Shell of battery cell and battery cell

Abstract

The utility model discloses a shell of a battery monomer and the battery monomer, and relates to the technical field of batteries, the battery monomer comprises: a shell main body, the shell main body comprises a plurality of shell walls, the plurality of shell walls jointly define an assembly space, and a part of the shell walls form a welding area; a protective layer is arranged on the inner surface of the shell wall on which the welding area is formed; an insulating layer is arranged on the inner surface of the other part of the shell wall, and an insulating layer is arranged on the surface, deviating from the corresponding shell wall, of the protective layer. The protective layer is arranged on the inner surface of the shell wall forming the welding area, so that the smoothness and the strength of the inner surface of the shell body can be improved, an electrode assembly assembled in the shell body is protected from being scratched by a welding seam, and the insulating layers are arranged on the inner surface of the other part of the shell wall and the surface, deviating from the corresponding shell wall, of the protective layer. The corrosion resistance of the shell main body can be improved, and the risk of liquid leakage of the battery monomer caused by corrosion of the shell main body is reduced, so that the use safety and the service life of the battery monomer are improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery technology field especially is related to a kind of shell of battery monomer and the shell of battery monomer with it. BACKGROUND

[0002] In the related art, the shell of the battery monomer is formed by closing the shell after bending through high-frequency welding or laser welding process. Therefore, the shell has a weld, and the surface of the weld is uneven, which may scratch the electrode assembly. In addition, the corrosion resistance of the shell is poor, and after internal or external short circuit of the electrode assembly, the shell is easily corroded to cause the battery monomer to leak, which affects the service life of the battery monomer. SUMMARY

[0003] The utility model aims at at least one of the technical problems existing in the prior art. To this end, one object of the utility model is to provide a shell of battery monomer, which protects the electrode assembly from being scratched by the weld and reduces the risk of battery monomer leakage.

[0004] The utility model further provides a battery monomer.

[0005] The shell of the battery monomer according to the utility model embodiment comprises: a shell body, the shell body comprises a plurality of shell walls, the plurality of shell walls collectively define an assembly space for assembling an electrode assembly of the battery monomer, and part of the shell walls form a welding area; a protective layer, the inner surface of the shell wall forming the welding area is provided with the protective layer; and an insulating layer, the inner surface of another part of the shell walls and the surface of the protective layer away from the corresponding shell wall are provided with the insulating layer.

[0006] The shell of the battery monomer according to the utility model embodiment can improve the smoothness and strength of the inner surface of the shell body by providing the protective layer on the inner surface of the shell wall forming the welding area, protect the electrode assembly assembled in the shell body from being scratched by the weld, and reduce the risk of short circuit of the battery monomer by providing the insulating layer on the inner surface of another part of the shell walls and the surface of the protective layer away from the corresponding shell wall, improve the corrosion resistance of the shell body, reduce the risk of battery monomer leakage caused by corrosion of the shell body, and thus improve the use safety and service life of the battery monomer.

[0007] In some embodiments of the utility model, the structural strength of the protective layer is greater than that of the insulating layer.

[0008] In some embodiments of the utility model, the thickness of the protective layer is H1, which satisfies the relationship: 0.05mm≤H1≤0.5mm.

[0009] In some embodiments of the utility model, the thickness of the insulating layer is H2, which satisfies the relationship: 0.02mm≤H2≤0.2mm.

[0010] In some embodiments of the utility model, the insulation layer arranged on the other part of the shell wall and the insulation layer arranged on the protective layer are integrally formed.

[0011] In some embodiments of the utility model, the thickness of the insulation layer arranged on the other part of the shell wall is equal to the thickness of the insulation layer arranged on the protective layer.

[0012] In some embodiments of the utility model, the surface roughness of the insulation layer is Ra, satisfying the relationship: 0.1 μm≤Ra≤1 μm, the insulation resistance of the insulation layer is greater than or equal to 0.5 G Ω , and the thermal conductivity of the insulation layer is greater than or equal to 0.2 W / (mk).

[0013] In some embodiments of the utility model, the hardness of the protective layer is greater than or equal to 3H, the shear strength of the protective layer is greater than or equal to 10 MPa, and the surface roughness of the protective layer is Rb, satisfying the relationship: 0.2 μm≤Rb≤0.4 μm.

[0014] In some embodiments of the utility model, the plurality of shell walls are sequentially connected at the head and tail to form an annular structure.

