Battery cell

Abstract

The utility model provides a battery cell. The battery cell comprises a shell; the electrode assembly is arranged in the shell; an insulating film wrapping the electrode assembly to insulate the electrode assembly; the insulating film comprises a bottom insulating layer and a plurality of side insulating layers, and the bottom insulating layer and the plurality of side insulating layers are arranged between the shell and the electrode assembly; the bottom supporting plate is arranged between the shell and the bottom insulating layer; positioning holes are formed in the bottom supporting plate and the bottom insulating layer, and the positioning holes of the bottom supporting plate and the bottom insulating layer are oppositely arranged; the coating film group is partially arranged between the shell and the side insulating layers and covers a gap formed between two adjacent side insulating layers; the part of the coating film group is also arranged between the shell and the bottom supporting plate and covers the positioning hole of the bottom supporting plate; according to the application, the coating film layers are additionally arranged on the insulating films and the bottom supporting plate, so that the gaps formed between the adjacent side insulating layers and the positioning holes of the bottom supporting plate can be shielded and blocked, the battery cell is prevented from being damaged due to short circuit between the electrode assembly and the shell, and the quality of the battery cell is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of battery cells, in particular to a battery cell. BACKGROUND

[0002] A battery cell is an important component of a battery; in general, the electrode assembly in the battery cell is wrapped by a Mylar film, and the Mylar film serves as the insulating film of the battery cell; the main principle is to isolate the electrode assembly and the shell by using the insulation and barrier properties of the Mylar film, so as to prevent the electrode assembly and the shell from being in direct contact and causing short circuit or mechanical damage; in order to improve the wrapping effect of the Mylar film on the electrode assembly, it is necessary to divide the Mylar film into a bottom insulating layer and a plurality of side insulating layers connected to each other, and when wrapping the electrode assembly, the plurality of side insulating layers are bent and folded, so that the plurality of side insulating layers respectively cover the surfaces of the electrode assembly and complete the wrapping process; since the plurality of side insulating layers are wrapped on different sides of the electrode assembly, there will be a gap between adjacent side insulating layers after folding; if the electrode assembly falls into the gap, it may cause short circuit between the electrode assembly and the shell and damage the battery cell, affecting the product quality of the battery cell. CONTENT OF THE UTILITY MODEL

[0003] Therefore, the purpose of the present application is to provide a battery cell to solve the above-mentioned technical problems.

[0004] In order to achieve the above purpose, the present application provides a battery cell, which comprises:

[0005] a shell;

[0006] an electrode assembly arranged in the shell;

[0007] an insulating film wrapped around the electrode assembly to insulate the electrode assembly; the insulating film comprises a bottom insulating layer and a plurality of side insulating layers, and the bottom insulating layer and the plurality of side insulating layers are arranged between the shell and the electrode assembly;

[0008] a bottom support plate arranged between the shell and the bottom insulating layer; the bottom support plate and the bottom insulating layer are both provided with positioning holes, and the positioning holes of the two are oppositely arranged;

[0009] a wrapping film set, part of the wrapping film set is arranged between the shell and the side insulating layer and covers the gap formed between the adjacent two side insulating layers; part of the wrapping film set is also arranged between the shell and the bottom support plate and covers the positioning hole of the bottom support plate.

[0010] From the above, it can be seen that the electric core provided by the application, the gap formed between the two adjacent side insulation layers and the positioning hole of the bottom supporting plate are shielded and plugged by the covering film set, the blocking effect of the insulation film between the shell and the motor assembly is improved, the material of the falling pole piece is prevented from entering the gap or the positioning hole to form a microcircuit and cause the short circuit of the electric core, the quality of the electric core is improved, and the service life of the electric core is prolonged. BRIEF DESCRIPTION OF DRAWINGS

[0011] In order to more clearly illustrate the technical solutions in the application or related art, the drawings needed to be used in the embodiments or related art description will be briefly introduced. Obviously, the drawings in the following description are only embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0012] Figure 1 It is a structural schematic diagram of the electric core;

[0013] Figure 2 It is a schematic diagram of the insulation film;

[0014] Figure 3 It is a side view of the insulation film on the surface of the electrode assembly;

[0015] Figure 4 It is a schematic diagram of the connection relationship between the bottom supporting plate and the insulation film;

[0016] Figure 5 It is a protective schematic diagram of the gap formed between the two adjacent side insulation layers;

[0017] Figure 6 It is a protective schematic diagram of the insulation film and the bottom supporting plate by the covering film set;

[0018] Figure 7 It is an explosion schematic diagram of the covering film set;

[0019] Figure 8 It is a schematic diagram of the position of the first covering layer on the insulation film;

[0020] Figure 9 It is a schematic diagram of the connection relationship between the second covering layer and the bottom supporting plate;

[0021] Figure 10A It is a structural schematic diagram of the first covering layer;

[0022] Figure 10B It is a structural schematic diagram of the second covering layer;

[0023] Figure 11A It is a structural schematic diagram of the first second covering layer;

[0024] Figure 11B A schematic diagram of a first second cladding layer structure.

