Battery cell and electric equipment

Abstract

The invention provides a battery cell and electric equipment, a shell of the battery cell further comprises a first wall and a second wall which are oppositely arranged along the thickness direction of the battery cell, the first wall comprises a first main body wall and a first step wall, and the first step wall is sunken towards the direction close to the second wall relative to the first main body wall. The battery cell further comprises an electrode assembly and an electrode terminal, the electrode assembly is arranged in the shell, and the electrode assembly comprises a first pole piece and a second pole piece which are opposite in polarity. The electrode terminal is arranged on the first step wall and electrically connected with the first pole piece, and the thickness H0 of the first step wall meets the condition that H0 is smaller than or equal to 0.2 mm. The reinforcing structure is formed between the first main body wall and the first step wall, so that the possibility that the first step wall deforms after being stressed is low, the sealing effectiveness between the electrode terminal and the first step wall can be kept, the risk of electrolyte leakage is reduced, and the safety of the battery cell is improved.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and more particularly, to an electric core and an electrical device using the same. Background Art

[0002] With the rapid development of electronic information technology, various electronic devices are also developing towards the direction of intelligence and multi-functionality, and the safety requirements for batteries are getting higher and higher.

[0003] Currently, in order to improve the energy density of the electric core, the thickness of the outer shell of the electric core is relatively thin, so that the outer shell is prone to deformation when the electric core is stressed, resulting in the sealing failure and liquid leakage between the electrode terminal disposed on the outer shell and the outer shell, affecting the safety of the electric core. Summary of the Invention

[0004] The present application provides an electric core and an electrical device using the same, which can improve the safety of the electric core.

[0005] In a first aspect, the present application provides an electric core, which includes an outer shell. The outer shell further includes a first wall and a second wall oppositely disposed along the thickness direction of the electric core. The first wall includes a first main wall and a first stepped wall. Along the length direction of the electric core, the first stepped wall is located at one end of the first main wall, and the first stepped wall is recessed towards the second wall relative to the first main wall. The first stepped wall and the first main wall are connected by a first connecting wall. The electric core further includes an electrode assembly and an electrode terminal. The electrode assembly is disposed in the outer shell and includes a first pole piece and a second pole piece with opposite polarities. The electrode terminal is disposed on the first stepped wall and is electrically connected to the first pole piece. The thickness H0 of the first stepped wall satisfies H0 ≤ 0.2 mm.

[0006] In the above technical solution, since the thickness H0 of the first stepped wall satisfies H0 ≤ 0.2 mm, the energy density of the electric core can be improved, and the space at the corresponding position of the step can be increased. However, if the electrode terminal is disposed on the side wall of the outer shell, under mechanical abuse conditions such as rolling and dropping, the side wall of the outer shell is prone to deformation under the impact of the electrode assembly, while the electrode terminal is not easily deformed, resulting in the sealing failure between the side wall and the electrode terminal. By making the first stepped wall located at one end of the first main wall along the length direction of the electric core, the first stepped wall is recessed towards the second wall relative to the first main wall, and the electrode terminal is disposed on the first stepped wall; when the electric core is subjected to an external force, the first main wall is stressed before the first stepped wall, so that the possibility of the first stepped wall being deformed by stress is relatively low, and the possibility of the electrode terminal being directly stressed is also relatively low. Moreover, a reinforcing structure is formed between the first main wall and the first stepped wall, so that the possibility of the first stepped wall being deformed after being stressed is relatively low, the sealing effectiveness between the electrode terminal and the first stepped wall can be maintained, the risk of electrolyte leakage can be reduced, and it is beneficial to improve the safety of the electric core.

[0007] In some embodiments of the present application, the length of the battery cell is L1, the width of the battery cell is W1, and the thickness of the battery cell is H1, satisfying L1 > W1, L1 > H1, and 3 mm ≤ W1 ≤ 20 mm.

[0008] In the above technical solution, the length of the battery cell is L1, the width of the battery cell is W1, and the thickness of the battery cell is H1, satisfying L1 > W1, L1 > H1, and 3 mm ≤ W1 ≤ 20 mm, that is, the battery cell is a narrow and long battery cell. By disposing the electrode terminal at one end of the outer casing along the length direction of the battery cell, the space occupied by the electrode terminal can be made smaller.

[0009] When W1 ≥ 3 mm, it is convenient for the preparation of the electrode assembly and the assembly of the electrode assembly and the outer casing; when W1 ≤ 20 mm, the applicable range of the battery cell can be made wider; therefore, when 3 mm ≤ W1 ≤ 20 mm, it is both convenient for the preparation of the electrode assembly and the assembly of the electrode assembly and the outer casing, and the applicable range of the battery cell can be made wider.

[0010] In some embodiments of the present application, the electrode assembly is located between the first main body wall and the second wall, and along the thickness direction of the battery cell, the projection of the electrode assembly does not overlap with the projection of the electrode terminal.

[0011] In the above technical solution, by making the electrode assembly located between the first main body wall and the second wall, and along the thickness direction of the battery cell, the projection of the electrode assembly does not overlap with the projection of the electrode terminal, no space needs to be reserved for the electrode terminal between the first main body wall and the second wall, and the space between the first main body wall and the second wall for accommodating the electrode assembly is larger, which is beneficial to improving the energy density of the battery cell. On the other hand, the problem that the electrode assembly may hit the electrode terminal due to shaking in the outer casing does not need to be considered.

[0012] In some embodiments of the present application, along the length direction of the battery cell, the distance between the electrode assembly and the first connecting wall is G, satisfying 0.5 mm ≤ G ≤ 4 mm.

[0013] In the above technical solution, when G ≥ 0.5 mm, the possibility of interference generated when the electrode assembly is inserted into the outer casing can be reduced, thereby facilitating the preparation of the battery cell; when G ≤ 4 mm, the space in the outer casing for accommodating the electrode assembly can be made larger, which is beneficial to improving the energy density of the battery cell; therefore, when 0.5 mm ≤ G ≤ 4 mm, it is both possible to reduce the possibility of interference generated when the electrode assembly is inserted into the outer casing, thereby facilitating the preparation of the battery cell, and the space in the outer casing for accommodating the electrode assembly can be made larger, which is beneficial to improving the energy density of the battery cell.

[0014] In some embodiments of the present application, 1 mm ≤ G ≤ 2.5 mm.

[0015] In the above technical solution, when G ≥ 1 mm, the possibility of interference generated when the electrode assembly is inserted into the housing can be further reduced, thus facilitating the preparation of the battery cell; when G ≤ 2.5 mm, the space in the housing for accommodating the electrode assembly can be further increased, which is beneficial to improving the energy density of the battery cell; and since the projection of the electrode assembly does not overlap with the projection of the electrode terminal, there is no need to reserve space for the electrode terminal, and G can be made within 2.5 mm. Therefore, when 1 mm ≤ G ≤ 2.5 mm, it can not only reduce the possibility of interference generated when the electrode assembly is inserted into the housing, thus facilitating the preparation of the battery cell, but also increase the space in the housing for accommodating the electrode assembly, which is beneficial to improving the energy density of the battery cell.

[0016] In some embodiments of the present application, the battery cell further includes a first electrical connector and a transfer board. Along the length direction of the battery cell, the first electrical connector is disposed at one end of the electrode assembly close to the first step wall and is connected to the first electrode tab. The transfer board is disposed in the housing and between the first step wall and the second wall. The first electrical connector is connected to the transfer board, and the transfer board is connected to the electrode terminal.

[0017] In the above technical solution, since the size of the electrode terminal is small, when the electrode terminal is installed in the housing, the sealing area between the electrode terminal and the housing is small, the sealing effect is not good, and the problem of electrolyte leakage is likely to occur. By providing the transfer board, the transfer board is disposed in the housing and between the first step wall and the second wall. The first electrical connector is connected to the transfer board, and the transfer board is connected to the electrode terminal, so that a seal can be formed between the transfer board and the housing, thereby increasing the sealing area between the electrode terminal and the housing, improving the sealing effect, and reducing the possibility of electrolyte leakage.

[0018] In some embodiments of the present application, the thickness direction of the transfer board is parallel to the thickness direction of the battery cell. The transfer board has a first connection area connected to the first electrical connector and a second connection area connected to the electrode terminal. The first connection area and the second connection area are spaced apart along the width direction of the battery cell.

[0019] In the above technical solution, since the current layer-by-layer stacking and connection of the electrode terminal, the transfer board, and the first electrical connector will occupy a large space in the thickness direction of the battery cell, affecting the energy density of the battery cell. By making the thickness direction of the transfer board parallel to the thickness direction of the battery cell, the transfer board has a first connection area connected to the first electrical connector and a second connection area connected to the electrode terminal, and the first connection area and the second connection area are spaced apart along the width direction of the battery cell, so that the electrode terminal and the first electrical connector can be disposed on the same side of the transfer board, thereby making the overall thickness of the electrode terminal, the transfer board, and the first electrical connector in the thickness direction of the battery cell smaller, which is beneficial to improving the energy density of the battery cell.

