An electric core, a preparation method thereof, a battery module, a battery box and a power utilization device

Abstract

The application relates to the technical field of batteries, in particular to a battery cell and a preparation method thereof, a battery module, a battery box and a power utilization device. The battery cell comprises positive electrode sheets and negative electrode sheets which are stacked and alternately arranged, a diaphragm or a solid electrolyte layer is arranged between any positive electrode sheet and the adjacent negative electrode sheet; the positive electrode sheet is provided with a positive electrode lead-out area and a first hollow area which are arranged at intervals, at least one side surface of the positive electrode lead-out area is provided with a positive electrode lead-out part, the negative electrode sheet is provided with a negative electrode lead-out area and a second hollow area which are arranged at intervals, at least one side surface of the negative electrode lead-out area is provided with a negative electrode lead-out part; the diaphragm or the solid electrolyte layer is provided with a third hollow area corresponding to the positive electrode lead-out part, and the diaphragm or the solid electrolyte layer is provided with a fourth hollow area corresponding to the negative electrode lead-out part; each positive electrode lead-out part penetrates through each second hollow area and each third hollow area to electrically connect the positive electrode lead-out parts to each other, and each negative electrode lead-out part penetrates through each first hollow area and the fourth hollow area to electrically connect the negative electrode lead-out parts to each other.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery cell and its preparation method, a battery module, a battery box, and an electrical device. Background Technology

[0002] The electrode tab is a core component of power batteries with extremely high safety risks; it is a crucial part of welding the internal structure of the battery cell and external components. (Refer to...) Figure 1 Existing tabs have protrusions for connecting to external components. These protrusions extend from the edge of the cell to the top cover of the battery pack to connect to external devices. Space needs to be reserved inside the battery pack for these protrusions, resulting in a loss of approximately 8%-12% in space utilization. Furthermore, the existing tab structures require die-cutting to remove excess material, leading to material waste.

[0003] In addition, before the aforementioned battery cells are installed into the housing, the protruding parts of the tabs need to be bent. However, the existing solution cannot guarantee that the bending direction of all tabs is controlled. Some tabs are bent in random directions and may be inserted into the battery cells in reverse. This can cause the position of the electrode to change easily during actual use, which may lead to a short circuit between the positive and negative electrodes, triggering the risk of thermal runaway. Summary of the Invention

[0004] This application discloses a battery cell and its preparation method, a battery module, a battery box, and an electrical device, which are used to solve the problems of space and material waste and high risk of thermal runaway when the existing tabs are used in battery devices.

[0005] To achieve the above objectives, this application provides the following technical solution:

[0006] A first aspect provides a battery cell comprising stacked and alternately arranged positive and negative electrode sheets, wherein a separator or solid electrolyte layer is provided between any positive electrode sheet and its adjacent negative electrode sheet; the positive electrode sheet has a spaced-apart positive electrode lead-out region and a first hollow region, and at least one side surface of the positive electrode lead-out region has a positive electrode lead-out portion; the negative electrode sheet has a spaced-apart negative electrode lead-out region and a second hollow region, and at least one side surface of the negative electrode lead-out region has a negative electrode lead-out portion; the separator or solid electrolyte layer has a third hollow region corresponding to the positive electrode lead-out portion, and the separator or solid electrolyte layer has a fourth hollow region corresponding to the negative electrode lead-out portion; each positive electrode lead-out portion passes through each second hollow region and each third hollow region to electrically connect the positive electrode lead-out portions to each other, and each negative electrode lead-out portion passes through each first hollow region and each fourth hollow region to electrically connect the negative electrode lead-out portions to each other.

[0007] The first aspect provides a battery cell in which, when the positive electrode, negative electrode, and separator or solid electrolyte layer constitute the battery cell, each positive electrode lead penetrates each second hollow area and each third hollow area to achieve mutual electrical connection between each positive electrode, and each negative electrode lead penetrates each first hollow area and each fourth hollow area to achieve mutual electrical connection between each negative electrode, and the separator or solid electrolyte layer can maintain the insulation between the positive electrode and the negative electrode.

