Battery cell and electric equipment

Abstract

The invention provides a battery cell and electric equipment, the battery cell comprises a shell, an electrode assembly, an electrode terminal and a sealing nail, the shell 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; a liquid injection hole is formed in the second wall, and at least part of the liquid injection hole is located in the projection of the first step wall when observed in the thickness direction of the battery cell. The electrode terminal is arranged on the first step wall and electrically connected with the first pole piece, and the second pole piece is electrically connected with the shell. And the sealing nail seals the liquid injection hole. And the reinforcing structure is formed between the first main body wall and the first step wall, so that the possibility of deformation of the first step wall after being stressed is low, the risk of electrolyte leakage is reduced, and the safety of the battery cell is improved. And the liquid injection hole can reuse the space reserved for the electrode terminal between the first step wall and the second wall, so that the energy density of the battery cell can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and in particular, 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. During the use of the electric core, the electrode assembly will shake inside the outer shell, making the outer shell prone to deformation, 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, an electrode assembly, an electrode terminal, and a sealing nail. The outer shell 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 body 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 body wall, and the first stepped wall is recessed towards the second wall relative to the first main body wall. The first stepped wall and the first main body wall are connected by a first connecting wall. The second wall is provided with a liquid injection hole, and at least a part of the liquid injection hole is located within the projection of the first stepped wall when observed along the thickness direction of the electric core. The electrode assembly is disposed inside the outer shell and is located between the first main body wall and the second wall. The electrode assembly includes a first pole piece and a second pole piece with opposite polarities. The electrode terminal is disposed on the first stepped wall, the electrode terminal is electrically connected to the first pole piece, and the second pole piece is electrically connected to the outer shell. The sealing nail is disposed on the second wall and seals the liquid injection hole.

[0006] In the above technical solution, since the electrode terminal is currently arranged on the side wall of the housing, in order to make the sealing area between the electrode terminal and the housing meet the sealing requirements, the thickness of the housing needs to be set relatively large. In the embodiment of the present application, 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, the thickness of the housing can be set smaller to be applicable to more types of electrical equipment; and when the battery cell is subjected to an external force, the first main wall is stressed first before the first step wall, so that the possibility of the first step 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 step wall, so that the possibility of the first step wall being deformed after being stressed is relatively low, the sealing effectiveness between the electrode terminal and the first step wall can be maintained, the risk of electrolyte leakage is reduced, and the safety of the battery cell is improved.

[0007] Since the liquid injection hole is currently arranged on the side wall of the housing, in order to make the sealing area between the sealing nail and the housing meet the sealing requirements, the thickness of the housing needs to be set relatively large. In the embodiment of the present application, by making the second wall provided with a liquid injection hole, at least part of the liquid injection hole is located within the projection of the first step wall when observed along the thickness direction of the battery cell, the sealing nail is arranged on the second wall and the liquid injection hole is sealed, the thickness of the housing can be set smaller to be applicable to more types of electrical equipment; and when injecting liquid through the liquid injection hole, the space reserved for the electrode terminal between the first step wall and the second wall can be reused, which is convenient for the electrolyte to be smoothly injected into the interior of the housing, making the space utilization rate inside the housing higher and conducive to improving the energy density of the battery cell.

[0008] In some embodiments of the present application, the width of the sealing nail is D1, and the thickness of the battery cell is H1, satisfying D1 > H1 - 1mm.

[0009] In the above technical solution, since the liquid injection hole is currently arranged on the side wall of the housing, in order to meet the welding requirements between the sealing nail and the housing, a width of 0.5mm needs to be reserved on both sides of the liquid injection hole along the thickness direction of the battery cell. In the embodiment of the present application, the width of the sealing nail is D1, and the thickness of the battery cell is H1, satisfying D1 > H1 - 1mm. The sealing nail cannot be arranged on the side wall of the housing, but can be arranged on the second wall of the housing, so that the influence of the sealing nail on the thickness of the battery cell is relatively small.

[0010] 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 3mm ≤ W1 ≤ 20mm.

[0011] In the above technical solution, the length of the battery cell is L1, and the width of the battery cell is W1, satisfying L1 > W1, L1 > H1, and 3 mm ≤ W1 ≤ 20 mm, that is, the battery cell is a narrow and long battery cell. By arranging the electrode terminal at one end of the housing along the length direction of the battery cell, the space occupied by the electrode terminal can be made smaller.

[0012] When W1 ≥ 3 mm, it is convenient for the preparation of the electrode assembly and the assembly of the electrode assembly and the housing; 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 housing, and the applicable range of the battery cell can be made wider.

[0013] In some embodiments of the present application, the thickness of the battery cell is H1, and 0.5 mm ≤ H1 ≤ 4 mm.

[0014] 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 housing; when H1 ≤ 4 mm, the applicable range of the battery cell can be made wider; therefore, when 0.5 mm ≤ H1 ≤ 4 mm, it is both convenient for the preparation of the electrode assembly and the assembly of the electrode assembly and the housing, and the applicable range of the battery cell can be made wider.

[0015] In some embodiments of the present application, 0.5 mm ≤ H1 ≤ 2.5 mm.

[0016] 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 housing; when H1 ≤ 2.5 mm, the applicable range of the battery cell can be further made wider; therefore, when 0.5 mm ≤ H1 ≤ 2.5 mm, it is both convenient for the preparation of the electrode assembly and the assembly of the electrode assembly and the housing, and the applicable range of the battery cell can be further made wider. And in this solution, the electrode terminal and the liquid injection hole are arranged on the stepped wall, and the thickness H1 can be made below 2.5 mm, which is convenient for manufacturing an ultra-thin battery cell.

[0017] In some embodiments of the present application, along the thickness direction of the battery cell, the projection of the electrode terminal does not overlap with the projection of the sealing nail, and they are arranged along the width direction of the battery cell.

[0018] In the above technical solution, by making the projection of the electrode terminal not overlap with the projection of the sealing nail along the thickness direction of the battery cell, when injecting liquid through the liquid injection hole, the possibility of the electrolyte being blocked by the electrode terminal is relatively low, which is beneficial to the smooth injection of the electrolyte into the housing; by making the projection of the electrode terminal and the projection of the sealing nail arranged along the width direction of the battery cell, the structure of the battery cell is compact, which is beneficial to improving the energy density of the battery cell.

