of the body part 11, and a plurality of diamond-shaped pole tabs 12 are arranged along the length direction of the body part 11. The pole piece 10 forms a structure of a plurality of electrode layers stacked in the wound state, and the pole tabs 12 are folded or flattened at the end of the pole piece 10 along the winding axial direction to the winding center 101 to align and fix with each layer of the plurality of electrode layers.

[0047] The outermost pole tab 12 of the plurality of pole tabs 12 is not provided with a through hole 120, that is, the surface of the outermost pole tab 12 away from the body part 11 along the stacking direction of the pole tabs 12 is a complete surface, and the outermost pole tab 12 is not provided with a through hole 120 or other holes, grooves, notches, etc., especially the surface of the above-mentioned pole tab 12 directed outward from the battery cell assembly 100 is relatively smooth and complete, so as to be welded with an external electrical connection structure, to avoid the occurrence of a virtual welding phenomenon, to ensure the welding strength of the pole tab 12, and to further improve the stability and reliability of the current loop formed by the battery cell assembly 100.

[0048] In a specific example, the pole piece 10 is wound in a cylindrical shape, and the pole tabs 12 are stacked at the two ends of the battery cell assembly 100 along the axial direction, one end being a positive pole tab 123 and the other end being a negative pole tab 124. The edge of the pole tab 12 in the width direction of the pole piece 10 is cut into a diamond shape, and one side of the diamond shape is connected with the edge of the body part 11. Then the pole tab 12 is folded towards the winding center 101 as the pole piece 10 is wound, and is flattened at the two ends of the battery cell assembly 100. A plurality of layers of pole tabs 12 near the winding center 101 are provided with through holes 120 at the geometric center, and the two layers of pole tabs 12 located at the outermost side along the winding axial direction are provided with complete surfaces and are welded with an external electrical connection structure. The plurality of pole tabs 12 are stacked along the winding axial direction and aligned at the edges, so that the through holes 120 on the plurality of layers of pole tabs 12 are connected in an up-down direction, to achieve rapid liquid permeation.

[0049] The part of the tab 12 close to the winding center 101 of the electrode sheet 10 forms a through hole 120 in the electrode assembly 100 of the embodiment of the present application, so that the electrolyte can quickly permeate from the through hole 120 to the main body part 11, thereby improving the efficiency of the liquid injection process in the electrode assembly 100 and the battery manufacturing process. At the same time, the outermost circle of the plurality of tabs 12 is not provided with a through hole 120, which guarantees the welding strength of the outermost circle of the tab 12 and the external element, so that the reliability of the electrode assembly 100 is higher. In addition, in the case of battery formation or thermal runaway, the through hole 120 on the tab 12 can also make the gas generated inside the battery quickly pass through, accelerate the battery exhaust, and improve the safety performance of the battery.

[0050] Please refer to FIG. 1 and FIG. 3, in some embodiments, the length direction of the main body part 11 in the flat state has two ends, which are the winding core end 15 and the winding tail end 16. The winding core end 15 is the winding starting end of the electrode sheet 10 in the winding state of the electrode sheet 10, and the winding tail end 16 is the winding end of the electrode sheet 10 in the winding state of the electrode sheet 10. The plurality of tabs 12 are distributed along the winding direction, the tab 12 close to the winding tail end 16 is the first tab 121, and the tab 12 close to the winding core end 15 is the second tab 122. The number of the second tab 122 is greater than the number of the first tab 121, and the through hole 120 is formed on the second tab 122.

[0051] Specifically, taking the electrode sheet 10 in the flat state as an example, the winding core end 15 and the winding tail end 16 are located at the two opposite wide sides of the electrode sheet 10 along the length direction. The electrode sheet 10 is wound along the length direction of itself and can be wound to form a cylindrical shape. The winding center 101 forms a center hole 103. The winding starting end is the winding core end 15, and the winding end is the winding tail end 16. After winding, the winding core end 15 is located at the innermost layer in the radial direction of the electrode assembly 100 and can form the inner wall surface of the center hole 103; the winding tail end 16 is located at the outermost layer in the radial direction of the electrode assembly 100 and covers the outer peripheral surface 105 of the electrode assembly 100. The width direction of the main body part 11 in the flat state is the winding axial direction. The winding direction of the electrode sheet 12 in the winding state can be clockwise or counterclockwise. The winding direction of the electrode sheet 12 in the winding state is defined as the winding radial direction, and the winding radial direction can be in the same direction as the circumferential direction of the center hole 103.

