Battery cell and battery

Abstract

The embodiment of the utility model provides a kind of electric core and battery, it is related to battery technical field.The utility model discloses an insulating protective layer is set, insulating protective layer is set on the inner side wall and inner bottom wall of shell, insulating protective layer is isolated with electrolyte, first, insulating protective layer prevents the formation of ion channel, that is, prevents the formation of current loop between shell and electrolyte, second, insulating protective layer can also preserve liquid to electrolyte, reduce the loss of electrolyte, improve the cycle performance of electric core, third, the insulating protective layer on inner side wall is higher than the liquid level height of electrolyte, can avoid in the use process because of the influence of vibration working condition causes electrolyte to splash and lead to electrolyte and shell contact;Further, in the use process, even if electronic channel is destroyed, to make shell and negative short circuit, because of the difference of ion channel, shell-electrolyte-negative current loop still cannot be formed, can prevent the shell of battery from being corroded and leaking.

Description

Technical Field

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

[0002] When the potential of the lithium-ion battery casing is less than 1.8V (VS*Li+ / Li), a current loop is formed between the casing, electrolyte, and negative electrode. The casing comes into contact with lithium ions in the electrolyte. At low potential, the casing undergoes an electrochemical reaction with the lithium ions, resulting in lithium intercalation and the formation of a lithium-aluminum alloy. This leads to casing pulverization and corrosion, causing leakage.

[0003] In related technologies, to address the aforementioned problems, on the one hand, PET / PI tape is applied to the exposed negative electrode of the battery cell, and Mylar film is wrapped around the cell for insulation protection to reduce the short circuit between the casing and the negative electrode; on the other hand, a blue film is wrapped around the outside of the casing to insulate and protect the battery casing from external short circuits. Although this solution provides some protection against battery short circuits, various problems still arise in actual use. For example, if a metal foreign object punctures the blue film, it cannot prevent the formation of a current loop between the casing, electrolyte, and negative electrode, and the battery may still experience casing corrosion and leakage. Utility Model Content

[0004] The purpose of this invention is to provide a battery cell and battery that can isolate the casing from the electrolyte, prevent the formation of ion channels, and prevent the battery casing from being corroded and leaking.

[0005] The embodiments of this utility model can be implemented as follows:

[0006] In a first aspect, the present invention provides a battery cell, comprising: a housing, wherein the inner wall of the housing includes an inner side wall and an inner bottom wall, the inner side wall and the inner bottom wall are connected to form a receiving cavity, and the receiving cavity contains an electrolyte;

[0007] An insulating protective layer is provided to isolate the housing from the electrolyte. The insulating protective layer is provided on both the inner sidewall and the inner bottom wall. The insulating protective layer on the inner sidewall is higher than the liquid level of the electrolyte.

[0008] In an optional embodiment, the height of the inner sidewall is H, and the liquid level of the electrolyte is greater than 1 / 3H.

[0009] In an optional embodiment, the height of the insulating protective layer located on the inner sidewall is greater than 1 / 2H;

[0010] Alternatively, the height of the insulating protective layer located on the inner sidewall is greater than or equal to 2 / 3H.

[0011] In an optional embodiment, the thickness of the insulating protective layer is less than or equal to 1 mm.

[0012] In an optional embodiment, the insulating protective layer is bonded and fixed to the inner sidewall and the inner bottom wall.

[0013] In an optional embodiment, the insulating protective layer includes any one of polyester film tape, polyimide tape, polytetrafluoroethylene tape, and polyetheretherketone tape.

[0014] In an optional embodiment, the insulating protective layer is formed by coating on the inner sidewall and the inner bottom wall.

[0015] In an optional embodiment, the insulating protective layer includes at least one of an acrylic resin insulating protective layer, a polyurethane resin insulating protective layer, and an epoxy resin insulating protective layer.

[0016] In an optional embodiment, the housing includes a square housing, and the inner sidewall of the housing includes a first inner sidewall, a second inner sidewall, a third inner sidewall, and a fourth inner sidewall connected in sequence, wherein the bottom edges of the first inner sidewall, the second inner sidewall, the third inner sidewall, and the fourth inner sidewall are connected to the four sides of the inner bottom wall.