[0019] In some embodiments of the present application, along the length direction of the battery cell, the distance between the electrode assembly and the first connection wall is G, satisfying 0.5 mm ≤ G ≤ 4 mm.

[0020] In the above technical solution, when G ≥ 0.5 mm, the possibility of interference generated when the electrode assembly is inserted into the outer shell can be reduced, thus facilitating the preparation of the battery cell; when G ≤ 4 mm, the space for accommodating the electrode assembly in the outer shell 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 can not only reduce the possibility of interference generated when the electrode assembly is inserted into the outer shell, thus facilitating the preparation of the battery cell, but also make the space for accommodating the electrode assembly in the outer shell larger, which is beneficial to improving the energy density of the battery cell.

[0021] In some embodiments of the present application, 1 mm ≤ G ≤ 2.5 mm.

[0022] In the above technical solution, when G ≥ 1 mm, the possibility of interference generated when the electrode assembly is inserted into the outer shell can be further reduced, thus facilitating the preparation of the battery cell; when G ≤ 2.5 mm, the space for accommodating the electrode assembly in the outer shell can be further made larger, which is beneficial to improving the energy density of the battery cell; 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 outer shell, 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, thus facilitating the preparation of the battery cell, but also make the space for accommodating the electrode assembly in the outer shell larger, which is beneficial to improving the energy density of the battery cell.

[0023] 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 outer shell and is located 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.

[0024] In the above technical solution, due to the small size of the electrode terminal, when the electrode terminal is installed in the outer shell, the sealing area between the electrode terminal and the outer shell is small, and 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 outer shell and is located 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 outer shell, thereby increasing the sealing area between the electrode terminal and the outer shell, improving the sealing effect, and reducing the possibility of electrolyte leakage.

[0025] In some embodiments of the present application, the thickness direction of the adapter board is parallel to the thickness direction of the battery cell. The adapter 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 along the width direction of the battery cell.

[0026] In the above technical solution, since the current electrode terminal, adapter board, and first electrical connector are stacked and connected in sequence, it 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 adapter board parallel to the thickness direction of the battery cell, the adapter 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 along the width direction of the battery cell, so that the electrode terminal and the first electrical connector can be arranged on the same side of the adapter board, thereby making the overall thickness of the electrode terminal, adapter board, and first electrical connector in the thickness direction of the battery cell smaller, which is beneficial to improving the energy density of the battery cell.

[0027] 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 board is W2, satisfying 80% ≤ W2 / W1 ≤ 99%.

[0028] In the above technical solution, when W2 / W1 ≥ 80%, it can make the area of the adapter board larger, facilitating the connection of the adapter board with the first electrical connector and the electrode terminal; when W2 / W1 ≤ 99%, it can reduce the possibility of interference when the adapter board is installed in the housing, thus facilitating the preparation of the battery cell; therefore, when 80% ≤ W2 / W1 ≤ 99%, it can not only facilitate the connection of the adapter board with the first electrical connector and the electrode terminal, but also reduce the possibility of interference when the adapter board is installed in the housing, thus facilitating the preparation of the battery cell.

[0029] 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, it will make the preparation of the battery cell difficult, 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 preparation difficulty of the battery cell can be reduced, and the risk of short circuit of the battery cell can be reduced.

[0030] 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 0.01 ≤ L2 / L1 ≤ 0.5.

[0031] In the above technical solution, when L2 / L1 ≥ 0.01, it can make the first stepped wall have enough space to set the electrode terminal, which is beneficial to reducing the preparation difficulty of the battery cell and improving the preparation efficiency of the battery cell; when L2 / L1 ≤ 0.5, it can make the space occupied by the electrode terminal smaller, and there is more space in the outer shell to accommodate 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 not only make the first stepped wall have enough space to set the electrode terminal, 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 terminal smaller, and there is more space in the outer shell to accommodate the electrode assembly, which is beneficial to improving the energy density of the battery cell.

[0032] In some embodiments of the present application, along the length direction of the battery cell, the length of the first stepped wall is L2, satisfying 1.5 mm ≤ L2 ≤ 10 mm.

[0033] In the above technical solution, when L2 ≥ 1.5 mm, it can make the first stepped wall have enough space to set the electrode terminal, 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 terminal smaller, and there is more space in the outer shell to accommodate 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 stepped wall have enough space to set the electrode terminal, 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 terminal smaller, and there is more space in the outer shell to accommodate the electrode assembly, which is beneficial to improving the energy density of the battery cell.

[0034] In some embodiments of the present application, 2.5 mm ≤ L2 ≤ 8 mm.

[0035] In the above technical solution, when L2 ≥ 2.5 mm, it can further make the first stepped wall have enough space to set the electrode terminal, 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 terminal smaller, and there is more space in the outer shell to accommodate 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 stepped wall have enough space to set the electrode terminal, 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 terminal smaller, and there is more space in the outer shell to accommodate the electrode assembly, which is beneficial to improving the energy density of the battery cell.

[0036] In some embodiments of the present application, the second wall includes a second main wall and a second stepped wall. Along the length direction of the battery cell, the second stepped wall is located at one end of the second main wall. The second stepped wall is recessed towards the first wall relative to the second main wall, and the second stepped wall and the second main wall are connected by a second connecting wall. The liquid injection hole is arranged on the second stepped 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 projections of the first stepped wall and the second stepped wall overlap.

[0037] In the above technical solution, by making the second stepped wall located at one end of the second main wall along the length direction of the battery cell, the second stepped wall is recessed towards the first wall relative to the second main wall, the liquid injection hole is arranged on the second stepped wall, and along the thickness direction of the battery cell, the projections of the first stepped wall and the second stepped wall overlap, when the battery cell is subjected to an external force, the second main wall is stressed before the second stepped wall, so that the possibility of the second stepped wall being deformed by stress is relatively low, and the possibility of the sealing nail being directly stressed is also relatively low. Moreover, a strengthening structure is formed between the first main wall and the first stepped wall and between the second main wall and the second stepped wall, further making the strength of the part of the housing where the electrode terminal and the sealing nail are located higher, and further reducing the possibility of the first stepped wall and the second stepped wall being deformed by stress, which can maintain the sealing effectiveness between the electrode terminal and the first stepped wall and the sealing effectiveness between the sealing nail and the second stepped wall, further reducing the risk of electrolyte leakage and being beneficial to improving the safety of the battery cell.