[0015] In some embodiments of the utility model, further comprising: a cover body, the shell body has at least one open port communicating with the assembly space, and each open port is provided with a cover body.

[0016] The battery monomer according to the utility model embodiment comprises: a shell, the shell is the shell of the battery monomer in the above embodiment; and an electrode assembly, the electrode assembly is installed in the assembly space.

[0017] Additional aspects and advantages of the utility model will be given in part in the following description, some will become obvious from the following description, or be understood through the practice of the utility model. BRIEF DESCRIPTION OF DRAWINGS

[0018] The above and / or additional aspects and advantages of the utility model will become apparent and more readily appreciated from the following description of the embodiments, with reference to the following drawings, in which:

[0019] Figure 1 is a structure schematic view of the shell according to the utility model embodiment;

[0020] Figure 2 is a cross-sectional schematic view of the shell according to the utility model embodiment;

[0021] Figure 3 is a longitudinal cross-sectional schematic view of the shell according to the utility model embodiment.

[0022] Reference signs:

[0023] Shell 100;

[0024] housing body 1; shell wall 11; open port 12;

[0025] assembly space 111; welding area 112;

[0026] protective layer 2; insulation layer 3; cover 4. DETAILED DESCRIPTION

[0027] The embodiments of the present application are described in detail below, examples of which are shown in the drawings, wherein the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary only, and are used only for explaining the present application, and cannot be understood as a limitation of the present application.

[0028] The following describes the shell 100 according to the embodiments of the present application with reference to Figures 1-3 The shell 100 according to the embodiments of the present application is described below.

[0029] As shown in Figures 1-3 The shell 100 of the battery cell according to the embodiments of the present application includes: a housing body 1, the housing body 1 includes a plurality of shell walls 11, the plurality of shell walls 11 collectively define an assembly space 111 for assembling an electrode assembly of the battery cell, and part of the shell walls 11 are formed with a welding area 112; a protective layer 2, an inner surface of the shell wall 11 formed with the welding area 112 is provided with the protective layer 2; an insulation layer 3, an inner surface of another part of the shell walls 11 is provided with the insulation layer 3, and a surface of the protective layer 2 away from the corresponding shell wall 11 is provided with the insulation layer 3.

[0030] Among them, as some embodiments of the present application, the housing body 1 can be constructed as an aluminum shell. The housing body 1 includes a plurality of shell walls 11, for example: the housing body 1 can include four shell walls 11. The plurality of shell walls 11 collectively define an assembly space 111, which can provide an assembly position for the electrode assembly of the battery cell, so that the electrode assembly can be assembled in the housing body 1, which is conducive to reliable work of the electrode assembly in the assembly space 111, reduces the interference of the external environment on the electrode assembly, thereby improving the service life of the battery cell.

[0031] As some embodiments of the present application, the aluminum plate after bending can be closed by a process such as high-frequency welding or laser welding to form the shell body 1 of the battery monomer, and thus, the partial shell wall 11 is formed with a welding area 112, for example, one shell wall 11 is formed with a welding area 112. The shell wall 11 formed with the welding area 112 can be provided with a protective layer 2, which can be formed on the inner surface of the shell wall 11. In this way, the position of the protective layer 2 is reasonable, and the protective layer 2 is arranged between the corresponding shell wall 11 and the electrode assembly, which is beneficial to improve the strength of the corresponding shell wall 11 and the smoothness of the inner surface of the corresponding shell wall 11, and reduce the risk of the electrode assembly being scratched by the weld.

[0032] Another part of the shell wall 11 can be provided with an insulating layer 3, which refers to the shell wall 11 that does not form a welding area 112. The insulating layer 3 is arranged on the inner surface of the other part of the shell wall 11, so that the insulating layer 3 is arranged between the corresponding shell wall 11 and the electrode assembly to insulate the corresponding shell wall 11 and the electrode assembly. The surface of the protective layer 2 away from the corresponding shell wall 11 is also provided with an insulating layer 3 to insulate the protective layer 2 and the electrode assembly, so that the electrode assembly and the corresponding shell wall 11, and the electrode assembly and the protective layer 2 are both provided with an insulating layer 3. The inner surface of the shell wall 11 formed with the welding area 112 and the electrode assembly can be sequentially provided with a protective layer 2 and an insulating layer 3, and the inner surface of the shell wall 11 in other areas and the electrode assembly can be provided with an insulating layer 3.