[0008] The battery cell in the first aspect replaces the tabs of the existing structure with positive and negative leads, avoiding the design of protruding parts, effectively improving the internal space utilization of the battery device, and increasing the volume density by 8%-12%. Moreover, the tabless design completely avoids the problem of thermal runaway caused by the tabs being inserted backward into the battery cell. In addition, the battery cell of this application avoids the die-cutting process, which can improve the utilization rate of raw materials and reduce the loss of raw materials.

[0009] Furthermore, the positive electrode sheet includes a positive current collector and a positive coating coated on at least one side of the positive current collector. The first hollow area is an opening that penetrates the positive current collector and the positive coating, so that each negative electrode lead-out portion can penetrate the first hollow area to achieve mutual electrical connection. The positive electrode lead-out portion is directly connected to the positive current collector in the positive electrode lead-out area, thereby maintaining good conductivity between the positive electrode lead-out portion and the positive current collector.

[0010] Furthermore, the negative electrode sheet includes a negative current collector and a negative electrode coating applied to at least one side of the negative current collector. The second hollow area is an opening that penetrates the negative current collector and the negative electrode coating, so that each positive electrode lead-out portion can penetrate the second hollow area to achieve mutual electrical connection. The negative electrode lead-out portion is directly connected to the negative current collector in the negative electrode lead-out area, thereby maintaining good conductivity between the negative electrode lead-out portion and the negative current collector.

[0011] Furthermore, the positive electrode lead is located at the edge of the positive electrode plate, and the negative electrode lead is located at the edge of the negative electrode plate. The purpose of placing both at the edges is to facilitate processing and assembly.

[0012] Furthermore, both the positive and negative electrode leads are metal leads, thus possessing good conductivity and solderability.

[0013] Furthermore, the orthogonal projection of the third hollow area onto the positive electrode plate is located in the positive electrode lead-out area, and the orthogonal projection of the fourth hollow area onto the negative electrode plate is located in the negative electrode lead-out area, so as to maintain insulation between adjacent positive and negative electrode plates.

[0014] Furthermore, the battery cell also includes a battery cell housing for encapsulating the positive and negative electrode plates. The battery cell housing has a first connecting portion and a second connecting portion. The positive electrode lead is electrically connected to the first connecting portion, and the negative electrode lead is electrically connected to the second connecting portion. The first and second connecting portions can improve the strength of the connection.

[0015] Furthermore, the first connecting part is a first metal block, the second connecting part is a second metal block, and the first metal block and the second metal block are insulated from each other to prevent the battery from short-circuiting.

[0016] The second aspect provides a method for preparing a battery cell according to the first aspect, the method comprising the following steps:

[0017] A positive electrode sheet with a positive lead-out region and a first hollow region is prepared;

[0018] A negative electrode sheet with a negative electrode lead-out region and a second hollow region is prepared;

[0019] Prepare a diaphragm with a third hollow region and a fourth hollow region, or prepare a solid electrolyte layer with a third hollow region and a fourth hollow region;

[0020] A battery cell is obtained by assembling a positive electrode, a negative electrode, and a separator, or by assembling a positive electrode, a negative electrode, and a solid electrolyte layer.

[0021] The battery cell prepared using the second method avoids the tabs and has the same advantages as the battery cell in the first method, which will not be elaborated here.

[0022] Furthermore, the preparation of the positive electrode sheet having a positive electrode lead-out region and a first hollow region includes the following steps:

[0023] A positive electrode coating is applied to the positive current collector, and the positive electrode coating in a predetermined area is cleaned by laser to obtain the positive electrode lead-out area;

[0024] The preparation of a negative electrode sheet having a negative electrode lead-out region and a second hollow region includes the following steps:

[0025] A negative electrode coating is applied to the negative electrode current collector, and the negative electrode coating in a predetermined area is cleaned by laser to obtain the negative electrode lead-out area.

[0026] The method of obtaining the positive and negative electrode lead-out areas by laser cleaning of a preset area is simple to operate and improves work efficiency.

[0027] The third aspect provides a battery module comprising either the battery cell of the first aspect or a battery cell prepared using the preparation method of the second aspect. The battery cell of this application avoids the tabs, improving the space utilization of raw materials and battery devices, and avoiding the problem of thermal runaway caused by the tabs being inserted backwards into the battery cell.

[0028] A fourth aspect provides a battery box comprising the battery module of the third aspect and a battery housing for encapsulating the battery module. The battery box of this application has the same advantages as the battery module of the third aspect, which will not be elaborated here.

