Battery cell housing assembly, battery cell, and battery pack

Abstract

The utility model relates to battery technology field discloses electric core shell body subassembly, electric core and battery package, wherein the electric core shell body subassembly, include: shell and apron, shell is equipped with the opening along Z direction at least one end, and the one end of shell is located the opening and is outwardly bent and forms the step portion, and the step portion includes the support section and the welding section that are connected, and the support section extends along X Y plane, and the welding section extends along Z direction, apron is covered and is equipped in the opening, along Z direction, the bottom of apron and support section abut, and the sidewall of apron and welding section are welded and are connected, the utility model discloses the step portion is arranged in the one end of shell and is equipped with the opening, can promote the structural strength of shell, reduce the thermal deformation of shell, and still can support apron to prevent apron subsidence, ensure the welding sealing quality of apron and shell, to promote the use security of electric core.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to a cell housing assembly, a cell, and a battery pack. Background Technology

[0002] In existing battery structures, the cell casing and cover are generally connected by welding to form a sealed space that accommodates the electrode assembly.

[0003] In blade batteries, the casing is typically formed by bending and welding sheet metal, resulting in a relatively thin wall thickness. When welding the casing to the cover plate, the structural strength of the thin casing is relatively weak, making it susceptible to the effects of welding heat. This can lead to severe thermal deformation of the casing's large surface area, resulting in poor sealing between the cover plate and the casing, ultimately affecting the safety of the battery cell. Utility Model Content

[0004] In view of this, the present invention provides a battery cell housing assembly, a battery cell, and a battery pack to solve the problem that thinner housings are easily affected by welding heat, resulting in severe thermal deformation, which leads to poor welding sealing between the cover plate and the housing and affects the safety of battery cell use.

[0005] In a first aspect, this utility model provides a battery cell housing assembly, comprising: The housing has an opening at at least one end along the Z direction, and the housing is bent outward at the end of the opening to form a stepped portion. The stepped portion includes a support section and a welded section connected to each other. The support section extends along the XY plane, and the welded section extends along the Z direction. A cover plate is placed over the opening, with its bottom abutting against the support section along the Z direction, and its sidewalls welded to the welding section.

[0006] Beneficial Effects: The battery cell housing assembly of this utility model features a stepped portion at one end of the housing with an opening. This stepped portion includes a support section extending along the XY plane and a welding section extending along the Z direction, forming a reinforced structure. This enhances the structural strength of the housing and reduces thermal deformation during welding. Simultaneously, the support section of the stepped portion also supports the cover plate, preventing it from sinking during assembly with the housing and maintaining the flatness of the top surface of the cover plate and the top surface of the welding section during welding. This ensures the quality of the weld seal between the cover plate and the housing, thereby improving the safety of the battery cell in use.

[0007] In one optional embodiment, the thickness of the shell is T1, and the thickness of the welded section is T2, satisfying 0 < T2 / T1 ≤ 2.

[0008] Beneficial effects: By controlling T2 / T1 within a suitable range, the structural strength of the shell can be guaranteed, and thermal deformation of the shell can be reduced. If the value of T2 / T1 is too large, material differences and cracks are prone to occur at the connection between the support section and the welded section, leading to a decrease in the structural strength and performance of the shell. If the value of T2 / T1 is too small, the thickness of the welded section is too thin, and the welded section is prone to deformation and breakage.

[0009] In one alternative implementation, 0.3 mm ≤ T1 ≤ 1 mm.

[0010] Beneficial effects: By controlling the value of T1 within a suitable range, the structural strength of the casing can be further guaranteed, the thermal deformation of the casing can be reduced, and the casing can be avoided from being too thick, occupying too much space, and affecting the energy density of the battery cell.

[0011] In one alternative embodiment, the step portion has a step surface that supports the cover plate, the step surface having a width of W1 along the X or Y direction, satisfying W1=T2, 0.3 mm≤W1≤2 mm.