[0038] In some embodiments of the present application, the surface of the second wall facing away from the first wall is a plane.

[0039] 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.

[0040] In some embodiments of the present application, the second wall has a first region that overlaps with the projection of 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 arranged 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 pole piece, and the other end is connected to the first region of the second wall.

[0041] In the above technical solution, by making the second wall have a first region that overlaps with the projection of the first stepped wall along the thickness direction of the battery cell, along the length direction of the battery cell, the second electrical connector is arranged 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 pole piece, and the other end is connected to the first region of the second wall, so that 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.

[0042] In some embodiments of the present application, the liquid injection hole and the first region are arranged along the width direction of the battery cell.

[0043] In the above technical solution, by arranging the liquid injection hole and the first region along the width direction of the battery cell, the space occupied by the liquid injection hole and the first region in the length direction of the battery cell is smaller, which is beneficial to improving the energy density of the battery cell.

[0044] In some embodiments of the present application, along the thickness direction of the battery cell, the projection of the second electrical connection member and the projection of the electrode terminal at least partially overlap.

[0045] In the above technical solution, by making the projection of the second electrical connection member and the projection of the electrode terminal at least partially overlap along the thickness direction of the battery cell, the second electrical connection member and the electrode terminal are arranged more compactly in the spaced space between the first step wall and the second wall, which can save the internal space of the housing and is beneficial to improving the energy density of the battery cell.

[0046] In some embodiments of the present application, the electrode assembly is 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.

[0047] In the above technical solution, since there will be a gap between the winding-type electrode assembly and the top corner of the housing, by making the electrode assembly 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 housing can be higher, which is beneficial to improving the energy density of the battery cell.

[0048] In some embodiments of the present application, the first wall includes a third step wall. Along the length direction of the battery cell, the third step wall is located at one end of the first main wall opposite to the first step wall. The third step wall is recessed towards the second wall relative to the first main wall, and the third step wall is connected to the first main wall through a third connecting wall.

[0049] In the above technical solution, by making the third step wall located at one end of the first main wall and the first step wall along the length direction of the battery cell, and the third step wall is recessed towards the second wall relative to the first main wall, a reinforcing structure is formed between the first main wall and the third step wall, and the possibility of the third step wall deforming after being stressed is lower, which is beneficial to improving the safety of the battery cell.

[0050] In some embodiments of the present application, the housing includes a first housing and a second housing. The first housing includes a first wall, the second housing includes a second wall, and the first housing and the second housing are welded.

[0051] In the above technical solution, by making the outer shell include a first housing and a second housing, the first housing includes a first wall, the second housing includes a second wall, and the first housing and the second housing are welded, it is convenient to assemble and connect the electrode assembly and the electrode terminal to the first housing and the second housing, which is beneficial to improving the preparation efficiency of the battery cell.

[0052] In some embodiments of the present application, the wall thickness of the first housing is H2, and the wall thickness of the second housing is H3, satisfying 0.01 mm ≤ H2 ≤ 0.2 mm, 0.01 mm ≤ H3 ≤ 0.2 mm.

[0053] In the above technical solution, when H2 ≥ 0.01 mm, the strength of the first housing can be relatively high, reducing the possibility of the first housing deforming under force, 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 relatively small, leaving more space inside the outer shell for accommodating the electrode assembly, which is beneficial to improving 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, reduce the possibility of the first housing deforming under force, and be beneficial to improving the safety of the battery cell, but also make the space occupied by the first housing relatively small, leaving more space inside the outer shell for accommodating the electrode assembly, which is beneficial to improving the energy density of the battery cell.

[0054] When H3 ≥ 0.01 mm, the strength of the second housing can be relatively high, reducing the possibility of the second housing deforming under force, 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 relatively small, leaving more space inside the outer shell for accommodating the electrode assembly, which is beneficial to improving 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, reduce the possibility of the second housing deforming under force, and be beneficial to improving the safety of the battery cell, but also make the space occupied by the second housing relatively small, leaving more space inside the outer shell for accommodating the electrode assembly, which is beneficial to improving the energy density of the battery cell.

[0055] In some embodiments of the present application, 0.03 mm ≤ H2 ≤ 0.16 mm, 0.03 mm ≤ H3 ≤ 0.16 mm.

[0056] In the above technical solution, when H2 ≥ 0.03 mm, the strength of the first housing can be further increased, the possibility of the first housing deforming under stress can be reduced, 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 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 ≤ H2 ≤ 0.16 mm, both the strength of the first housing can be further increased, the possibility of the first housing deforming under stress can be reduced, which is beneficial to improving the safety of the battery cell, and the space occupied by the first 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.

[0057] When H3 ≥ 0.03 mm, the strength of the second housing can be further increased, the possibility of the second housing deforming 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, both the strength of the second housing can be further increased, the possibility of the second housing deforming under stress can be reduced, which is beneficial to improving the safety of the battery cell, and 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.

[0058] In some embodiments of the present application, the outer housing is a steel shell, the first electrode plate is a positive electrode plate, and the second electrode plate is a negative electrode plate.

[0059] In the above technical solution, since the electrical connector connected to the positive electrode plate 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 to corrode the electrical connector and the outer housing. Therefore, the positive electrode plate needs to be led out through an electrode terminal. The negative current collector and the electrical connector connected to the negative electrode plate are generally copper, and aluminum and steel electrical connection will not produce a strong corrosion effect. Therefore, the negative electrode plate can be directly connected to the steel shell.

[0060] 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

[0061] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can also be obtained based on these drawings.