[0029] The fifth aspect provides an electrical device that includes the battery box of the fourth aspect. The electrical device of this application has the same advantages as the battery box of the fourth aspect, which will not be repeated here. Attached Figure Description

[0030] Figure 1 A schematic diagram of the electrode structure of an existing battery cell;

[0031] Figure 2 This is an exploded view of a battery cell according to an embodiment of this application;

[0032] Figure 3 This is a front view of a positive electrode sheet according to an embodiment of this application;

[0033] Figure 4 This is a front view of a negative electrode sheet according to an embodiment of this application;

[0034] Figure 5 This is a front view of the diaphragm according to one embodiment of this application;

[0035] Figure 6 This is a schematic diagram of the structure of a positive electrode sheet according to an embodiment of this application;

[0036] Figure 7 This is a schematic diagram of the structure of a negative electrode sheet according to an embodiment of this application;

[0037] Figure 8 This is a front view of a battery cell according to an embodiment of this application;

[0038] Figure 9 This is a schematic diagram of the structure of a battery cell according to one embodiment of this application;

[0039] Figure 10 This is an exploded view of the battery cell housing according to one embodiment of this application;

[0040] Figure 11 This is a flowchart illustrating the manufacturing and assembly process of a battery cell according to one embodiment of this application.

[0041] Figure 12 This is a flowchart illustrating the manufacturing and assembly process of existing battery cells.

[0042] Reference numerals: 10-cell; 20-cell casing; 21-side plate; 22-cover plate; 23-bottom plate;

[0043] 110 - Positive electrode sheet; 111 - Positive current collector; 112 - Positive electrode coating; 120 - Positive electrode lead; 130 - Negative electrode sheet; 131 - Negative current collector; 132 - Negative electrode coating; 140 - Negative electrode lead; 150 - Separator;

[0044] 01-Positive electrode lead-out area; 02-First hollowed-out area; 03-Negative electrode lead-out area; 04-Second hollowed-out area; 05-Third hollowed-out area; 06-Fourth hollowed-out area; 07-First connecting part; 08-Second connecting part;

[0045] 001 - Protrusion. Detailed Implementation

[0046] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0047] The electrode tab is a core component of power batteries with extremely high safety risks; it is a crucial part of welding the internal structure of the battery cell and external components. (Refer to...) Figure 1 The existing tabs have protrusions 001 for connecting to external components. These protrusions 001 extend from the edge of the cell to the top cover of the battery pack to connect to external devices. Space needs to be reserved inside the battery pack housing for these protrusions, resulting in a loss of approximately 8%-12% in space utilization. Furthermore, the existing tabs require die-cutting to remove excess material, leading to material waste. Additionally, the protrusions 001 are prone to reverse insertion into the cell after being installed in the housing, potentially causing thermal runaway.

[0048] In view of this, an embodiment of this application provides a battery cell. Figure 2 This is an exploded view of a battery cell according to an embodiment of this application, with reference to... Figure 2 The battery cell 10 includes stacked and alternately arranged positive electrode plates 110 and negative electrode plates 130, and a separator 150 or a solid electrolyte layer is provided between any positive electrode plate 110 and the adjacent negative electrode plate 130.

[0049] The distinction between a separator and a solid electrolyte layer depends on the type of battery. Currently, batteries on the market can be broadly categorized into liquid batteries and solid batteries based on their electrolyte state. A liquid battery cell consists of a positive electrode, a negative electrode, and a separator, with the separator located between the positive or negative electrode. A solid battery cell consists of a positive electrode, a negative electrode, and a solid electrolyte layer, with the solid electrolyte layer located between the positive and negative electrode.

[0050] Figure 3 This is a front view of the positive electrode sheet according to an embodiment of this application. Figure 4 This is a front view of the negative electrode sheet according to an embodiment of this application. Figure 5 This is a front view of the diaphragm according to one embodiment of this application, and is also referred to Figures 3 to 5The positive electrode 110 has a positive electrode lead-out area 01 and a first hollow area 02 spaced apart. At least one side surface of the positive electrode lead-out area 01 has a positive electrode lead-out portion 120. The negative electrode 130 has a negative electrode lead-out area 03 and a second hollow area 04 spaced apart. At least one side surface of the negative electrode lead-out area 03 has a negative electrode lead-out portion 140. The separator 150 has a third hollow area 05 corresponding to the positive electrode lead-out portion 120, and the separator 150 has a fourth hollow area 06 corresponding to the negative electrode lead-out portion 140. The shapes of the positive electrode lead-out area 01, negative electrode lead-out area 03, first hollow area 02, second hollow area 04, third hollow area 05, and fourth hollow area 06 are not limited and can be rectangular, circular, or other shapes.