[0012] Beneficial effects: The stepped portion of the casing is formed by bending, and setting the width of the stepped portion equal to the thickness of the welded section facilitates processing. By controlling the value of W1 within a suitable range, it can be ensured that the support section has sufficient support area to support the cover plate. If the value of W1 is too small, the stepped portion will not be able to effectively support the cover plate, making it difficult to guarantee the welding quality. If the value of W1 is too large, the stepped portion will be too thick, occupying a large space and easily affecting the energy density of the battery cell.

[0013] In one optional embodiment, the length of the welded segment along the Z direction is L1, and the thickness of the cover plate is T3, satisfying L1=T3 and 1.5 mm≤L1≤3 mm.

[0014] Beneficial effects: Setting the length of the welding section to be consistent with the thickness of the cover plate ensures that the top surface of the cover plate and the top surface of the welding section are on the same plane, forming a flat welding surface, which is beneficial to improving the welding quality of the cover plate and the welding section. Controlling the length of the welding section, i.e., the thickness of the cover plate, within a suitable range ensures the structural strength of the cover plate and avoids the cover plate occupying too much space, which would affect the energy density of the battery cell.

[0015] In one optional embodiment, the cover plate is butt-welded to the welding section, and the weld penetration depth after welding is H1, which satisfies 1 / 3≤H1 / L1≤3 / 4.

[0016] Beneficial effects: The cover plate and the welded section are butt-welded to form a closed, sealed space. By controlling H1 / L1 within a suitable range, the welding quality between the cover plate and the welded section can be guaranteed. If the value of H1 / L1 is too large, the penetration depth is too deep, posing a risk of weld penetration into the shell, and the heat-affected zone of the weld is large, easily causing thermal deformation of the shell. If the value of H1 / L1 is too small, the penetration depth is too shallow, and the firmness between the cover plate and the shell is low.

[0017] In one alternative embodiment, the weld width after welding is W2, which satisfies 0.1 mm ≤ W2 ≤ 1 mm.

[0018] Beneficial effects: By controlling W2 within a suitable range, the welding quality between the cover plate and the welded section can be further guaranteed. If the value of W2 is too large, the weld width will be too wide, resulting in a large heat-affected zone and making the shell prone to thermal deformation. If the value of W2 is too small, the weld width will be too thin, resulting in a lower degree of bonding between the cover plate and the shell.

[0019] In one alternative embodiment, the housing has a first chamfer on the inner periphery at one end of the opening.

[0020] Beneficial effects: An insulating plate is also provided on the side of the cover plate near the housing. The insulating plate is installed inside the housing. By setting the first chamfer, it can be avoided that the insulating plate and the housing will rub against each other during the assembly of the insulating plate, resulting in foreign objects remaining inside the housing.

[0021] In one optional embodiment, a second chamfer is provided at the internal connection between the support section and the welding section, and a third chamfer is provided around the bottom perimeter of the cover plate corresponding to the second chamfer.

[0022] Beneficial effects: By setting the second and third chamfers, on the one hand, it can prevent the cover plate and the step from rubbing against each other and forming foreign objects left inside the shell. On the other hand, it can also prevent stress concentration at the connection between the support section and the welded section, thereby further improving the structural strength of the shell.

[0023] Secondly, this utility model also provides a battery cell, comprising: pole group; The aforementioned battery cell housing assembly further includes a terminal post on the cover plate, and the electrode group is disposed inside the housing and electrically connected to the terminal post.

[0024] Beneficial effects: The battery cell of this utility model has a stepped portion at one end of the housing with an opening. The stepped portion has a support section extending along the XY plane and a welding section extending along the Z direction, forming a reinforced structure that can improve the structural strength of the housing and reduce thermal deformation of the housing during welding. At the same time, the support section of the stepped portion can also support the cover plate, preventing the cover plate from sinking when it is assembled with the housing, and maintaining the flatness of the top surface of the cover plate and the top surface of the welding section during welding, ensuring the welding sealing quality of the cover plate and the housing, thereby improving the safety of the battery cell in use.

[0025] Thirdly, the present invention also provides a battery pack, comprising: at least one of the above-mentioned battery cells.

