Battery cell casing and battery cell

Abstract

A battery cell casing (100) and a battery cell. The battery cell casing (100) comprises a casing body (1) and a first insulating coating (3) provided on the outer side surface of the casing body (1). The first insulating coating (3) in the battery cell casing (100) can reduce the risk of corrosion and damage of the casing body (1), thereby prolonging the service life.

Description

Battery shell and battery cell

[0001] This application claims priority to Chinese patent applications filed with the China Patent Office on August 29, 2023, with application number 202322329309.2, filed with the China Patent Office on April 30, 2024, with application number 202420954060.6, and filed with the China Patent Office on July 2, 2024, with application number 202421545698.0. The entire contents of the above applications are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of battery technology, and in particular to a battery cell casing and a battery cell. Background Art

[0003] A battery cell usually includes a shell and a core package. The shell protects the core package to prevent it from being bumped or corroded. SUMMARY OF THE INVENTION

[0004] In the related art, the surface of the battery cell casing is easily contaminated with dust, which poses a risk of corrosion and damage, affecting the service life.

[0005] The present application provides a battery cell casing, which includes a casing body and a first insulating coating disposed on an outer surface of the casing body.

[0006] The present application also provides a battery cell, which includes the aforementioned battery cell casing. Beneficial effects

[0007] The battery cell housing provided in the present application includes a housing body and a first insulating coating disposed on the outer surface of the housing body. The first insulating coating can reduce the risk of corrosion and damage to the housing body and extend its service life.

[0008] The battery cell provided in the present application can reduce the impact of external corrosion by adopting the battery cell casing as described above, thereby extending the service life of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG1 is a schematic diagram of the three-dimensional structure of a battery cell housing provided in an embodiment of the present application;

[0010] FIG2 is a second schematic diagram of the three-dimensional structure of a battery cell housing provided in an embodiment of the present application;

[0011] FIG3 is an enlarged schematic diagram of point A in FIG2 ;

[0012] FIG4 is an enlarged schematic diagram of point C in FIG1 ;

[0013] FIG5 is a front view of a battery cell housing provided in an embodiment of the present application;

[0014] FIG6 is a side view of a battery cell housing provided in an embodiment of the present application;

[0015] FIG7 is a bottom view of a battery cell housing provided in an embodiment of the present application;

[0016] FIG8 is a top view of a battery cell housing provided in an embodiment of the present application;

[0017] FIG9 is an enlarged schematic diagram of point B in FIG8 ;

[0018] FIG10 is a third schematic diagram of the three-dimensional structure of the battery cell housing provided in an embodiment of the present application;

[0019] FIG11 is an enlarged schematic diagram of point D in FIG10 ;

[0020] FIG12 is an exploded view of a battery cell according to an embodiment of the present application;

[0021] FIG13 is a partial cross-sectional view 1 of a battery cell housing provided in an embodiment of the present application;

[0022] FIG14 is a second partial cross-sectional view of a cell casing provided in an embodiment of the present application;

[0023] FIG15 is a first schematic diagram of a second protective layer of a battery cell casing provided in an embodiment of the present application;

[0024] FIG16 is a second schematic diagram of the second protective layer of the battery cell casing provided in an embodiment of the present application;

[0025] FIG17 is a third schematic diagram of the second protective layer of the battery cell casing provided in an embodiment of the present application;

[0026] FIG18 is a schematic diagram of the processing of the cylinder provided in an embodiment of the present application;

[0027] FIG19 is a first structural diagram of a battery cell provided in an embodiment of the present application;

[0028] FIG20 is a schematic diagram of a cross-sectional structure of a battery cell housing according to an embodiment of the present application;

[0029] FIG21 is a schematic diagram of the front structure of a battery cell housing according to an embodiment of the present application;

[0030] FIG22 is a second structural diagram of a battery cell provided in an embodiment of the present application;

[0031] FIG23 is a second schematic cross-sectional view of a cell casing according to an embodiment of the present application;

[0032] FIG24 is a second schematic diagram of the front structure of the battery cell housing provided in an embodiment of the present application;

[0033] FIG25 is a schematic structural diagram of a second insulating coating provided in an embodiment of the present application;

[0034] FIG26 is a second exploded view of a battery cell provided in an embodiment of the present application;

[0035] FIG27 is a second structural schematic diagram of the battery cell provided in an embodiment of the present application.

[0036] Description of reference numerals:

[0037] 100. Battery cell casing; 1. Casing body; 110. Cylinder; 120. Bottom plate; 10. Accommodation cavity; 11. Casing surface; 111. First side surface; 112. Second side surface; 113. Bottom surface; 12. Connection surface; 13. Transition surface; 21. First rough layer; 22. Second rough layer; 23. Third rough layer; 3. First insulating coating layer; 4. First protective layer; 5. Second protective layer; 51. Insulating layer; 52. Anti-corrosion layer; 6. Base layer; 7. Second insulating coating layer; 71. Groove; 200. Battery cell; 210. Cover plate; 220. Core pack; 221. Positive electrode tab; 222. Negative electrode tab; 231. Positive electrode post; 232. Negative electrode post; 241. Resistor; 242. Insulator. Modes for Carrying Out the Invention

[0038] In the description of this application, unless otherwise specified or limited, the terms "connected," "connect," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and can refer to internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0039] In this application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature includes the first feature being directly above and obliquely above the second feature, with the first feature having a higher horizontal height than the second feature. A first feature being "below," "below," and "below" a second feature includes the first feature being directly below and obliquely below the second feature, with the first feature having a lower horizontal height than the second feature.

[0040] In the description of this embodiment, terms such as "upper," "lower," "left," "right," "front," and "rear" are used to refer to positions or locations based on the positions or locations shown in the accompanying drawings. These terms are intended to facilitate description and simplify operation, and are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and do not have any special meanings.

[0041] In a first aspect, as shown in FIG1 , an embodiment of the present application provides a battery cell housing 100, comprising a housing body 1 and a first insulating coating 3 disposed on the outer surface of the housing body 1. The first insulating coating 3 disposed on the outer surface of the housing body 1 can provide insulation and protection for the housing body 1.

[0042] In some embodiments, as shown in Figures 2 to 4 , the housing body 1 includes at least two housing surfaces 11 and a connecting surface 12 disposed between adjacent housing surfaces 11, with adjacent housing surfaces 11 disposed at an angle. A first rough layer 21 is disposed on the outer surface of the housing surface 11, and a second rough layer 22 is disposed on the outer surface of the connecting surface 12. The roughness R1 of the first rough layer 21 and the roughness R2 of the second rough layer 22 satisfy the following relationship: R1 < R2.

[0043] In the related art, the cell casing 100 is typically subjected to a uniform surface treatment, and then a first insulating coating 3 is applied to the surface-treated cell casing 100. However, due to differences in the adhesion of the first insulating coating 3 to different areas of the cell casing 100, the first insulating coating 3 can easily fall off in some areas during use, leading to corrosion of the cell casing 100. Specifically, due to the curvature of the connecting surface 12 between adjacent casing surfaces 11 of the cell casing 100, the first insulating coating 3 has poor adhesion and is more likely to fall off than other areas.