[0025] Reference signs:

[0026] 100, shell;

[0027] 200, electrode assembly;

[0028] 300, insulation film; 310, bottom insulation layer; 320, side insulation layer;

[0029] 400, bottom support plate; 401, positioning hole;

[0030] 500, cladding film set; 510, first cladding layer; 511, first cladding surface; 512, second cladding surface; 520, second cladding layer; 521, third cladding surface; 522, fourth cladding surface;

[0031] 600, top cover. DETAILED DESCRIPTION

[0032] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to specific embodiments and drawings.

[0033] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present application should be understood as the common meanings understood by those skilled in the art to which the embodiments of the present application belong. The terms “first”, “second” and similar terms used in the embodiments of the present application do not represent any order, number or importance, but are only used to distinguish different components. The terms “include” or “contain” and similar terms mean that the elements or objects before the terms cover the elements or objects listed after the terms and their equivalents, and do not exclude other elements or objects. The terms “connect” or “connected” and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms “upper”, “lower”, “left”, “right” and the like only represent relative positional relationships, and when the absolute positions of the described objects change, the relative positional relationships may also change accordingly.

[0034] The embodiments of the present application will be described in detail below with reference to the drawings.

[0035] With the rapid development of portable electronic devices, electric vehicles, and energy storage systems, the demand for battery modules such as lithium-ion batteries as efficient and reliable energy storage solutions is increasing. During the design and manufacturing process of the battery, the cell as a key component of the battery directly affects the overall performance and safety of the cell. The principle of energy storage of the cell is based on the electrode assembly 200 (including the positive electrode, negative electrode, and separator) inside the cell. Through the chemical reaction between the electrode sheet and the electrolyte, the conversion and storage of electrical energy are achieved. In order to ensure electrical insulation between the electrode assembly 200 and the shell 100 and prevent the electrode assembly 200 from being scratched by the edge of the shell 100 during assembly, which may cause short circuit and mechanical damage to the cell, Mylar film is usually used to wrap the electrode assembly 200 and serve as an insulating film 300 for the electrode assembly 200.

[0036] Mylar film is widely used in the packaging of cells due to its excellent insulation performance, mechanical strength, and thermal stability. Specifically, Figure 2 is a schematic view of the insulating film 300 in this application, Figure 3 is a side view of the insulating film 300 on the surface of the electrode assembly 200, as Figure 2 and Figure 3 shown, when the insulating film 300 is made of Mylar film, the insulating film 300 can be divided into a bottom insulating layer 310 and a side insulating layer 320. The bottom insulating layer 310 is used to protect the bottom of the electrode assembly 200, while the side insulating layer 320 is responsible for wrapping the four sides of the electrode assembly 200 to ensure complete isolation of the electrode assembly 200 from the shell 100. During the packaging process of the cell, in order to improve the wrapping effect of the insulating film 300 on the electrode assembly 200, the side insulating layer 320 of the insulating film 300 needs to be accurately folded and gathered towards the side of the electrode assembly 200, so that multiple side insulating layers 320 are tightly attached to each side of the electrode assembly 200, completing the final wrapping process and ensuring good safety and reliability of the cell.

[0037] However, in actual practice, due to the multi-region structure of the insulating film 300 and the complex folding process, a gap may be formed between adjacent side insulating layers 320 covering the surface of the electrode assembly 200, which may become a potential safety hazard for the cell. Especially after a long period of charge and discharge cycles, the electrode sheet material (such as active material or conductive agent particles) in the electrode assembly 200 may fall off due to vibration or other factors and accidentally enter the gap. The fallen electrode sheet material may connect with the electrode assembly 200 and the shell 100 respectively and form a microcircuit. Once this happens, it may cause a short circuit between the electrode assembly 200 and the shell 100, leading to a decrease in the performance of the cell or damage to the cell, and even causing thermal runaway of the cell, affecting the quality and service life of the cell.

[0038] Furthermore, in the battery cell, a bottom support plate 400 is provided between the bottom of the bottom insulating layer 310 of the insulating film 300 and the bottom of the housing 100. The bottom insulating layer 310 covers the bottom support plate 400 in its orthogonal projection, so that the bottom insulating layer 310 is supported and protected by the bottom support plate 400; wherein, Figure 4 This is a schematic diagram showing the connection relationship between the base plate 400 and the insulating film 300, as shown below. Figure 4 As shown, the bottom support plate 400 and the bottom insulating layer 310 are respectively provided with positioning holes 401 for positioning the bottom insulating layer 310 and the bottom support plate 400, and can be connected by heat fusion. When the electrode material in the electrode assembly 200 falls off, the electrode material in the electrode assembly 200 may also accidentally enter the positioning hole 401, thereby forming a microcircuit between the electrode assembly 200 and the housing 100 support and causing a short circuit. This will also lead to a decrease in cell performance, damage and thermal runaway.