[0062] Figure 1 Schematic diagram of the three-dimensional structure of the battery cell provided by some embodiments of the present application;

[0063] Figure 2 For Figure 1 Partial enlarged structure diagram of the battery cell at position A in

[0064] Figure 3 Explosion structure diagram of the battery cell provided by some embodiments of the present application;

[0065] Figure 4 Schematic diagram of the structure of the battery cell from one perspective provided by some embodiments of the present application;

[0066] Figure 5 For Figure 4 Cross-sectional structure diagram of the battery cell along the C-C direction in

[0067] Figure 6 For Figure 5 Partial enlarged structure diagram of the battery cell at position E in

[0068] Figure 7 For Figure 4 Cross-sectional structure diagram of the battery cell along the B-B direction in

[0069] Figure 8 For Figure 7 Partial enlarged structure diagram of the battery cell at position D in

[0070] Figure 9 Schematic diagram of the three-dimensional structure of the partial structure of the battery cell provided by some embodiments of the present application;

[0071] Figure 10 Partial enlarged structure diagram of the partial structure of the battery cell provided by some embodiments of the present application;

[0072] Figure 11 Schematic diagram of the three-dimensional structure of the battery cell provided by other embodiments of the present application;

[0073] Figure 12 Schematic diagram of the three-dimensional structure of the battery cell provided by other embodiments of the present application;

[0074] Figure 13 For Figure 12 Partial enlarged structure diagram of the battery cell at position F in

[0075] Icons: 10 - battery cell; 100 - housing; 101 - first housing; 102 - second housing; 110 - first wall; 111 - first main body wall; 112 - first stepped wall; 113 - first connecting wall; 114 - third stepped wall; 115 - third connecting wall; 120 - second wall; 120a - liquid injection hole; 121 - second main body wall; 122 - second stepped wall; 123 - second connecting wall; 200 - electrode assembly; 210 - first electrode tab; 220 - second electrode tab; 310 - electrode terminal; 320 - first electrical connector; 330 - adapter board; 340 - first insulating member; 350 - second insulating member; 410 - sealing nail; 510 - 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

[0076] To make the objectives, technical solutions and advantages of this application clearer, the following will clearly describe the technical solutions in the embodiments of this application with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are some but not all of the embodiments of this application. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art belong to the scope of protection of this application.

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

[0078] The terms "first", "second", etc. in the description and claims of this application or the above accompanying 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 this application means that the specific features, structures or characteristics described in combination with the embodiments can be included in at least one embodiment of this application. The phrase appears in various positions in the description 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 this application, the same reference numerals represent the same components, and for the sake of brevity, the detailed description of the same components is omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components shown in the accompanying drawings in the embodiments of this application, 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 this application.

[0081] With the development of the new energy industry, batteries are gradually evolving towards higher energy density and higher 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 becoming thinner and thinner. Under mechanical abuse conditions (such as drum tests and drop tests), the outer shell is prone to deformation under the external force or the impact force of the electrode assembly. On the side wall where the electrode terminal is provided, 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, which affects 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, an electrode assembly, an electrode terminal, and a sealing nail. The outer shell includes a first wall and a second wall that are 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 relative to the first main wall towards the direction close to the second wall. The first stepped wall and the first main wall are connected by a first connecting wall. The second wall is provided with a liquid injection hole, and at least a part of the liquid injection hole is located within the projection of the first stepped wall when observed along the thickness direction of the battery cell. The electrode assembly is disposed inside the outer shell and is located between the first main wall and the second wall. The electrode assembly includes a first electrode plate and a second electrode plate with opposite polarities. The electrode terminal is disposed on the first stepped wall, and the electrode terminal is electrically connected to the first electrode plate. The second electrode plate is electrically connected to the outer shell. The sealing nail is disposed on the second wall and seals the liquid injection hole.

[0083] In the battery cell with this structure, by making the first stepped wall located at one end of the first main wall along the length direction of the battery cell, and the first stepped wall is recessed relative to the first main wall towards the direction close to the second wall, and the electrode terminal is disposed on the first stepped wall, when the battery cell is subjected to an external force, the first main wall is stressed first, 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 strengthening structure is formed between the first main wall and the first stepped wall, making the possibility of the first stepped wall being deformed after being stressed relatively low, which can maintain the sealing effectiveness between the electrode terminal and the first stepped wall, reduce the risk of electrolyte leakage, and is beneficial to improving the safety of the battery cell. By making the second wall provided with a liquid injection hole, and at least a part of the liquid injection hole is located within the projection of the first stepped wall when observed along the thickness direction of the battery cell, and the sealing nail is disposed on the second wall and seals the liquid injection hole, when injecting liquid through the liquid injection hole, the space reserved for the electrode terminal between the first stepped wall and the second wall can be reused, facilitating the smooth injection of the electrolyte into the interior of the outer shell, making the space utilization rate inside the outer shell higher, and being beneficial to improving the energy density of the battery cell.

[0084] The battery cell provided by the embodiments 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. The embodiments of the present application do not limit this. The electrochemical device can be in a cylindrical shape, a flat shape, a cuboid shape, or other shapes, etc. The embodiments of the present application do not limit this either.

[0085] The embodiments of the present application provide 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 3 , Figure 1 which is a schematic perspective view of the battery cell provided by some embodiments of the present application; Figure 2 is Figure 1 a partial enlarged structural view of the A position of the battery cell in Figure 3 which is an exploded structural view of the battery cell provided by some embodiments of the present application.

[0087] The embodiments of the present application provide a battery cell 10, which includes a housing 100, an electrode assembly 200, an electrode terminal 310, and a sealing nail 410. The housing 100 includes a first wall 110 and a second wall 120 that are oppositely arranged along the thickness direction X of the battery cell. The first wall 110 includes a first main wall 111 and a first step wall 112. Along the length direction Y of the battery cell, the first step wall 112 is located at one end of the first main wall 111. The first step wall 112 is recessed relative to the first main wall 111 in a direction approaching the second wall 120. The first step wall 112 and the first main wall 111 are connected by a first connecting wall 113. The second wall 120 is provided with a liquid injection hole 120a. When observing along the thickness direction X of the battery cell, at least a part of the liquid injection hole 120a is located within the projection of the first step wall 112. The electrode assembly 200 is disposed within the housing 100 and is located between the first main wall 111 and the second wall 120. The electrode assembly 200 includes a first pole piece 210 and a second pole piece 220 with opposite polarities. The electrode terminal 310 is disposed on the first step wall 112. The electrode terminal 310 is electrically connected to the first pole piece 210, and the second pole piece 220 is electrically connected to the housing 100. The sealing nail 410 is disposed on the second wall 120 and seals the liquid injection hole 120a.