[0017] The first inner sidewall and the third inner sidewall are disposed opposite to each other, and the insulating protective layer is disposed on the first inner sidewall and the third inner sidewall;

[0018] The second inner sidewall is disposed opposite to the fourth inner sidewall, and the second inner sidewall and the fourth inner sidewall are large surfaces and are not provided with the insulating protective layer.

[0019] Secondly, this utility model provides a battery, including the battery cell described in any of the foregoing embodiments.

[0020] The beneficial effects of the battery cell and battery provided in this embodiment of the present invention include:

[0021] By setting an insulating protective layer, which is located on the inner sidewall and bottom wall of the casing, the insulating protective layer isolates the casing from the electrolyte. Firstly, the insulating protective layer prevents the formation of ion channels, thus preventing the formation of a current loop between the casing and the electrolyte. Secondly, the insulating protective layer can also retain electrolyte, reducing electrolyte loss and improving the cycle performance of the cell. Thirdly, the insulating protective layer located on the inner sidewall is higher than the electrolyte level, which can prevent electrolyte from splashing and contacting the casing due to vibration during use. Furthermore, even if the electron channels are damaged during use, causing a short circuit between the casing and the negative electrode, the casing-electrolyte-negative electrode current loop cannot be formed due to the different ion channels, thus preventing the battery casing from being corroded and leaking. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the battery cell structure provided in this embodiment;

[0024] Figure 2 This is a top view of the housing provided in this embodiment;

[0025] Figure 3 A schematic diagram of a structure for providing an insulating protective layer on the inner wall of the housing in this embodiment;

[0026] Figure 4 Another structural schematic diagram of providing an insulating protective layer on the inner wall of the housing in this embodiment;

[0027] Figure 5 A partial cross-sectional view showing the insulating protective layer provided on the inner wall of the housing in this embodiment;

[0028] Figure 6 A cross-sectional view showing an insulating protective layer provided on the inner wall of the housing in this embodiment;

[0029] Figure 7 Another cross-sectional view showing the insulating protective layer provided on the inner wall of the housing in this embodiment.

[0030] Icons: 100 - Cell; 110 - Housing; 111 - Inner wall; 1111 - First inner wall; 1112 - Second inner wall; 1113 - Third inner wall; 1114 - Fourth inner wall; 112 - Inner bottom wall; 120 - Electrode assembly; 130 - End cap; 200 - Insulating protective layer; Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0033] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0034] In the description of this utility model, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the utility model product is usually placed during use, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0035] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0036] It should be noted that, where there is no conflict, the features in the embodiments of this utility model can be combined with each other.

[0037] The following describes in detail the overall structure, working principle, and technical effects of the battery cell 100 and battery provided by this utility model through embodiments and in conjunction with the accompanying drawings.

[0038] When the potential of the lithium-ion battery casing is less than 1.8V (VS*Li+ / Li), a current loop is formed between the casing, electrolyte, and negative electrode. The casing comes into contact with lithium ions in the electrolyte. At low potential, the casing undergoes an electrochemical reaction with lithium ions, and lithium is intercalated in the casing to form a lithium-aluminum alloy, which leads to the pulverization of the casing and corrosion and leakage of the casing 110.

[0039] For a lithium-ion battery casing to corrode, the following two conditions must be met: 1. Electron channel (short circuit), that is, the casing is short-circuited with the negative electrode, so that the casing potential is within its lithium intercalation potential range (the potential is low enough); 2. Ion channel (electrolyte), that is, the electrolyte is in contact with the inside of the casing.