[0033] By arranging the insulating layer 3 between the electrode assembly and the corresponding shell wall 11, and between the electrode assembly and the protective layer 2, the risk of short circuit of the electrode assembly can be reliably reduced, the corrosion resistance of the shell body 1 can be improved, the risk of battery monomer leakage caused by short circuit corrosion of the electrode assembly to the shell body 1 can be reduced, and thus the use safety and service life of the battery monomer can be improved. It should be noted that the insulating layer 3 can improve the smoothness of the inner surface of the shell wall 11, which is beneficial to reduce the assembly difficulty of the battery monomer. As some embodiments of the present application, the insulating layer 3 can be composed of an insulating material with a medium particle size.

[0034] Specifically, the inner surface of the shell wall 11 forming the welding area 112 is coated with a protective layer 2 to reduce the risk of the welding area 112 scratching the electrode assembly. The inner surface of the shell wall 11 forming the welding area 112 is coated with an insulating layer 3, and the surface of the protective layer 2 away from the corresponding shell wall 11 is provided with an insulating layer 3, which improves the smoothness and insulation of the overall inner surface of the shell body 1, thereby facilitating the assembly of the electrode assembly in the assembly space 111 and reducing the assembly difficulty of the battery monomer. The battery monomer includes the shell body 1, the protective layer 2, the insulating layer 3 and the electrode assembly, without other insulation or protection assemblies, and is easy to assemble. In addition, the volume of the protective layer 2 and the insulating layer 3 can be reduced to make the assembly space 111 for assembling the electrode assembly larger, thereby facilitating the improvement of the energy density of the battery monomer.

[0035] As some embodiments of the present application, the protective layer 2 has the characteristics of resisting electrolyte corrosion and having super-high hardness, and can play the role of flattening the weld and improving the strength of the welding area 112. The protective layer 2 is composed of solute and solvent, wherein the solute is a super-hard powder material with a particle size of ≤10 μm, including but not limited to diamond-like carbon (DLC), cubic boron nitride (cBN), nitrogen carbide (C3N4) and the like. The hardness of the protective layer 2 is ≥3H, the pressure resistance is ≥4000DC, the adhesion is ≥0 grade, the shear strength is ≥10MPa, and the surface roughness RA is between 0.2 microns and 0.4 microns.

[0036] As some embodiments of the present application, the insulating layer 3 has the characteristics of resisting electrolyte corrosion and insulation. The insulating layer 3 is composed of solute and solvent, wherein the particle size of the solute is 30 μm-80 μm, including but not limited to polytetrafluoroethylene, polyethylene, chlorovinyl copolymer resin, polyvinyl butyral, vinylidene chloride, perchloroethylene, chlorosulfonated polyethylene and the like. The surface roughness RA of the insulating layer 3 is between 0.1 microns and 1 microns, the insulation impedance is ≥0.5GΩ (the test condition is DC 1000V 5S), and the thermal conductivity is ≥0.2W / (mk).

[0037] It should be noted that the coating method of the protective layer 2 and the insulating layer 3 can be but is not limited to gas deposition technology (PVD), powder electrostatic spraying, UV spraying, UV printing and the like.

[0038] The shell body 1 of the present application is verified in actual production, and the verification results are as follows:

[0039] Example 1: For a two-end opening shell body 1 with a size of 600*100*10, the thickness of the protective layer 2 is set to 0.15mm, and the thickness of the insulating layer 3 is set to 0.008mm. And 100 battery cells (i.e. battery monomers) are trial-produced with the shell body 1.

[0040] Example 2: for the two-end opening shell body 1 with the size of 600*100*10, the thickness of the protective layer 2 is set to 0.15mm, the thickness of the insulation layer 3 is set to 0.005mm, and 100 battery cells are trial-produced by using the shell body 1.

[0041] Comparative Example 1: for the two-end opening shell body 1 with the size of 600*100*10, only one layer of insulation coating is arranged on the welding seam side, and the thickness of the insulation coating is set to 0.008mm, and 100 battery cells are trial-produced by using the shell body 1.

[0042] Comparative Example 2: for the two-end opening shell body 1 with the size of 600*100*10, no coating treatment is performed on the inner surface of the aluminum shell, and after the electrode assembly is wrapped with a pp insulation film with a thickness of 0.1mm, the electrode assembly is put into the shell, and 100 battery cells are trial-produced by using the shell body 1.