[0044] As shown in Figures 1 and 4, the first insulating coating 3 is provided on the first rough layer 21 and the second rough layer 22. The first rough layer 21 and the second rough layer 22 can improve the adhesion effect of the first insulating coating 3 to the shell body 1. Since the roughness of the first rough layer 21 and the second rough layer 22 is different, the problem of different adhesion effects between the shell surface 11 and the connecting surface 12 due to structural differences is compensated, so that the first insulating coating 3 has basically consistent adhesion effects on the first rough layer 21 and the second rough layer 22, avoiding cracking or falling off problems caused by different adhesion effects in different areas.

[0045] For example, as shown in Figures 1 and 4, the first insulating coating 3 is located on the surface of the housing 100. The housing body 1, the first rough layer 21, the second rough layer 22, and the first insulating coating 3 are arranged in order from the inside out. The first rough layer 21 and the second rough layer 22 are disposed on the housing body 1 and are stably bonded to the housing body 1. The surfaces of the first rough layer 21 and the second rough layer 22 form a plurality of tiny gaps, with a microstructure of protrusions and depressions. The first insulating coating 3 is disposed on the surfaces of the first rough layer 21 and the second rough layer 22. The material particles in the first insulating coating 3 can be embedded in the tiny gaps in the first rough layer 21 and the second rough layer 22, making full contact with the microstructure. This improves the bonding strength between the first insulating coating 3 and the first rough layer 21 and the second rough layer, allowing it to stably adhere to the surfaces of the first rough layer 21 and the second rough layer 22.

[0046] In the battery cell casing 100 provided in the embodiment of the present application, the outer surfaces of the outer shell surface 11 and the connecting surface 12 are respectively provided with a first rough layer 21 and a second rough layer 22, and there is a difference between the roughness R1 of the first rough layer 21 and the roughness R2 of the second rough layer 22, that is, R1 < R2, which can enable the connecting surface 12 to have a better adhesion effect on the first insulating coating 3, compensate for the problem of poor adhesion to the first insulating coating 3 due to the bending of the connecting surface 12, so that the first insulating coating 3 can achieve good adhesion with both the outer shell surface 11 and the connecting surface 12, reducing or avoiding the problem of the first insulating coating 3 falling off due to poor adhesion of the connecting surface 12 during use.

[0047] Specifically, since the connection surface 12 is curved, etc., the effect of its surface adhesion to the first insulating coating 3 is affected. By setting its roughness to be greater, its adhesion to the first insulating coating 3 can be improved. Since the outer shell surface 11 has a relatively flat surface, its adhesion to the first insulating coating 3 is better than that of the connection surface 12, and its roughness can be lowered to reduce preprocessing time and save costs.

[0048] In some embodiments, one side of the battery cell housing 100 is open to facilitate the installation of the battery cell. After the battery cell is installed, a cover is provided at the opening to form a closed accommodating cavity. The battery cell housing 100 can be cylindrical or rectangular. When the battery cell housing 100 is cylindrical, one of the circular surfaces of the cylinder is open, and its outer shell surface 11 includes a cylindrical surface and a circular surface, and a connecting surface 12 is provided between the cylindrical surface and the circular surface. A first rough layer 21 is provided on the outer surface of the cylindrical surface and the circular surface, and a second rough layer 22 is provided on the outer surface of the connecting surface 12. By setting the roughness of the first rough layer 21 and the second rough layer 22 to be different, the first insulating coating 3 can have good adhesion everywhere in the housing 100.

[0049] When the cell casing 100 is a rectangular parallelepiped, as shown in Figures 1-7, one side of the casing 100 is open, and its casing surface 11 includes two opposing first side surfaces 111, two second side surfaces 112, and a bottom surface 113. A connecting surface 12 is provided between each two adjacent surfaces. The outer surfaces of the two first side surfaces 111, the two second side surfaces 112, and the bottom surface 113 are all provided with a first roughened layer 21, and the outer surface of the connecting surface 12 is provided with a second roughened layer 22. By providing different roughness levels for the first and second roughened layers 21, 22, the first insulating coating 3 can be effectively adhered to all portions of the cell casing 100.

[0050] The first rough layer 21 and the second rough layer 22 can be formed by various methods such as sandblasting, sandpaper polishing and laser cleaning.

[0051] For example, the housing body 1 can be surface treated by sandblasting to form the first rough layer 21 and the second rough layer 22. The sandblasting material can be selected from quartz sand, silica sand, steel balls, garnet sand, aluminum oxide, or steel shot. To form the first rough layer 21 and the second rough layer 22 with different roughness on the outer surfaces of the housing surface 11 and the connecting surface 12, sandblasting materials of different sizes can be used, and different sandblasting speeds can be set.

[0052] In some embodiments, the roughness R1 of the first rough layer 21 satisfies: 3.2≤Ra≤12.5, 6.3≤Rz≤50.

[0053] When the roughness of the first rough layer 21 is too low, its adhesion to the first insulating coating 3 is poor, reducing the bonding area between the first insulating coating 3 and the first rough layer 21 and making the first insulating coating 3 more susceptible to detachment. However, when the roughness of the first rough layer 21 is too high, the excessive presence of protrusions and depressions reduces the number of contact points between the first insulating coating 3 and the first rough layer 21. Furthermore, the material in the first insulating coating 3 cannot fully penetrate the gaps in the first rough layer 21, thus reducing adhesion. However, ensuring that the roughness R1 of the first rough layer 21 satisfies the following conditions: 3.2 ≤ Ra ≤ 12.5, 6.3 ≤ Rz ≤ 50 can improve the adhesion of the first rough layer 21 to the first insulating coating 3. Furthermore, the material in the first insulating coating 3 can better fill the tiny gaps on the surface of the first rough layer 21, resulting in a better bonding effect.

[0054] For example, when sandblasting is used to form the first rough layer 21, the particle size of the sandblasting material can be set to 10 μm-300 μm, and the sandblasting speed can be set to 10 m / s. 3 / h-100m 3 / h, the distance between the sandblasting nozzle and the shell surface is 0.25-2cm, and the number of sandblasting times can be set to more than twice.

[0055] It should be noted that Ra and Rz both represent roughness, where Ra represents the arithmetic mean of the absolute values ​​of the profile deviations within the sampling length, and Rz represents the sum of the average of the five largest profile peak heights and the average of the five largest profile valley depths within the sampling length.

[0056] In some embodiments, the roughness R2 of the second rough layer 22 satisfies: 6.3≤Ra≤50, 25≤Rz≤100.

[0057] Similar to the first rough layer 21, the second rough layer 22 is also susceptible to similar problems when its roughness is too low or too high. Furthermore, the roughness of the second rough layer 22 is greater than that of the first rough layer 21. This maintains the roughness of the second rough layer 22 within an appropriate range while providing better adhesion to the first rough layer 21, compensating for the poor adhesion of the first insulating coating 3 due to the curvature of the connecting surface 12. Therefore, the roughness R2 of the second rough layer 22 satisfies the following conditions: 6.3 ≤ Ra ≤ 50, 25 ≤ Rz ≤ 100.

[0058] For example, when sandblasting is used to form the second rough layer 22, the particle size of the sandblasting material can be set to 5 μm-100 μm, and the sandblasting speed can be set to 8 m / s. 3 / h-80m 3 / h, the distance between the sandblasting nozzle and the shell surface is 0.25-2cm, and the number of sandblasting times can be set to more than twice.