[0039] In some embodiments, Figure 5 A schematic diagram illustrating the protection of the gap formed between two adjacent side insulation layers 320, as shown below. Figure 5 As shown, the insulating film 300 and the base plate 400 are covered with a whole sheet of encapsulating film (not shown in the figure). This whole sheet of encapsulating film covers the bottom corner area of ​​the insulating film 300 away from the top cover 600, so that the whole sheet of encapsulating film covers the base plate 400 and the surface of multiple side insulating layers 320. This allows the whole sheet of encapsulating film to shield and seal the gaps formed between the positioning holes 401 of the base plate 400 and adjacent side insulating layers 320, preventing the formation of microcircuits between the electrode assembly 200 and the housing 100 through detached electrode material; Figure 5 As shown, when using a full-sheet covering layer, it is necessary to first cover one side of the insulating film 300 assembly, then fold it horizontally to wrap the adjacent side insulating layer 320, and then fold the side insulating layer 320 towards the bottom and cover the bottom of the base plate 400. Because there is a gap between the insulating film 300 and the cell assembly, the insulating film 300 is always in a fluffy state, making it difficult to cover and difficult to cover the electrode assembly 200 tightly. Because the full-sheet covering film has a single-sided adhesive layer, when the full-sheet covering layer is covered on the insulating film 300 and the base plate 400, some areas of the full-sheet covering layer are not completely adhered to the surface of the base plate 400, so there is a risk of unfolding or falling off.

[0040] In view of this, the application provides an electric core, which comprises a shell 100, an electrode assembly 200, an insulating film 300, a bottom supporting plate 400 and a wrapping film set 500; the electrode assembly 200 is arranged in the shell 100; the insulating film 300 is wrapped on the electrode assembly 200 to insulate the electrode assembly 200; the insulating film 300 comprises a bottom insulating layer 310 and a plurality of side insulating layers 320, and the bottom insulating layer 310 and the plurality of side insulating layers 320 are arranged between the shell 100 and the electrode assembly 200; the bottom supporting plate 400 is arranged between the shell 100 and the bottom insulating layer 310, and the bottom supporting plate 400 and the bottom insulating layer 310 are both provided with positioning holes 401, and the positioning holes 401 of the two are oppositely arranged; part of the wrapping film set 500 is arranged between the shell 100 and the side insulating layer 320 and covers the gap formed between the adjacent two side insulating layers 320; part of the wrapping film set 500 is also arranged between the shell 100 and the bottom supporting plate 400 and covers the positioning hole 401 of the bottom supporting plate 400.

[0041] Specifically, please refer to Figure 1 、 Figure 6 and Figure 7 , Figure 1 is a structural schematic view of the electric core, Figure 6 is a protective schematic view of the wrapping film set 500 on the insulating film 300 and the bottom supporting plate 400, Figure 7 is an explosion schematic view of the wrapping film set 500.

[0042] The application provides an electric core, as shown in Figure 1 、 Figure 2 、 Figure 6 and Figure 7 , which comprises a shell 100, an electrode assembly 200, an insulating film 300 and a bottom supporting plate 400; wherein the electrode assembly 200, the insulating film 300 and the bottom supporting plate 400 are all arranged in the shell 100, and the shell 100 can be used to contain and protect the electrode assembly 200, the insulating film 300 and the bottom supporting plate 400; the electrode assembly 200 is arranged in the shell 100 and can be formed by a positive electrode, a negative electrode and a separator, and is used to realize the input and output of electric energy.

[0043] As for the insulating film 300, the insulating film 300 is wrapped on the bottom and the entire side surface of the electrode assembly 200, and when the electrode assembly 200 is assembled in the shell 100, the insulating film 300 can not only shield and protect the surface of the electrode assembly 200, but also realize electrical insulation; specifically, as shown in Figure 2As shown, the insulation film 300 includes a bottom insulation layer 310 and side insulation layers 320, the bottom insulation layer 310 is arranged between the shell 100 and the electrode assembly 200, and is used to wrap and cover the bottom of the electrode assembly 200; the side insulation layers 320 are arranged in multiple, and when the side insulation layers 320 are folded towards the side of the electrode assembly 200, the side insulation layers 320 can cover the side of the electrode assembly 200 to protect the side of the electrode assembly 200; for example, when the battery cell is a square shell battery cell, four side insulation layers 320 can be arranged in the insulation film 300, and the two oppositely arranged side insulation layers 320 can be arranged in the same shape.

[0044] As for the bottom support plate 400, the bottom support plate 400 is arranged between the shell 100 and the bottom insulation layer 310, and the area of the bottom support plate 400 is less than or equal to the area of the bottom insulation layer 310, which is used to support and protect the bottom insulation layer 310, can strengthen the blocking effect between the bottom of the electrode assembly 200 and the bottom of the shell 100, prevent the short circuit or damage caused by the contact between the electrode assembly 200 and the foreign matter existing in the shell 100, and ensure the quality of the battery cell; at the same time, the bottom insulation layer 310 of the insulation film 300 and the bottom support plate 400 are both provided with positioning holes 401, and the positioning holes 401 of the two are oppositely arranged to accurately connect the bottom support plate 400 and the bottom insulation layer 310.