[0051] The presence of a positive electrode lead-out portion 120 on one side surface of the positive electrode lead-out area 01, or on both sides of the positive electrode lead-out area 01, is within the scope of protection of this application. Preferably, the presence of positive electrode lead-out portions 120 on both sides of the positive electrode lead-out area 01 facilitates the electrical connection between the various positive electrode plates 110.

[0052] Similarly, whether the negative electrode lead-out area 03 has a negative electrode lead-out portion 140 on one side surface or both sides surface has a negative electrode lead-out portion 140, both are within the protection scope of this application. Preferably, the negative electrode lead-out area 03 has a negative electrode lead-out portion 140 on both sides surface, which facilitates the electrical connection between each negative electrode piece 130.

[0053] It is understandable that, for the solid-state battery cell 10, the solid electrolyte layer is provided with a third hollow area 05 corresponding to the positive electrode lead-out portion 120 and a fourth hollow area 06 corresponding to the negative electrode lead-out portion 140.

[0054] Figure 6 This is a schematic diagram of the structure of a positive electrode sheet according to an embodiment of this application, with reference to... Figure 6 The positive electrode 110 includes a positive current collector 111 and a positive electrode coating 112 coated on at least one surface of the positive current collector 111. The first hollow area 02 is an opening penetrating the positive current collector 111 and the positive electrode coating 112. The positive electrode lead-out portion 120 is directly connected to the positive current collector 111 in the positive electrode lead-out area 01. The positive current collector 111 may have the positive electrode coating 112 on one surface or on both surfaces. Preferably, the positive current collector 111 has the positive electrode coating 112 on both surfaces.

[0055] Figure 7 This is a schematic diagram of the negative electrode sheet according to an embodiment of this application, with reference to... Figure 7The negative electrode sheet 130 includes a negative electrode current collector 131 and a negative electrode coating 132 coated on at least one surface of the negative electrode current collector 131. The second hollow area 04 is an opening penetrating the negative electrode current collector 131 and the negative electrode coating 132. The negative electrode lead-out portion 140 is directly connected to the negative electrode current collector 131 in the negative electrode lead-out area 03. The negative electrode current collector 131 may have a negative electrode coating 132 on one surface or on both surfaces. Preferably, both surfaces of the negative electrode current collector 131 are provided with a negative electrode coating 132.

[0056] The positive electrode lead-out portion 120 is located at the edge of the positive electrode plate 110, and the negative electrode lead-out portion 140 is located at the edge of the negative electrode plate 130. The purpose of both being located at the edge is to facilitate processing and assembly.

[0057] In an optional embodiment, both the positive electrode lead 120 and the negative electrode lead 140 are metal leads. The positive electrode lead 120 and the negative electrode lead 140 can be made of aluminum, copper, nickel, or alloys of the above metals, because these materials have good conductivity and weldability, facilitating the welding connection between adjacent positive electrode plates 110 through the positive electrode lead 120, or between adjacent negative electrode plates 130 through the negative electrode lead 140.

[0058] Preferably, the shape of the positive electrode lead-out portion 120 is the same as the shape of the positive electrode lead-out region 01, and the area of ​​the positive electrode lead-out portion 120 is smaller than the area of ​​the positive electrode lead-out region 01. Preferably, the shape of the negative electrode lead-out portion 140 is the same as the shape of the negative electrode lead-out region 03, and the area of ​​the negative electrode lead-out portion 140 is smaller than the area of ​​the negative electrode lead-out region 03.