[0043] The comparison results are shown in the following table:

[0044] Indicator Surface roughness / μm Insulation resistance / GΩ Hardness Shear strength / Mpa The yield of the trial production of the battery cell in the process Reference standard ISO 25178 DC 1000V 5S GB / T 6739-2006 IS04587 / Example 1 0.4 μm 1.2 5H 30 100％ Example 2 0.4 μm 1.1 5H 30 100％ Comparative Example 1 0.8 μm 1 3H 10 97％ Comparative Example 2 1 μm 0 (not insulated) / / 95％

[0045] According to the comparison table, the application can effectively improve the battery cell trial production yield.

[0046] Therefore, by arranging the protective layer 2 on the inner surface of the shell wall 11 forming the welding area 112, the smoothness of the inner surface of the shell 11 and the strength of the shell 11 can be improved, the electrode assembly assembled in the shell body 1 is protected from being scratched by the welding seam, and by arranging the insulation layer 3 on the inner surface of the other part of the shell wall 11 and the surface of the protective layer 2 away from the corresponding shell wall 11, the corrosion resistance of the shell body 1 can be improved, the risk of battery cell leakage caused by corrosion of the shell body 1 can be reduced, and the use safety and service life of the battery cell can be improved.

[0047] In some embodiments of the utility model, as shown in Figure 2 The structural strength of the protective layer 2 is greater than that of the insulation layer 3.

[0048] The protective layer 2 plays a role in flattening the welding seam and improving the strength of the welding area 112, and the insulation layer 3 plays an insulation role, so the structural strength of the protective layer 2 is greater than that of the insulation layer 3, and such arrangement can reasonably arrange the protective layer 2 and the insulation layer 3, the insulation performance of the insulation layer 3 is irrelevant to the strength of the insulation layer 3, and the insulation effect can be achieved by the insulation layer 3 with smaller strength. The structural strength of the protective layer 2 is conducive to reliably protecting the electrode assembly and reducing the risk of the welding seam piercing the protective layer 2, thereby reducing the risk of the welding seam scratching the electrode assembly.

[0049] Further, since the welding area 112 of the shell body 1 is formed by split welding, the structural strength of the welding area 112 is lower than other parts of the shell body 1, and the structural strength of the protective layer 2 can reliably improve the strength of the welding area 112, reduce the risk of deformation or even cracking of the welding area 112 caused by stress of the battery monomer, thereby reducing the risk of liquid leakage of the battery monomer from the welding area 112, and improving the service life of the battery monomer.

[0050] In some embodiments of the utility model, as shown in Figure 3 The thickness of the protective layer 2 is greater than the thickness of the insulating layer 3.

[0051] The protective layer 2 plays a role in flattening the weld and improving the strength of the welding area 112, and the insulating layer 3 plays an insulating role, so the thickness of the protective layer 2 is greater than the thickness of the insulating layer 3. Such arrangement can reasonably arrange the protective layer 2 and the insulating layer 3, and the smaller thickness of the insulating layer 3 can achieve the insulating effect and reduce the occupation of the assembly space 111 by the insulating layer 3, which is beneficial to improving the volume energy density of the battery monomer.

[0052] The greater thickness of the protective layer 2 is conducive to reliably protecting the electrode assembly and reducing the risk of the weld piercing the protective layer 2, thereby reducing the risk of the weld scratching the electrode assembly. Further, since the welding area 112 of the shell body 1 is formed by split welding, the structural strength of the welding area 112 is lower than other parts of the shell body 1, and the thickness of the protective layer 2 can reliably improve the strength of the welding area 112, reduce the risk of deformation or even cracking of the welding area 112 caused by stress of the battery monomer, thereby reducing the risk of liquid leakage of the battery monomer from the welding area 112, and improving the service life of the battery monomer.

[0053] In some embodiments of the utility model, as shown in Figure 3 The thickness of the protective layer 2 is H1, and the relationship 0.05mm≤H1≤0.5mm is satisfied.

[0054] The thickness H1 of the protective layer 2 can satisfy the relationship 0.05mm≤H1≤0.5mm, that is, the thickness H1 of the protective layer 2 can be set to any value between 0.05mm and 0.5mm, for example, the thickness H1 of the protective layer 2 can be set to 0.05mm, 0.15mm or 0.5mm, but the present application is not limited thereto, and the thickness H1 of the protective layer 2 can also be set to other values, as long as the thickness H1 of the protective layer 2 can satisfy the relationship 0.05mm≤H1≤0.5mm.