[0026] Beneficial effects: Since the battery pack includes battery cells, it has the same effects as the battery cells, which will not be elaborated here. Attached Figure Description

[0027] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the structure of a battery cell according to an embodiment of the present utility model; Figure 2 This is an exploded view of a battery cell according to an embodiment of the present utility model; Figure 3 This is a partial cross-sectional view of a battery cell according to an embodiment of the present utility model; Figure 4 for Figure 3 A magnified view of part A in the diagram; Figure 5 This is a partial cross-sectional view of a battery cell after the casing and cover plate have been welded together, according to an embodiment of the present utility model. Figure 6 This is a partially enlarged schematic diagram of the housing of a battery cell housing assembly according to an embodiment of the present utility model; Figure 7 This is a schematic diagram of the structure of a cover plate of a battery cell housing assembly according to an embodiment of the present utility model; Figure 8 This is a structural schematic diagram from another perspective of the cover plate of a battery cell housing assembly according to an embodiment of the present utility model.

[0029] Explanation of reference numerals in the attached figures: 1. Shell; 101. Opening; 102. Stepped section; 1021. Support section; 1022. Welded section; 1023. Stepped surface; 1024. Second chamfer; 103. First chamfer; 2. Cover plate; 201. Third chamfer; 3. Electrode assembly; 4. Electrode post. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0031] The following is combined Figures 1 to 8 The following describes embodiments of the present invention.

[0032] According to an embodiment of the present invention, a battery cell housing assembly is provided, mainly comprising: a housing 1 and a cover plate 2. The housing 1 has an opening 101 at at least one end along the Z-direction. The end of the housing 1 located at the opening 101 is bent outward to form a stepped portion 102. The stepped portion 102 includes a supporting section 1021 and a welding section 1022 connected to each other. The supporting section 1021 extends along the XY plane, and the welding section 1022 extends along the Z-direction. The cover plate 2 is placed over the opening 101. Along the Z-direction, the bottom of the cover plate 2 abuts against the supporting section 1021, and the sidewall of the cover plate 2 is welded to the welding section 1022.

[0033] The battery cell housing assembly provided in this embodiment of the present invention features a stepped portion 102 at one end of the housing 1 with an opening 101. The stepped portion 102 includes a support section 1021 extending along the XY plane and a welding section 1022 extending along the Z direction, forming a reinforced structure that enhances the structural strength of the housing 1 and reduces thermal deformation during welding. Simultaneously, the support section 1021 of the stepped portion 102 also supports the cover plate 2, preventing it from sinking during assembly with the housing 1 and maintaining the flatness of the top surface of the cover plate 2 and the top surface of the welding section 1022 during welding. This ensures the welding seal quality between the cover plate 2 and the housing 1, thereby improving the safety of the battery cell.

[0034] Specifically, in the Z direction, such as Figure 1 and Figure 2 As shown by arrow Z in the diagram, the X direction is as follows: Figure 2 As shown by the arrow X in the diagram, the Y direction is as follows: Figure 2 As indicated by arrow Y, the XY plane is the plane formed by the X and Y directions.

[0035] In embodiments of this utility model, the "shell 1" is a component used to provide a receiving space to house the electrode assembly 3 and isolate it from the outside world. The material of the shell 1 includes, but is not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0036] In this embodiment of the invention, the "cover plate 2" is used to close the opening 101 of the housing 1 and is welded to the housing 1 to form a sealed space for accommodating the electrode assembly 3. The cover plate 2 can be made of aluminum alloy, stainless steel, etc.

[0037] Specifically, the cover plate 2 is first pre-installed at the opening 101 of the housing 1. At this time, the support section 1021 supports the cover plate 2 to prevent it from sinking. Then, the cover plate 2 is welded and fixed to the welding section 1022 to achieve a seal. The cover plate 2 may also be provided with components such as pole post 4, insulating plate, and sealing ring. This embodiment of the utility model does not limit the scope of the invention.