[0088] Since the electrode terminal 310 is currently disposed on the sidewall of the outer shell 100, in order to make the sealing area between the electrode terminal 310 and the outer shell 100 meet the sealing requirements, the thickness of the outer shell 100 needs to be set relatively large. In the embodiment of the present application, 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, and the first stepped wall 112 is recessed relative to the first main wall 111 in a direction approaching the second wall 120. The electrode terminal 310 is disposed on the first stepped wall 112, so that the thickness of the outer shell 100 can be set smaller to be applicable to more types of electrical equipment; and when the battery cell 10 is subjected to an external force, the first main wall 111 is stressed before 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 sealing 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] Since the liquid injection hole 120a is currently disposed on the sidewall of the outer shell 100, in order to make the sealing area between the sealing nail 410 and the outer shell 100 meet the sealing requirements, the thickness of the outer shell 100 needs to be set relatively large. In the embodiment of the present application, the second wall 120 is provided with the liquid injection hole 120a. When observing along the thickness direction X of the battery cell, at least a part of the liquid injection hole 120a is located within the projection of the first stepped wall 112. The sealing nail 410 is disposed on the second wall 120 and seals the liquid injection hole 120a, so that the thickness of the outer shell 100 can be set smaller to be applicable to more types of electrical equipment; and when injecting liquid through the liquid injection hole 120a, the space reserved for the electrode terminal 310 between the first stepped wall 112 and the second wall 120 can be reused, which is convenient for the electrolyte to be smoothly injected into the interior of the outer shell 100, making the space utilization rate inside the outer shell 100 higher and conducive to improving the energy density of the battery cell 10.

[0090] In some embodiments, when observing along the thickness direction X of the battery cell, a part of the liquid injection hole 120a is located within the projection of the first stepped wall 112, so that when injecting liquid through the liquid injection hole 120a, part of the electrolyte can directly flow into the space between the first stepped wall 112 and the second wall 120, and part of the electrolyte can flow into the outer shell 100 through the space between the electrode assembly 200 and the second wall 120.

[0091] In some embodiments, when observing along the thickness direction X of the battery cell, the liquid injection hole 120a is located within the projection of the first stepped wall 112, so that when injecting liquid through the liquid injection hole 120a, the electrolyte can all directly flow into the space between the first stepped wall 112 and the second wall 120, which can improve the injection speed of the electrolyte.

[0092] In some embodiments, the outer shell 100 can be made of materials with high strength, such as metal materials like steel and aluminum alloy, so that the outer shell 100 has high stress-bearing performance, and further can reduce the possibility of deformation or damage of the outer shell 100 due to stress or environmental changes, and thus can make the reliability of the battery cell 10 higher.

[0093] In other embodiments, the outer shell 100 can also be made of non-metal materials with high strength, such as carbon fiber and hard plastic.

[0094] 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.

[0095] In other embodiments, the top corners of the battery cell 10 can also be square.

[0096] In some embodiments, the electrode terminal 310 can be made of materials 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.

[0097] In some embodiments, the electrode terminal 310 can be arranged in shapes such as square, circular, and oval.

[0098] In some embodiments, the first step wall 112 can be formed by partial stretching or stamping.

[0099] 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, or 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.

[0100] See also Figures 4 to 6 , Figure 4A perspective structural schematic diagram of the battery cell provided by some embodiments of the present application; Figure 5 is Figure 4 The cross-sectional structural schematic diagram of the battery cell along the C-C direction in Figure 6 is Figure 5 The partial enlarged structural schematic diagram of the E position of the battery cell in

[0101] In some embodiments, the width of the sealing nail 410 is D1, and the thickness of the battery cell 10 is H1, satisfying D1 > H1 - 1 mm. For example, D1 can be H1 - 0.8 mm, H1 - 0.5 mm, H1 - 0.3 mm, H1 or 1.2 * H1, etc.

[0102] Among them, when the sealing nail 410 is circular, the width of the sealing nail 410 is the diameter of the sealing nail 410. When the sealing nail 410 is rectangular, oval, or racetrack-shaped, the width of the sealing nail 410 is the width of the sealing nail 410 along the thickness direction X of the battery cell.

[0103] Since a liquid injection hole 120a is currently provided on the side wall of the outer shell 100, to meet the welding requirements of the sealing nail 410 and the outer shell 100, a width of 0.5 mm needs to be reserved on both sides of the liquid injection hole 120a along the thickness direction X of the battery cell. In the embodiments of the present application, the width of the sealing nail 410 is D1, and the thickness of the battery cell 10 is H1, satisfying D1 > H1 - 1 mm. The sealing nail 410 cannot be provided on the side wall of the outer shell 10, but can be provided on the second wall 120 of the outer shell 10, so that the influence of the sealing nail 410 on the thickness of the battery cell 10 is relatively small.

[0104] See also Figure 4 and Figure 7 , Figure 7 is Figure 4 The cross-sectional structural schematic diagram of the battery cell along the B-B direction in

[0105] In some embodiments, the length of the battery cell 10 is L1, the width of the battery cell 10 is W1, and the thickness of the battery cell 10 is H1, satisfying L1 > W1, L1 > H1, and 3 mm ≤ W1 ≤ 20 mm. For example, W1 can be 3 mm, 7 mm, 10 mm, 15 mm, or 20 mm, etc.

[0106] By making the length of the battery cell 10 be L1 and the width of the battery cell 10 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.

[0107] 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 housing 100; when W1≤20 mm, the applicable range of the battery cell 10 is 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 housing 100, and the applicable range of the battery cell 10 is wider.

[0108] In some embodiments, the thickness of the battery cell 10 is H1, and 0.5 mm≤H1≤4 mm. For example, H1 can be 0.5 mm, 1 mm, 2 mm, 3 mm or 4 mm, etc.

[0109] When H1≥0.5 mm, it is convenient for the preparation of the electrode assembly 200 and the assembly of the electrode assembly 200 and the housing 100; when H1≤4 mm, the applicable range of the battery cell 10 is 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 and the housing 100, and the applicable range of the battery cell 10 is wider. In some embodiments, 0.5 mm≤H1≤2.5 mm. For example, H1 can be 0.5 mm, 1.2 mm, 1.8 mm, 2.1 mm or 2.5 mm, etc.

[0110] When H1≥0.5 mm, it is convenient for the preparation of the electrode assembly 200 and the assembly of the electrode assembly 200 and the housing 100; when H1≤2.5 mm, the applicable range of the battery cell 10 is further wider; therefore, when 0.5 mm≤H1≤2.5 mm, it is both convenient for the preparation of the electrode assembly 200 and the assembly of the electrode assembly 200 and the housing 100, and the applicable range of the battery cell 10 is further wider. And in this solution, the electrode terminal 310 and the liquid injection hole 120a are arranged on the stepped wall, and the thickness H1 can be made less than 2.5 mm, which is convenient for manufacturing an ultra-thin battery cell.