[0059] In some embodiments, the thickness of the first rough layer 21 is 50-120 μm. A thicker first rough layer 21 increases its roughness, which increases the contact area with the first insulating coating 3 and improves adhesion. A thinner first rough layer 21 decreases its roughness and reduces adhesion. However, if the first rough layer 21 is too thick, it can affect the strength of the housing body 1, and the material of the first insulating coating 3 may not easily penetrate the tiny gaps in the first rough layer 21 and achieve a tight bond with it. Therefore, the thickness of the first rough layer 21 is set to 50-120 μm.

[0060] In some embodiments, the thickness of the second rough layer 22 is 100-200 μm. Similarly, the thicker the second rough layer 22, the greater its roughness, which can increase the contact area with the first insulating coating 3 and thus improve adhesion. However, the thinner the second rough layer 22, the smaller its roughness, and the poorer adhesion. However, if the thickness of the second rough layer 22 is too large, it will easily affect the strength of the housing body 1, and the material of the first insulating coating 3 will not easily enter the tiny gaps in the second rough layer 22 and achieve a tight bond with it. Because the second rough layer 22 is disposed on the connection surface 12, relative to the housing surface 11, due to its curved structure, its adhesion to the first insulating coating 3 is poor. A larger thickness can improve adhesion while maintaining an appropriate thickness range. Therefore, the thickness of the second rough layer 22 is set to 100-200 μm.

[0061] As shown in Figures 8 and 9, the thickness of the first rough layer 21 is D1, and the thickness of the second rough layer is D2. By reasonably setting the thickness of the two, the adhesion effect of the first rough layer 21 and the second rough layer 22 to the first insulating coating 3 can be ensured, while also avoiding the deterioration of the strength of the shell body 1 due to the excessive thickness of the first rough layer 21 and the second rough layer 22.

[0062] For example, if the shell body 1 is surface treated by sandblasting, the thickness of the first rough layer 21 and the second rough layer 22 can be controlled by adjusting the sandblasting process parameters, such as the particle size of the sandblasting material, the number of sandblasting times, etc.

[0063] In some embodiments, the connecting surface 12 is a rounded or chamfered portion. By configuring the connecting surface 12 as a rounded or chamfered portion, adjacent outer shell surfaces 11 can be connected while enhancing the structural strength of the outer shell 100. The rounded or chamfered portions also increase the transition area between adjacent outer shell surfaces 11, facilitating the formation of a second roughness layer 22 with varying degrees of roughness on the rounded or chamfered portions. The rounded or chamfered portions also disperse stress and reduce stress concentration, thereby lowering the risk of damage to the outer shell 100.

[0064] In some embodiments, as shown in Figures 8 and 9 , the connecting surface 12 is a rounded corner portion with a radius of 2 mm to 4 mm. Compared to a chamfered corner portion, the rounded corner portion provides a smoother transition with the adjacent outer shell surface 11, reducing sharp edges. This allows for a smooth transition between the first roughened layer 21 and the second roughened layer 22, reducing stress concentration issues that occur during sharp edge transitions and reducing the risk of cracking or shedding of the first insulating coating 3 at these sharp edges.

[0065] By setting the fillet radius of the fillet to 2mm-4mm, the area of ​​the fillet can be guaranteed, which facilitates the formation of the second rough layer 22, while ensuring that the adjacent shell surfaces 11 can have a smooth transition, reducing or avoiding the appearance of sharp corners, and reducing the risk of cracking or falling off of the insulating coating at the sharp corners.

[0066] For example, as shown in FIG9 , R in the figure is the fillet radius of the fillet.

[0067] In other embodiments of the present application, as shown in Figures 10 and 11, a transition surface 13 is provided on the side of the outer shell surface 11 close to the connection surface 12. The outer surface of the transition surface 13 is provided with a third rough layer 23, and the roughness R3 of the third rough layer 23 satisfies: R1 < R3 < R2.

[0068] That is, there is a transition surface 13 on the outer shell surface 11, the transition surface 13 is arranged close to the connecting surface 12, and the outer surface of the transition surface 13 is provided with a third rough layer 23, and the roughness of the third rough layer 23 is greater than the roughness of the first rough layer 21, but less than the roughness of the second rough layer 22.

[0069] It is understood that the first rough layer 21, the third rough layer 23, and the second rough layer 22 are sequentially connected in the region formed by the adjacent outer shell surface 11 and the connection surface 12. The third rough layer 23 can reduce the stress concentration at the contact point of the first rough layer 21 and the second rough layer 22 caused by the large difference in roughness between the first rough layer 21 and the second rough layer 22, which can cause the first insulating coating 3 to crack or fall off at the contact point of the first rough layer 21 and the second rough layer 22.

[0070] By providing the third rough layer 23 on the transition surface 13 , the stress concentration problem caused by the difference in roughness can be dispersed, thereby improving the adhesion effect.

[0071] In some embodiments, the roughness R3 of the third rough layer 23 satisfies: 6.3≤Ra≤12.5, 12.5≤Rz≤50.

[0072] It is understood that the third rough layer 23 is disposed between the first rough layer 21 and the second rough layer 22 and is used to achieve a transition from the second rough layer 22 having a higher roughness to the first rough layer 21 having a lower roughness. By ensuring that the roughness R3 of the third rough layer 23 satisfies the following conditions: 6.3 ≤ Ra ≤ 12.5, 12.5 ≤ Rz ≤ 50, a good transition can be achieved and good adhesion of the third rough layer 23 to the first insulating coating 3 can be ensured.

[0073] In some embodiments, as shown in Figures 10 and 11 , a transition surface 13 is provided on at least one side of the outer shell surface 11 in the first direction X. The width of the transition surface 13 along the first direction X is W1, and the width of the outer shell surface along the first direction is W2; 0.5% ≤ W1 / W2 ≤ 1%. If the transition surface 13 is too narrow, the stress concentration caused by the difference in roughness cannot be effectively alleviated. If the transition surface 13 is too wide, it will occupy the outer shell surface 11, affecting the adhesion of the first insulating coating 3 to the outer shell surface 11.

[0074] It is understood that when the transition surface 13 is provided on the outer shell surface 11 and has the third rough layer 23, the first insulating coating 3 is also provided on the surfaces of the first rough layer 21, the second rough layer 22, and the third rough layer 23. Because the third rough layer 23 provides a transition between the first rough layer 21 and the second rough layer 22, the problem of cracking and shedding of the first insulating coating 3 caused by excessive roughness in adjacent areas is reduced.

[0075] In some embodiments, as shown in Figures 12 and 13, the shell body 1 has a housing cavity 10 for accommodating the core package 220, and the side of the shell body 1 facing the housing cavity 10 is the inner side. The first protective layer 4 is disposed on the inner side of the shell body 1, and the first protective layer 4 covers the entire inner side of the shell body 1. The second protective layer 5 is disposed on the side of the first protective layer 4 facing away from the shell body 1, and the second protective layer 5 has the same area as the first protective layer 4. When the core package 220 is installed in the housing cavity 10, the core package 220 can contact the second protective layer 5. The first protective layer 4 includes multiple anti-corrosion layers 52 and multiple insulating layers 51, and the multiple anti-corrosion layers 52 are arranged in an alternating manner with the multiple insulating layers 51. It can also be understood that the anti-corrosion layer 52 is located between two adjacent insulating layers 51, or that the insulating layer 51 is located between two adjacent anti-corrosion layers 52. The second protective layer 5 includes multiple anti-corrosion layers 52 and multiple insulating layers 51, and the multiple anti-corrosion layers 52 are arranged in an alternating manner with the multiple insulating layers 51. The anti-corrosion layer 52 in the first protective layer 4 is staggered with the anti-corrosion layer 52 in the second protective layer 5, and the insulating layer 51 in the first protective layer 4 is staggered with the insulating layer 51 in the second protective layer 5. It can also be understood that the overall structures of the first protective layer 4 and the second protective layer 5 are similar, but the anti-corrosion layers 52 and insulating layers 51 are distributed in different positions. Along the material thickness direction of the housing body 1 (the W direction in the figure), the insulating layer 51 in the first protective layer 4 corresponds to the anti-corrosion layer 52 in the second protective layer 5.