[0038] In one embodiment, such as Figure 4 As shown, the thickness of the shell 1 is T1, and the thickness of the welded section 1022 is T2, satisfying 0 < T2 / T1 ≤ 2. By controlling T2 / T1 within a suitable range, the structural strength of the shell 1 can be guaranteed, and the thermal deformation of the shell 1 can be reduced. If the value of T2 / T1 is too large, material differences and cracks are likely to occur at the connection between the support section 1021 and the welded section 1022, leading to a decrease in the structural strength and performance of the shell 1. If the value of T2 / T1 is too small, the thickness of the welded section 1022 will be too thin, and the welded section 1022 will be prone to deformation and breakage.

[0039] Furthermore, in one embodiment, 1≤T2 / T1≤2.

[0040] Furthermore, in one embodiment, 0.3 mm ≤ T1 ≤ 1 mm. By controlling the value of T1 within a suitable range, the structural strength of the housing 1 can be further guaranteed, the thermal deformation of the housing 1 can be reduced, and the housing 1 can be avoided from being too thick, occupying too much space, and affecting the energy density of the battery cell.

[0041] For example, in this embodiment of the present invention, T1 can be 0.3 mm, T2 can be 0.3 mm, then T2 / T1 is 1; or, T1 can be 0.5 mm, T2 can be 0.8 mm, then T2 / T1 is 1.6; or, T1 can be 1 mm, T2 can be 2 mm, then T2 / T1 is 2.

[0042] In one embodiment, such as Figure 4 and Figure 6As shown, the stepped portion 102 has a stepped surface 1023 supporting the cover plate 2. The width of the stepped surface 1023 along the X or Y direction is W1, satisfying W1=T2, 0.3 mm≤W1≤2 mm. The stepped portion 102 of the housing 1 is formed by bending. Setting the width of the stepped portion 102 equal to the thickness of the welding section 1022 facilitates processing. By controlling the value of W1 within a suitable range, it can be ensured that the supporting section 1021 has sufficient supporting area to support the cover plate 2. If the value of W1 is too small, the stepped portion 102 is insufficient to effectively support the cover plate 2, making it difficult to guarantee the welding quality. If the value of W1 is too large, the stepped portion 102 is too thick, occupying a large space and easily affecting the energy density of the battery cell.

[0043] For example, in this embodiment of the present invention, W1 can be 0.3 mm, 0.4 mm, 0.8 mm, 1 mm, 1.5 mm, 2 mm, etc.

[0044] In one embodiment, such as Figure 4 As shown, the length of the welding segment 1022 along the Z direction is L1, and the thickness of the cover plate 2 is T3, satisfying L1=T3 and 1.5 mm≤L1≤3 mm. Setting the length of the welding segment 1022 and the thickness of the cover plate 2 to be consistent ensures that the top surface of the cover plate 2 and the top surface of the welding segment 1022 are on the same plane, forming a flat welding surface, which is beneficial to improving the welding quality of the cover plate 2 and the welding segment 1022. Controlling the length of the welding segment 1022, i.e., the thickness of the cover plate 2, within a suitable range ensures the structural strength of the cover plate 2 and avoids the cover plate 2 occupying too much space, thus affecting the energy density of the battery cell.

[0045] For example, in this embodiment of the present invention, L1 can be 1.5 mm, 2 mm, 2.5 mm, 3 mm, etc.

[0046] In one embodiment, such as Figure 5 As shown, the cover plate 2 and the welding section 1022 are butt-welded, and the weld penetration depth is H1, satisfying 1 / 3 ≤ H1 / L1 ≤ 3 / 4. The cover plate 2 and the welding section 1022 are laser-welded together to form a closed, sealed space. By controlling H1 / L1 within a suitable range, the welding quality of the cover plate 2 and the welding section 1022 can be guaranteed. If the value of H1 / L1 is too large, the penetration depth is too deep, posing a risk of welding through the shell 1, and the heat-affected zone is large, easily causing thermal deformation of the shell 1. If the value of H1 / L1 is too small, the penetration depth is too shallow, and the firmness between the cover plate 2 and the shell 1 is low.

[0047] For example, in this embodiment of the invention, H1 / L1 can be 1 / 3, 1 / 2, 3 / 4, etc.