[0111] In some embodiments, along the thickness direction X of the battery cell, the projection of the electrode terminal 310 does not overlap with the projection of the sealing nail 410, and they are arranged along the width direction Z of the battery cell.

[0112] By making the projection of the electrode terminal 310 not overlap with the projection of the sealing nail 410 along the thickness direction X of the battery cell, when injecting liquid through the liquid injection hole 120a, the possibility of the electrolyte being blocked by the electrode terminal 310 is relatively low, which is beneficial to the smooth injection of the electrolyte into the interior of the housing 100; by making the projection of the electrode terminal 310 and the projection of the sealing nail 410 arranged along the width direction Z of the battery cell, the structure of the battery cell 10 is compact, which is beneficial to improving the energy density of the battery cell 10.

[0113] See Figure 8 , Figure 8 For Figure 7Partial enlarged structural schematic diagram of the D position of the middle battery cell.

[0114] In some embodiments, along the length direction Y of the battery cell, the distance G between the electrode assembly 200 and the first connection wall 113 satisfies 0.5 mm ≤ G ≤ 4 mm. For example, G can be 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm, etc.

[0115] When G ≥ 0.5 mm, the possibility of interference generated when the electrode assembly 200 is installed in the housing 100 can be reduced, thus facilitating the preparation of the battery cell 10; when G ≤ 4 mm, the space in the housing 100 for accommodating the electrode assembly 200 can be made larger, which is beneficial to improving the energy density of the battery cell 10; therefore, when 0.5 mm ≤ G ≤ 4 mm, both the possibility of interference generated when the electrode assembly 200 is installed in the housing 100 can be reduced, thus facilitating the preparation of the battery cell 10, and the space in the housing 100 for accommodating the electrode assembly 200 can be made larger, which is beneficial to improving the energy density of the battery cell 10.

[0116] 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.

[0117] When G ≥ 1 mm, the possibility of interference generated when the electrode assembly 200 is installed in the housing 100 can be further reduced, thus facilitating the preparation of the battery cell 10; when G ≤ 2.5 mm, the space in the housing 100 for accommodating the electrode assembly 200 can be further made larger, which is beneficial to improving the energy density of the battery cell 10; therefore, when 1 mm ≤ G ≤ 2.5 mm, both the possibility of interference generated when the electrode assembly 200 is installed in the housing 100 can be reduced, and since the projection of the electrode assembly 200 does not overlap with the projection of the electrode terminal 310, there is no need to reserve space for the electrode terminal 310, and G can be made within 2.5 mm, thus facilitating the preparation of the battery cell 10, and the space in the housing 100 for accommodating the electrode assembly 200 can be made larger, which is beneficial to improving the energy density of the battery cell 10.

[0118] See Figure 1 、 Figure 5 、 Figure 6 and Figure 9 , Figure 9 is a perspective schematic diagram of the partial structure of the battery cell provided by some embodiments of the present application.

[0119] In some embodiments, the battery cell 10 further includes a first electrical connector 320 and an adapter board 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 board 330 is disposed within 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 board 330, and the adapter board 330 is connected to the electrode terminal 310.

[0120] 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, and the sealing effect is not good, which easily causes the problem of electrolyte leakage. By providing the adapter board 330, the adapter board 330 is disposed within 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 board 330, and the adapter board 330 is connected to the electrode terminal 310, so that a seal can be formed between the adapter board 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.

[0121] 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 board 330, which is convenient for connecting the first electrical connector 320 to the adapter board 330.

[0122] In some embodiments, the thickness direction of the adapter board 330 is 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 apart along the width direction Z of the battery cell.

[0123] Since currently stacking and connecting the electrode terminal 310, the adapter board 330, and the first electrical connector 320 in sequence will occupy a 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, and the first connection area and the second connection area are spaced apart along the width direction Z of the battery cell, so that the electrode terminal 310 and the first electrical connector 320 can be disposed on the same side of the adapter board 330, thereby making 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 smaller, which is beneficial to improving the energy density of the battery cell 10.

[0124] See Figure 10, Figure 10 Partial enlarged structural schematic diagram of part of the structure of the battery cell provided by some embodiments of the present application.

[0125] 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 plate 330 is W2, satisfying 80% ≤ W2 / W1 ≤ 99%. For example, W2 / W1 can be 80%, 85%, 90%, 95% or 99%, etc.

[0126] When W2 / W1 ≥ 80%, it can make the area of the adapter plate 330 larger, which is convenient for connecting the adapter plate 330 with the first electrical connector 320 and the electrode terminal 310; when W2 / W1 ≤ 99%, it can reduce the possibility of interference when the adapter plate 330 is installed in the housing 100, thus facilitating the preparation of the battery cell 10; therefore, when 80% ≤ W2 / W1 ≤ 99%, it can not only facilitate the connection of the adapter plate 330 with the first electrical connector 320 and the electrode terminal 310, but also reduce the possibility of interference when the adapter plate 330 is installed in the housing 100, thus facilitating the preparation of the battery cell 10.

[0127] 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 the battery cell 10 is provided with two electrode terminals 310 with opposite polarities, 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. Therefore, by making 80% ≤ W2 / W1 ≤ 99%, that is, only one electrode terminal 310 is provided on the first step wall 112, the preparation difficulty of the battery cell 10 can be reduced, and the risk of short circuit of the battery cell 10 can be reduced.

[0128] See Figure 6 and Figure 9 , in some embodiments, the first step wall 112 is provided with a first through hole, and the electrode terminal 310 passes through the first through hole.

[0129] 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 step 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 step wall 112. By providing the first insulating member 340 and the second insulating member 350, insulation between the electrode terminal 310 and the first step wall 112, and insulation between the adapter plate 330 and the first step wall 112 can be achieved, reducing the risk of short circuit of the battery cell 10.

[0130] See Figure 4, 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.

[0131] When L2 / L1 ≥ 0.01, 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 / 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 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.

[0132] 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.

[0133] 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.

[0134] 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.

[0135] 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 make the space occupied by the electrode terminal 310 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 both 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, and further make the space occupied by the electrode terminal 310 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.

[0136] See Figure 1 and Figure 8 , 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 approaching the first wall 110. The second stepped wall 122 and the second main wall 121 are connected by a second connecting wall 123. The liquid injection hole 120a is arranged on the second stepped wall 122. 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.