[0052] The tabs 12 are distributed at the ends of the electrode sheet 10 in the width direction, and the positive tab 123 and negative tab 124 are located at both ends of the cell assembly 100 in the axial direction. The first tab 121 is close to the winding end 16 when the electrode sheet 10 is flattened. In the stacked positive tab 123 and negative tab 124, the first tab 121 is located on the side away from the main body 11 along the winding axis, and at least covers both ends of the cell assembly 100 in the axial direction. The second tab 122 is close to the winding core end 15 when the electrode sheet 10 is flattened. In the stacked positive tab 123 and negative tab 124, it is located on the side close to the main body 11 along the winding axis.

[0053] The number of second tabs 122 is greater than the number of first tabs 121. The second tabs 122 have through holes 120 to create as many channels as possible for the electrolyte to pass through. The first tabs 121, in the wound state of the electrode sheet 10, are located on the outer ring among the multiple tabs 12 and are used for welding to external electrical connections. The number of first tabs 121 welded to external electrical connections is less than the total number of first tabs 121. The first tabs 121 do not have through holes, and their surfaces are complete, improving the adhesion rate and welding strength of the tabs 12. This, in turn, facilitates the widening of the current channel, reduces the internal resistance of the battery cell 200 or the battery pack, and improves charge and discharge performance.

[0054] Please refer to Figures 1 and 6. Figure 6 is a schematic diagram of the stacked structure of the tabs 12 at one end of the axially upward ends of the cell assembly 100. In some embodiments, at least one first tab 121 is disposed on the side of the second tab 122 opposite to the main body 11.

[0055] Specifically, defining the winding axis as the vertical direction, the first electrode 121 is stacked above the second electrode 122 along the winding axis, with the position of the main body 11 as the bottom, and the second electrode 122 closer to the main body 11 is positioned lower than the second electrode 122. At least one first electrode 121 is provided at each end of the cell assembly 100 along the winding axis, that is, at the positive and negative terminals of the cell assembly 100.

[0056] Thus, the complete surface of the second tab 122 is retained on both the positive and negative terminals of the cell assembly 100 to enhance the welding strength of the tab 12.

[0057] Referring to Figures 6 and 7, in some embodiments, the through holes 120 formed on the plurality of second tabs 122 are at least partially opposite and connected.

[0058] Specifically, due to the compact stacking of the tabs 12, when the electrolyte penetrates into the cell assembly 100 through the through-holes 120, it also flows and wets along the surface of the tabs 12 where the through-holes 120 are located, which may slow down the rate at which the electrolyte penetrates into the cell assembly 100. Therefore, the multiple through-holes 120 are aligned with each other along the stacking direction of the tabs 12, that is, the winding axis, and are at least partially connected to each other, reducing the obstruction to the penetration of the electrolyte from the tabs 12 into the main body 11.

[0059] Thus, the through holes 120 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 cell assembly 100 along the winding axis.

[0060] Referring to Figure 6, in some embodiments, the through holes 120 formed on the plurality of second tabs 122 are aligned and connected along the winding axis.

[0061] Specifically, to ensure accurate alignment with the multilayer electrodes, multiple tabs 12 are identical in shape and size, and are stacked sequentially facing each other along the winding axis. The through-holes 120 formed on the second tabs 122 are all located at the same position. In the embodiment shown in Figure 6, the through-holes 120 are circular holes located at the geometric center of the square tabs 12. The through-holes 120 formed on the multiple second tabs 122 are arranged linearly along the stacking direction of the tabs 12, that is, along the winding axis, allowing the electrolyte to quickly penetrate from the outer end of the cell assembly 100 to the inner end along the arrangement direction of the through-holes 120.

[0062] Furthermore, each second tab 122 has a through hole 120 formed thereon, and multiple through holes 120 are aligned and connected along the winding axis, thereby forming a linear channel that runs through the axial direction of the cell assembly 100, further promoting the penetration of electrolyte.