[0045] In addition, the battery cell provided by the application also includes a cladding film group 500; as shown in Figure 6 and Figure 7 As shown, part of the cladding film group 500 can be arranged between the shell 100 and the side insulation layer 320, and part can be arranged between the shell 100 and the bottom support plate 400; wherein the part of the cladding film group 500 arranged between the shell 100 and the side insulation layer 320 can be connected with at least two adjacent side insulation layers 320, and can cover the gap formed between the two adjacent side insulation layers 320, so as to block and shield the gap formed between the two connected side insulation layers 320; similarly, the part of the cladding film group 500 arranged between the shell 100 and the bottom support plate 400 can be connected with the bottom support plate 400, so that the cladding film group 500 can cover the positioning hole 401 of the bottom support plate 400 and block it, thereby realizing the blocking between the electrode assembly 200 and the shell 100, preventing the material of the falling electrode sheet from causing the short circuit of the electrode assembly 200 and the shell 100, reducing the risk of thermal runaway of the battery cell, improving the product quality of the battery cell, and prolonging the service life of the battery cell.

[0046] In addition, the cladding film group 500 can be fixed on the surface of the insulating film 300 and the bottom support plate 400 by adhesion, improving the connection effect of the cladding film group 500 on the insulating film 300 and the bottom support plate 400. Since the cladding film group 500 can cover the side insulation layer 320 of the insulating film 300 and the bottom support plate 400, the firmness of the connection between the bottom support plate 400 and the insulating film 300 can be improved. Under the action of the cladding film group 500, the bottom support plate 400 can be in full contact with the bottom insulation layer 310, and the bottom insulation layer 310 can be tightly pressed against the bottom of the battery cell, which is conducive to reducing the fluffiness of the bottom of the insulating film 300 and improving the tightness of the insulating film 300 wrapping the electrode assembly 200.

[0047] It should be noted that the shell 100 is further described in combination with the above embodiments. For example, the shell 100 can be made of aluminum or aluminum alloy, which has light weight and high strength. In order to further enhance the insulation effect inside the shell 100, the inner side wall of the shell 100 can be coated with at least one layer of insulating surface by coating process, which can enhance the insulation effect of the shell 100, reduce the corrosion of the electrolyte on the shell 100, and improve the quality of the battery cell.

[0048] In some embodiments, the cladding film group 500 includes a first cladding layer 510. The first cladding layer 510 is arranged between the shell 100 and the side insulation layer 320. The first cladding layer 510 covers at least two side insulation layers 320, and the gap formed between the adjacent two side insulation layers 320.

[0049] Specifically, referring to Figure 8 , Figure 8 is a schematic view of the connection relationship between the first cladding layer 510 and the insulating film 300.

[0050] As for the cladding film group 500, part of the cladding film group 500 is arranged between the shell 100 and the side insulation layer 320, which is used to cover the gap formed between the adjacent two side insulation layers 320 to prevent the electrode assembly 200 and the shell 100 from short-circuiting through the material of the pole piece in the gap. Figures 6-8 As shown in the figure, the cladding film group 500 can include a first cladding layer 510 arranged in the shell 100 and the side insulation layer 320 support, so that the first cladding layer 510 can span the adjacent two side insulation layers 320 and correspondingly cover the surface thereof, thereby shielding and plugging the gap formed between the adjacent two side insulation layers 320, preventing the material of the pole piece of the electrode assembly 200 from entering the gap and causing the battery cell to short-circuit, and improving the quality of the battery cell.

[0051] In some embodiments, along the height direction of the electrode assembly 200, the height of the first cladding layer 510 is greater than the height of the gap formed between the adjacent two side insulation layers 320.

[0052] In terms of the first cladding layer 510, by applying the first cladding layer 510 in the battery cell, the gap formed between the two adjacent side insulation layers 320 can be shielded and plugged, so as to avoid the material of the electrode tab of the electrode assembly 200 from falling off and entering the gap, thereby causing the short circuit between the electrode assembly 200 and the shell 100, avoiding the damage of the battery cell, and reducing the risk of thermal runaway of the battery cell. In the height direction of the electrode assembly 200, the height of the first cladding layer 510 can be set to be greater than the height of the gap formed between the two adjacent side insulation layers 320, so as to ensure the sufficient plugging effect of the first cladding layer 510 on the gap formed between the two adjacent side insulation layers 320.

[0053] Exemplarily, when the height of the gap formed between the two adjacent side insulation layers 320 is 12.5 mm, in the height direction of the electrode assembly 200, the height of the first cladding layer 510 can be set to be greater than 12.5 mm, such as 13 mm or 14 mm, so as to plug the gap formed between the two adjacent side insulation layers 320.

[0054] In some embodiments, the first cladding layer 510 includes two first cladding surfaces 511, and the two first cladding surfaces 511 are connected and arranged in cross. The two first cladding surfaces 511 are both parallel to the height direction of the electrode assembly 200 and respectively cover the two adjacent side insulation layers 320. The connection area of the two first cladding surfaces 511 corresponds to the gap formed between the two adjacent side insulation layers 320.

[0055] Specifically, please refer to Figure 10A , Figure 10A for the structural schematic diagram of the first cladding layer.