[0076] The insulating layer 51 is formed by spraying. Plastics such as PVC (polyvinyl chloride), PE (polyethylene), and PTFE (polytetrafluoroethylene) can be used for the insulating layer 51. The anti-corrosion layer 52 is composed of a material with excellent corrosion resistance, such as ceramic powder. The anti-corrosion layer 52 can be formed entirely by spraying ceramic powder or by spraying a mixture of ceramic and plastic powders. The anti-corrosion layer 52 has insulating properties. The addition of ceramic powder enhances its corrosion resistance, thereby improving the protective layer's resistance to electrolyte corrosion and extending the service life of the first and second protective layers 4 and 5.

[0077] It is understood that by providing the first protective layer 4 and the second protective layer 5, the core package 220 is isolated from the outer shell body 1 by two protective layers. Compared to the related art of wrapping the core package 220 with a protective film, this structure can eliminate the use of a protective film, that is, the first protective layer 4 and the second protective layer 5, which provide insulating protection, are directly sprayed on the inner side of the outer shell body 1. When installing the core package 220, the core package 220 can be directly placed into the accommodating cavity 10, which reduces the coating process and avoids coating the core package 220, making it easier to control the production quality of the single cell. At the same time, by providing the anti-corrosion layer 52 on the two protective layers, the anti-corrosion performance of the protective layer is enhanced, delaying the corrosion damage of the protective layer by the electrolyte. By staggering the insulating layer 51 and the anti-corrosion layer 52 in the two protective layers, part of the insulating layer 51 and part of the anti-corrosion layer 52 can be directly formed on the shell body 1, thereby improving the bonding strength between the insulating layer 51, the anti-corrosion layer 52 and the shell body 1, thereby improving the overall anti-corrosion performance of the first protective layer 4 and the overall anti-corrosion performance of the second protective layer 5.

[0078] In some embodiments, the sum of the thicknesses of the first protective layer 4 and the second protective layer 5 is 150 μm-200 μm. It is understandable that under the corrosive effect of the electrolyte, the first protective layer 4 and the second protective layer 5 will gradually be corroded. By setting appropriate thicknesses, the service life of the two protective layers meets the design requirements to ensure that the single battery can operate safely within the design life. Specifically, the total thickness of the first protective layer 4 and the second protective layer 5 includes but is not limited to 150 μm, 155 μm, 160 μm, 165 μm, 170 μm, 175 μm, 180 μm, 185 μm, 190 μm, 195 μm, and 200 μm. In actual applications, the thicknesses of the first protective layer 4 and the second protective layer 5 can be the same or different, and it is only necessary to control the total thickness of the two protective layers between 150 μm and 200 μm.

[0079] In some embodiments, the insulating layer 51 accounts for ≥50% of the first protective layer 4. This can also be understood as meaning that the ratio of the total volume of the multiple insulating layers 51 to the volume of the first protective layer 4 is ≥50%. This structure enhances the insulation performance of the first protective layer 4 near the inner side of the shell body 1, thereby strengthening the insulation isolation effect on the shell body 1. In the second protective layer 5, the anti-corrosion layer 52 accounts for ≥50%. This can also be understood as meaning that the ratio of the total volume of the multiple anti-corrosion layers 52 to the volume of the second protective layer 5 is ≥50%. This structure enhances the anti-corrosion performance of the second protective layer 5 near the core package 220, thereby delaying corrosion damage to the second protective layer 5 by the electrolyte.

[0080] In some embodiments, as shown in Figure 12, the shell body 1 includes a cylinder 110 and a bottom plate 120. The cylinder 110 is a cavity structure with openings at both ends. The bottom plate 120 is arranged at one of the open ends of the cylinder 110, and the bottom plate 120 is used to seal the corresponding open end. The bottom plate 120 is welded and fixed to the cylinder 110. A accommodating cavity 10 is formed between the cylinder 110 and the bottom plate 120. In a specific application, the cylinder 110 can be cylindrical, and correspondingly, the bottom plate 120 is a circular plate, and the shell body 1 formed is also cylindrical, which is used to make cylindrical single cells. Alternatively, the cylinder 110 can be in the shape of a rectangular parallelepiped, and correspondingly, the bottom plate 120 is a square plate, and the shell body 1 formed is also a rectangular parallelepiped, which is used to make square single cells.

[0081] In an optional embodiment, as shown in FIG18 , the shell body 1 is a rectangular parallelepiped structure, that is, the cylinder 110 is a rectangular parallelepiped structure. The cylinder 110 is formed by bending a square plate, and the joint seam formed after bending is located on the non-bending edge, that is, the joint seam is located on one of the side surfaces. During the production process of the shell body 1, a first protective layer 4 and a second protective layer 5 are sprayed on the inner side surface of the cylinder 110 before bending, and then the cylinder 110 is bent. This method allows the spraying operation to be performed when the cylinder 110 is in a planar state, which is convenient for operation. At the same time, the bottom plate 120 is sprayed on one side of the accommodating cavity 10 to form the first protective layer 4 and the second protective layer 5, and finally the bottom plate 120 is welded and fixed to the cylinder 110. Of course, in other embodiments, within the operating capacity of the spraying equipment, the cylinder 110 can also be bent first, and the spraying operation can be performed after the bottom plate 120 is welded to form the shell body 1.

[0082] In some embodiments, as shown in Figure 14, the shell further includes a base layer 6, which is spray-formed on the side of the shell body 1 facing the accommodating cavity 10, that is, the base layer 6 is formed on the inner side of the shell body 1. The first protective layer 4 is provided on the base layer 6. The material of the base layer 6 is the same as that of the shell body 1. In this embodiment, the shell body 1 is an aluminum shell, and the base layer 6 is formed by spraying aluminum powder on the inner side of the shell body 1. The purpose of forming the base layer 6 by spraying is to improve the roughness of the inner side of the shell body 1, making the side for combining with the first protective layer 4 smoother, and improving the bonding strength between the first protective layer 4 and the shell body 1. Of course, in other embodiments, the base layer 6 can also be eliminated, and the bonding strength between the first protective layer 4 and the shell body 1 can be improved by polishing the inner side of the shell body 1.

[0083] In some embodiments, as shown in FIG15 , the shell body 1 is a rectangular parallelepiped structure, and the description is made with reference to one of the large surfaces of the shell body 1. In the second protective layer 5, a plurality of anti-corrosion layers 52 are spaced apart along the first direction (the X direction in the figure). An insulating layer 51 is provided between two adjacent anti-corrosion layers 52, that is, a plurality of insulating layers 51 and a plurality of anti-corrosion layers 52 are staggered along the first direction. Correspondingly, the arrangement of the insulating layer 51 and the anti-corrosion layer 52 in the first protective layer 4 is the same as that of the second protective layer 5, except that the positions of the insulating layer 51 in the first protective layer 4 and the insulating layer 51 in the second protective layer 5 are staggered, that is, the insulating layer 51 in the first protective layer 4 is in contact with the anti-corrosion layer 52 in the second protective layer 5, and the anti-corrosion layer 52 in the first protective layer 4 is in contact with the insulating layer 51 in the second protective layer 5.