[0048] Furthermore, in one embodiment, such as Figure 5As shown, the weld width after welding is W2, which satisfies 0.1 mm ≤ W2 ≤ 1 mm. By controlling W2 within a suitable range, the welding quality between the cover plate 2 and the welding section 1022 can be further guaranteed. If the value of W2 is too large, the weld width will be too wide, resulting in a large heat-affected zone and easily causing thermal deformation of the shell 1. If the value of W2 is too small, the weld width will be too thin, resulting in a lower degree of firmness between the cover plate 2 and the shell 1.

[0049] For example, in this embodiment of the present invention, W2 can be 0.1 mm, 0.2 mm, 0.4 mm, 0.6 mm, 0.8 mm, 1 mm, etc.

[0050] In one embodiment, such as Figure 5 and Figure 6 As shown, the inner periphery of the housing 1 at one end of the opening 101 is provided with a first chamfer 103. The cover plate 2 is also provided with an insulating plate on the side near the housing 1. The insulating plate is installed inside the housing 1. By providing the first chamfer 103, it is possible to avoid the insulating plate and the housing 1 scraping against each other during the assembly of the insulating plate, so that foreign objects remain inside the housing 1.

[0051] In one embodiment, such as Figures 5 to 8 As shown, a second chamfer 1024 is provided at the internal connection between the support section 1021 and the welding section 1022, and a third chamfer 201 is provided around the bottom of the cover plate 2 corresponding to the second chamfer 1024. By providing the second chamfer 1024 and the third chamfer 201, on the one hand, it can prevent the cover plate 2 and the step 102 from rubbing against each other and forming foreign objects remaining inside the shell 1; on the other hand, it can also prevent stress concentration at the connection between the support section 1021 and the welding section 1022, thereby further improving the structural strength of the shell 1.

[0052] For example, if the cover plate 2 and the housing 1 are aluminum cover and aluminum housing, by setting the second chamfer 1024 and the third chamfer 201, it is possible to prevent aluminum wires from being scraped out when the cover plate 2 is assembled with the housing 1.

[0053] According to an embodiment of the present invention, on the other hand, as... Figures 1 to 3 As shown, a battery cell is also provided, including: an electrode group 3 and a battery cell housing assembly. A terminal post 4 is also provided on the cover plate 2, and the electrode group 3 is disposed within the housing 1 and electrically connected to the terminal post 4.

[0054] The battery cell provided in this embodiment of the present invention has a stepped portion 102 at one end of the housing 1 where the opening 101 is provided. The stepped portion 102 is provided with a support section 1021 extending along the XY plane and a welding section 1022 extending along the Z direction, forming a reinforced structure that can improve the structural strength of the housing 1 and reduce the thermal deformation of the housing 1 during welding. At the same time, the support section 1021 of the stepped portion 102 can also support the cover plate 2, preventing the cover plate 2 from sinking when it is assembled with the housing 1, and maintaining the flatness of the top surface of the cover plate 2 and the top surface of the welding section 1022 during welding, ensuring the welding sealing quality of the cover plate 2 and the housing 1, thereby improving the safety of the battery cell in use.

[0055] In this embodiment of the invention, "cell" refers to a single battery cell capable of independent charging and discharging. A cell may be cylindrical, cuboid, or other shapes, and this embodiment of the invention is not limited in this respect.

[0056] For example, such as Figure 1 and Figure 2 As shown, the battery cell is a blade battery cell. The housing 1 of the blade battery cell has openings 101 at both ends, and a cover plate 2 is provided at each opening 101.

[0057] In this embodiment of the invention, the electrode assembly 3 includes a positive electrode, a negative electrode, and an isolation element. During the charging and discharging process of the battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The isolation element, disposed between the positive and negative electrodes, serves to prevent short circuits between the positive and negative electrodes while allowing active ions to pass through.