[0059] In an optional embodiment, the orthogonal projection of the third hollow region 05 onto the positive electrode 110 is located in the positive electrode lead-out region 01, meaning that only the positive electrode lead-out portion 120 passes through the third hollow region 05. At the same time, the separator 150 or the solid electrolyte layer can maintain the insulation between adjacent positive electrode 110 and negative electrode 130. The orthogonal projection of the fourth hollow region 06 onto the negative electrode 130 is located in the negative electrode lead-out region 03, meaning that only the negative electrode lead-out portion 140 passes through the fourth hollow region 06. At the same time, the separator 150 or the solid electrolyte layer can maintain the insulation between adjacent positive electrode 110 and negative electrode 130.

[0060] Figure 8 This is a front view of a battery cell according to an embodiment of this application. Figure 9 This is a schematic diagram of the structure of a battery cell according to an embodiment of this application, with reference to... Figure 8 and Figure 9Each positive lead 120 passes through each second hollow area 04 and each third hollow area 05 to electrically connect each positive lead 120 to each other, and each negative lead 140 passes through each first hollow area 02 and each fourth hollow area 06 to electrically connect each negative lead 140 to each other.

[0061] The adjacent positive electrode leads 120 can be connected by bolts after drilling and tapping, or they can be directly welded using welding wire. This application does not limit the connection method of each positive electrode lead 120. Preferably, the positive electrode leads 120 are connected by ultrasonic welding.

[0062] Figure 10 This is an exploded view of the battery cell housing according to an embodiment of the present application. The battery cell 10 also includes a battery cell housing 20 for encapsulating the positive electrode 110 and the negative electrode 130. The positive electrode lead-out portion 120 and the negative electrode lead-out portion 140 are electrically connected to the battery cell housing 20, and then connected to external components through the battery cell housing 20 to supply power to the external components.

[0063] The battery cell housing 20 includes a bottom plate 23, a side plate 21, and a cover plate 22 disposed opposite to the bottom plate 23. The bottom plate 23 and the side plate 21 surrounding the bottom plate 23 form a cavity. A bare battery cell composed of a positive electrode sheet 110 and a negative electrode sheet 130 stacked in layers is disposed in the cavity. The cover plate 22 covers the top of the cavity to encapsulate the bare battery cell.

[0064] Continue to refer to Figure 10 The inner wall of the cell housing 20 is provided with a first connecting part 07 and a second connecting part 08. The first connecting part 07 is electrically connected to the positive electrode lead-out part 120, and the second connecting part 08 is electrically connected to the negative electrode lead-out part 140. The first connecting part 07 and the second connecting part 08 can be provided on the cover plate 22, the bottom plate 23, or the side plate 21 of the cell housing 20. The first connecting part 07 and the second connecting part 08 can be provided on opposite inner walls or on the same side of the inner wall. For example, both the first connecting part 07 and the second connecting part 08 can be provided on the cover plate 22, or the first connecting part 07 can be provided on the cover plate 22, and the second connecting part 08 can be provided on the bottom plate 23. This application does not limit the location of the first connecting part 07 and the second connecting part 08; the specific design will depend on the actual production conditions.

[0065] In existing battery cell housings, the cover plate has a positive terminal and a negative terminal. The positive terminal tab of the bare battery cell is connected to the positive terminal, and the negative terminal tab is connected to the negative terminal. Compared to existing battery cell structures, the cover plate 22 of the battery cell in this embodiment is designed to be more flexible. The cover plate 22 can have both a first connecting part 07 and a second connecting part 08, or it can have only one of them, with the other located on the base plate 23, or neither the first connecting part 07 nor the second connecting part 08 can be located on the cover plate 22.

[0066] The first connecting part 07 is a first metal block, the second connecting part 08 is a second metal block, and the first metal block and the second metal block are insulated from each other to avoid short circuit of the battery caused by the connection between the positive electrode 110 and the negative electrode 130.

[0067] The function of the first connecting part 07 is to enhance the firmness of the connection between the positive lead 120 and the cell housing 20, and to protect the cell housing 20 from damage caused by welding or other connection methods. The function of the second connecting part 08 is to enhance the firmness of the connection between the negative lead 140 and the cell housing 20, and to protect the cell housing 20 from damage caused by welding or other connection methods.