[0055] The application takes the thickness H1 of the protective layer 2 as an example, which is set to 0.15 mm. In this way, the thickness of the protective layer 2 is set reasonably, which is conducive to reliably protecting the electrode assembly by the protective layer 2, reduces the risk of the weld piercing the protective layer 2 due to the protective layer 2 being too thin, thereby reducing the risk of the weld scratching the electrode assembly, and also reduces the risk of the production cost of the battery monomer increasing due to the protective layer 2 being set too thick, which is conducive to the low-cost design of the battery monomer.

[0056] In some embodiments of the utility model, as shown in Figure 3 The thickness of the insulation layer 3 is H2, and the relationship 0.02mm≤H2≤0.2mm is satisfied.

[0057] The thickness H2 of the insulation layer 3 can satisfy the relationship 0.02mm≤H2≤0.2mm, that is, the thickness H2 of the insulation layer 3 can be set to any value between 0.02mm and 0.2mm, for example, the thickness H2 of the insulation layer 3 can be set to 0.02mm, 0.08mm or 0.2mm, but the application is not limited to this, the thickness H2 of the insulation layer 3 can also be set to other values, as long as the thickness H2 of the insulation layer 3 can satisfy the relationship 0.02mm≤H2≤0.2mm.

[0058] The application takes the thickness H2 of the insulation layer 3 as an example, which is set to 0.08mm. In this way, the thickness of the insulation layer 3 is set reasonably, which is conducive to reliably protecting the electrode assembly by the insulation layer 3, reduces the risk of the insulation layer 3 failing due to the insulation layer 3 being too thin, and also reduces the risk of the production cost of the battery monomer increasing due to the insulation layer 3 being set too thick, which is conducive to the low-cost design of the battery monomer.

[0059] In some embodiments of the utility model, as shown in Figure 2 The insulation layer 3 arranged on the other part of the shell wall 11 and the insulation layer 3 arranged on the protective layer 2 are integrally formed.

[0060] In some embodiments of the utility model, the insulation layer 3 arranged on the other part of the shell wall 11 and the insulation layer 3 arranged on the protective layer 2 are integrally formed, that is, all the insulation layers 3 of the battery monomer are integrally formed. In this way, the insulation layer 3 arranged on the other part of the shell wall 11 and the insulation layer 3 arranged on the protective layer 2 can be processed by one process, which is conducive to improving the production efficiency of the shell 100 and the battery monomer, and by integrally forming the insulation layer 3 arranged on the other part of the shell wall 11 and the insulation layer 3 arranged on the protective layer 2, the risk of the insulation layer 3 arranged on the other part of the shell wall 11 and the insulation layer 3 arranged on the protective layer 2 having a gap can be reduced, thereby improving the insulation performance of the insulation layer 3.

[0061] In some embodiments of the utility model, as shown in Figure 2As shown, the thickness of the insulation layer 3 arranged on the other part of the shell wall 11 is equal to the thickness of the insulation layer 3 arranged on the protective layer 2.

[0062] The thickness of the insulation layer 3 arranged on the other part of the shell wall 11 is equal to the thickness of the insulation layer 3 arranged on the protective layer 2, which can improve the thickness uniformity of the insulation layer 3, thereby improving the uniformity of the insulation effect of the insulation layer 3, reducing the risk of a gap at the joint of the insulation layer 3 arranged on the other part of the shell wall 11 and the insulation layer 3 arranged on the protective layer 2 due to uneven thickness of the insulation layer 3, thereby improving the insulation performance of the insulation layer 3, and also reducing the risk of increased assembly difficulty of the electrode assembly due to uneven thickness of the insulation layer 3, thereby improving the assembly efficiency of the battery monomer.

[0063] In some embodiments of the utility model, as shown in Figure 2 The surface roughness of the insulation layer 3 is Ra, and the relationship formula is 0.1 μm≤Ra≤1 μm, the insulation resistance of the insulation layer 3 is greater than or equal to 0.5G Ω , and the thermal conductivity of the insulation layer 3 is greater than or equal to 0.2 W / (mk).

[0064] The surface roughness of the insulation layer 3 is Ra, and the relationship formula is 0.1 μm≤Ra≤1 μm, that is, the surface roughness of the insulation layer 3 can be set to any value between 0.1 μm and 1 μm, for example, the surface roughness of the insulation layer 3 can be set to 0.1 μm, 0.5 μm or 1 μm, but the application is not limited to this, the surface roughness of the insulation layer 3 can also be set to other values, as long as the surface roughness of the insulation layer 3 can satisfy the relationship formula: 0.1 μm≤Ra≤1 μm.