[0020] In some embodiments of the present application, the width of the battery cell is W1, and along the width direction of the battery cell, the width of the adapter plate is W2, satisfying 80% ≤ W2 / W1 ≤ 99%.

[0021] In the above technical solution, when W2 / W1 ≥ 80%, the area of the adapter plate can be made larger, which is convenient for connecting the adapter plate to the first electrical connector and the electrode terminal; when W2 / W1 ≤ 99%, the possibility of interference generated when the adapter plate is inserted into the housing can be reduced, thus facilitating the preparation of the battery cell; therefore, when 80% ≤ W2 / W1 ≤ 99%, it is both convenient for connecting the adapter plate to the first electrical connector and the electrode terminal, and can reduce the possibility of interference generated when the adapter plate is inserted into the housing, thus facilitating the preparation of the battery cell.

[0022] Since the width W1 of the battery cell satisfies 3 mm ≤ W1 ≤ 20 mm, the width of the battery cell is small. If two electrode terminals with opposite polarities are provided on the battery cell and the two electrode terminals are arranged along the width direction of the battery cell, the difficulty of preparing the battery cell will be relatively high, and there is a risk of contact short circuit between the two electrode terminals. Therefore, by making 80% ≤ W2 / W1 ≤ 99%, that is, only one electrode terminal is provided on the first step wall, the difficulty of preparing the battery cell can be reduced, and the risk of short circuit of the battery cell can be reduced.

[0023] In some embodiments of the present application, the length of the battery cell is L1, and along the length direction of the battery cell, the length of the first step wall is L2, satisfying 0.01 ≤ L2 / L1 ≤ 0.5.

[0024] In the above technical solution, when L2 / L1 ≥ 0.01, the first step wall can have sufficient space for arranging the electrode terminal, which is beneficial to reducing the difficulty of preparing the battery cell and improving the preparation efficiency of the battery cell; when L2 / L1 ≤ 0.5, the space occupied by the electrode terminal can be made smaller, and there is more space in the housing for accommodating the electrode assembly, which is beneficial to improving the energy density of the battery cell; therefore, when 0.01 ≤ L2 / L1 ≤ 0.5, it can both make the first step wall have sufficient space for arranging the electrode terminal, which is beneficial to reducing the difficulty of preparing the battery cell and improving the preparation efficiency of the battery cell, and make the space occupied by the electrode terminal smaller, and there is more space in the housing for accommodating the electrode assembly, which is beneficial to improving the energy density of the battery cell.

[0025] In some embodiments of the present application, along the length direction of the battery cell, the length of the first step wall is L2, satisfying 1.5 mm ≤ L2 ≤ 10 mm.

[0026] In the above technical solution, when L2 ≥ 1.5 mm, it can make the first step wall have enough space for arranging the electrode terminals, which is beneficial to reducing the preparation difficulty of the battery cell and improving the preparation efficiency of the battery cell; when L2 ≤ 10 mm, it can make the space occupied by the electrode terminals smaller, and there is more space in the outer shell for accommodating the electrode assembly, which is beneficial to improving the energy density of the battery cell; therefore, when 1.5 mm ≤ L2 ≤ 10 mm, it can not only make the first step wall have enough space for arranging the electrode terminals, which is beneficial to reducing the preparation difficulty of the battery cell and improving the preparation efficiency of the battery cell, but also make the space occupied by the electrode terminals smaller, and there is more space in the outer shell for accommodating the electrode assembly, which is beneficial to improving the energy density of the battery cell.

[0027] In some embodiments of the present application, 2.5 mm ≤ L2 ≤ 8 mm.

[0028] In the above technical solution, when L2 ≥ 2.5 mm, it can further make the first step wall have enough space for arranging the electrode terminals, which is beneficial to reducing the preparation difficulty of the battery cell and improving the preparation efficiency of the battery cell; when L2 ≤ 8 mm, it can further make the space occupied by the electrode terminals smaller, and there is more space in the outer shell for accommodating the electrode assembly, which is beneficial to improving the energy density of the battery cell; therefore, when 2.5 mm ≤ L2 ≤ 8 mm, it can not only further make the first step wall have enough space for arranging the electrode terminals, which is beneficial to reducing the preparation difficulty of the battery cell and improving the preparation efficiency of the battery cell, but also further make the space occupied by the electrode terminals smaller, and there is more space in the outer shell for accommodating the electrode assembly, which is beneficial to improving the energy density of the battery cell.

[0029] In some embodiments of the present application, the second wall includes a second main wall and a second step wall. Along the length direction of the battery cell, the second step wall is located at one end of the second main wall, and the second step wall is recessed relative to the second main wall in a direction close to the first wall. The second step wall and the second main wall are connected by a second connecting wall; the electrode assembly is located between the first main wall and the second main wall. Along the thickness direction of the battery cell, the projection of the first step wall and the projection of the second step wall overlap.

[0030] In the above technical solution, by making the second step wall be located at one end of the second main wall along the length direction of the battery cell, and the second step wall is recessed relative to the second main wall in a direction close to the first wall, and along the thickness direction of the battery cell, the projection of the first step wall and the projection of the second step wall overlap, a reinforcing structure is formed between the second main wall and the second step wall, further making the strength of the part of the housing where the electrode terminals are located higher, making the possibility of deformation of the first step wall under force lower, being able to maintain the sealing effectiveness between the electrode terminals and the first step wall, reducing the risk of electrolyte leakage, and being beneficial to improving the safety of the battery cell.

[0031] In some embodiments of the present application, the surface of the second wall facing away from the first wall is a plane.

[0032] In the above technical solution, by making the surface of the second wall facing away from the first wall a plane, it is convenient to prepare and form the second wall, which is beneficial to improving the preparation efficiency of the battery cell.

[0033] In some embodiments of the present application, the second electrode tab is electrically connected to the outer casing.

[0034] In the above technical solution, since the width W1 of the battery cell satisfies 3 mm ≤ W1 ≤ 20 mm and the width of the battery cell is small, if two electrode terminals with opposite polarities are provided on the battery cell and the two electrode terminals are arranged along the width direction of the battery cell, it will make the preparation of the battery cell difficult and there is a risk of contact short circuit between the two electrode terminals. By making the second electrode tab electrically connected to the outer casing, it is possible to eliminate the need to provide an electrode terminal for the corresponding second electrode tab, that is, only one electrode terminal needs to be provided on the first stepped wall, which can reduce the preparation difficulty of the battery cell and the risk of short circuit of the battery cell.

[0035] In some embodiments of the present application, the second wall has a first region that projects and overlaps with the first stepped wall along the thickness direction of the battery cell. The battery cell further includes a second electrical connector. Along the length direction of the battery cell, the second electrical connector is disposed at one end of the electrode assembly close to the first stepped wall. One end of the second electrical connector is connected to the second electrode tab, and the other end is connected to the first region.

[0036] In the above technical solution, by making the second wall have a first region that projects and overlaps with the first stepped wall along the thickness direction of the battery cell, and along the length direction of the battery cell, the second electrical connector is disposed at one end of the electrode assembly close to the first stepped wall, with one end of the second electrical connector connected to the second electrode tab and the other end connected to the first region, the first electrical connector and the second electrical connector can share the space between the first stepped wall and the second wall, which is beneficial to improving the energy density of the battery cell.

[0037] In some embodiments of the present application, along the thickness direction of the battery cell, the projection of the second electrical connector at least partially overlaps with the projection of the electrode terminal.

[0038] In the above technical solution, by making the projection of the second electrical connector at least partially overlap with the projection of the electrode terminal along the thickness direction of the battery cell, the second electrical connector and the electrode terminal are arranged more compactly in the spaced space between the first stepped wall and the second wall, which can save the internal space of the outer casing and is beneficial to improving the energy density of the battery cell.

[0039] In some embodiments of the present application, the first electrical connector and the second electrical connector are spaced apart along the width direction of the battery cell.

[0040] In the above technical solution, by arranging the first electrical connector and the second electrical connector at intervals in the width direction of the battery cell, the risk of contact short circuit between the first electrical connector and the second electrical connector can be reduced, which is beneficial to improving the safety of the battery cell.

[0041] In some embodiments of the present application, the electrode assembly has a laminated structure, and the electrode assembly includes a plurality of positive electrode plates and a plurality of negative electrode plates laminated along its thickness direction.

[0042] In the above technical solution, since there will be a gap between the electrode assembly with a wound structure and the top corner of the outer shell, by making the electrode assembly have a laminated structure, and the electrode assembly includes a plurality of positive electrode plates and a plurality of negative electrode plates laminated along its thickness direction, the utilization rate of the internal space of the outer shell can be higher, which is beneficial to improving the energy density of the battery cell.

[0043] In some embodiments of the present application, the first wall includes a third stepped wall. Along the length direction of the battery cell, the third stepped wall is located at one end of the first main wall opposite to the first stepped wall. The third stepped wall is recessed towards the second wall relative to the first main wall, and the third stepped wall is connected to the first main wall through a third connecting wall.