[0084] In some embodiments, as shown in FIG16 , the housing body 1 is a rectangular parallelepiped structure, and the description is made with reference to one of the large surfaces of the housing body 1. The second protective layer 5 includes a plurality of protective areas arranged along the first direction, and a plurality of anti-corrosion layers 52 and an insulating layer 51 are provided in each protective area. The length of the protective area extends along the second direction (Z direction in the figure). Within each protective area, a plurality of anti-corrosion layers 52 are spaced apart along the second direction, and an insulating layer 51 is provided between two adjacent anti-corrosion layers 52. The anti-corrosion layers 52 and the insulating layers 51 in two adjacent protective areas are staggered. It can also be understood that, along the first direction, in two adjacent protective areas, the anti-corrosion layer 52 is in contact with the insulating layer 51. Correspondingly, the arrangement of the insulating layer 51 and the anti-corrosion layer 52 in the first protective layer 4 is the same as that in the second protective layer 5, except that the insulating layer 51 in the first protective layer 4 and the insulating layer 51 in the second protective layer 5 are staggered, that is, the insulating layer 51 in the first protective layer 4 is in contact with the anti-corrosion layer 52 in the second protective layer 5, and the anti-corrosion layer 52 in the first protective layer 4 is in contact with the insulating layer 51 in the second protective layer 5. This structure allows the anti-corrosion layer 52 and the insulating layer 51 to be evenly distributed in the corresponding first protective layer 4 or second protective layer 5.

[0085] In some embodiments, as shown in Figure 17, the shell body 1 is a rectangular parallelepiped structure, and one of the large surfaces of the shell body 1 is used as a reference for description. The second protective layer 5 includes a plurality of protection areas, and the plurality of protection areas are distributed in a "U" shape, that is, the plurality of protection areas are distributed in sequence from the middle to the periphery of the corresponding side surface. In two adjacent protection areas, an anti-corrosion layer 52 is set in one protection area, and an insulating layer 51 is set in the other protection area. Correspondingly, the arrangement of the insulating layer 51 and the anti-corrosion layer 52 in the first protective layer 4 is the same as that in the second protective layer 5, except that the positions of the insulating layer 51 in the first protective layer 4 and the insulating layer 51 in the second protective layer 5 are staggered, that is, the insulating layer 51 in the first protective layer 4 is connected to the anti-corrosion layer 52 in the second protective layer 5, and the anti-corrosion layer 52 in the first protective layer 4 is connected to the insulating layer 51 in the second protective layer 5.

[0086] It should be noted that the primary purpose of the aforementioned distribution patterns of the insulating layer 51 and the anti-corrosion layer 52 is to ensure that the insulating layer 51 and the anti-corrosion layer 52 are evenly distributed within the first protective layer 4 or the second protective layer 5, thereby improving the overall insulation and anti-corrosion performance of the first protective layer 4 and the second protective layer 5. In practical applications, the insulating layer 51 and the anti-corrosion layer 52 can be distributed in the aforementioned patterns on one side surface of the housing body 1, or on the entire housing body 1 in its unfolded state (i.e., the inner side surface of the housing body 1).

[0087] In some embodiments, the core package 220 is provided with a tab at least at one end in the first direction X. A second insulating coating 7 is provided circumferentially on the inner sidewall of the end of the housing body 1 that is aligned with the tab. The width of the housing body 1 along the first direction X is H, and the width of the second insulating coating 7 along the first direction X is h, where 0.05H≤h≤0.2H.

[0088] Since a second insulating coating 7 is provided on the inner side wall of the area where the shell body 1 and the tab are aligned, a good insulating relationship is maintained between the tab and the shell body 1, and there is no need to stick insulating glue on the outside of the tab, thereby reducing the risk of short circuit caused by the falling off of the insulating glue. The tab can also be set closer to the shell body 1, further freeing up the space inside the shell body 1, increasing the volume of the core package 220, and improving the energy efficiency of the battery cell.

[0089] The width of the outer shell body 1 in the first direction X is H, and the width of the second insulating coating 7 in the first direction X is h, where 0.05H≤h≤0.2H. Since the second insulating coating 7 has a certain thickness, it will occupy the space within the outer shell body 1. By properly arranging the distribution area of ​​the second insulating coating 7, the insulation effect between the outer shell body 1 and the tab can be ensured, and the thickness of the outer shell body 1 in other areas can be reduced, thereby increasing the design energy of the battery.

[0090] The width h of the second insulating coating 7 in the first direction X and the width H of the upper end of the housing body 1 in the first direction X can be set to: h=0.05H, h=0.1H, h=0.15H or h=0.2H.

[0091] The second insulating coating 7 can be made by blue film pasting, etching or spraying, etc., which is not limited in this application, as long as insulation can be achieved.

[0092] When spraying the second insulating coating 7, materials for the second insulating coating 7 primarily include polyester, epoxy, and polyethylene. To improve the service life and insulation performance of the second insulating coating 7, polyoxymethylene (POM) and polytetrafluoroethylene (PTFE) can be selected as the materials for the second insulating coating 7. This ensures that the resulting second insulating coating 7 has excellent hardness, adhesion, and wear resistance. For example, the mass ratio of POM to PTFE is 96:4.

[0093] When applying the second insulating coating 7, an electrostatic spraying process can be selected, which has the advantages of being clean, energy-saving, and efficient. For example, during the electrostatic spraying process, the spraying voltage can be set to 40kV, the powder supply pressure can be set to 0.3MPa, the curing time can be set to 10min, and the curing temperature can be set to 180°C.

[0094] In some embodiments, the housing body 1 may be an aluminum shell. Aluminum alloys have the characteristics of low density, high specific strength, and high specific modulus, and can provide sufficient mechanical strength and stability while maintaining lightweight. Aluminum and aluminum alloys have good corrosion resistance and excellent thermal conductivity, which helps improve the corrosion resistance and thermal conductivity of the battery, thereby improving the safety and stability of the battery. Aluminum alloys are easy to process into various shapes and sizes, and the processing difficulty is relatively low.

[0095] In some embodiments, the housing body 1 includes two end plates disposed at opposite ends of the first direction X, and a side plate disposed between the two end plates;

[0096] A second insulating coating 7 is provided on the inner side wall of the end plate of the housing body 1 at one end facing the tab;

[0097] A second insulating coating 7 is provided on the circumference of the inner side wall of one end of the side plate that is aligned with the tab.

[0098] In the related art, an insulating film is usually provided on the inner wall of the end plate in the shell body 1, and insulation is achieved between the tab and the inner wall of the end plate by the insulating film, but the insulating film also has the risk of aging, corrosion, and falling off.

[0099] In an embodiment of the present application, the second insulating coating 7 is simultaneously provided on the inner side walls of the end plate and the side plate corresponding to the tab, and the tab, the side plate and the end plate are all insulated by the second insulating coating 7, thereby reducing or avoiding the short circuit problem caused by contact between the tab inside the battery and the outer shell body 1.