[0068] Embodiments of this application also provide a method for preparing a battery cell. Figure 11 This is a flowchart illustrating the manufacturing and assembly process of a battery cell according to one embodiment of this application. Figure 11 The preparation method in this application includes the following steps:

[0069] A positive electrode sheet with a positive lead-out region and a first hollow region is prepared;

[0070] A negative electrode sheet with a negative electrode lead-out region and a second hollow region is prepared;

[0071] Prepare a diaphragm with a third hollow region and a fourth hollow region, or prepare a solid electrolyte layer with a third hollow region and a fourth hollow region;

[0072] A bare cell is obtained by assembling a positive electrode, a negative electrode, and a separator, or by assembling a positive electrode, a negative electrode, and a solid electrolyte layer.

[0073] The positive lead of the bare battery cell is connected to the first connecting part of the battery cell housing, and the negative lead of the bare battery cell is connected to the second connecting part of the battery cell housing. The bare battery cell and the battery cell housing are assembled to obtain the battery cell.

[0074] The preparation of the positive electrode sheet having a positive electrode lead-out region and a first hollow region includes the following steps:

[0075] A positive electrode coating is applied to the positive current collector, and the positive electrode coating in a predetermined area is cleaned by laser to obtain the positive electrode lead-out area;

[0076] The preparation of a negative electrode sheet having a negative electrode lead-out region and a second hollow region includes the following steps:

[0077] A negative electrode coating is applied to the negative electrode current collector, and the negative electrode coating in a predetermined area is cleaned by laser to obtain the negative electrode lead-out area.

[0078] The positive electrode lead-out area and the negative electrode lead-out area can also be reserved directly during the coating process.

[0079] It is understandable that the first hollow area can be cut out on the positive current collector before the positive electrode coating is applied, or the positive electrode coating can be applied on the positive current collector first, and then the preset area can be cut to obtain the first hollow area.

[0080] The above description of the preparation process also applies to the negative electrode.

[0081] To further illustrate the beneficial effects of the cell fabrication method in this application, the fabrication process of existing structured cells is described. Figure 12 This is a flowchart of the manufacturing and assembly process for existing battery cells, with reference to... Figure 12 The existing method for fabricating battery cells includes the following steps:

[0082] 1) A positive electrode coating is applied to the positive current collector to obtain a positive electrode coil, and a negative electrode coating is applied to the negative current collector to obtain a negative electrode coil;

[0083] 2) After rolling, the positive electrode roll is die-cut to obtain the positive electrode tab; after rolling, the negative electrode roll is die-cut to obtain the negative electrode tab.

[0084] 3) Die-cut the positive electrode to obtain the positive electrode sheet, and die-cut the negative electrode to obtain the negative electrode sheet;

[0085] 4) A bare cell is obtained by stacking the positive electrode, negative electrode, and separator, or by stacking the positive electrode, negative electrode, and solid electrolyte.

[0086] 5) The positive and negative tabs of the bare cell are connected to the cover plate of the cell housing and installed into the cell housing to form the cell.

[0087] Compared with the existing battery cell manufacturing process, the battery cell manufactured by the method in this application eliminates the tab design. Each positive electrode lead penetrates through each second and third hollowed-out area and is electrically connected to the others, while each negative electrode lead penetrates through each first and fourth hollowed-out area and is electrically connected to the others. The battery cells in various possible embodiments of this application, as well as the battery cells manufactured by the method in this application, have the following beneficial effects:

[0088] 1. The design of the electrode tabs is avoided, so that the assembled battery cells do not have the electrode tab bending and shaping process, and completely avoid the thermal runaway problem caused by the reverse insertion of the electrode tabs;

[0089] 2. This battery cell does not have the protruding tabs of the existing structure, which effectively improves space utilization and increases volume density by 8%-12%;

[0090] 3. The preparation method in this application reduces the die-cutting process, which can improve the utilization rate of copper and aluminum foil and reduce the loss of copper and aluminum foil materials;

[0091] 4. The connection position between the cell casing and the positive or negative lead can be adjusted as needed, thereby changing the traditional cover design and making the existing cell casing design more flexible.

[0092] Based on the same inventive concept, embodiments of this application also provide a battery module, which includes the battery cells of the embodiments of this application or the battery cells prepared using the preparation method of the embodiments of this application.

[0093] An embodiment of this application also provides a battery box, which includes the battery module described above and a battery box body for encapsulating the battery module.

[0094] An embodiment of this application also provides an electrical device, which includes the aforementioned battery box. Specifically, in this embodiment, the electrical device may be an electric vehicle, etc.