[0040] To address the two conditions mentioned above: Firstly, related technologies insulate the battery cell casing by wrapping it with a blue film to prevent external short circuits. Secondly, related technologies reduce the risk of short circuits between the casing and the negative electrode by applying PET / PI tape to the exposed negative electrode and wrapping the cell with Mylar film for insulation protection. However, when wrapping the cell with Mylar film, to facilitate core assembly, an opening is usually designed at the bottom of the Mylar film, and the sides are sealed using an intermittent hot-melt process (not completely sealed to facilitate electrolyte outflow), with PET tape used to seal the bottom corners. However, in actual design, to maintain the battery's electrical performance (such as cycle performance), there is usually excess electrolyte after the electrode roll is fully wetted. At this point, the electrolyte flows out from the sides and bottom of the Mylar film, remaining inside the casing and between the inner wall of the casing and the Mylar film. This means that the ion channels under battery corrosion conditions are not completely isolated, i.e., the electrolyte is in contact with the inside of the casing.

[0041] In summary, although the above solutions provide some protection against battery short circuits, various problems will inevitably arise during actual use. For example, if a metal foreign object punctures the blue film, it cannot prevent the formation of a current loop between the casing, electrolyte, and negative electrode, and the battery may still experience casing corrosion and leakage.

[0042] Therefore, please refer to Figure 1 This utility model proposes a battery cell 100 and a battery, which can be used in a battery to isolate the casing 110 from the electrolyte and prevent the formation of a current loop between the casing 110 and the electrolyte.

[0043] The battery proposed in this utility model can be a single cell or a battery module; wherein, a single cell includes a cell 100; wherein, a battery module includes multiple electrically connected cells 100 and a housing, and the multiple cells 100 are encapsulated in the housing.

[0044] Please refer to Figures 1-4The present invention proposes a battery cell 100, which includes a housing 110. The inner wall of the housing 110 includes an inner side wall 111 and an inner bottom wall 112. The inner side wall 111 and the inner bottom wall 112 are connected to form a receiving cavity, and the receiving cavity contains an electrolyte.

[0045] An insulating protective layer 200 is used to isolate the housing 110 from the electrolyte. An insulating protective layer 200 is provided on both the inner side wall 111 and the inner bottom wall 112. The insulating protective layer 200 on the inner side wall 111 is higher than the liquid level of the electrolyte.

[0046] Understandably, by setting an insulating protective layer 200, which is located on the inner sidewall 111 and inner bottom wall 112 of the housing 110, the insulating protective layer 200 isolates the housing 110 from the electrolyte. Firstly, the insulating protective layer 200 prevents the formation of ion channels, that is, it prevents the formation of a current loop between the housing 110 and the electrolyte. Secondly, the insulating protective layer 200 can also retain the electrolyte, reducing electrolyte loss and improving the cycle performance of the cell 100. Thirdly, the insulating protective layer 200 located on the inner sidewall 111 is higher than the electrolyte level, which can prevent electrolyte from splashing and contacting the housing 110 due to vibration during use. Furthermore, even if the electron channel is damaged during use, causing the housing 110 to short-circuit with the negative electrode, the housing 110-electrolyte-negative electrode current loop cannot be formed due to the different ion channels, thus preventing the battery housing 110 from being corroded and leaking.

[0047] In this embodiment, the battery cell 100 includes a housing 110, an electrode assembly 120, and an end cap 130.

[0048] In this embodiment, the inner wall of the housing 110 includes an inner side wall 111 and an inner bottom wall 112. The inner side wall 111 and the inner bottom wall 112 are connected to form a receiving cavity, which contains an electrolyte. The electrode assembly 120 is housed in the receiving cavity, and the end cap 130 is sealed to the open end of the housing 110. The tabs of the electrode assembly 120 are electrically connected to the posts of the end cap 130.

[0049] In this embodiment, the housing 110 can be a steel housing, an aluminum housing, or a composite metal housing (such as a copper-aluminum composite housing).

[0050] In this embodiment, please refer to Figure 1 Since cell 100 is a square cell 100, the casing 110 is also a square casing 110; please refer to... Figure 2The inner sidewall 111 of the housing 110 includes a first inner sidewall 1111, a second inner sidewall 1112, a third inner sidewall 1113 and a fourth inner sidewall 1114 connected in sequence. The bottom edges of the first inner sidewall 1111, the second inner sidewall 1112, the third inner sidewall 1113 and the fourth inner sidewall 1114 are connected to the four sides of the inner bottom wall 112.