[0044] In the above technical solution, by making the third stepped wall be located at one end of the first main wall and the first stepped wall along the length direction of the battery cell, and the third stepped wall is recessed towards the second wall relative to the first main wall, a strengthening structure is formed between the first main wall and the third stepped wall, so that the possibility of deformation of the third stepped wall after being stressed is relatively low, which is beneficial to improving the safety of the battery cell.

[0045] In some embodiments of the present application, the outer shell includes a first shell and a second shell. The first shell includes a first wall, the second shell includes a second wall, and the first shell and the second shell are welded.

[0046] In the above technical solution, by making the outer shell include a first shell and a second shell, the first shell includes a first wall, the second shell includes a second wall, and the first shell and the second shell are welded, it is convenient to assemble and connect the electrode assembly, the electrode terminals with the first shell and the second shell, which is beneficial to improving the preparation efficiency of the battery cell.

[0047] In some embodiments of the present application, the wall thickness of the first shell is H2, and the wall thickness of the second shell is H3, satisfying 0.01 mm ≤ H2 ≤ 0.2 mm, 0.01 mm ≤ H3 ≤ 0.2 mm.

[0048] In the above technical solution, when H2 ≥ 0.01 mm, the strength of the first housing can be made relatively high, reducing the possibility of the first housing deforming under stress, which is beneficial to improving the safety of the battery cell; when H2 ≤ 0.2 mm, the space occupied by the first housing can be made relatively small, enabling more space inside the outer housing for accommodating the electrode assembly, which is beneficial to increasing the energy density of the battery cell; therefore, when 0.01 mm ≤ H2 ≤ 0.2 mm, it can not only make the strength of the first housing relatively high, reducing the possibility of the first housing deforming under stress and being beneficial to improving the safety of the battery cell, but also make the space occupied by the first housing relatively small, enabling more space inside the outer housing for accommodating the electrode assembly and being beneficial to increasing the energy density of the battery cell.

[0049] When H3 ≥ 0.01 mm, the strength of the second housing can be made relatively high, reducing the possibility of the second housing deforming under stress, which is beneficial to improving the safety of the battery cell; when H3 ≤ 0.2 mm, the space occupied by the second housing can be made relatively small, enabling more space inside the outer housing for accommodating the electrode assembly, which is beneficial to increasing the energy density of the battery cell; therefore, when 0.01 mm ≤ H3 ≤ 0.2 mm, it can not only make the strength of the second housing relatively high, reducing the possibility of the second housing deforming under stress and being beneficial to improving the safety of the battery cell, but also make the space occupied by the second housing relatively small, enabling more space inside the outer housing for accommodating the electrode assembly and being beneficial to increasing the energy density of the battery cell.

[0050] In some embodiments of the present application, 0.03 mm ≤ H2 ≤ 0.16 mm, and 0.03 mm ≤ H3 ≤ 0.16 mm.

[0051] In the above technical solution, when H2 ≥ 0.03 mm, the strength of the first housing can be further made relatively high, reducing the possibility of the first housing deforming under stress, which is beneficial to improving the safety of the battery cell; when H2 ≤ 0.16 mm, the space occupied by the first housing can be further made relatively small, enabling more space inside the outer housing for accommodating the electrode assembly, which is beneficial to increasing the energy density of the battery cell; therefore, when 0.03 mm ≤ H2 ≤ 0.16 mm, it can not only further make the strength of the first housing relatively high, reducing the possibility of the first housing deforming under stress and being beneficial to improving the safety of the battery cell, but also further make the space occupied by the first housing relatively small, enabling more space inside the outer housing for accommodating the electrode assembly and being beneficial to increasing the energy density of the battery cell.

[0052] When H3≥0.03 mm, the strength of the second housing can be further increased, the possibility of deformation of the second housing under stress can be reduced, which is beneficial to improving the safety of the battery cell; when H3≤0.16 mm, the space occupied by the second housing can be further reduced, so that there is more space inside the outer housing for accommodating the electrode assembly, which is beneficial to improving the energy density of the battery cell; therefore, when 0.03 mm≤H3≤0.16 mm, the strength of the second housing can be further increased, the possibility of deformation of the second housing under stress can be reduced, which is beneficial to improving the safety of the battery cell, and at the same time, the space occupied by the second housing can be further reduced, so that there is more space inside the outer housing for accommodating the electrode assembly, which is beneficial to improving the energy density of the battery cell.

[0053] In some embodiments of the present application, the thickness of the battery cell is H1, and 0.5 mm≤H1≤4 mm is satisfied.

[0054] In the above technical solution, when H1≥0.5 mm, it is convenient for the preparation of the electrode assembly and the assembly of the electrode assembly and the outer housing; when H1≤4 mm, the applicable range of the battery cell can be wider; therefore, when 0.5 mm≤H1≤4 mm, it is convenient for the preparation of the electrode assembly and the assembly of the electrode assembly and the outer housing, and at the same time, the applicable range of the battery cell can be wider.

[0055] In some embodiments of the present application, the outer housing is a steel shell, the first electrode sheet is a positive electrode sheet, and the second electrode sheet is a negative electrode sheet.

[0056] In some embodiments of the present application, the width of the first step wall is greater than the thickness of the battery cell.

[0057] In the above technical solution, the size of the electrode terminal and the connection area between the electrode terminal and the outer housing can be set to be larger, and the connection strength between the electrode terminal and the outer housing is higher.

[0058] In the above technical solution, since the electrical connector connected to the positive electrode sheet is generally made of the same material as the positive current collector, and the material of the positive current collector is aluminum, if aluminum is electrically connected to steel, an electrochemical reaction will occur, corroding the electrical connector and the outer housing. Therefore, the positive electrode sheet needs to be led out through the electrode terminal. The negative current collector and the electrical connector connected to the negative electrode sheet are generally copper, and aluminum is electrically connected to steel without a strong corrosion effect. Therefore, the negative electrode sheet can be directly connected to the steel shell.

[0059] In a second aspect, the present application provides an electrical device, including the battery cell as described above, and the battery cell is used to provide electrical energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] To more clearly illustrate the technical solutions of the embodiments of the present application, the accompanying drawings required for the embodiments will be briefly introduced below. It should be understood that the following accompanying drawings only show some embodiments of the present application and should not be regarded as limiting the scope. For those of ordinary skill in the art, other related accompanying drawings can also be obtained based on these drawings.

[0061] Figure 1 Schematic diagram of the three-dimensional structure of the battery cell provided in some embodiments of the present application;

[0062] Figure 2 For Figure 1 Schematic diagram of the enlarged partial structure at position A of the battery cell in

[0063] Figure 3 Schematic diagram of the structure of the battery cell from one perspective provided in some embodiments of the present application;

[0064] Figure 4 For Figure 3 Schematic diagram of the cross-sectional structure of the battery cell along B-B in

[0065] Figure 5 For Figure 4 Schematic diagram of the enlarged partial structure at position D of the battery cell in

[0066] Figure 6 For Figure 3 Schematic diagram of the cross-sectional structure of the battery cell along the C-C direction in

[0067] Figure 7 For Figure 6 Schematic diagram of the enlarged partial structure at position E of the battery cell in

[0068] Figure 8 Schematic diagram of the three-dimensional structure of the partial structure of the battery cell provided in some embodiments of the present application;

[0069] Figure 9 Schematic diagram of the enlarged partial structure of the partial structure of the battery cell provided in some embodiments of the present application;

[0070] Figure 10 For Figure 1 Schematic diagram of the enlarged partial structure at position A of the battery cell from another perspective in

[0071] Figure 11 Schematic diagram of the three-dimensional structure of the battery cell provided in some other embodiments of the present application;

[0072] Figure 12 Schematic diagram of the exploded structure of the battery cell provided in some embodiments of the present application;

[0073] Figure 13 Schematic diagram of the three-dimensional structure of the battery cell provided in some other embodiments of the present application;

[0074] Figure 14 For Figure 13 Partial enlarged structural schematic diagram of the F position of the battery cell in the middle.

[0075] Icon: 10 - battery cell; 100 - housing; 100a - side wall; 101 - first housing; 102 - second housing; 110 - first wall; 111 - first main body wall; 112 - first step wall; 113 - first connecting wall; 114 - third step wall; 115 - third connecting wall; 120 - second wall; 121 - second main body wall; 122 - second step wall; 123 - second connecting wall; 200 - electrode assembly; 210 - first pole piece; 220 - second pole piece; 310 - electrode terminal; 320 - first electrical connector; 330 - adapter plate; 340 - first insulating member; 350 - second insulating member; 410 - second electrical connector; X - thickness direction of the battery cell; Y - length direction of the battery cell; Z - width direction of the battery cell. Detailed implementation manners

[0076] To make the objectives, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be clearly described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art shall fall within the protection scope of the present application.

[0077] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present application belongs; the terms used in the description of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "including" and "having" and any variations thereof in the description and claims of the present application and the above drawings are intended to cover non - exclusive inclusion.

[0078] The terms "first", "second", etc. in the description and claims of the present application or the above drawings are used to distinguish different objects and are not used to describe a specific order or primary - secondary relationship.

[0079] Referring to "embodiments" in the present application means that the specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase appears at various positions in the description and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments.