[0065] The surface roughness of the insulation layer 3 is set to 0.5 μm in the application, which can reasonably set the surface roughness of the insulation layer 3, which is conducive to improving the smoothness of the overall inner surface of the shell main body 1, reducing the risk of increased assembly difficulty of the electrode assembly due to the roughness of the insulation layer 3, thereby improving the assembly efficiency of the battery monomer, and also reducing the risk of increased production cost of the battery monomer due to the excessively high roughness requirement of the insulation layer 3, which is conducive to the low-cost design of the battery monomer.

[0066] The insulation resistance of the insulation layer 3 can be a reasonable value greater than or equal to 0.5G Ω , for example: 0.55G Ω , 0.6G Ω , etc., by setting the insulation resistance of the insulation layer 3 to be greater than or equal to 0.5G ΩThe insulation impedance of the insulation layer 3 can be set to a reasonable value, which is conducive to reliable insulation of the insulation layer 3. The thermal conductivity of the insulation layer 3 can be greater than or equal to 0.2 W / (mk), for example, 0.25 W / (mk), 0.3 W / (mk), and the like. In this way, the insulation layer 3 has good thermal conductivity, which is conducive to reliable operation of the battery monomer.

[0067] In some embodiments of the utility model, as shown in Figure 2 The hardness of the protective layer 2 is greater than or equal to 3H, the shear strength of the protective layer 2 is greater than or equal to 10 MPa, and the surface roughness of the protective layer 2 is Rb, which satisfies the relationship: 0.2 μm≤Rb≤0.4 μm.

[0068] The hardness of the protective layer 2 is greater than or equal to 3H (Hardness, hardness), for example, 4H, 5H, and the like. In this way, the protective layer 2 has certain durability and wear resistance, so that the protective layer 2 can withstand a certain pressure and wear. The shear strength of the protective layer 2 is greater than or equal to 10 MPa, for example, the shear strength of the protective layer 2 can be but not limited to 10 MPa, 11 MPa, 15 MPa, and the like, so that the protective layer 2 has strong shear resistance. By setting the hardness of the protective layer 2 and the shear strength of the protective layer 2 to reasonable values, the protective layer 2 can reliably protect the electrode assembly and reduce the risk of the weld penetrating the protective layer 2.

[0069] The surface roughness Rb of the protective layer 2 satisfies the relationship: 0.2 μm≤Rb≤0.4 μm, that is, the surface roughness Rb of the protective layer 2 can be set to any value between 0.2 μm and 0.4 μm, for example, the surface roughness Rb of the protective layer 2 can be set to 0.2 μm, 0.3 μm or 0.4 μm, but the present application is not limited thereto. The surface roughness Rb of the protective layer 2 can also be set to other values, as long as the surface roughness Rb of the protective layer 2 can satisfy the relationship: 0.2 μm≤Ra≤4 μm.

[0070] The surface roughness Rb of the protective layer 2 is set to 0.3 μm, which is an example of the present application. In this way, the surface roughness of the protective layer 2 is set reasonably, which is conducive to improving the smoothness of the inner surface of the protective layer 2, reducing the risk of increasing the difficulty of setting the insulation layer 3 due to the excessive roughness of the protective layer 2, thereby improving the production efficiency of the battery monomer. It can also reduce the risk of increasing the production cost of the battery monomer due to the excessively high requirement for the roughness of the protective layer 2, which is conducive to the low-cost design of the battery monomer.

[0071] In some embodiments of the utility model, as shown in Figure 3 The plurality of shell walls 11 are connected in sequence to form an annular structure.

[0072] As some embodiments of the present application, the shell wall 11 can be provided as four. The four shell walls 11 are sequentially connected head to tail to form a ring structure, so that the four shell walls 11 surround the assembly space 111, which can provide an assembly position for the electrode assembly, so that the electrode assembly can be assembled in the shell body 1. By assembling the electrode assembly from the open end of the ring structure into the assembly space 111, the assembly difficulty of the electrode assembly can be reduced, thereby realizing the effect of smoothly assembling the electrode assembly in the shell body 1, facilitating reliable work of the electrode assembly in the assembly space 111, reducing the interference of the external environment on the electrode assembly, and thereby improving the service life of the battery monomer.