[0095] Obviously, those skilled in the art can make various modifications and variations to the embodiments of this application without departing from the spirit and scope of this application. Therefore, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application also intends to include these modifications and variations.

Claims

1. A battery cell, characterized in that, It includes stacked and alternately arranged positive and negative electrode sheets, wherein a membrane or solid electrolyte layer is provided between any positive electrode sheet and the adjacent negative electrode sheet; The positive electrode sheet has a positive electrode lead-out area and a first hollow area arranged at intervals, and a positive electrode lead-out portion is provided on at least one side surface of the positive electrode lead-out area. The negative electrode sheet has a negative electrode lead-out area and a second hollow area arranged at intervals, and a negative electrode lead-out portion is provided on at least one side surface of the negative electrode lead-out area. The diaphragm or the solid electrolyte layer is provided with a third hollow area corresponding to the positive electrode lead-out portion, and the diaphragm or the solid electrolyte layer is provided with a fourth hollow area corresponding to the negative electrode lead-out portion; Each of the positive electrode leads penetrates each of the second and third hollow areas to electrically connect the positive electrode leads to each other, and each of the negative electrode leads penetrates each of the first and fourth hollow areas to electrically connect the negative electrode leads to each other. The battery cell also includes a battery cell housing for encapsulating the positive electrode and the negative electrode. The battery cell housing is provided with a first connecting portion and a second connecting portion. The positive electrode lead-out portion is electrically connected to the first connecting portion, and the negative electrode lead-out portion is electrically connected to the second connecting portion. The first connecting part is a first metal block, the second connecting part is a second metal block, and the first metal block and the second metal block are insulated from each other; The positive electrode includes a positive current collector and a positive electrode coating applied to at least one side of the positive current collector. The first hollow area is an opening that penetrates the positive current collector and the positive electrode coating. The positive electrode lead-out portion is directly connected to the positive current collector in the positive electrode lead-out area. The negative electrode sheet includes a negative electrode current collector and a negative electrode coating coated on at least one side of the negative electrode current collector. The second hollow area is an opening that penetrates the negative electrode current collector and the negative electrode coating. The negative electrode lead-out portion is directly connected to the negative electrode current collector in the negative electrode lead-out area. Both the positive electrode lead-out section and the negative electrode lead-out section are metal leads-out sections.

2. The battery cell according to claim 1, characterized in that, The positive electrode lead-out portion is located at the edge of the positive electrode plate, and the negative electrode lead-out portion is located at the edge of the negative electrode plate.

3. The battery cell according to claim 1, characterized in that, The orthogonal projection of the third hollow area on the positive electrode sheet is located in the positive electrode lead-out area; the orthogonal projection of the fourth hollow area on the negative electrode sheet is located in the negative electrode lead-out area.

4. A method for preparing a battery cell as described in any one of claims 1-3, characterized in that, Includes the following steps: Prepare the positive electrode sheet having the positive electrode lead-out region and the first hollow region; Prepare the negative electrode sheet having the negative electrode lead-out region and the second hollow region; Prepare the diaphragm having the third hollow region and the fourth hollow region, or prepare the solid electrolyte layer having the third hollow region and the fourth hollow region; The battery cell is obtained by assembling the positive electrode, the negative electrode, and the separator, or by assembling the positive electrode, the negative electrode, and the solid electrolyte layer.

5. The preparation method according to claim 4, characterized in that, The preparation of a positive electrode sheet having the positive electrode lead-out region and the first hollow region includes the following steps: A positive electrode coating is applied to the positive current collector, and the positive electrode coating in a predetermined area is cleaned by laser to obtain the positive electrode lead-out area; The preparation of the negative electrode sheet having the negative electrode lead-out region and the second hollow region includes the following steps: A negative electrode coating is applied to the negative electrode current collector, and the negative electrode coating in a predetermined area is cleaned by laser to obtain the negative electrode lead-out area.

6. A battery module, characterized in that, This includes battery cells as described in any one of claims 1-3 or battery cells prepared using the preparation method described in claim 4 or 5.

7. A battery box, characterized in that, It includes the battery module as described in claim 6 and a battery housing for encapsulating the battery module.

8. An electrical appliance, characterized in that, Includes the battery box as described in claim 7.

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