[0051] Please refer to Figure 3 The first inner sidewall 1111 and the third inner sidewall 1113 are arranged opposite to each other, the first inner sidewall 1111 and the third inner sidewall 1113 are the short sides, and an insulating protective layer 200 is provided on the first inner sidewall 1111 and the third inner sidewall 1113.

[0052] The second inner sidewall 1112 and the fourth inner sidewall 1114 are arranged opposite to each other, and the second inner sidewall 1112 and the fourth inner sidewall 1114 are large surfaces and are not provided with an insulating protective layer 200.

[0053] Understandably, firstly, due to gravity, the electrolyte tends to accumulate at the bottom of the casing 110 inside the battery; therefore, if there is an electron channel (such as a short circuit) between the casing 110 and the negative electrode, the area of ​​the casing 110's inner bottom wall 112 in contact with the electrolyte will preferentially experience electrochemical corrosion. Secondly, since the casing 110 is usually formed by stamping and stretching, the first inner sidewall 1111, the third inner sidewall 1113, and the inner bottom wall 112 of the casing 110 suffer from lattice defects due to plastic deformation, resulting in high local internal stress, which easily becomes a corrosion initiation point. Thirdly, in square batteries, the tabs of the core are usually welded close to the first inner sidewall 1111 and the third inner sidewall 1113 in two directions. If the tab welding is poor or the insulating adhesive fails, the tab may directly contact the first inner sidewall 1111 and the third inner sidewall 1113 of the casing 110, forming an electron channel and leading to localized electrochemical corrosion. Therefore, by providing an insulating protective layer 200 on the inner bottom wall 112, the first inner side wall 1111, and the third inner side wall 1113, the formation of ion channels can be prevented, that is, the formation of a current loop between the shell 110 and the electrolyte can be prevented; at the same time, this arrangement can also save material costs.

[0054] In an optional embodiment, an insulating protective layer 200 is provided on the inner bottom wall 112, the first inner side wall 1111, and the third inner side wall 1113. Further, an insulating protective layer 200 is provided at the two corner areas of the first inner side wall 1111 and the second inner side wall 1112 and the fourth inner side wall 1114, and an insulating protective layer 200 is provided at the two corner areas of the third inner side wall 1113 and the second inner side wall 1112 and the fourth inner side wall 1114.

[0055] Understandably, since the shell 110 is typically formed by stamping and stretching, lattice defects and high local internal stress are caused by plastic deformation at the corners of the inner wall 111 and the corners between the inner wall 111 and the inner bottom wall 112, making them prone to corrosion initiation points. Therefore, an insulating protective layer 200 is provided at the corners of the inner wall 111 and the corners between the inner wall 111 and the inner bottom wall 112 of the shell 110 to prevent preferential corrosion of the shell 110 at these corners.

[0056] In an optional embodiment, please refer to Figure 4 An insulating protective layer 200 is provided on the first inner sidewall 1111, the second inner sidewall 1112, the third inner sidewall 1113, the fourth inner sidewall 1114 and the inner bottom wall 112.

[0057] Understandably, this setup further ensures the safety performance of the battery cell 100.

[0058] In one embodiment, the battery cell 100 is a cylindrical battery cell 100, therefore the housing 110 includes a cylindrical housing 110, the inner sidewall 111 of the housing 110 is a cylindrical inner sidewall 111, the circular bottom edge of the cylindrical inner sidewall 111 is connected to the circular outer edge of the inner bottom wall 112; both the cylindrical inner sidewall 111 and the inner bottom wall 112 are provided with an insulating protective layer 200.

[0059] In this embodiment, the battery cell 100 includes an insulating protective layer 200.

[0060] The insulating protective layer 200 is used to isolate the shell 110 from the electrolyte. The insulating protective layer 200 is provided on both the inner side wall 111 and the inner bottom wall 112. The insulating protective layer 200 on the inner side wall 111 is higher than the liquid level of the electrolyte.

[0061] In this embodiment, please refer to Figures 6-7 The height of the inner wall 111 is H. The electrolyte level is usually maintained at about 1 / 3 of the total height of the shell 110. Therefore, the electrolyte level is greater than 1 / 3H.