[0100] It should be noted that in the embodiment of the present application, the shape of the shell body 1 can be a cylindrical, rectangular or other structure. Corresponding to the shape of the shell body 1, the shape of the core package 220 can also be a cylindrical or rectangular structure. When the shell body 1 is a cylindrical structure, it includes end plates arranged at opposite ends and a cylindrical side wall connected between the two end plates. The manufacturing process of the cylindrical battery is relatively simple, and the structure is relatively compact, which is easy to achieve large-scale production. When the shell body 1 is a rectangular structure, it includes end plates arranged at opposite ends and four side plates arranged between the two end plates. The rectangular structure battery has high stability, can work in different environments, has a wide range of usage scenarios, and is safe and reliable.

[0101] Example 1

[0102] As shown in Figures 19-21, in this embodiment, the tabs include a positive pole tab 221 and a negative pole tab 222; the positive pole tab 221 and the negative pole tab 222 are both arranged at the same end of the core package 220 in the first direction X; a second insulating coating 7 is provided on the inner side wall of the end plate at one end of the shell body 1 corresponding to the positive pole tab 221 and the negative pole tab 222; a second insulating coating 7 is provided on the circumferential direction of the inner side wall of the side plate at one end corresponding to the positive pole tab 221 and the negative pole tab 222.

[0103] In this embodiment, the battery cell adopts a top-out tab structure, with the positive direction of the first direction X being upward and the negative direction being downward. As shown in Figure 19 , the positive electrode tab 221 and the negative electrode tab 222 are both disposed at the upper end of the housing body 1 ; correspondingly, as shown in Figure 20 , a second insulating coating 7 is circumferentially provided on the inner sidewall of the end plate at the upper end of the housing body 1 and on the inner sidewall of the upper end of the side plate.

[0104] By adopting the design method of ejecting the tabs, it is easier to connect the tabs to external devices or circuits during the battery cell assembly process, and it can flexibly adapt to the requirements of different battery shapes and sizes, making the internal space layout of the battery more reasonable, which helps to improve the energy density of the battery and reduce the overall volume and weight of the battery, thereby achieving the needs of lightweight and miniaturization; in addition, the use of the ejecting tab method can also simplify some process steps in the battery manufacturing process, reduce material input, and help reduce the production cost of the battery.

[0105] When the core package 220 is installed in the shell body 1, the positions where the positive electrode tab 221 and the negative electrode tab 222 contact the shell body 1 are provided with a second insulating coating 7, thereby ensuring the insulation effect between the positive electrode tab 221 and the negative electrode tab 222 and the shell body 1.

[0106] Furthermore, as shown in Figure 21, the width of the distribution area of ​​the second insulating coating 7 in the first direction X is h, and the overall width of the shell body 1 in the first direction X is H, 0.05H≤h≤0.2H, which can not only ensure the insulation effect between the tab and the shell body 1, but also avoid the distribution area of ​​the second insulating coating 7 being too large, affecting the space of the core package 220, thereby improving the space utilization rate in the battery and helping to improve the design energy of the battery.

[0107] Example 2

[0108] As shown in Figures 22-24, in this embodiment, the tabs include a positive pole tab 221 and a negative pole tab 222; the positive pole tab 221 and the negative pole tab 222 are respectively arranged at opposite ends of the core package 220 in the first direction X; the inner walls of the two end plates in the shell body 1, as well as the inner walls of the side plates at both ends in the first direction X are circumferentially provided with a second insulating coating 7.

[0109] That is, a second insulating coating 7 is provided on the inner side walls of the end plates and side plates at one end of the positive electrode tab 221 and the negative electrode tab 222, and the outer shell body 1 is insulated from the positive electrode tab 221 and the negative electrode tab 222 to prevent internal short circuit problems of the battery.

[0110] In this embodiment, the battery cell adopts a side-outlet tab structure, with the positive direction of the first direction X being the right and the negative direction being the left; as shown in FIG22 , the positive pole tab 221 is located at the left end of the shell body 1, and the negative pole tab 222 is located at the right end of the shell body 1. As shown in FIG23 , the end plates at the left and right ends of the shell body 1, as well as the side plates are provided with a second insulating coating 7 in the circumferential direction of the left and right ends.

[0111] Since the tabs extend from the side of the shell body 1, they can be more easily docked with external connectors or circuit boards, reducing the difficulty of assembly and improving production efficiency; the design of the side-outlet tabs helps to optimize the current path, reduce the current transmission distance inside the battery, thereby reducing the internal resistance, and then increasing the energy output of the battery during discharge; the side-outlet tab design makes the battery structure more compact and improves space utilization.

[0112] When the core package 220 is installed in the shell body 1, the positions where the positive electrode tab 221 and the negative electrode tab 222 contact the shell body 1 are provided with a second insulating coating 7, thereby ensuring the insulation effect between the positive electrode tab 221 and the negative electrode tab 222 and the shell body 1.

[0113] Furthermore, as shown in Figure 24, the width of the distribution area of ​​the second insulating coating 7 in the first direction X is h, and the overall width of the shell body 1 in the first direction X is H, 0.05H≤h≤0.2H, which can not only ensure the insulation effect between the tab and the shell body 1, but also avoid the distribution area of ​​the second insulating coating 7 being too large, affecting the space of the core package 220, thereby improving the space utilization rate in the battery and helping to improve the design energy of the battery.

[0114] In some embodiments, as shown in FIG25 , a groove 71 is provided on the second insulating coating 7 ; the extension direction of the groove 71 is the same as the extension direction of the tab, and the width of the groove 71 is greater than or equal to the width of the tab; the tab is disposed in the groove 71 .

[0115] The tabs are positioned in the grooves 71 of the second insulating coating 7 to reduce friction and movement between the tabs and the outer shell 1 during battery use, thereby reducing the probability of wear of the tabs and the outer shell 1 and extending the life of the battery.

[0116] It should be understood that the extension direction of the groove 71 is the length direction of the groove 71. Taking the structure of the battery cell in Example 1 as an example, after the pole ear extends out from the core package 220, it first extends along the first direction X, and after bending at a position close to the end plate of the shell body 1, it continues to extend in a direction perpendicular to the first direction X; correspondingly, the groove 71 in the second insulating coating 7 on the inner side wall of the side plate of the shell body 1 also extends along the first direction X, while the groove 71 on the inner side wall of the end plate extends in a direction perpendicular to the first direction X; the pole ear can be embedded in the groove 71, and the groove 71 serves to limit the pole ear, thereby reducing the shaking and friction of the pole ear.

[0117] Furthermore, the width of the groove 71 is D, and the width of the tab is d, wherein 1.1d≤D≤1.3d.

[0118] That is, the width of the groove 71 is slightly larger than the width of the tab, so that the tab can be smoothly embedded in the groove 71 during the assembly of the battery cell, and during the use of the battery cell, the shaking of the tab in the width direction can be reduced, ensuring the positioning of the tab and further reducing the probability of tab wear.

[0119] Exemplarily, the width D of the groove 71 and the width d of the tab can be set to: D=1.1d, D=1.2d or D=1.3d.

[0120] In some embodiments, the second insulating coating 7 has coating stripes; the extending direction of the coating stripes is the same as the extending direction of the tab.

[0121] The coating stripes in the second insulating coating 7 can effectively block the conduction of current, thereby improving the insulation effect of the second insulating coating 7 . The design of the coating stripes combines material science and engineering principles, and can ensure the stability of the second insulating coating 7 .