[0080] In the embodiments of the present application, the same reference numerals denote the same components, and for the sake of brevity, in different embodiments, the detailed description of the same components is omitted. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only for illustrative purposes and should not constitute any limitation to the present application.

[0081] With the development of the new energy industry, batteries are gradually developing towards high energy density and high power density. However, in order to increase the energy density of the battery cell, the thickness of the outer shell of the battery cell is getting thinner and thinner. Under mechanical abuse conditions (rolling test, drop test), the outer shell is prone to deformation under the external force or the impact force of the electrode assembly. On the side wall provided with the electrode terminal, due to the deformation of the side wall while the electrode terminal does not deform, the seal between the electrode terminal and the side wall will be pulled, resulting in detachment from the electrode terminal or the side wall, and further leading to seal failure and electrolyte leakage, affecting the safety of the battery cell.

[0082] To improve the safety of the battery cell, the present application provides a battery cell, which includes an outer shell. The outer shell includes a first wall and a second wall oppositely arranged along the thickness direction of the battery cell. The first wall includes a first main wall and a first stepped wall. Along the length direction of the battery cell, the first stepped wall is located at one end of the first main wall, and the first stepped wall is recessed towards the second wall relative to the first main wall. The first stepped wall and the first main wall are connected by a first connecting wall. The battery cell further includes an electrode assembly and an electrode terminal. The electrode assembly is disposed inside the outer shell and includes a first electrode plate and a second electrode plate with opposite polarities. The electrode terminal is disposed on the first stepped wall and is electrically connected to the first electrode plate. The thickness H0 of the first stepped wall satisfies H0 ≤ 0.2 mm.

[0083] In the battery cell with such a structure, since the thickness H0 of the first step wall satisfies H0 ≤ 0.2 mm, the energy density of the battery cell can be improved and the space at the position corresponding to the step can be increased. However, if the electrode terminal is arranged on the side wall of the outer shell, under mechanical abuse conditions such as rolling and dropping, the side wall of the outer shell is prone to deformation under the impact of the electrode assembly, while the electrode terminal is not easily deformed, resulting in the failure of the seal between the side wall and the electrode terminal. By making the first step wall located at one end of the first main wall along the length direction of the battery cell, the first step wall is recessed relative to the first main wall in the direction close to the second wall, and the electrode terminal is arranged on the first step wall, so that the size of the electrode terminal and the connection area between the electrode terminal and the outer shell can be set larger, and the connection strength between the electrode terminal and the outer shell is higher; when the battery cell is subjected to an external force, the first main wall is stressed before the first step wall, so that the possibility of the first step wall being deformed by stress is lower, and the possibility of the electrode terminal being directly stressed is also lower. Moreover, a reinforcing structure is formed between the first main wall and the first step wall, so that the possibility of the first step wall being deformed after being stressed is lower, the sealing effectiveness between the electrode terminal and the first step wall can be maintained, the risk of electrolyte leakage can be reduced, and it is beneficial to improve the safety of the battery cell.

[0084] The battery cell provided by the embodiment of the present application can be a secondary battery or a primary battery, for example, it can be a lithium-ion battery, a sodium-ion battery, a magnesium-ion battery, etc., and the embodiment of the present application does not limit this. The electrochemical device can be in a cylindrical shape, a flat shape, a cuboid shape or other shapes, etc., and the embodiment of the present application does not limit this either.

[0085] The embodiment of the present application provides an electrical device using the battery cell as a power source. The electrical device can be, but is not limited to, a mobile phone, a tablet computer, a laptop computer, an electric toy, an electric tool, a battery car, an electric vehicle, a ship, a spacecraft, etc.

[0086] See Figures 1 to 4 , Figure 1 is a schematic three-dimensional structure diagram of the battery cell provided by some embodiments of the present application; Figure 2 is Figure 1 a partially enlarged structure diagram of the A position of the battery cell in Figure 3 is a schematic structure diagram of one perspective of the battery cell provided by some embodiments of the present application; Figure 4 is Figure 3 a sectional structure diagram of the battery cell in

[0087] An embodiment of the present application provides a battery cell 10, which includes a housing 100. The housing 100 includes side walls 100a opposite to each other in a first direction. The housing 100 further includes a first wall 110 and a second wall 120 oppositely arranged in the thickness direction X of the battery cell. The first wall 110 includes a first main wall 111 and a first stepped wall 112. Along the length direction Y of the battery cell, the first stepped wall 112 is located at one end of the first main wall 111. The first stepped wall 112 is recessed relative to the first main wall 111 in a direction approaching the second wall 120. The first stepped wall 112 and the first main wall 111 are connected by a first connecting wall 113. The battery cell 10 further includes an electrode assembly 200 and an electrode terminal 310. The electrode assembly 200 is disposed in the housing 100. The electrode assembly 200 includes a first electrode tab 210 and a second electrode tab 220 with opposite polarities. The electrode terminal 310 is disposed on the first stepped wall 112. The electrode terminal 310 is electrically connected to the first electrode tab 210. The thickness H0 of the first stepped wall 112 satisfies H0≤0.2 mm.

[0088] Since the thickness H0 of the first stepped wall 112 satisfies H0≤0.2 mm, the thickness of the first stepped wall 112 is small, which can improve the energy density of the battery cell 10 and increase the space at the corresponding position of the step. However, if the electrode terminal 310 is disposed on the side wall 100a of the housing 100, under mechanical abuse conditions such as rolling and dropping, the side wall 100a of the housing 100 is prone to deformation under the impact of the electrode assembly 200, while the electrode terminal 310 is not easily deformed, resulting in the failure of the seal between the side wall 100a and the electrode terminal 310. By arranging the first stepped wall 112 at one end of the first main wall 111 along the length direction Y of the battery cell, the first stepped wall 112 is recessed relative to the first main wall 111 in a direction approaching the second wall 120, and the electrode terminal 310 is disposed on the first stepped wall 112, the size of the electrode terminal 310 and the connection area between the electrode terminal 310 and the housing 100 can be set to be relatively large, and the connection strength between the electrode terminal 310 and the housing 100 is relatively high; when the battery cell 10 is subjected to an external force, the first main wall 111 is stressed prior to the first stepped wall 112, so that the possibility of the first stepped wall 112 being deformed by stress is relatively low, and the possibility of the electrode terminal 310 being directly stressed is also relatively low. Moreover, a reinforcing structure is formed between the first main wall 111 and the first stepped wall 112, so that the possibility of the first stepped wall 112 being deformed after being stressed is relatively low, the seal effectiveness between the electrode terminal 310 and the first stepped wall 112 can be maintained, the risk of electrolyte leakage is reduced, and the safety of the battery cell 10 is improved.

[0089] See Figure 4 and Figure 5 , Figure 5 is Figure 4 a partially enlarged structural schematic diagram of the D position of the battery cell in

[0090] In some embodiments, the outer shell 100 includes a first housing 101 and a second housing 102. The first housing 101 includes a first wall 110, and the second housing 102 includes a second wall 120. The first housing 101 and the second housing 102 are connected. The side wall 100a is integrally formed with the first housing 101.

[0091] By making the outer shell 100 include the first housing 101 and the second housing 102, the first housing 101 includes the first wall 110, the second housing 102 includes the second wall 120, and the first housing 101 and the second housing 102 are connected, it is convenient to assemble and connect the electrode assembly 200 and the electrode terminal 310 to the first housing 101 and the second housing 102, which is beneficial to improving the preparation efficiency of the battery cell 10.

[0092] In some other embodiments, the side wall 100a may also be integrally formed with the second housing 102.

[0093] In some other embodiments, the side wall 100a may also be prepared separately from the first housing 101 and the second housing 102 and then connected.

[0094] In some embodiments, the length of the battery cell 10 is L1, and the width of the battery cell 10 is W1, satisfying L1 > W1, L1 > H1, and 3 mm ≤ W1 ≤ 20 mm. For example, W1 can be 3 mm, 10 mm, 15 mm, 20 mm, etc.

[0095] By making the length of the battery cell be L1 and the width of the battery cell be W1, satisfying L1 > W1, L1 > H1, and 3 mm ≤ W1 ≤ 20 mm, that is, the battery cell 10 is a narrow and long battery cell. By arranging the electrode terminal 310 at one end of the outer shell 100 along the length direction Y of the battery cell, the space occupied by the electrode terminal 310 can be made smaller.

[0096] When W1 ≥ 3 mm, it is convenient for the preparation of the electrode assembly 200 and the assembly of the electrode assembly 200 and the outer shell 100; when W1 ≤ 20 mm, the applicable range of the battery cell 10 can be made wider; therefore, when 3 mm ≤ W1 ≤ 20 mm, it is both convenient for the preparation of the electrode assembly 200 and the assembly of the electrode assembly 200 and the outer shell 100, and the applicable range of the battery cell 10 can be made wider.

[0097] In some embodiments, the outer shell 100 can be made of a material with high strength, such as metal materials like steel and aluminum alloy, so that the outer shell 100 has high mechanical properties, and further, the possibility of the outer shell 100 being deformed or damaged due to force or environmental changes can be made lower, and further, the reliability of the battery cell 10 can be made higher.