[0073] In some embodiments of the present application, as shown in Figures 2-3 The shell 100 can further include: a cover body 4, and the shell body 1 has at least one open port 12 communicating with the assembly space 111, and each open port 12 is provided with a cover body 4.

[0074] The open port 12 can be configured as the open end of the above-mentioned embodiments. As some embodiments of the present application, the shell body 1 has one open port 12 communicating with the assembly space 111. As some embodiments of the present application, the shell body 1 has two open ports 12 communicating with the assembly space 111. Taking the shell body 1 having two open ports 12 communicating with the assembly space 111 as an example for description, the open port 12 communicates with the assembly space 111, and the electrode assembly can be assembled in the assembly space 111 through the open port 12, which is beneficial to reduce the assembly difficulty of the electrode assembly, thereby realizing the effect of smoothly assembling the electrode assembly in the shell body 1. After the electrode assembly is assembled, the two cover bodies 4 can respectively close the two open ports 12, so that the shell 100 is configured as a closed structure, which is beneficial to reliable work of the electrode assembly in the assembly space 111, thereby realizing the effect of completed assembly of the battery monomer.

[0075] The battery monomer according to the embodiments of the present application comprises: a shell 100, which is the shell 100 of the battery monomer of the above-mentioned embodiments; and an electrode assembly, which is installed in the assembly space 111.

[0076] The electrode assembly can reliably work in the assembling space 111, the interference of external environment on the electrode assembly is reduced, and the service life of the battery monomer is improved. The inner surface of the shell wall 11 forming the welding area 112 is provided with the protective layer 2, the strength and smoothness of the inner surface are improved, the electrode assembly assembled in the shell 100 is prevented from being scratched by the welding seam, the inner surface of another part of the shell wall 11 and the surface of the protective layer 2 away from the corresponding shell wall 11 are provided with the insulating layer 3, the corrosion resistance of the shell body 1 is improved, the risk of battery monomer leakage caused by corrosion of the shell body 1 is reduced, and the service safety and service life of the battery monomer are improved.

[0077] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the exemplary description of the above terms does not necessarily mean the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0078] Although the embodiments of the present application have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and purposes of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. A housing for a battery cell, characterized by The application relates to a battery cell shell. The shell body comprises a plurality of shell walls, which jointly define an assembly space for assembling an electrode assembly of the battery cell, and part of the shell walls are formed with welding areas. The inner surface of the shell wall formed with the welding area is provided with a protective layer. The inner surface of another part of the shell wall is provided with an insulating layer, and the surface of the protective layer away from the corresponding shell wall is provided with the insulating layer.

2. The battery cell housing of claim 1, wherein, The structural strength of the protective layer is greater than that of the insulating layer.

3. The battery cell housing of claim 1, wherein, The thickness of the protective layer is H1, and the relationship 0.05mm<=H1<=0.5mm is met.

4. The battery cell housing of claim 1, wherein, The thickness of the insulating layer is H2, and the relationship 0.02mm<=H2<=0.2mm is met.

5. The battery cell housing of any one of claims 1-4, wherein, The insulating layer provided on the other part of the shell wall and the insulating layer provided on the protective layer are integrally formed.

6. The battery cell housing of any one of claims 1-4, wherein, The thickness of the insulating layer provided on the other part of the shell wall is equal to the thickness of the insulating layer provided on the protective layer.

7. The battery cell housing of any one of claims 1-4, wherein, The surface roughness of the insulating layer is Ra, satisfying the relationship: 0.1 μm≤Ra≤1 μm, the insulating impedance of the insulating layer is greater than or equal to 0.5 G Ω , and the thermal conductivity of the insulating layer is greater than or equal to 0.2 W / (mk).

8. The battery cell housing of any one of claims 1-4, wherein, The hardness of the protective layer is greater than or equal to 3H, the shear strength of the protective layer is greater than or equal to 10MPa, and the surface roughness of the protective layer is Rb, and the relationship 0.2um<=Rb<=0.4um is met.

9. The battery cell housing of any one of claims 1-4, wherein, The plurality of shell walls are sequentially connected in a ring structure.

10. The battery cell housing of any one of claims 1-4, wherein, The application further relates to a battery cell shell. The shell body has at least one open port in communication with the assembly space, and each open port is provided with a cover body.

11. A battery cell, characterized by The application further relates to a battery cell. The electrode assembly is installed in the assembly space. ​

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