[0122] By setting the extension direction of the coating stripes to be the same as the extension direction of the tab, the friction between the tab and the coating stripes can be reduced, thereby reducing the friction damage between the tab and the second insulating coating 7.

[0123] In some embodiments, the thickness of the second insulating coating 7 is 1-2 mm.

[0124] The thickness of the insulating coating is an important parameter that affects the insulation performance, mechanical properties and service life of the coating. In specific applications, the thickness of the insulating coating is required to be 1-2mm, which is determined based on the required electrical insulation strength, wear resistance, corrosion resistance and expected service life of the coating.

[0125] It should be noted that the thickness of the second insulating coating 7 is not selected arbitrarily, but needs to be determined according to specific industry standards, national standards or International Electrotechnical Commission standards (IEC standards).

[0126] At the same time, different types of second insulating coating 7 materials may also have different thickness requirements. In addition, the construction method and process of the insulating coating may also affect the final coating thickness.

[0127] Therefore, when selecting and applying the insulating coating, it is necessary to comprehensively consider various factors, including the coating material, performance requirements, construction conditions, and relevant standards and specifications. This is to ensure that the second insulating coating 7 has good insulation performance, mechanical properties, and service life, thereby meeting the needs of actual applications.

[0128] Illustratively, the thickness of the second insulating coating 7 may be 1 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm or 2 mm.

[0129] In a second aspect, an embodiment of the present application further provides a battery cell 200 , comprising the battery cell housing 100 as described above.

[0130] In some embodiments, as shown in FIG26 , the battery cell 200 includes a battery cell housing 100 , a cover plate 210 , and a battery cell (not shown). The cover plate 210 may be disposed on the opening of the battery cell housing 100 to form a receiving cavity for receiving the battery cell.

[0131] In other embodiments, as shown in Figures 12 and 27, the battery cell 200 includes a core pack 220, a cover plate 210 and a battery cell shell 100. The core pack 220 is composed of pole pieces and diaphragms wound or stacked in a certain order, and stores electrical energy through electrochemical reactions. The core pack 220 has positive and negative electrode ears. The cover plate 210 is covered on the open end of the shell body 1, and the cover plate 210 is located at the end of the cylinder 110 away from the bottom plate 120, and the cover plate 210 is welded and fixed to the cylinder 110 so that the accommodating cavity 10 of the shell body 1 is in a sealed state. The core pack 220 is installed in the accommodating cavity 10, and the positive and negative electrode ears of the core pack 220 are electrically connected to the positive and negative poles in the cover plate 210 respectively, so that the current is externally conducted through the positive and negative poles. The cover plate 210 is also provided with an injection hole, through which electrolyte is injected into the accommodating cavity 10, so that the electrolyte infiltrates the core package 220 and undergoes an electrochemical reaction with the core package 220. By providing a first protective layer 4 and a second protective layer 5 on the inner side of the outer shell body 1, the two protective layers serve to insulate and isolate the core package 220 from the outer shell body 1. During the production process, it is avoided to wrap the protective film on the outside of the core package 220, thereby effectively avoiding quality problems such as bubbles, glue shortage, glue squeeze, and wear caused by the protective film. The core package 220 can be directly loaded into the accommodating cavity 10, which simplifies the assembly process of the single cell and facilitates quality control. At the same time, under the anti-corrosion effect of the first protective layer 4 and the second protective layer 5, the corrosion effect of the electrolyte on the protective layer is delayed, which is conducive to extending the service life of the single cell.

[0132] In some embodiments, as shown in FIG27 , the housing body 1 is a rectangular parallelepiped structure, with the length, thickness, and height of the housing body 1 corresponding to the length, thickness, and height of the battery cell. The ratio of the length L1 to the height L2 of the housing body 1 is 6:5-2:1; the ratio of the height L2 to the thickness T of the housing body 1 is 2:1-25:7. The length L of the housing body 1 is 300-400 mm, including but not limited to 300 mm, 310 mm, 320 mm, 330 mm, 340 mm, 350 mm, 360 mm, 370 mm, 380 mm, 390 mm, and 400 mm. The thickness T of the housing body 1 is 70-100 mm, including but not limited to 70 mm, 75 mm, 80 mm, 85 mm, 90 mm, 95 mm, and 100 mm. The height dimension H of the housing body 1 is 200-250mm, and the height dimension L2 of the housing body 1 includes but is not limited to 200mm, 215mm, 220mm, 225mm, 230mm, 235mm, 240mm, 245mm, and 250mm. It is understood that setting the aspect ratio of the housing body 1 between 6:5 and 2:1 allows the battery cell to have a larger surface area (the surface area being the two opposing sides of the housing body 1 in the thickness direction), which facilitates heat dissipation from the battery cell. With this aspect ratio, the housing body 1 creates a more reasonable internal space within the accommodating cavity 10, which helps improve the utilization rate of the active material within, thereby extending the battery cell's lifespan and meeting user demands for extended battery life and capacity.

[0133] In other embodiments, the battery cell 200 further includes a pole, one end of which is disposed outside the shell body 1 , and the other end of which penetrates the shell body 1 and is connected to the tab.

[0134] The pole establishes a connection between the internal and external circuits of the battery cell, allowing electrical energy to be transmitted between the two. The pole is responsible for outputting the electrical energy stored in the battery to the external circuit, or inputting the electrical energy in the external circuit into the battery for storage.

[0135] During the connection process between the pole and the tab, technologies such as laser welding can be used to ensure a firm connection between the pole and the tab while meeting the safety and performance requirements of the battery.

[0136] As shown in Figures 19 and 22, the poles include a positive pole 231 and a negative pole 232; a resistor 241 is provided between the positive pole 231 and the outer wall of the shell body 1; and an insulating member 242 is provided between the negative pole 232 and the outer wall of the shell body 1.

[0137] The positive electrode post 231 is connected to the positive electrode tab 221 , and the negative electrode post 232 is connected to the negative electrode tab 222 .

[0138] That is, the battery cell adopts a positive weak conductivity setting, a resistor 241 is present between the positive electrode post 231 and the outer shell body 1, and the negative electrode post 232 and the outer shell body 1 are insulated; according to the voltage division principle of Ohm's law, the voltage between the outer shell body 1 and the positive electrode post 231 is approximately equal to the open circuit voltage of the battery, and the outer shell body 1 is positively charged, thereby destroying the corrosion conditions of the outer shell body 1 and delaying the corrosion of the outer shell body 1; and the negative electrode post 232 is insulated from the outer wall of the outer shell body 1 by an insulating member 242 to prevent short circuit; inside the outer shell body 1, the insulation effect is ensured by a second insulating coating 7 arranged in the corresponding areas of the positive electrode tab 221 and the negative electrode tab 222, thereby reducing or avoiding the problem of short circuit within the battery.

Claims

1. A battery cell casing, comprising a casing body and a first insulating coating disposed on an outer surface of the casing body.

2. The battery cell casing according to claim 1, wherein: The shell body includes at least two shell surfaces and a connecting surface arranged between adjacent shell surfaces, and the adjacent shell surfaces are arranged at an angle; The outer surface of the outer shell surface is provided with a first rough layer, and the outer surface of the connecting surface is provided with a second rough layer; the first rough layer and the second rough layer are provided between the outer shell body and the first insulating coating; The roughness R1 of the first rough layer and the roughness R2 of the second rough layer satisfy: R1<R2.