[0098] In some other embodiments, the outer shell 100 can also be made of non-metal materials with high strength, such as carbon fiber and hard plastic.

[0099] In some embodiments, the battery cell 10 is arranged in a cuboid shape, and the top corners are rounded, which can better fit into the rounded battery compartment in the electrical device.

[0100] In some other embodiments, the top corners of the battery cell 10 can also be arranged as square corners.

[0101] In some embodiments, the electrode terminal 310 can be made of a material with good electrical conductivity, such as metal materials like lead or copper. The material of the electrode terminal 310 can be the same as that of the current collector of the first electrode sheet 210.

[0102] In some embodiments, the electrode terminal 310 can be arranged in shapes such as square, circular, oval, etc.

[0103] In some embodiments, the first step wall 112 can be formed by partial stretching or stamping.

[0104] The battery cell 10 further includes an electrolyte, which is contained in the outer shell 100. The electrode assembly 200 is composed of a positive electrode sheet, a negative electrode sheet, and a separator. The electrochemical device mainly works by the movement of metal ions between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet includes a positive current collector and a positive active material layer, and the positive active material layer is coated on the surface of the positive current collector. The part of the positive current collector without the coated positive active material layer serves as the positive electrode tab to realize the electrical energy input or output of the positive electrode sheet through the positive electrode tab. Taking a lithium-ion battery as an example, the material of the positive current collector can be aluminum, and the positive active material can be lithium cobaltate, lithium iron phosphate, ternary material, lithium manganate, etc. The negative electrode sheet includes a negative current collector and a negative active material layer, and the negative active material layer is coated on the surface of the negative current collector. The part of the negative current collector without the coated negative active material layer serves as the negative electrode tab to realize the electrical energy input or output of the negative electrode sheet through the negative electrode tab. The material of the negative current collector can be copper, and the negative active material can be carbon material or silicon material, etc. The material of the separator can be polypropylene (PP) or polyethylene (PE), etc. The electrolyte can include organic solvents, electrolyte lithium salts, etc.

[0105] In some embodiments, the electrode assembly 200 is located between the first main body wall 111 and the second wall 120. Along the thickness direction X of the battery cell, the projection of the electrode assembly 200 does not overlap with the projection of the electrode terminal 310.

[0106] By positioning the electrode assembly 200 between the first main body wall 111 and the second wall 120, along the thickness direction X of the battery cell, the projection of the electrode assembly 200 does not overlap with the projection of the electrode terminal 310. This enables the space between the first main body wall 111 and the second wall 120 to not need to reserve space for the electrode terminal 310, and the space between the first main body wall 111 and the second wall 120 for accommodating the electrode assembly 200 is relatively large, which is conducive to improving the energy density of the battery cell 10. On the other hand, there is no need to consider the problem of the electrode assembly 200 hitting the electrode terminal 310 due to shaking within the outer casing 100.

[0107] In some embodiments, along the length direction Y of the battery cell, the distance between the electrode assembly 200 and the first connecting wall 113 is G, satisfying 0.5 mm ≤ G ≤ 4 mm. For example, G can be 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm, etc.

[0108] When G ≥ 0.5 mm, the possibility of interference generated when the electrode assembly 200 is inserted into the outer casing 100 can be reduced, thus facilitating the preparation of the battery cell 10; when G ≤ 4 mm, the space within the outer casing 100 for accommodating the electrode assembly 200 can be made larger, which is conducive to improving the energy density of the battery cell 10; therefore, when 0.5 mm ≤ G ≤ 4 mm, it can both reduce the possibility of interference generated when the electrode assembly 200 is inserted into the outer casing 100, thus facilitating the preparation of the battery cell 10, and make the space within the outer casing 100 for accommodating the electrode assembly 200 larger, which is conducive to improving the energy density of the battery cell 10.

[0109] In some embodiments, 1 mm ≤ G ≤ 2.5 mm. For example, G can be 1 mm, 1.2 mm, 1.8 mm, 2.5 mm, etc.

[0110] When G ≥ 1 mm, the possibility of interference generated when the electrode assembly 200 is inserted into the outer casing 100 can be further reduced, thus facilitating the preparation of the battery cell 10; when G ≤ 2.5 mm, the space within the outer casing 100 for accommodating the electrode assembly 200 can be further made larger, which is conducive to improving the energy density of the battery cell 10; and since the projection of the electrode assembly 200 does not overlap with the projection of the electrode terminal 310 and there is no need to reserve space for the electrode terminal 310, G can be made within 2.5 mm. Therefore, when 1 mm ≤ G ≤ 2.5 mm, it can both reduce the possibility of interference generated when the electrode assembly 200 is inserted into the outer casing 100, thus facilitating the preparation of the battery cell 10, and make the space within the outer casing 100 for accommodating the electrode assembly 200 larger, which is conducive to improving the energy density of the battery cell 10.

[0111] See Figure 1 、 Figures 5 to 8 , Figure 6 is Figure 3 the schematic cross-sectional structure diagram of the battery cell along the C-C direction inFigure 7 is Figure 6 a partially enlarged structural schematic diagram of the E position of the battery cell in the middle; Figure 8 is a three-dimensional schematic diagram of the partial structure of the battery cell provided by some embodiments of the present application.

[0112] In some embodiments, the battery cell 10 further includes a first electrical connector 320 and an adapter plate 330. Along the length direction Y of the battery cell, the first electrical connector 320 is disposed at one end of the electrode assembly 200 close to the first step wall 112 and is connected to the first electrode tab 210. The adapter plate 330 is disposed in the housing 100 and between the first step wall 112 and the second wall 120. The first electrical connector 320 is connected to the adapter plate 330, and the adapter plate 330 is connected to the electrode terminal 310.

[0113] Since the size of the electrode terminal 310 is small, when the electrode terminal 310 is installed in the housing 100, the sealing area between the electrode terminal 310 and the housing 100 is small, the sealing effect is not good, and the problem of electrolyte leakage is likely to occur. By providing the adapter plate 330, the adapter plate 330 is disposed in the housing 100 and between the first step wall 112 and the second wall 120. The first electrical connector 320 is connected to the adapter plate 330, and the adapter plate 330 is connected to the electrode terminal 310, so that a seal can be formed between the adapter plate 330 and the housing 100, thereby increasing the sealing area between the electrode terminal 310 and the housing 100, improving the sealing effect, and reducing the possibility of electrolyte leakage.

[0114] In some embodiments, the material of the first electrical connector 320 can be the same as the material of the current collector of the first electrode tab 210, which is convenient for connecting the first electrical connector 320 to the first electrode tab 210. The material of the first electrical connector 320 can be the same as the material of the adapter plate 330, which is convenient for connecting the first electrical connector 320 to the adapter plate 330.

[0115] In some embodiments, the thickness direction of the adapter plate 330 is parallel to the thickness direction X of the battery cell. The adapter plate 330 has a first connection area connected to the first electrical connector 320 and a second connection area connected to the electrode terminal 310. The first connection area and the second connection area are spaced apart along the width direction Z of the battery cell.

[0116] Since the current sequential stacking and connection of the electrode terminal 310, the adapter board 330, and the first electrical connector 320 will occupy a relatively large space in the thickness direction X of the battery cell, affecting the energy density of the battery cell 10. By making the thickness direction of the adapter board 330 parallel to the thickness direction X of the battery cell, the adapter board 330 has a first connection area connected to the first electrical connector 320 and a second connection area connected to the electrode terminal 310. The first connection area and the second connection area are spaced along the width direction Z of the battery cell, enabling the electrode terminal 310 and the first electrical connector 320 to be disposed on the same side of the adapter board 330. As a result, the overall thickness of the electrode terminal 310, the adapter board 330, and the first electrical connector 320 in the thickness direction X of the battery cell is relatively small, which is beneficial to improving the energy density of the battery cell 10.

[0117] See Figure 9 , Figure 9 is a partial enlarged structural schematic diagram of a part of the structure of the battery cell provided by some embodiments of the present application.

[0118] In some embodiments, the width of the battery cell 10 is W1, and along the width direction Z of the battery cell, the width of the adapter board 330 is W2, satisfying 80% ≤ W2 / W1 ≤ 99%. For example, W2 / W1 can be 80%, 85%, 90%, 95%, or 99%, etc.

[0119] When W2 / W1 ≥ 80%, the area of the adapter board 330 can be made relatively large, facilitating the connection of the adapter board 330 to the first electrical connector 320 and the electrode terminal 310; when W2 / W1 ≤ 99%, the possibility of interference when the adapter board 330 is inserted into the housing 100 can be reduced, thus facilitating the preparation of the battery cell 10; therefore, when 80% ≤ W2 / W1 ≤ 99%, it is both convenient for the adapter board 330 to be connected to the first electrical connector 320 and the electrode terminal 310, and can reduce the possibility of interference when the adapter board 330 is inserted into the housing 100, thus facilitating the preparation of the battery cell 10.