[0062] Alternatively, please refer to Figure 7 The height of the insulating protective layer 200 located on the inner sidewall 111 is greater than 1 / 2H.

[0063] Alternatively, please refer to Figure 6 The height of the insulating protective layer 200 located on the inner sidewall 111 is greater than or equal to 2 / 3H.

[0064] It is understandable that setting the height of the insulating protective layer 200 on the inner wall 111 to a height greater than 1 / 2H or greater than or equal to 2 / 3H not only avoids electrolyte splashing and contact between the electrolyte and the housing 110 due to vibration during use, but also saves material costs and improves the safety performance of the system.

[0065] In this embodiment, please refer to Figure 5 The thickness T of the insulating protective layer 200 is less than or equal to 1 mm. It is understandable that the gap between the core and the housing 110 is usually 5 mm. Setting the thickness T of the insulating protective layer 200 to less than or equal to 1 mm can ensure that the insulating protective layer 200 has a protective function, and can also ensure that the cell 100 does not have to sacrifice too much internal space to set the insulating protective layer 200.

[0066] In one embodiment, the insulating protective layer 200 is bonded and fixed to the inner sidewall 111 and the inner bottom wall 112.

[0067] Optionally, the insulating protective layer 200 includes any one of polyester film tape, polyimide tape, polytetrafluoroethylene tape, and polyetheretherketone tape.

[0068] In one embodiment, the insulating protective layer 200 is formed by coating on the inner sidewall 111 and the inner bottom wall 112.

[0069] The insulating protective layer 200 is coated onto the inner sidewall 111 and the inner bottom wall 112 by means of spraying, coating or other processes.

[0070] Optionally, the insulating protective layer 200 includes at least one of acrylic resin insulating protective layer, polyurethane resin insulating protective layer, and epoxy resin insulating protective layer.

[0071] It is understandable that the two methods proposed above for providing an insulating protective layer 200 to the inner wall of the casing 110 can be selected according to the actual situation. Furthermore, the insulating protective layer 200 made of the aforementioned material not only provides insulation and protection but also has the property of being resistant to electrolytes. It is insoluble in electrolytes and will not swell within the electrolyte, thus avoiding any impact on the battery.

[0072] Example 1:

[0073] Referring to Table 1, prepare the test sample. The inner wall of the housing 110 does not have an insulating protective layer 200. Before filling with electrolyte, test the AC resistance from the negative electrode to the housing 110. At this time, it will show 0Ω.

[0074] After adding electrolyte to a height of about 1 / 3H inside cell 100, it was sealed and left to stand for 30 days. The AC internal resistance from the negative electrode to the casing 110 was tested and found to be 50Ω.

[0075] Example 2:

[0076] Referring to Table 1, test samples were prepared. An acrylic resin insulating protective layer was sprayed onto the inner wall of the housing 110. Before the electrolyte was filled, the AC resistance from the negative electrode to the housing 110 was tested, and it was shown as 0Ω.

[0077] After adding electrolyte to a height of about 1 / 3H inside cell 100, it was sealed and left to stand for 30 days. The AC internal resistance from the negative electrode to the casing 110 was tested and found to be 20MΩ.

[0078] Example 3:

[0079] Referring to Table 1, prepare the test sample. Adhere and fix the polyester film tape to the inner wall of the housing 110. Before filling with electrolyte, test the AC resistance from the negative electrode to the housing 110. At this time, it will show 0Ω.

[0080] After adding electrolyte to a height of about 1 / 3H inside cell 100, it was sealed and left to stand for 30 days. The AC internal resistance from the negative electrode to the casing 110 was tested and found to be 100KΩ.

[0081]

[0082] Table 1

[0083] Referring to Table 1, and summarizing Examples 1-3 above, it can be seen that after adding electrolyte to the cell 100 to a height of approximately 1 / 3H and sealing it for 30 days, the AC internal resistance from the negative electrode to the casing 110 changes. The casing 110 in Example 1 has the lowest AC internal resistance, while the casing 110 with the acrylic resin insulating protective layer 200 sprayed in Example 2 has the highest internal resistance. Therefore, it is shown that both spraying and coating the insulating protective layer 200 onto the inner wall of the casing 110 and pasting the insulating protective layer 200 can, to a certain extent, prevent the electrolyte from contacting the casing 110 and prevent the formation of ion channels.