[0063] Thus, by having the through holes 120 formed on the multiple second tabs 122 aligned and connected along the winding axis, the electrolyte injection efficiency is improved, and the wetting effect of the electrode 10 is enhanced.

[0064] Referring to Figure 7, in some embodiments, the through holes 120 formed on the plurality of second tabs 122 are partially opposite and connected along the winding axial direction, and are staggered along the winding radial direction.

[0065] Specifically, multiple tabs 12 can be aligned and stacked along the winding axis, and the positions of the through holes 120 on the second tabs 122 can be staggered relative to each other along the winding radial direction. The through holes 120 on two adjacent second tabs 122 can be obliquely upward or obliquely downward opposite each other, and their positions in the winding radial direction partially overlap.

[0066] In another example, the positions of the plurality of second tabs 122 in the radial direction of the cell assembly 100 may be staggered, such that the through holes 120 on the second tabs 122 are staggered along the winding radial direction. In this embodiment, the through holes 120 on two adjacent second tabs 122 are obliquely upward or obliquely downward opposite to each other and connected.

[0067] Thus, the through holes 120 formed on the multiple second tabs 122 are obliquely upward or obliquely downward and interconnected with each other along the winding axis, so that the electrolyte can penetrate into the cell assembly 100 along the direction in which two adjacent through holes 120 are opposite and interconnected, thereby accelerating the wetting speed.

[0068] Please refer to Figures 3 and 6. In some embodiments, through holes 120 are formed on each of the multiple second tabs 122.

[0069] Specifically, there are multiple second tabs 122 to ensure that there are enough layers of tabs 12 with through holes 120 to allow the electrolyte to penetrate as quickly as possible. Each second tab 122 has a through hole 120, meaning that except for a few tabs 12 near the end of the roll 16, each tab 12 near the center end 15 or relatively far from the end of the roll 16 has at least one through hole 120.

[0070] This allows the electrolyte to penetrate the multi-layered stacked tabs 12 as quickly as possible.

[0071] Please refer to Figures 4 and 5. In some embodiments, among the plurality of second tabs 122, some of the second tabs 122 are formed with through holes 120, and the second tabs 122 with through holes 120 are arranged at intervals along the winding axis.

[0072] Specifically, as shown in Figure 8, in the flattened state of the electrode sheet 10, second electrode tabs 122 with through holes 120 and second electrode tabs 122 without through holes 120 are arranged alternately along the length direction of the electrode sheet 10. The electrode tabs 12 are stacked and flattened after being wound with the electrode sheet 10. In the stacked electrode tabs 12, along the winding axis, that is, along the stacking direction of the electrode tabs 12, second electrode tabs 122 with through holes 120 and second electrode tabs 122 without through holes 120 are arranged alternately along the length direction of the electrode sheet 10, with a layer of second electrode tabs 122 without through holes 122 between every two adjacent through holes 120.

[0073] As shown in Figure 5, with the electrode sheet 10 flattened, every two second electrode tabs 122 with through holes 120 and one second electrode tab 122 without through holes 120 are arranged sequentially along the length of the electrode sheet 10. In the stacked electrode tabs 12, along the stacking direction of the electrode tabs 12, that is, along the winding axis, the second electrode tabs 122 with through holes 120 and the second electrode tabs 122 without through holes 120 are arranged alternately, with each second electrode tab 122 without through holes 122 separated by two second electrode tabs 122 with through holes 120.

[0074] The size, spacing, and arrangement of the through holes 120 can be adjusted according to the application scenarios and requirements of different battery cell components 100, so as to be applied to various battery cells 200 and / or battery packs.

[0075] Thus, the second tabs 122 with through holes 120 are arranged at intervals along the winding axis, which to a certain extent maintains the overall strength and stability of the tabs 12 and reduces the risk of the tabs 12 breaking or deforming due to stress concentration during battery cycling.

[0076] Please refer to Figure 8. In some embodiments, the tabs 12 are connected sequentially along their width or length direction and stacked along their thickness direction.

[0077] Taking a square tab 12 as an example, multiple tabs 12 are connected or joined together along their width direction and stacked sequentially along their thickness direction, forming a stepped shape arranged diagonally downwards. In the electrolyte injection process, the electrolyte penetrates diagonally downwards along the edge of the tab 12, thereby accelerating the electrolyte penetration speed and improving the efficiency of the electrolyte injection process.