[0120] Since the width W1 of the battery cell 10 satisfies 3 mm ≤ W1 ≤ 20 mm, the width of the battery cell 10 is relatively small. If two electrode terminals 310 with opposite polarities are provided on the battery cell 10 and the two electrode terminals 310 are arranged along the width direction Z of the battery cell, the difficulty of preparing the battery cell 10 will be relatively high, and there is a risk of contact short circuit between the two electrode terminals 310. Therefore, by making 80% ≤ W2 / W1 ≤ 99%, that is, only one electrode terminal 310 is provided on the first step wall 112, the difficulty of preparing the battery cell 10 can be reduced, and the risk of short circuit of the battery cell 10 can be reduced.

[0121] See Figure 5 and Figure 8 , in some embodiments, the first step wall 112 is provided with a first through hole, and the electrode terminal 310 is disposed through the first through hole.

[0122] The battery cell 10 further includes a first insulating member 340 and a second insulating member 350. A part of the first insulating member 340 is disposed between the electrode terminal 310 and the outer surface of the first stepped wall 112, and another part of the first insulating member 340 is disposed between the electrode terminal 310 and the side wall of the first through hole. The second insulating member 350 is disposed between the adapter plate 330 and the inner surface of the first stepped wall 112. By providing the first insulating member 340 and the second insulating member 350, insulation between the electrode terminal 310 and the first stepped wall 112 and insulation between the adapter plate 330 and the first stepped wall 112 can be achieved, reducing the risk of short circuit of the battery cell 10.

[0123] See Figure 3 , in some embodiments, along the length direction Y of the battery cell, the length of the first stepped wall 112 is L2, satisfying 0.01 ≤ L2 / L1 ≤ 0.5. For example, L2 / L1 can be 0.01, 0.05, 0.1, 0.3, or 0.5, etc.

[0124] When L2 / L1 ≥ 0.01, it can enable the first stepped wall 112 to have sufficient space for disposing the electrode terminal 310, which is beneficial to reducing the manufacturing difficulty of the battery cell 10 and improving the manufacturing efficiency of the battery cell 10; when L2 / L1 ≤ 0.5, it can enable the space occupied by the electrode terminal 310 to be smaller, and there is more space in the outer shell 100 for accommodating the electrode assembly 200, which is beneficial to improving the energy density of the battery cell 10; therefore, when 0.01 ≤ L2 / L1 ≤ 0.5, it can both enable the first stepped wall 112 to have sufficient space for disposing the electrode terminal 310, which is beneficial to reducing the manufacturing difficulty of the battery cell 10 and improving the manufacturing efficiency of the battery cell 10, and enable the space occupied by the electrode terminal 310 to be smaller, and there is more space in the outer shell 100 for accommodating the electrode assembly 200, which is beneficial to improving the energy density of the battery cell 10.

[0125] In some embodiments, along the length direction Y of the battery cell, the length of the first stepped wall 112 is L2, satisfying 1.5 mm ≤ L2 ≤ 10 mm. For example, L2 can be 1.5 mm, 2 mm, 5 mm, 7 mm, or 10 mm, etc.

[0126] When L2≥1.5 mm, it can enable the first stepped wall 112 to have sufficient space for arranging the electrode terminal 310, which is beneficial to reducing the preparation difficulty of the battery cell 10 and improving the preparation efficiency of the battery cell 10; when L2≤10 mm, it can enable the space occupied by the electrode terminal 310 to be smaller, and there is more space in the outer shell 100 for accommodating the electrode assembly 200, which is beneficial to improving the energy density of the battery cell 10; therefore, when 1.5 mm≤L2≤10 mm, it can not only enable the first stepped wall 112 to have sufficient space for arranging the electrode terminal 310, which is beneficial to reducing the preparation difficulty of the battery cell 10 and improving the preparation efficiency of the battery cell 10, but also enable the space occupied by the electrode terminal 310 to be smaller, and there is more space in the outer shell 100 for accommodating the electrode assembly 200, which is beneficial to improving the energy density of the battery cell 10.

[0127] In some embodiments, 2.5 mm≤L2≤8 mm. For example, L2 can be 2.5 mm, 3 mm, 4 mm, 6 mm or 8 mm, etc.

[0128] When L2≥2.5 mm, it can further enable the first stepped wall 112 to have sufficient space for arranging the electrode terminal 310, which is beneficial to reducing the preparation difficulty of the battery cell 10 and improving the preparation efficiency of the battery cell 10; when L2≤8 mm, it can further enable the space occupied by the electrode terminal 310 to be smaller, and there is more space in the outer shell 100 for accommodating the electrode assembly 200, which is beneficial to improving the energy density of the battery cell 10; therefore, when 2.5 mm≤L2≤8 mm, it can not only further enable the first stepped wall 112 to have sufficient space for arranging the electrode terminal 310, which is beneficial to reducing the preparation difficulty of the battery cell 10 and improving the preparation efficiency of the battery cell 10, but also further enable the space occupied by the electrode terminal 310 to be smaller, and there is more space in the outer shell 100 for accommodating the electrode assembly 200, which is beneficial to improving the energy density of the battery cell 10.

[0129] See Figure 1 and Figure 10 , Figure 10 is Figure 1 a partial enlarged structural schematic diagram of another perspective of the A position of the battery cell in

[0130] In some embodiments, the second wall 120 includes a second main wall 121 and a second stepped wall 122. Along the length direction Y of the battery cell, the second stepped wall 122 is located at one end of the second main wall 121. The second stepped wall 122 is recessed relative to the second main wall 121 in a direction close to the first wall 110. The second stepped wall 122 and the second main wall 121 are connected by a second connecting wall 123. The electrode assembly 200 is located between the first main wall 111 and the second main wall 121. Along the thickness direction X of the battery cell, the projection of the first stepped wall 112 and the projection of the second stepped wall 122 overlap.

[0131] Among them, when the offset of the projection of the first step wall 112 relative to the projection of the second step wall 122 along the thickness direction X of the battery cell is within the threshold error range (e.g., 5 mm), it belongs to the range where the projection of the first step wall 112 and the projection of the second step wall 122 overlap in the present application.

[0132] By making the second step wall 122 located at one end of the second main wall 121 along the length direction Y of the battery cell, the second step wall 122 is recessed relative to the second main wall 121 in a direction approaching the first wall 110, and the projection of the first step wall 112 and the projection of the second step wall 122 overlap along the thickness direction X of the battery cell, a reinforcing structure is formed between the second main wall 121 and the second step wall 122, further making the strength of the part of the housing where the electrode terminal 310 is located higher, making the possibility of deformation of the first step wall 112 under force lower, being able to maintain the sealing effectiveness between the electrode terminal 310 and the first step wall 112, reducing the risk of electrolyte leakage, and being beneficial to improving the safety of the battery cell 10.

[0133] In some embodiments, the second step wall 122 can be formed by partial stretching or stamping.

[0134] See Figure 11 , Figure 11 which is a schematic three-dimensional structure diagram of the battery cell provided in some other embodiments of the present application.

[0135] In some other embodiments, the surface of the second wall 120 facing away from the first wall 110 is a plane.

[0136] By making the surface of the second wall 120 facing away from the first wall 110 a plane, it is convenient to prepare and form the second wall 120, which is beneficial to improving the preparation efficiency of the battery cell 10.

[0137] See Figure 5 , in some embodiments, the second electrode tab 220 is electrically connected to the outer shell 100.

[0138] Since the width W1 of the battery cell 10 satisfies 3 mm ≤ W1 ≤ 20 mm and the width of the battery cell 10 is small, if two electrode terminals 310 with opposite polarities are provided on the battery cell 10 and the two electrode terminals 310 are arranged along the width direction Z of the battery cell, it will make the preparation of the battery cell 10 more difficult, and there is a risk of contact short circuit between the two electrode terminals 310. By making the second electrode tab 220 electrically connected to the outer shell 100, it is possible to make it unnecessary to provide an electrode terminal 310 for the corresponding second electrode tab 220, that is, only one electrode terminal 310 needs to be provided on the first step wall 112, which can reduce the preparation difficulty of the battery cell 10 and reduce the risk of short circuit of the battery cell 10.

[0139] In some embodiments, the second wall 120 has a first region that overlaps with the projection of the first stepped wall 112 along the thickness direction X of the battery cell. The battery cell 10 further includes a second electrical connector 410. Along the length direction Y of the battery cell, the second electrical connector 410 is disposed at one end of the electrode assembly 200 close to the first stepped wall 112. One end of the second electrical connector 410 is connected to the second pole piece 220, and the other end is connected to the first region.

[0140] By making the second wall 120 have a first region that overlaps with the projection of the first stepped wall 112 along the thickness direction X of the battery cell, and along the length direction Y of the battery cell, the second electrical connector 410 is disposed at one end of the electrode assembly 200 close to the first stepped wall 112, with one end of the second electrical connector 410 connected to the second pole piece 220 and the other end connected to the first region, the first electrical connector 320 and the second electrical connector 410 can share the space between the first stepped wall 112 and the second wall 120, which is beneficial to improving the energy density of the battery cell 10.