[0056] In terms of the first cladding layer 510, the first cladding layer 510 can plug the gap formed between the two adjacent side insulation layers 320, so as to prevent the short circuit or damage of the battery cell; for example, Figure 10AAs shown, the first cladding layer 510 can include two first cladding surfaces 511, which are connected and cross arranged, so that the two first cladding surfaces 511 can be arranged in parallel to the height direction of the electrode assembly 200, and can cover the adjacent two side insulation layers 320 respectively, so that the first cladding surfaces 511 correspond to the surfaces of the side insulation layers 320 to be bonded; in a plane perpendicular to the height direction of the electrode assembly 200, the cross section of the first cladding layer 510 formed by the two first cladding surfaces 511 in the plane can be L-shaped; since a gap can be formed between the adjacent two side cladding layers, when the two first cladding layers 510 cover the adjacent two side insulation layers 320, the connecting area of the two first cladding surfaces 511 can correspond to cover the gap formed between the adjacent two side insulation layers 320, thereby achieving the plugging of the gap; and since one first cladding layer 510 corresponds to one gap, it has good independence, avoiding the material of the electrode sheet falling into the gap to cause the shell 100 and the electrode assembly 200 to be short-circuited.

[0057] Exemplarily, when the battery cell is a square shell battery cell, the insulation film 300 wrapped around the square shell battery cell has four gaps, and each gap can be covered by one first cladding layer 510, so four first cladding layers 510 can be used, which will not be described here.

[0058] In some embodiments, the first cladding layer 510 further includes a second cladding surface 512, one of the two first cladding surfaces 511 is connected and cross arranged with the second cladding surface 512, and the other is parallel to the second cladding surface 512; the side insulation layer 320 covered by the first cladding surface 511 parallel to the second cladding surface 512 is arranged opposite to the side insulation layer 320 covered by the second cladding surface 512; the connecting area between the first cladding surface 511 and the second cladding surface 512 and the connecting area between the two first cladding surfaces 511 cover at least one gap formed between the adjacent three side insulation layers 320.

[0059] As for the first cladding layer 510, it can also plug the gap formed between the adjacent three side insulation layers 320 to prevent the battery cell from being short-circuited or damaged; specifically, as shown in FIG. 6, the first cladding layer 510 can include two first cladding surfaces 511, which are connected and cross arranged, so that the two first cladding surfaces 511 can be arranged in parallel to the height direction of the electrode assembly 200, and can cover the adjacent two side insulation layers 320 respectively, so that the first cladding surfaces 511 correspond to the surfaces of the side insulation layers 320 to be bonded; in a plane perpendicular to the height direction of the electrode assembly 200, the cross section of the first cladding layer 510 formed by the two first cladding surfaces 511 in the plane can be L-shaped; since a gap can be formed between the adjacent two side cladding layers, when the two first cladding layers 510 cover the adjacent two side insulation layers 320, the connecting area of the two first cladding surfaces 511 can correspond to cover the gap formed between the adjacent two side insulation layers 320, thereby achieving the plugging of the gap; and since one first cladding layer 510 corresponds to one gap, it has good independence, avoiding the material of the electrode sheet falling into the gap to cause the shell 100 and the electrode assembly 200 to be short-circuited. Figure 10BAs shown, the first cladding layer 510 includes a second cladding surface 512 in addition to the two first cladding surfaces 511; one of the two first cladding surfaces 511 is connected and arranged transversely to the second cladding surface 512, and the other is parallel to the second cladding surface 512, so that the second cladding surface 512 and the two first cladding surfaces 511 can cover and bond to the three adjacent side insulation layers 320, respectively; at the same time, since the side insulation layer 320 covered by the second cladding surface 512 is arranged opposite to the side insulation layer 320 covered by the first cladding surface 511 parallel to the second cladding surface 512, the cross section of the first cladding layer 510 in a plane perpendicular to the height direction of the electrode assembly 200 can be U-shaped; and for the three adjacent side insulation layers 320, the three adjacent side insulation layers 320 can form one or two gaps, so that when the first cladding layer 510 covers the three adjacent side insulation layers 320, the connection area between the first cladding surface 511 and the second cladding surface 512 and the connection area between the two first cladding surfaces 511 can cover at least one gap formed between the three adjacent side insulation layers 320, i.e., the first cladding layer 510 can cover one gap or two gaps, thereby achieving the plugging of the gap; when the first cladding layer 510 simultaneously plugs two gaps, the utilization rate of the first cladding layer 510 can be improved to avoid the material of the electrode sheet falling into the gap and causing short circuit between the shell 100 and the electrode assembly 200.

[0060] For example, when the battery cell is a square shell battery cell, the insulation film 300 wrapped around the square shell battery cell has four gaps, and adjacent two of the four gaps can be shielded and covered by the first cladding layer 510, so two first cladding layers 510 can be used, which will not be described here.

[0061] In addition, for the first cladding layer 510, in a plane perpendicular to the height direction of the electrode assembly 200, by setting the cross section of the first cladding layer 510 as U-shaped or L-shaped, the bonding effect of the first cladding layer 510 on the surface of the side insulation layer 320 can be improved, avoiding the unfolding or falling off of the first cladding layer 510 due to insufficient adhesion, and ensuring the plugging effect of the first cladding layer 510 on the gap formed between the two adjacent side insulation layers 320.

[0062] In some embodiments, the cladding film set 500 further includes a second cladding layer 520; at least part of the second cladding layer 520 is located between the shell 100 and the bottom support plate 400, and covers the positioning hole 401 of the bottom support plate 400; the orthographic projection of the bottom support plate 400 on the second cladding layer 520 at least partially coincides with the second cladding layer 520, and the orthographic projection of the positioning hole 401 of the bottom support plate 400 on the second cladding layer 520 is located in the second cladding layer 520.