[0078] Please refer to Figures 1 and 2. In some embodiments, the battery cell assembly 100 is wound into a cylindrical shape, and a central hole 103 is formed at the winding center 101 of the battery cell assembly 100, which extends through both ends of the battery cell assembly 100 in the axial direction.

[0079] Specifically, the battery cell assembly 100 achieves charging and discharging functions through chemical reactions at the positive and negative electrodes. However, some chemical reactions can easily generate gas, increasing internal pressure and thus affecting the cycle life of the battery cell assembly 100. The winding center 101 of the battery cell assembly 100 forms a central hole 103, which extends through both ends of the circumference of the battery cell assembly 100. Gas generated on all the tightly stacked and bonded electrode sheets 10 and the separator in the battery cell assembly 100 can flow into the central hole 103.

[0080] 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 safety of charging and discharging.

[0081] Referring to 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, and the tab 12 is disposed on one side of the current collector 111 in the width direction and electrically connected to the current collector 111. The distance d between the edge of the active material layer 112 in the width direction of the electrode 10 and the tab 12 is greater than or equal to 0.5 mm.

[0082] Specifically, the battery cell assembly 100 uses an electrolyte to wet the active material layer 112, causing active particles in the active material to move between the positive electrode 13 and the negative electrode 14, resulting in a chemical reaction that generates electrical energy. The active material layer 112 is formed by laminating or coating the active material with the main body 11. The active material layer 112 of the positive electrode 13 and the active material layer 112 of the negative electrode 14 use different active materials that can undergo corresponding chemical reactions.

[0083] Taking a lithium-ion battery cell 200 as an example, the current collector 111 of the positive electrode can be aluminum foil, the material of the main body 11 can be aluminum, and the active material layer 112 can be coated with active materials such as lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide. The current collector 111 of the negative electrode can be copper foil, and the active material layer 112 can be made of carbon or silicon. A separator is disposed between the active material layer 112 of the positive electrode 13 and the negative electrode 14, and the material of the separator can be PP (polypropylene) or PE (polyethylene).

[0084] In this way, the electrolyte can quickly penetrate into the main body 11 through the through hole 120, thereby fully wetting the active material on the active material layer 112 in a short time, thus improving the electrolyte wetting effect and improving the charging and discharging performance of the battery cell assembly 100.

[0085] Please refer again to Figures 1 and 2. In a second aspect, the present invention provides a battery cell 200, which includes a housing 210 and a cell assembly 100 of any of the above embodiments. The housing 210 is used to house the cell assembly 100, and the electrode 12 is a positive electrode 13 and / or a negative electrode 14.

[0086] Specifically, the battery cell 200 can be a cylindrical battery cell 200, a prismatic battery cell 200, a pouch battery cell 200, or other shaped battery cells 200. Prismatic battery cells 200 include, but are not limited to, prismatic battery cells 200, blade-shaped battery cells 200, and multi-prismatic batteries, such as hexagonal prismatic batteries. The cell assembly 100 is the component in the battery cell 200 where the electrochemical reaction occurs. The casing 210 can contain one or more cell assemblies 100. The material of the casing 210 can include, but is not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, and plastic.

[0087] The battery cell 200 of this application embodiment includes the cell assembly 100 of the above embodiment, and therefore has all the beneficial effects of the cell assembly 100 provided in the embodiments of this application.

[0088] Thirdly, the present invention proposes a battery pack (not shown) comprising a plurality of battery cells 200 of the above embodiments.

[0089] Specifically, the battery cell 200 is the smallest unit that makes up the battery pack. Multiple battery cells 200 in the battery pack can be connected in series, parallel, or a combination thereof. A combination thereof means that multiple battery cells 200 are connected in both series and parallel. The battery pack can be a pouch cell, cylindrical cell, or prismatic cell. The battery pack may also include a housing and a busbar. The housing houses the battery cells 200; the busbar connects to the tabs 12 in the battery cells 200 to achieve electrical connection between multiple battery cells 200.