[0141] In some embodiments, along the thickness direction X of the battery cell, the projection of the second electrical connector 410 at least partially overlaps with the projection of the electrode terminal 310.

[0142] By making the projection of the second electrical connector 410 at least partially overlap with the projection of the electrode terminal 310 along the thickness direction X of the battery cell, the second electrical connector 410 and the electrode terminal 310 are arranged more compactly in the spaced space between the first stepped wall 112 and the second wall 120, which can save the internal space of the housing 100 and is beneficial to improving the energy density of the battery cell 10.

[0143] See Figure 12 , Figure 12 which is an exploded structural schematic diagram of the battery cell provided by some embodiments of the present application.

[0144] In some embodiments, the first electrical connector 320 and the second electrical connector 410 are spaced apart along the width direction Z of the battery cell.

[0145] By making the first electrical connector 320 and the second electrical connector 410 spaced apart along the width direction Z of the battery cell, the risk of short circuit due to contact between the first electrical connector 320 and the second electrical connector 410 can be reduced, which is beneficial to improving the safety of the battery cell 10.

[0146] In some embodiments, the electrode assembly 200 is a stacked structure, and the electrode assembly 200 includes a plurality of positive pole pieces and a plurality of negative pole pieces stacked along its thickness direction.

[0147] Since there will be a gap between the electrode assembly 200 with a winding structure and the top corner of the outer shell 100, by making the electrode assembly 200 a stacked structure, the electrode assembly 200 includes a plurality of positive electrode plates and a plurality of negative electrode plates stacked along its thickness direction, which can make the utilization rate of the internal space of the outer shell 100 higher and is beneficial to improving the energy density of the battery cell 10.

[0148] In some other embodiments, the electrode assembly 200 can be a winding structure, and the electrode assembly 200 is formed by winding after laminating a positive electrode plate, a separator, and a negative electrode plate.

[0149] See Figure 13 and Figure 14 , Figure 13 is a three-dimensional structural schematic diagram of the battery cell provided in some other embodiments of the present application; Figure 14 is Figure 13 a partial enlarged structural schematic diagram of the F position of the battery cell in

[0150] In some embodiments, the first wall 110 includes a third stepped wall 114. Along the length direction Y of the battery cell, the third stepped wall 114 is located at one end of the first main body wall 111 opposite to the first stepped wall 112. The third stepped wall 114 is recessed towards the second wall 120 relative to the first main body wall 111, and the third stepped wall 114 is connected to the first main body wall 111 through a third connecting wall 115.

[0151] By making the third stepped wall 114 located at one end of the first main body wall 111 and the first stepped wall 112 along the length direction Y of the battery cell, and the third stepped wall 114 is recessed towards the second wall 120 relative to the first main body wall 111, a strengthening structure is formed between the first main body wall 111 and the third stepped wall 114, making it less likely for the third stepped wall 114 to deform under force, which is beneficial to improving the safety of the battery cell 10.

[0152] In some embodiments, the third stepped wall 114 can be formed by partial stretching or stamping.

[0153] In some other embodiments, the battery cell 10 can include a second electrode terminal (not shown in the figure), and the second electrode terminal is arranged on the third stepped wall 114 and is electrically connected to the second electrode plate 220. When the battery cell 10 is subjected to an external force, the first main body wall 111 is stressed before the third stepped wall 114, so that it is less likely for the third stepped wall 114 to deform under force, and the possibility of the second electrode terminal being directly stressed is also lower. Moreover, a strengthening structure is formed between the first main body wall 111 and the third stepped wall 114, making it less likely for the third stepped wall 114 to deform under force, which can maintain the sealing effectiveness between the second electrode terminal and the third stepped wall 114, reduce the risk of electrolyte leakage, and is beneficial to improving the safety of the battery cell 10.

[0154] See Figure 12 , in some embodiments, the first housing 101 and the second housing 102 are welded.

[0155] By welding the first housing 101 and the second housing 102, the connection strength between the first housing 101 and the second housing 102 can be made relatively high, and the stability and reliability of the outer housing 100 are relatively high.

[0156] In other embodiments, the first housing 101 and the second housing 102 may also be adhesively connected.

[0157] In some embodiments, the wall thickness of the first housing 101 is H2, satisfying 0.01 mm ≤ H2 ≤ 0.2 mm. For example, H2 may be 0.01 mm, 0.05 mm, 0.1 mm, 0.15 mm, or 0.2 mm, etc.

[0158] When H2 ≥ 0.01 mm, the strength of the first housing 101 can be made relatively high, reducing the possibility of the first housing 101 deforming under force, which is beneficial to improving the safety of the battery cell 10; when H2 ≤ 0.2 mm, the space occupied by the first housing 101 can be made relatively small, enabling the interior of the outer housing 100 to have more space for accommodating the electrode assembly 200, which is beneficial to improving the energy density of the battery cell 10; therefore, when 0.01 mm ≤ H2 ≤ 0.2 mm, both the strength of the first housing 101 can be made relatively high, reducing the possibility of the first housing 101 deforming under force, which is beneficial to improving the safety of the battery cell 10, and the space occupied by the first housing 101 can be made relatively small, enabling the interior of the outer housing 100 to have more space for accommodating the electrode assembly 200, which is beneficial to improving the energy density of the battery cell 10.

[0159] In some embodiments, the wall thickness of the second housing 102 is H3, 0.01 mm ≤ H3 ≤ 0.2 mm. For example, H3 may be 0.01 mm, 0.05 mm, 0.1 mm, 0.15 mm, or 0.2 mm, etc.

[0160] When H3≥0.01 mm, the strength of the second housing 102 can be relatively high, reducing the possibility of the second housing 102 deforming under stress, which is beneficial to improving the safety of the battery cell 10; when H3≤0.2 mm, the space occupied by the second housing 102 can be relatively small, leaving more space inside the outer housing 100 for accommodating the electrode assembly 200, which is beneficial to improving the energy density of the battery cell 10; therefore, when 0.01 mm≤H3≤0.2 mm, both the strength of the second housing 102 can be relatively high, reducing the possibility of the second housing 102 deforming under stress, which is beneficial to improving the safety of the battery cell 10, and the space occupied by the second housing 102 can be relatively small, leaving more space inside the outer housing 100 for accommodating the electrode assembly 200, which is beneficial to improving the energy density of the battery cell 10.

[0161] In some embodiments, 0.03 mm≤H2≤0.16 mm. For example, H2 can be 0.03 mm, 0.06 mm, 0.08 mm, 0.13 mm or 0.16 mm, etc.

[0162] When H2≥0.03 mm, the strength of the first housing 101 can be further increased, reducing the possibility of the first housing 101 deforming under stress, which is beneficial to improving the safety of the battery cell 10; when H2≤0.16 mm, the space occupied by the first housing 101 can be further reduced, leaving more space inside the outer housing 100 for accommodating the electrode assembly 200, which is beneficial to improving the energy density of the battery cell 10; therefore, when 0.03 mm≤H2≤0.16 mm, both the strength of the first housing 101 can be further increased, reducing the possibility of the first housing 101 deforming under stress, which is beneficial to improving the safety of the battery cell 10, and the space occupied by the first housing 101 can be further reduced, leaving more space inside the outer housing 100 for accommodating the electrode assembly 200, which is beneficial to improving the energy density of the battery cell 10.

[0163] In some embodiments, 0.03 mm≤H3≤0.16 mm. For example, H3 can be 0.03 mm, 0.06 mm, 0.08 mm, 0.13 mm or 0.16 mm, etc.

[0164] When H3 ≥ 0.03 mm, the strength of the second housing 102 can be further increased, reducing the possibility of deformation of the second housing 102 under force, which is beneficial to improving the safety of the battery cell 10; when H3 ≤ 0.16 mm, the space occupied by the second housing 102 can be further reduced, enabling more space inside the outer housing 100 for accommodating the electrode assembly 200, which is beneficial to increasing the energy density of the battery cell 10; therefore, when 0.03 mm ≤ H3 ≤ 0.16 mm, both the strength of the second housing 102 can be further increased, reducing the possibility of deformation of the second housing 102 under force, which is beneficial to improving the safety of the battery cell 10, and the space occupied by the second housing 102 can be further reduced, enabling more space inside the outer housing 100 for accommodating the electrode assembly 200, which is beneficial to increasing the energy density of the battery cell 10.

[0165] In some embodiments, the thickness of the battery cell 10 is H1, satisfying 0.5 mm ≤ H1 ≤ 4 mm. For example, H1 can be 0.5 mm, 1 mm, 1 mm, 3 mm, or 4 mm, etc.

[0166] When H1 ≥ 0.5 mm, it is convenient for the preparation of the electrode assembly 200 and the assembly of the electrode assembly 200 with the outer housing 100; when H1 ≤ 4 mm, the application range of the battery cell 10 can be wider; therefore, when 0.5 mm ≤ H1 ≤ 4 mm, it is both convenient for the preparation of the electrode assembly 200 and the assembly of the electrode assembly 200 with the outer housing 100, and the application range of the battery cell 10 can be wider.