[0063] Specifically, please refer toFigure 9 , Figure 9 FIG. 4 is a schematic diagram of the connection relationship between the second cladding layer 520 and the bottom support plate 400.

[0064] In terms of the cladding film set 500, in addition to plugging the gap between the two adjacent side insulation layers 320, the cladding film set 500 can also plug the positioning hole 401 of the bottom support plate 400, so as to avoid the material of the electrode assembly 200 falling off from entering the positioning hole 401 and forming a microcircuit with the electrode assembly 200 and the shell 100; as shown in FIGS. 5 and 6, the cladding film set 500 further includes a second cladding layer 520, and the second cladding layer 520 is arranged between the shell 100 and the bottom support plate 400, and is arranged in the height direction of the shell 100, so that the second cladding layer 520 can fully cover the bottom of the bottom support plate 400, so as to ensure the covering effect of the second cladding layer 520 on the surface of the bottom support plate 400; at the same time, by arranging the bottom support plate 400 in the orthographic projection of the second cladding layer 520 and at least partially overlapping the second cladding layer 520, the orthographic projection of the positioning hole 401 of the bottom support plate 400 in the second cladding layer 520 is located in the second cladding layer 520, so as to ensure that the second cladding layer 520 fully covers the positioning hole 401 of the bottom support plate 400, thereby achieving the positioning shielding and plugging, so as to avoid the material of the electrode assembly 200 falling off from entering the positioning hole 401 and causing the short circuit between the electrode assembly 200 and the shell 100. Figure 6 , Figure 7 and Figure 9 As shown in FIGS. 5 and 6, the cladding film set 500 further includes a second cladding layer 520, and the second cladding layer 520 is arranged between the shell 100 and the bottom support plate 400, and is arranged in the height direction of the shell 100, so that the second cladding layer 520 can fully cover the bottom of the bottom support plate 400, so as to ensure the covering effect of the second cladding layer 520 on the surface of the bottom support plate 400; at the same time, by arranging the bottom support plate 400 in the orthographic projection of the second cladding layer 520 and at least partially overlapping the second cladding layer 520, the orthographic projection of the positioning hole 401 of the bottom support plate 400 in the second cladding layer 520 is located in the second cladding layer 520, so as to ensure that the second cladding layer 520 fully covers the positioning hole 401 of the bottom support plate 400, thereby achieving the positioning shielding and plugging, so as to avoid the material of the electrode assembly 200 falling off from entering the positioning hole 401 and causing the short circuit between the electrode assembly 200 and the shell 100.

[0065] In some embodiments, the bottom support plate 400 is provided with a plurality of groups of positioning holes 401, and each group of positioning holes 401 is provided with two positioning holes; along the extension direction of the line connecting the two positioning holes 401 in each group, the width of the second cladding layer 520 is greater than the distance between the two positioning holes 401 in each group and less than or equal to the width of the bottom support plate 400.

[0066] As for the second cladding layer 520, by covering part of the second cladding layer 520 on the bottom supporting plate 400, the second cladding layer 520 can block and shield the positioning hole 401 of the bottom supporting plate 400, so as to avoid the material of the falling pole piece from entering the positioning hole 401 and causing short circuit between the electrode assembly 200 and the shell 100; wherein the bottom supporting plate 400 can be provided with multiple groups of positioning holes 401, and each group of positioning holes 401 can be provided with two, along the extension direction of the connecting line between the two positioning holes 401 in each group, by making the width of the second cladding layer 520 greater than the distance between the two positioning holes 401 in each group, the second cladding layer 520 can fully cover the positioning hole 401, so as to ensure the blocking effect of the positioning hole 401 and prevent short circuit between the electrode assembly 200 and the shell 100; and by making the width of the second cladding layer 520 less than or equal to the width of the bottom supporting plate 400, the second cladding layer 520 can be fully covered on the surface of the bottom supporting plate 400, so as to reduce the risk of unfolding and falling of the second cladding layer 520.

[0067] In some embodiments, the second cladding layer 520 includes two third cladding surfaces 521, and the two third cladding surfaces 521 are connected and arranged in cross; one of the two third cladding surfaces 521 is parallel to the height direction of the electrode assembly 200 and covers one side of the insulating layer 320; and the other is perpendicular to the height direction of the electrode assembly 200 and covers the bottom supporting plate 400 and the positioning hole 401 of the bottom supporting plate 400.

[0068] Specifically, please refer to Figure 11A , Figure 11A for the first structure diagram of the second cladding layer.

[0069] As for the second cladding layer 520, the second cladding layer 520 can cover part of the bottom supporting plate 400 and can block the positioning hole 401 on the bottom supporting plate 400 to prevent short circuit or damage of the battery cell; for example Figure 11AAs shown, the second cladding layer 520 can include two third cladding surfaces 521 connected to each other, and the two third cladding surfaces 521 are connected to and cross each other, so that one of the two third cladding surfaces 521 is arranged perpendicular to the height direction of the electrode assembly 200, and the other is arranged parallel to the height direction of the electrode assembly 200; at this time, in a plane parallel to the height direction of the electrode assembly 200, the second cladding layer 520 formed by the two third cladding surfaces 521 can have an L-shaped cross section in the plane; since the base plate 400 is provided with the positioning hole 401, one of the two third cladding surfaces 521 can cover the side insulation layer 320, and the other can cover the base plate 400 and the positioning hole 401 of the base plate 400, so as to not only improve the firmness between the base plate 400 and the insulation film 300, but also seal the positioning hole 401 of the base plate 400, so as to avoid that the material of the electrode plate falls into the positioning hole 401 and causes the shell 100 and the electrode assembly 200 to be short-circuited.