[0137] Among them, when along the thickness direction X of the battery cell, the offset of the projection of the first stepped wall 112 relative to the projection of the second stepped wall 122 is within the threshold error range (for example, 5 mm), it belongs to the range where the projection of the first stepped wall 112 and the projection of the second stepped wall 122 in this application overlap.

[0138] By making the second stepped wall 122 located at one end of the second main wall 121 along the length direction Y of the battery cell, the second stepped wall 122 is recessed relative to the second main wall 121 in a direction closer to the first wall 110, the liquid injection hole 120a is arranged on the second stepped wall 122, and 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, so that when an external force acts on the battery cell 10, the second main wall 121 is stressed prior to the second stepped wall 122, thereby making the possibility of the second stepped wall 122 being deformed by stress relatively low, and the possibility of the sealing nail 410 being directly stressed is also relatively low. Moreover, a strengthening structure is formed between the first main wall 111 and the first stepped wall 112, and between the second main wall 121 and the second stepped wall 122, further making the strength of the part of the housing where the electrode terminal 310 and the sealing nail 410 are located higher, and further reducing the possibility of the first stepped wall 112 and the second stepped wall 122 being deformed by stress, capable of maintaining the sealing effectiveness between the electrode terminal 310 and the first stepped wall 112, and the sealing effectiveness between the sealing nail 410 and the second stepped wall 122, further reducing the risk of electrolyte leakage, and being beneficial to improving the safety of the battery cell 10.

[0139] In some embodiments, the second stepped wall 122 can be formed by means of sectional stretching or stamping.

[0140] 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.

[0141] In some embodiments, the surface of the second wall 120 facing away from the first wall 110 is a plane.

[0142] By making the surface of the second wall 120 facing away from the first wall 110 a plane, it is possible to facilitate the preparation and forming of the second wall 120, which is beneficial to improving the preparation efficiency of the battery cell 10.

[0143] See Figure 6 , 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 510. Along the length direction Y of the battery cell, the second electrical connector 510 is arranged at one end of the electrode assembly 200 close to the first stepped wall 112. One end of the second electrical connector 510 is connected to the second pole piece 220, and the other end is connected to the first region of the second wall 120.

[0144] By making the second wall 120 have a first region that overlaps with the projection of the first stepped wall 112 in the thickness direction X of the battery cell, in the length direction Y of the battery cell, the second electrical connector 510 is disposed at one end of the electrode assembly 200 close to the first stepped wall 112. One end of the second electrical connector 510 is connected to the second pole piece 220, and the other end is connected to the first region of the second wall 120, so that the first electrical connector 320 and the second electrical connector 510 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.

[0145] Since the width W1 of the battery cell 10 satisfies 3 mm ≤ W1 ≤ 20 mm, the width of the battery cell 10 is small. If two electrode terminals 310 with opposite polarities are provided in the battery cell 10 and the two electrode terminals 310 are arranged in the width direction Z of the battery cell, the manufacturing difficulty of the battery cell 10 will be relatively high, and there is a risk of contact short circuit between the two electrode terminals 310. By electrically connecting the second pole piece 220 to the housing 100, it is possible to make it unnecessary to provide an electrode terminal 310 for the corresponding second pole piece 220, that is, only one electrode terminal 310 needs to be provided on the first stepped wall 112, which can reduce the manufacturing difficulty of the battery cell 10 and reduce the risk of short circuit in the battery cell 10.

[0146] In some embodiments, the liquid injection hole 120a and the first region are arranged in the width direction Z of the battery cell.

[0147] By arranging the liquid injection hole 120a and the first region in the width direction Z of the battery cell, the space occupied by the liquid injection hole 120a and the first region in the length direction Y of the battery cell is smaller, which is beneficial to improving the energy density of the battery cell 10.

[0148] In some embodiments, in the thickness direction X of the battery cell, the projection of the second electrical connector 510 and the projection of the electrode terminal 310 at least partially overlap.

[0149] By making the projection of the second electrical connector 510 and the projection of the electrode terminal 310 at least partially overlap in the thickness direction X of the battery cell, the second electrical connector 510 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.

[0150] See Figure 3 , in some embodiments, the electrode assembly 200 is a stacked structure, and the electrode assembly 200 includes a plurality of positive electrode plates and a plurality of negative electrode plates stacked in the thickness direction thereof.

[0151] Since there will be a gap between the electrode assembly 200 with a wound 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.

[0152] In some other embodiments, the electrode assembly 200 may be a wound structure, and the electrode assembly 200 is formed by winding after laminating a positive electrode plate, a separator, and a negative electrode plate.

[0153] See Figure 12 and Figure 13 , Figure 12 which is a schematic three-dimensional structure diagram of the battery cell provided in some other embodiments of the present application; Figure 13 is Figure 12 a partial enlarged structural diagram of the F position of the battery cell in

[0154] 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.

[0155] 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, so that the possibility of deformation of the third stepped wall 114 after being stressed is relatively low, which is beneficial to improving the safety of the battery cell 10.

[0156] In some embodiments, the third stepped wall 114 can be formed by partial stretching or stamping.

[0157] In some other embodiments, the battery cell 10 may include a second electrode terminal 310 disposed on the third stepped wall 114 and electrically connected to the second electrode tab 220. When an external force acts on the battery cell 10, the first main wall 111 is stressed prior to the third stepped wall 114, so that the possibility of the third stepped wall 114 being deformed by the force is relatively low, and the possibility of the second electrode terminal 310 being directly stressed is also relatively low. Moreover, a reinforcing structure is formed between the first main wall 111 and the third stepped wall 114, so that the possibility of the third stepped wall 114 being deformed after being stressed is relatively low, the sealing effectiveness between the second electrode terminal 310 and the third stepped wall 114 can be maintained, the risk of electrolyte leakage is reduced, and the safety of the battery cell 10 is improved.

[0158] See Figure 3 , in some embodiments, the outer casing 100 includes a first casing 101 and a second casing 102. The first casing 101 includes a first wall 110, the second casing 102 includes a second wall 120, and the first casing 101 and the second casing 102 are welded.