3. The battery cell casing according to claim 2, wherein: The roughness R1 of the first rough layer satisfies: 3.2≤Ra≤12.5, 6.3≤Rz≤50; And / or, the roughness R2 of the second rough layer satisfies: 6.3≤Ra≤50, 25≤Rz≤100.

4. The battery cell casing according to claim 3, wherein: The thickness of the first rough layer is 50-120 μm; And / or, the second rough layer has a thickness of 100-200 μm.

5. The battery cell casing according to any one of claims 2 to 4, wherein: The connecting surface is a rounded corner or a chamfered corner.

6. The battery cell casing according to claim 5, wherein: The connecting surface is a rounded corner portion, and the rounded corner radius of the rounded corner portion is 2mm-4mm.

7. The battery cell casing according to any one of claims 2 to 6, wherein: A transition surface is provided on one side of the outer shell surface close to the connecting surface; The outer surface of the transition surface is provided with a third rough layer, and the roughness R3 of the third rough layer satisfies: R1<R3<R2.

8. The battery cell casing according to claim 7, wherein: The roughness R3 of the third rough layer satisfies: 6.3≤Ra≤12.5, 12.5≤Rz≤50.

9. The battery cell casing according to claim 7, wherein: The transition surface is arranged on at least one side of the outer shell surface in the first direction; The width of the transition surface along the first direction is W1, and the width of the outer shell surface along the first direction is W2; 0.5%≤W1 / W2≤1%.

10. The battery cell casing according to any one of claims 1 to 9, wherein: The shell body is provided with a receiving cavity for receiving the core package, and a first protective layer is provided on the side of the shell body facing the receiving cavity.

11. The battery cell casing according to claim 10, wherein: A second protective layer is disposed on the side of the first protective layer away from the shell body, the first protective layer and the second protective layer both include a plurality of anti-corrosion layers and a plurality of insulating layers, and the plurality of anti-corrosion layers and the plurality of insulating layers are arranged alternately; The anti-corrosion layer in the first protective layer and the anti-corrosion layer in the second protective layer are staggered in distribution, and the insulating layer in the first protective layer and the insulating layer in the second protective layer are staggered in distribution.

12. The battery cell casing according to claim 11, wherein: The sum of the thickness of the first protective layer and the second protective layer is 150 μm-200 μm.

13. The battery cell casing according to claim 11, wherein: In the first protective layer, the insulating layer accounts for ≥50%, and in the second protective layer, the anti-corrosion layer accounts for ≥50%.

14. The battery cell casing according to claim 10, wherein: The shell body comprises a cylinder and a bottom plate. The cylinder is a cavity structure with two ends open. The bottom plate is arranged at one of the open ends of the cylinder. The accommodating cavity is formed between the cylinder and the bottom plate.

15. The battery cell casing according to claim 11, wherein: In the first protective layer and the second protective layer, a plurality of the anti-corrosion layers are spaced apart and distributed along the first direction, and one insulating layer is arranged between two adjacent anti-corrosion layers.

16. The battery cell casing according to claim 11, wherein: The first protective layer and the second protective layer each include a plurality of protective areas arranged in sequence along the first direction, a plurality of anti-corrosion layers and a plurality of insulating layers are arranged in each of the protective areas, the plurality of anti-corrosion layers in each of the protective areas are spaced apart along the second direction, an insulating layer is arranged between two adjacent anti-corrosion layers, the anti-corrosion layers in two adjacent protective areas are staggered, and the insulating layers in two adjacent protective areas are staggered.

17. The battery cell casing according to claim 16, wherein: The first protective layer and the second protective layer each include a plurality of protective regions, and the protective regions are distributed in a "U" shape. In two adjacent protective regions, one of the protective regions is configured as the anti-corrosion layer, and the other of the protective regions is configured as the insulating layer. 18 . The battery cell casing according to claim 10 , further comprising a base layer, wherein the base layer is sprayed on a side of the casing body facing the accommodating cavity, and the first protective layer is disposed on the base layer.

19. The battery cell casing according to any one of claims 1 to 9, wherein: A second insulating coating is provided on the circumference of the inner side wall of one end of the shell body that is aligned with the pole ear of the core package.

20. The battery cell casing according to claim 19, wherein: The width of the shell body along the first direction is H, and the width of the second insulating coating along the first direction is h, wherein 0.05H≤h≤0.2H.

21. The battery cell casing according to claim 20, wherein: The housing body comprises two end plates arranged at two opposite ends of the first direction, and a side plate arranged between the two end plates; The second insulating coating is provided on the inner side wall of the end plate at one end of the battery cell housing that is aligned with the pole tab; The second insulating coating is provided on the circumference of the inner side wall of one end of the side plate that is aligned with the pole tab.

22. The battery cell casing according to claim 21, wherein: The tabs include a positive tab and a negative tab; The positive electrode tab and the negative electrode tab are both arranged at the same end of the core package in the first direction; The second insulating coating is provided on the inner side wall of the end plate at one end of the battery cell housing that is aligned with the positive electrode tab and the negative electrode tab; The second insulating coating is provided on the circumferential direction of the inner wall of one end of the side plate that is aligned with the positive electrode tab and the negative electrode tab.

23. The battery cell casing according to claim 21, wherein: The tabs include a positive tab and a negative tab; The positive electrode tab and the negative electrode tab are respectively arranged at two opposite ends of the core package in the first direction; The second insulating coating is provided on the inner side walls of the two end plates in the battery cell housing and on the circumferential direction of the inner side walls of the side plates at both ends in the first direction.

24. The battery cell casing according to any one of claims 19 to 23, wherein: The second insulating coating is provided with a groove; The extending direction of the groove is the same as the extending direction of the pole lug, and the width of the groove is greater than or equal to the width of the pole lug; The pole ear is arranged in the groove.

25. The battery cell casing according to claim 24, wherein: The width of the groove is D, and the width of the tab is d, wherein 1.1d≤D≤1.3d.

26. The battery cell casing according to any one of claims 19 to 25, wherein: The second insulating coating has coating stripes; the extending direction of the coating stripes is the same as the extending direction of the pole lug.

27. The battery cell casing according to any one of claims 19 to 25, wherein: The thickness of the second insulating coating is 1-2 mm.

28. A battery cell, comprising the battery cell casing according to any one of claims 1 to 27.

29. The battery cell according to claim 28, further comprising a core package and a top cover assembly, wherein the core package is installed in the accommodating cavity, and the top cover assembly is covered on the open end of the outer shell body and electrically connects the top cover assembly to the core package.

30. The battery cell according to claim 29, wherein: The shell body is in a rectangular parallelepiped structure, the ratio of the length dimension to the height dimension of the shell body is 6:5-2:1, and the ratio of the height dimension to the thickness dimension of the shell body is 2:1-25:

7.

31. The battery cell according to claim 28, further comprising a pole and a core package, wherein the core package is installed in the accommodating cavity of the battery cell shell, one end of the pole is arranged on the outside of the shell body, and the other end penetrates the shell body and is connected to the pole ear of the core package.

32. The battery according to claim 31, wherein The poles include a positive pole and a negative pole; A resistor sheet is arranged between the positive electrode column and the outer side wall of the shell body; An insulating member is arranged between the negative electrode column and the outer side wall of the shell body.

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