[0070] In some embodiments, the second cladding layer 520 further includes a fourth cladding surface 522, and one of the two third cladding surfaces 521 is connected to and crosses the fourth cladding surface 522, and the other is parallel to the fourth cladding surface 522; the side insulation layer 320 covered by the third cladding surface 521 parallel to the fourth cladding surface 522 is arranged opposite to the side insulation layer 320 covered by the fourth cladding surface 522.

[0071] Specifically, referring to Figure 11B , Figure 11B is a structural schematic view of the second cladding layer 520.

[0072] As for the second cladding layer 520, the second cladding layer 520 can cover part of the base plate 400, and can seal the positioning hole 401 of the base plate 400, so as to prevent the battery cell from being short-circuited or damaged; specifically, as shown Figure 11B , in addition to the third cladding surface 521, the second cladding layer 520 can further include a fourth cladding surface 522 connected to one of the two third cladding surfaces 521, wherein one of the two third cladding surfaces 521 is cross-connected to the fourth cladding surface 522, and the other is parallel to the fourth cladding surface 522, so that the side insulation layer 320 covered by the fourth cladding surface 522 is arranged opposite to the side insulation layer 320 covered by the third cladding surface 521; at this time, in a plane parallel to the height direction of the electrode assembly 200, the second cladding layer 520 formed by the two third cladding surfaces 521 and the fourth cladding surface 522 can have a U-shaped cross section in the plane, so as to not only improve the firmness between the base plate 400 and the insulation film 300, but also seal the positioning hole 401 of the base plate 400, so as to avoid that the material of the electrode plate falls into the positioning hole 401 and causes the shell 100 and the electrode assembly 200 to be short-circuited.

[0073] In addition, for the second covering layer 520, in a plane parallel to the height direction of the electrode assembly 200, by setting the cross section of the second covering layer 520 to be U-shaped or L-shaped, the adhesion effect of the second covering layer 520 on the surface of the side insulation layer 320 and the bottom support plate 400 can be achieved, and the second covering layer 520 can be prevented from being unfolded or falling off due to insufficient adhesion or the presence of an unadhered area of the second covering layer 520, thereby ensuring the plugging effect of the second covering layer 520 on the positioning hole 401 of the bottom support plate 400.

[0074] In combination with the above embodiments, the first covering layer 510 and the second covering layer 520 are further described. The first covering layer 510 and the second covering layer 520 can each be an insulating adhesive tape having an adhesive layer on one side. For example, when the first covering layer 510 covers the surface of the side insulation layer 320, the first covering layer 510 can be adhered to the surface of the side insulation layer 320 through the adhesive layer to improve the firmness of the connection between the first covering layer 510 and the side insulation layer 320. Similarly, when the second covering layer 520 covers the bottom of the bottom support plate 400, the second covering layer 520 can be adhered to the surface of the bottom support plate 400 through the adhesive layer to improve the firmness of the connection between the second covering layer 520 and the bottom support plate 400, and no further description is provided herein.

[0075] In some embodiments, the covering film set 500 is provided with an exhaust hole (not labeled in the figure), and the gap formed between two adjacent side insulation layers 320 and the positioning hole 401 of the bottom support plate 400 do not overlap with the normal projection of the covering film set 500 and the exhaust hole.

[0076] For the film set 500, part of the film set 500 covers the surface of the side insulation layer 320, used to seal the gap formed between the two adjacent side insulation layers 320, and part of the film set 500 covers the bottom of the bottom support plate 400, used to cover the positioning hole 401 of the bottom support plate 400; since the film set 500 includes the first covering layer 510 and the second covering layer 520, when the first covering layer 510 covers the surface of the side insulation layer 320, if there is a bubble between the first covering layer 510 and the side insulation layer 320, it will affect the firmness of the first covering layer 510 on the side insulation layer 320; therefore, by providing an exhaust hole in the first covering layer 510, and making the gap formed between the two adjacent side insulation layers 320 not coincide with the exhaust hole in the orthographic projection of the film set 500, the bulging probability of the connected first covering layer 510 can be reduced, and the firmness and flatness of the first covering layer 510 connected to the side insulation layer 320 can be improved; similarly, when the second covering layer 520 covers the surface of the bottom support plate 400, if there is a bubble between the second covering layer 520 and the bottom support plate 400, it will affect the firmness of the second covering layer 520 on the bottom support plate 400, therefore, by providing an exhaust hole in the second covering layer 520, and making the positioning hole 401 of the bottom support plate 400 not coincide with the exhaust hole in the orthographic projection of the film set 500, the bulging probability of the connected second covering layer 520 can be reduced, and the firmness and flatness of the second covering layer 520 connected to the bottom support plate 400 can be improved.