[0090] Each battery cell 200 in the battery pack can be a secondary battery or a primary battery. A primary battery, also known as a first-stage battery, cannot be recharged after its power is depleted and must be discarded. A secondary battery, also known as a rechargeable battery, secondary battery, or storage battery, can be used multiple times after being recharged. 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-metal hydride battery, or a lithium-ion battery, but is not limited to these.

[0091] The battery cell 200 with a multi-tab 12 structure provided in this application embodiment is particularly suitable for high-energy-density lithium-ion battery packs in electric vehicles, energy storage systems, and high-performance mobile devices. By forming through-holes 120 through several tabs 12 in the positive and negative electrodes to allow electrolyte to pass through quickly, not only is the battery manufacturing efficiency improved and the electrolyte wetting effect enhanced, but the safety and stability of the battery pack are also further strengthened.

[0092] Fourthly, the present invention provides an electrical device (not shown) comprising the battery cell 200 or battery pack described in the above embodiments.

[0093] The electrical devices disclosed in this application include electrical equipment that uses individual battery cells 200 or battery packs as power sources, or various energy storage systems that use batteries as energy storage elements. These electrical devices can be, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc. Electric vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc.

[0094] The electrical device in this application embodiment includes the battery cell 200 or battery pack of the above embodiments. By providing tabs 12 with through holes 120 in the cell assembly 100 of the battery cell 200, the wetting speed of the electrolyte is accelerated, the manufacturing efficiency of the battery cell 200 and the battery pack is improved, and the venting of the battery (including the battery pack and the battery cell 200) is accelerated, thereby improving the safety performance of the electrical device.

[0095] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0096] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A battery cell assembly (100), wherein, The battery cell assembly (100) includes an electrode (10), the electrode (10) includes a main body (11) and a plurality of tabs (12) connected to the main body (11). The electrode (10) is wound up. A portion of the tabs (12) near the winding center (101) of the electrode (10) has a through hole (120). The through hole (120) penetrates the tab (12) along the thickness direction. The outermost tab (12) among the plurality of tabs (12) does not have a through hole (120).

2. The battery cell assembly (100) according to claim 1, wherein, The main body (11) has a core end (15) and a tail end (16) in the length direction when it is flattened. The core end (15) is the starting end of the winding of the electrode (10) when the electrode (10) is wound. The tail end (16) is the ending end of the winding of the electrode (10) when the electrode (10) is wound. The electrode tab (12) is located on one side of the main body (11) in the width direction. A plurality of electrode tabs (12) are distributed at intervals along the winding direction. The electrode tab (12) near the tail end (16) is the first electrode tab (121), and the electrode tab (12) near the core end (15) is the second electrode tab (122). The number of second electrode tabs (122) is greater than the number of first electrode tabs (121). The through hole (120) is formed on the second electrode tab (122).

3. The cell assembly (100) according to claim 2, wherein, At least one of the first electrode tabs (121) is disposed on the side of the second electrode tab (122) opposite to the main body (11).

4. The cell assembly (100) according to claim 2, wherein, The through holes (120) formed on the plurality of second tabs (122) are at least partially opposite and connected.

5. The cell assembly (100) according to claim 4, wherein, The through holes (120) formed on the plurality of second tabs (122) are aligned and connected along the winding axis.

6. The cell assembly (100) according to claim 4, wherein, The through holes (120) formed on the plurality of second tabs (122) are opposite to and connected along the winding axial direction, and are staggered along the winding radial direction.

7. The cell assembly (100) according to claim 2, wherein, The through holes (120) are formed on each of the multiple second electrode tabs (122).

8. The cell assembly (100) according to claim 2, wherein, In a plurality of second tabs (122), some of the second tabs (122) are formed with the through holes (120), and the second tabs (122) with the through holes (120) are arranged at intervals along the winding axis.

9. The cell assembly (100) according to claim 1, wherein, 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 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). The distance between the edge of the active material layer (112) near the tab (12) in the width direction of the current collector (111) and the tab (12) is greater than or equal to 0.5 mm.

10. A single battery cell (200), wherein, The battery assembly includes a housing (210) and a cell assembly (100) according to any one of claims 1-9, wherein the housing (210) is used to house the cell assembly (100), and the electrode (10) is a positive electrode (13) and / or a negative electrode (14).

11. An electrical appliance, wherein, Includes the battery cell (200) as described in claim 10.

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