[0167] In some embodiments, the outer housing 100 is a steel shell, the first electrode tab 210 is a positive electrode tab, and the second electrode tab 220 is a negative electrode tab.

[0168] In some embodiments, the width of the first step wall 112 is greater than the thickness of the battery cell 10.

[0169] In the above technical solution, the size of the electrode terminal and the connection area between the electrode terminal and the outer housing can be set to be relatively large, and the connection strength between the electrode terminal and the outer housing is relatively high.

[0170] Since the electrical connector connected to the positive electrode tab is generally made of the same material as the positive current collector, and the material of the positive current collector is aluminum, if aluminum is electrically connected to steel, an electrochemical reaction will occur, corroding the electrical connector and the outer housing 100. Therefore, the positive electrode tab needs to be led out through the electrode terminal 310. The negative current collector and the electrical connector connected to the negative electrode tab are generally copper, and aluminum is not strongly corroded when electrically connected to steel. Therefore, the negative electrode tab can be directly connected to the steel shell.

[0171] In some other embodiments, when the material of the outer casing 100 is the same as or similar to the material properties of the positive current collector (for example, the outer casing 100 is an aluminum casing), the first electrode sheet 210 is the negative electrode sheet, and the second electrode sheet 220 is the positive electrode sheet.

[0172] An embodiment of the present application provides an electrical device, including the battery cell 10 of any of the above solutions, and the battery cell 10 is used to provide electrical energy for the electrical device.

[0173] The electrical device can be any of the aforementioned devices or systems that apply the battery cell 10.

[0174] The characteristics and performance of the battery cell of the present application are further described in detail below in conjunction with the embodiments.

[0175] Table 1 Drop Pass Rate Test of the Battery Cell

[0176] Wall thickness Drop passing rate Comparative example 1 0.1 mm 70％ Comparative example 2 0.15 mm 72％ Comparative example 3 0.2 mm 76％ Example 1 0.1 mm 89％ Example 2 0.15 mm 91％ Example 3 0.2 mm 95％

[0177] In Comparative Examples 1-3, the outer casing of the battery cell includes a top wall and a bottom wall disposed opposite to each other in the thickness direction thereof, and further includes a plurality of side walls connecting the top wall and the bottom wall. The electrode terminal is disposed on one of the side walls. The wall thickness in Comparative Examples 1-3 in Table 1 is the wall thickness of the side wall provided with the electrode terminal. In Examples 1-3, see Figure 1 , the electrode terminal is disposed on the first stepped wall, and the wall thickness in Examples 1-3 in Table 1 is the wall thickness of the first stepped wall.

[0178] Test method for the drop pass rate of the battery cell:

[0179] 1. Fully charge the finished battery cell, then install it in the fixture so that the battery cell drops from a height of 1.5 m, and each of the six faces of the battery cell drops 6 times. 10 battery cells are tested in each group, and each group is repeatedly tested 3 times.

[0180] 2. Test the change in the open circuit voltage of the battery cell before and after the drop and whether the battery cell catches fire or burns. Record the battery cells with voltage reduction and fire as failed.

[0181] The following conclusions can be obtained according to Table 1:

[0182] 1. Referring to Comparative Examples 1-3 and Examples 1-3, when the wall thickness is less than 0.2 mm, disposing the electrode terminal on the side wall of the outer casing will result in a lower drop pass rate of the battery cell, affecting the safety and reliability of the battery cell. In the present application, a reinforcing structure is formed between the first stepped wall and the first main wall, which can improve the drop pass rate of the battery cell and improve the safety and reliability of the battery cell.

[0183] 2. Referring to Examples 1-3, as the wall thickness of the first stepped wall increases, the drop pass rate will increase accordingly.

[0184] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other.

[0185] The above are only the preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A battery cell, comprising a shell, characterized in that: The housing comprises a first wall and a second wall arranged opposite to each other along the thickness direction of the battery core, the first wall comprises a first main body wall and a first step wall, along the length direction of the battery core, the first step wall is located at one end of the first main body wall, the first step wall is recessed relative to the first main body wall toward the direction close to the second wall, and the first step wall is connected to the first main body wall through a first connecting wall; The battery cell also includes: An electrode assembly is disposed in the housing, the electrode assembly comprising a first pole piece and a second pole piece with opposite polarities; An electrode terminal is disposed on the first step wall, the electrode terminal is electrically connected to the first pole piece, and a thickness H0 of the first step wall satisfies H0≤0.2 mm.

2. The battery cell according to claim 1, characterized in that: The length of the battery cell is L1, the width of the battery cell is W1, and the thickness of the battery cell is H1, satisfying L1>W1, L1>H1, and 3mm≤W1≤20mm.

3. The battery cell according to claim 1, characterized in that: The electrode assembly is located between the first main body wall and the second wall, and along the thickness direction of the battery core, the projection of the electrode assembly does not overlap with the projection of the electrode terminal.

4. The battery cell according to claim 3, characterized in that: Along the length direction of the battery core, the distance between the electrode assembly and the first connecting wall is G, which satisfies 0.5 mm ≤ G ≤ 4 mm.

5. The battery cell according to claim 4, characterized in that: 1mm≤G≤2.5mm.

6. The battery cell according to claim 3, characterized in that: The battery cell also includes: A first electrical connector, along the length direction of the battery core, the first electrical connector is disposed at one end of the electrode assembly close to the first step wall and connected to the first electrode sheet; An adapter plate is disposed in the housing and located between the first step wall and the second wall. The first electrical connector is connected to the adapter plate, and the adapter plate is connected to the electrode terminal.

7. The battery cell according to claim 6, characterized in that: The thickness direction of the adapter plate is parallel to the thickness direction of the battery cell. The adapter plate has a first connection area connected to the first electrical connector and a second connection area connected to the electrode terminal. The first connection area and the second connection area are spaced apart along the width direction of the battery cell.

8. The battery cell according to claim 6, characterized in that: The width of the battery cell is W1, and along the width direction of the battery cell, the width of the adapter plate is W2, satisfying 80%≤W2 / W1≤99%.

9. The battery cell according to claim 1, characterized in that: The length of the battery core is L1, and along the length direction of the battery core, the length of the first step wall is L2, satisfying 0.01≤L2 / L1≤0.

5.

10. The battery cell according to claim 1, characterized in that: Along the length direction of the battery core, the length of the first step wall is L2, satisfying 1.5mm≤L2≤10mm.

11. The battery cell according to claim 1, characterized in that: The second wall includes a second main body wall and a second step wall. Along the length direction of the battery core, the second step wall is located at one end of the second main body wall. The second step wall is recessed relative to the second main body wall toward the first wall. The second step wall is connected to the second main body wall through a second connecting wall. The electrode assembly is located between the first main body wall and the second main body wall. Along the thickness direction of the battery core, the projection of the first step wall and the projection of the second step wall overlap.

12. The battery cell according to claim 1, characterized in that: A surface of the second wall facing away from the first wall is a plane.

13. The battery cell according to claim 1, characterized in that: The second pole piece is electrically connected to the housing.

14. The battery cell according to claim 13, characterized in that: The second wall has a first area overlapping with the projection of the first step wall along the thickness direction of the battery core; The battery cell also includes: A second electrical connector is disposed along the length direction of the battery cell at one end of the electrode assembly close to the first step wall, one end of the second electrical connector is connected to the second electrode sheet, and the other end is connected to the first region.

15. The battery cell according to claim 14, characterized in that: Along the thickness direction of the battery cell, a projection of the second electrical connector at least partially overlaps with a projection of the electrode terminal.

16. The battery cell according to claim 14, characterized in that: The first electrical connector and the second electrical connector are spaced apart from each other along a width direction of the battery core.

17. The battery cell according to claim 1, characterized in that: The electrode assembly is a laminated structure, and includes a plurality of positive electrode sheets and a plurality of negative electrode sheets stacked along a thickness direction thereof.

18. The battery cell according to claim 1, characterized in that: The first wall includes a third step wall. Along the length direction of the battery cell, the third step wall is located at an end of the first main body wall opposite to the first step wall. The third step wall is recessed relative to the first main body wall toward the second wall. The third step wall is connected to the first main body wall via a third connecting wall.

19. The battery cell according to claim 1, characterized in that: The housing includes a first shell and a second shell, the first shell includes the first wall, the second shell includes the second wall, and the first shell and the second shell are welded.

20. The battery cell according to claim 19, characterized in that: The wall thickness of the first shell is H2, and the wall thickness of the second shell is H3, satisfying 0.01 mm≤H2≤0.2 mm, 0.01 mm≤H3≤0.2 mm.

21. The battery cell according to claim 1, characterized in that: The thickness of the battery cell is H1, satisfying 0.5 mm ≤ H1 ≤ 4 mm.

22. The battery cell according to claim 1, characterized in that: The shell is a steel shell, the first pole piece is a positive pole piece, and the second pole piece is a negative pole piece.

23. The battery cell according to claim 21, characterized in that: The width of the first step wall is greater than the thickness of the battery core.

24. An electrical equipment, characterized in that: The invention comprises a battery cell as described in any one of claims 1 to 23, wherein the battery cell is used to provide electrical energy.

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