[0159] By making the outer casing 100 include a first casing 101 and a second casing 102, the first casing 101 includes a first wall 110, the second casing 102 includes a second wall 120, and the first casing 101 and the second casing 102 are welded, the assembly and connection of the electrode assembly 200 and the electrode terminal 310 with the first casing 101 and the second casing 102 can be facilitated, which is conducive to improving the preparation efficiency of the battery cell 10.

[0160] In some other embodiments, the first casing 101 and the second casing 102 may also be adhesively connected.

[0161] In some embodiments, the wall thickness of the first casing 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, 0.2 mm, etc.

[0162] When H2 ≥ 0.01 mm, the strength of the first casing 101 can be relatively high, the possibility of the first casing 101 being deformed by the force is reduced, which is conducive to improving the safety of the battery cell 10; when H2 ≤ 0.2 mm, the space occupied by the first casing 101 can be relatively small, so that there is more space inside the outer casing 100 for accommodating the electrode assembly 200, which is conducive 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 casing 101 can be relatively high, the possibility of the first casing 101 being deformed by the force is reduced, which is conducive to improving the safety of the battery cell 10, and the space occupied by the first casing 101 can be relatively small, so that there is more space inside the outer casing 100 for accommodating the electrode assembly 200, which is conducive to improving the energy density of the battery cell 10.

[0163] In some embodiments, the wall thickness of the second housing 102 is H3, where 0.01 mm ≤ H3 ≤ 0.2 mm. For example, H3 can be 0.01 mm, 0.05 mm, 0.1 mm, 0.15 mm, 0.2 mm, etc.

[0164] When H3 ≥ 0.01 mm, the strength of the second housing 102 can be made 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 made relatively small, leaving 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 0.01 mm ≤ H3 ≤ 0.2 mm, it can not only make the strength of the second housing 102 relatively high, reduce the possibility of the second housing 102 deforming under stress, and be beneficial to improving the safety of the battery cell 10, but also make the space occupied by the second housing 102 relatively small, leaving 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, 0.03 mm ≤ H2 ≤ 0.16 mm. For example, H2 can be 0.03 mm, 0.06 mm, 0.08 mm, 0.13 mm, 0.16 mm, etc.

[0166] 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 increasing the energy density of the battery cell 10; therefore, when 0.03 mm ≤ H2 ≤ 0.16 mm, it can not only further increase the strength of the first housing 101, reduce the possibility of the first housing 101 deforming under stress, and be beneficial to improving the safety of the battery cell 10, but also further reduce the space occupied by the first housing 101, leaving 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.

[0167] 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, 0.16 mm, etc.

[0168] When H3≥0.03 mm, the strength of the second housing 102 can be further increased, the possibility of deformation of the second housing 102 under stress can be reduced, 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, so that there is 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≤H3≤0.16 mm, the strength of the second housing 102 can be further increased, the possibility of deformation of the second housing 102 under stress can be reduced, which is beneficial to improving the safety of the battery cell 10, and at the same time, the space occupied by the second housing 102 can be further reduced, so that there is 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.

[0169] In some embodiments, the outer housing 100 is a steel shell, the first electrode sheet 210 is a positive electrode sheet, and the second electrode sheet 220 is a negative electrode sheet.

[0170] 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 100. Therefore, the positive electrode sheet needs to be led out through the electrode terminal 310. The negative current collector and the electrical connector connected to the negative electrode sheet are generally made of copper, and the electrical connection between aluminum and steel will not produce a strong corrosion effect. Therefore, the negative electrode sheet can be directly connected to the steel shell.

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

[0172] The 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 devices or systems that use the battery cell 10 described above.

[0174] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0175] The above are only the preferred embodiments of the present application, and are not used to limit the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery cell, characterized in that: include: The housing comprises a first wall and a second wall which are arranged opposite to each other along the thickness direction of the battery core, wherein the first wall comprises a first main body wall and a first step wall, wherein the first step wall is located at one end of the first main body wall along the length direction of the battery core, the first step wall is recessed relative to the first main body wall in a direction close to the second wall, the first step wall is connected to the first main body wall through a first connecting wall, and the second wall is provided with a liquid injection hole, and when viewed along the thickness direction of the battery core, at least a portion of the liquid injection hole is located within a projection of the first step wall; an electrode assembly, disposed in the housing and located between the first main body wall and the second wall, 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 electrode piece, and the second electrode piece is electrically connected to the housing; A sealing nail is disposed on the second wall and seals the liquid injection hole.

2. The battery cell according to claim 1, characterized in that: The width of the sealing nail is D1, and the thickness of the battery cell is H1, satisfying D1>H1-1mm.

3. 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.

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

5. The battery cell according to claim 1, characterized in that: 0.5mm≤H1≤2.5mm.

6. The battery cell according to claim 1, characterized in that: Along the thickness direction of the battery cell, the projection of the electrode terminal does not overlap with the projection of the sealing nail, and they are arranged along the width direction of the battery cell.

7. The battery cell according to claim 1, 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.

8. The battery cell according to claim 7, characterized in that: 1mm≤G≤2.5mm.

9. The battery cell according to claim 1, 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.

10. The battery cell according to claim 9, 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.

11. The battery cell according to claim 9, 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%.

12. 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 0.01≤L2 / L1≤0.

5.

13. 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.

14. The battery cell according to claim 13, characterized in that: 2.5mm≤L2≤8mm.

15. 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 injection hole is provided on the second step 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.

16. 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.

17. The battery cell according to claim 1, characterized in that: The second wall has a first area overlapping with a projection of the first step wall along a thickness direction of the battery core; The battery cell also includes a second electrical connector, which is arranged at one end of the electrode assembly close to the first step wall along the length direction of the battery cell, one end of the second electrical connector is connected to the second pole piece, and the other end is connected to the first area of ​​the second wall.

18. The battery cell according to claim 17, characterized in that: The injection hole and the first area are arranged along a width direction of the battery core.

19. The battery cell according to claim 17, characterized in that: Along the thickness direction of the battery core, a projection of the second electrical connector at least partially overlaps with a projection of the electrode terminal.

20. 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.

21. 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.

22. 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.

23. The battery cell according to claim 1, 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.

24. The battery cell according to claim 23, characterized in that: 0.03mm≤H2≤0.16mm, 0.03mm≤H3≤0.16mm.

25. 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.

26. An electrical equipment, characterized in that: The invention comprises a battery cell as described in any one of claims 1 to 25, wherein the battery cell is used to provide electrical energy.

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