[0084] In summary, the battery cell 100 and battery provided in this embodiment of the present invention, by providing an insulating protective layer 200, which is disposed on the inner sidewall 111 and the inner bottom wall 112 of the housing 110, isolate the housing 110 from the electrolyte. Firstly, the insulating protective layer 200 prevents the formation of ion channels, i.e., prevents the formation of a current loop between the housing 110 and the electrolyte. Secondly, the insulating protective layer 200 can also retain the electrolyte, reducing electrolyte loss. To improve the cycle performance of the cell 100, the insulating protective layer 200 on the inner wall 111 is higher than the electrolyte level, which can prevent electrolyte from splashing and coming into contact with the casing 110 due to vibration during use. Furthermore, even if the electronic channel is damaged during use, causing the casing 110 to short-circuit with the negative electrode, the casing 110-electrolyte-negative electrode current loop cannot be formed due to the different ion channels, thus preventing the battery casing 110 from being corroded and leaking.

[0085] The above are merely specific embodiments of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model.

Claims

1. A battery cell, characterized in that, Includes: a housing, the inner wall of which includes an inner side wall and an inner bottom wall, the inner side wall and the inner bottom wall being connected to form a receiving cavity, the receiving cavity containing an electrolyte; An insulating protective layer is provided to isolate the housing from the electrolyte. The insulating protective layer is provided on both the inner sidewall and the inner bottom wall. The insulating protective layer on the inner sidewall is higher than the liquid level of the electrolyte. The inner sidewall of the shell includes a first inner sidewall, a second inner sidewall, a third inner sidewall, and a fourth inner sidewall connected in sequence. The bottom edges of the first inner sidewall, the second inner sidewall, the third inner sidewall, and the fourth inner sidewall are connected to the four sides of the inner bottom wall. The first inner sidewall and the third inner sidewall are arranged opposite to each other, and the second inner sidewall and the fourth inner sidewall are arranged opposite to each other. The second inner sidewall and the fourth inner sidewall are large surfaces. The insulating protective layer is provided on the first inner sidewall and the third inner sidewall; the insulating protective layer is provided at the two corner areas of the first inner sidewall and the second inner sidewall and the fourth inner sidewall, and the insulating protective layer is provided at the two corner areas of the third inner sidewall and the second inner sidewall and the fourth inner sidewall.

2. The battery cell according to claim 1, characterized in that, The height of the inner wall is H, and the liquid level of the electrolyte is greater than 1 / 3H.

3. The battery cell according to claim 2, characterized in that, The height of the insulating protective layer located on the inner sidewall is greater than 1 / 2H; Alternatively, the height of the insulating protective layer located on the inner sidewall is greater than or equal to 2 / 3H.

4. The battery cell according to claim 1, characterized in that, The thickness of the insulating protective layer is less than or equal to 1 mm.

5. The battery cell according to claim 1, characterized in that, The insulating protective layer is bonded and fixed to the inner sidewall and the inner bottom wall.

6. The battery cell according to claim 5, characterized in that, The insulating protective layer includes any one of polyester film tape, polyimide tape, polytetrafluoroethylene tape, and polyetheretherketone tape.

7. The battery cell according to claim 1, characterized in that, The insulating protective layer is formed by coating on the inner sidewall and the inner bottom wall.

8. The battery cell according to claim 7, characterized in that, The insulating protective layer includes at least one of acrylic resin insulating protective layer, polyurethane resin insulating protective layer, and epoxy resin insulating protective layer.

9. The battery cell according to claim 1, characterized in that, The housing includes a square housing, and the second inner sidewall and the fourth inner sidewall are not provided with the insulating protective layer.

10. A battery, characterized in that, Includes the battery cell described in any one of claims 1-9.

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