[0077] It should be noted that the above describes some embodiments of the present application. Other embodiments are within the scope of the appended claims. In some cases, the acts or steps recited in the claims can be performed in a different order than those described above and still achieve desirable results. Also, the processes depicted in the figures do not necessarily require the particular order shown or sequential order in order to achieve the desired results. In some implementations, multitasking and parallel processing can be advantageous.

[0078] Each of the embodiments in the present application is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be mutually referred to.

[0079] The description of the present application is given for example and description, and is not exhaustive or limits the present application to the disclosed form. Many modifications and changes are obvious to those skilled in the art. The embodiments are selected and described in order to better illustrate the principles and practical application of the present application, and to enable those skilled in the art to understand the present application so as to design various embodiments with various modifications suitable for specific purposes.

[0080] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and not intended to limit the scope of the application (including the claims) in any way. In fact, various modifications, substitutions, and changes can be suggested by the principles set forth in the application, and they are intended to fall within the scope of the application. The steps in the above embodiments or technical features among different embodiments can be implemented in any order, and there are many other changes to the aspects of the embodiments of the application as described above, which will be apparent to those skilled in the art. For the sake of brevity, they are not provided in detail.

[0081] Although the present application has been described in connection with the preferred embodiments thereof with reference to the drawings, it will be apparent to those skilled in the art that many alternatives, modifications and variations to the preferred embodiments can be made in light of the above description.

[0082] The embodiments of the present application are intended to cover all such alternatives, modifications and variations as falling within the scope of the appended claims. Accordingly, any omission, modification, equivalent replacement, improvement, etc. made in the spirit and principle of the embodiments of the present application should be included in the protection scope of the present application.

Claims

1. A battery cell, characterized in that, include: case; Electrode assembly, disposed within the housing; An insulating film is wrapped around the electrode assembly to insulate the electrode assembly; the insulating film includes a bottom insulating layer and a plurality of side insulating layers, the bottom insulating layer and the plurality of side insulating layers being disposed between the housing and the electrode assembly; A bottom support plate is disposed between the housing and the bottom insulating layer; Both the bottom support plate and the bottom insulating layer are provided with positioning holes, and the positioning holes of the two are arranged opposite to each other. A coating film assembly, a portion of which is disposed between the housing and the side insulation layer and covers the gap formed between two adjacent side insulation layers; a portion of which is also disposed between the housing and the bottom support plate and covers the positioning hole of the bottom support plate.

2. The battery cell according to claim 1, characterized in that, The coating membrane assembly includes: A first covering layer is disposed between the housing and the side insulation layer; the first covering layer covers at least two of the side insulation layers and the gap formed between two adjacent side insulation layers.

3. The battery cell according to claim 2, characterized in that, Along the height direction of the electrode assembly, the height of the first covering layer is greater than the height of the gap formed between two adjacent side insulating layers.

4. The battery cell according to claim 2, characterized in that, The first coating layer includes: Two first covering surfaces are connected and intersected; both first covering surfaces are parallel to the height direction of the electrode assembly and respectively cover two adjacent side insulating layers; the connecting area of ​​the two first covering surfaces correspondingly covers the gap formed between the two adjacent side insulating layers.

5. The battery cell according to claim 4, characterized in that, The first coating layer further includes: The second covering surface has one of the two first covering surfaces connected to and intersecting with the second covering surface, and the other parallel to the second covering surface; the side insulation layer covered by the first covering surface parallel to the second covering surface is disposed opposite to the side insulation layer covered by the second covering surface; the connection area between the first covering surface and the second covering surface and the connection area between the two first covering surfaces cover at least one gap formed between the three adjacent side insulation layers.

6. The battery cell according to claim 2, characterized in that, The coating membrane assembly further includes: A second covering layer, at least a portion of which is located between the housing and the base plate and covers the positioning hole of the base plate; the orthographic projection of the base plate onto the second covering layer at least partially coincides with the second covering layer, and the orthographic projection of the positioning hole of the base plate onto the second covering layer is located within the second covering layer.

7. The battery cell according to claim 6, characterized in that, The base plate is provided with multiple sets of positioning holes, and each set of positioning holes has two holes; along the extension direction of the line connecting the two positioning holes in each set, the width of the second covering layer is greater than the distance between the two positioning holes in each set, and less than or equal to the width of the base plate.

8. The battery cell according to claim 6, characterized in that, The second coating layer includes: Two third covering surfaces are connected and intersected; one of the two third covering surfaces is parallel to the height direction of the electrode assembly and covers a side insulating layer; the other is perpendicular to the height direction of the electrode assembly and covers the base plate and the positioning hole of the base plate.

9. The battery cell according to claim 8, characterized in that, The second coating layer further includes: The fourth covering surface consists of one of the two third covering surfaces connected to and intersecting with the fourth covering surface, and the other parallel to the fourth covering surface; the side insulation layer covered by the third covering surface parallel to the fourth covering surface is disposed opposite to the side insulation layer covered by the fourth covering surface.

10. The battery cell according to claim 1, characterized in that, The coating film assembly has an exhaust hole, and the gap formed between two adjacent side insulating layers and the positioning hole of the bottom plate do not coincide with the orthographic projection of the coating film assembly and the exhaust hole.

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