[0058] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0059] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0060] As an example, the positive electrode current collector can be a metal foil, a foamed metal, or a composite current collector. For example, as a metal foil, it can be silver-treated aluminum or stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium, etc. Foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0061] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this invention is not limited to these materials, and other conventional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate include, but are not limited to, at least one of lithium iron phosphate, lithium iron phosphate and carbon composites, lithium manganese phosphate, lithium manganese phosphate and carbon composites, lithium manganese iron phosphate, and lithium manganese iron phosphate and carbon composites.

[0062] In some embodiments, the negative electrode may be a negative electrode sheet, which may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0063] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0064] As an example, the negative electrode current collector can be a metal foil, a foamed metal, or a composite current collector. For example, as a metal foil, it can be silver-treated aluminum or stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, nickel, or titanium, etc. Composite current collectors can include a polymer material base layer and a metal layer. Foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloys, or foamed carbon, etc. Composite current collectors can be formed by forming a metal material (copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0065] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cells. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc.

[0066] In some embodiments, the separator is a separator membrane. This invention does not impose any particular limitation on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected.

[0067] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride, and ceramic.

[0068] In some embodiments, the electrode group 3 is provided with tabs that can conduct current from the electrode group 3. The tabs include a positive tab and a negative tab.

[0069] It should be noted that, in this embodiment of the utility model, the battery cell can be a lithium-ion battery, a sodium-ion battery, a sodium-lithium-ion battery, a lithium metal battery, a sodium metal battery, a lithium-sulfur battery, a magnesium-ion battery, a nickel-metal hydride battery, a nickel-cadmium battery, a lead-acid battery, etc., and this embodiment of the utility model is not limited to this.

[0070] According to an embodiment of the present invention, in another aspect, a battery pack is also provided, comprising: at least one battery cell.

[0071] Since the battery pack includes battery cells and has the same effect as the battery cells, it will not be elaborated on here.

[0072] It should be noted that when there are multiple battery cells, these cells are connected in series, parallel, or mixed connections through a busbar to form a battery module. The battery pack also includes a housing, in which the battery module or individual battery cell is housed.

[0073] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0074] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A cell housing assembly, characterized in that, include: The housing has an opening at at least one end along the Z direction, and the housing is bent outward at the end of the opening to form a stepped portion. The stepped portion includes a support section and a welded section connected to each other. The support section extends along the XY plane, and the welded section extends along the Z direction. A cover plate is placed over the opening, with its bottom abutting against the support section along the Z direction, and its sidewalls welded to the welding section.

2. The cell housing assembly according to claim 1, characterized in that, The thickness of the shell is T1, and the thickness of the welded section is T2, satisfying 0 < T2 / T1 ≤ 2.

3. The cell housing assembly according to claim 2, characterized in that, 0.3 mm ≤ T1 ≤ 1 mm.

4. The cell housing assembly according to claim 2, characterized in that, The step portion has a step surface that supports the cover plate. The width of the step surface along the X or Y direction is W1, which satisfies W1=T2 and 0.3 mm≤W1≤2 mm.

5. The cell housing assembly according to any one of claims 1 to 4, characterized in that, The length of the welded section along the Z direction is L1, and the thickness of the cover plate is T3, satisfying L1=T3 and 1.5 mm≤L1≤3 mm.

6. The cell housing assembly according to claim 5, characterized in that, The cover plate is welded to the welding section, and the weld penetration depth after welding is H1, which satisfies 1 / 3≤H1 / L1≤3 / 4.

7. The cell housing assembly according to claim 6, characterized in that, The weld width after welding is W2, which satisfies 0.1 mm ≤ W2 ≤ 1 mm.

8. The cell housing assembly according to any one of claims 1 to 4, characterized in that, The housing has a first chamfer on the inner periphery at one end of the opening; And / or, a second chamfer is provided at the internal connection between the support section and the welding section, and a third chamfer is provided around the bottom of the cover plate corresponding to the second chamfer.

9. A battery cell, characterized in that, include: pole group; According to any one of claims 1 to 8, the battery cell housing assembly further includes a terminal post on the cover plate, and the electrode group is disposed inside the housing and electrically connected to the terminal post.

10. A battery pack, characterized in that, include: At least one battery cell as described in claim 9.

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