Battery cell, battery, electric device and method for manufacturing battery cell

Abstract

The present application provides a battery cell, a battery, an electrical device and a method for preparing a battery cell. The battery cell includes a shell, an end cap assembly, an electrode assembly, a shell, a hollow structure with two ends open and a receiving portion; the end cap assembly includes a first end cap and a second end cap respectively covering the two ends of the shell; the electrode assembly is arranged in the receiving portion, including a plurality of first pole pieces and a plurality of second pole pieces with opposite polarities, the first pole piece is electrically connected to the first end cap, the second pole piece is electrically connected to the second end cap, and the orthographic projections of the first pole piece and the second pole piece on the first end cap are both closed shapes; wherein the plurality of first pole pieces and the plurality of second pole pieces are alternately nested along the radial direction of the shell. The embodiment of the present application changes the internal structure of the electrode assembly, splitting the traditional single first pole piece and the single second pole piece into a plurality of first pole pieces and a plurality of second pole pieces, thereby reducing the size of the single first pole piece and the single second pole piece, and reducing the processing difficulty of the electrode assembly.

Description

Technical Field

[0001] The present application relates to the field of batteries, and in particular to a battery cell, a battery, an electrical device, and a method for manufacturing the battery cell. Background Art

[0002] Energy conservation and emission reduction are the key to the sustainable development of the automotive industry. Electric vehicles have become an important part of the sustainable development of the automotive industry due to their advantages in energy conservation and environmental protection. For electric vehicles, battery technology is an important factor in their development, but batteries often face the problem of difficult processing during the manufacturing process. Summary of the invention

[0003] In view of the above problems, the present application provides a battery cell, a battery, an electrical device and a method for manufacturing a battery cell, which can reduce the difficulty of processing an electrode assembly.

[0004] In a first aspect, an embodiment of the present application provides a battery cell, including a shell, an end cover assembly, and an electrode assembly.

[0005] The shell is a hollow structure with openings at both ends and a receiving portion;

[0006] The end cover assembly comprises a first end cover and a second end cover respectively covering two ends of the shell;

[0007] The electrode assembly is disposed in the accommodating portion, and includes a plurality of first pole pieces and a plurality of second pole pieces with opposite polarities, the first pole piece is electrically connected to the first end cover, the second pole piece is electrically connected to the second end cover, and the orthographic projections of the first pole piece and the second pole piece on the first end cover are both closed shapes;

[0008] Wherein, a plurality of first pole pieces and a plurality of second pole pieces are alternately nested along the radial direction of the shell.

[0009] The embodiment of the present application changes the internal structure of the electrode assembly, splits the traditional single first pole piece and the single second pole piece into multiple first pole pieces and multiple second pole pieces, and makes the multiple first pole pieces and the multiple second pole pieces alternately nested along the radial direction of the shell, thereby reducing the size of the single first pole piece and the single second pole piece, reducing the processing difficulty of the electrode assembly, and improving the yield rate, ensuring mass production processing.

[0010] In some embodiments, the first pole piece includes a first substrate portion and a first coating portion disposed on a side of the first substrate portion close to the second pole piece, the first substrate portion protrudes from the first coating portion along a first direction and is electrically connected to the first end cap. The first end cap and the second end cap are disposed opposite to each other along the first direction.

[0011] In the embodiment of the present application, the length of the first substrate portion in the first direction is greater than the length of the first coating portion so that the first substrate portion protrudes beyond the first coating portion. The protruding portion of the first substrate portion can serve as a pole ear portion and be directly electrically connected to the first end cover, thereby realizing an integrated design of the first pole piece and the first end cover, and the structure is simple and reliable.

[0012] In some embodiments, the first end cover includes a first cover plate and a first protrusion protruding from the first cover plate along a first direction, wherein the first coating portion abuts against the first protrusion and is insulated from the first cover plate through the first protrusion.

[0013] In the embodiment of the present application, a plurality of first protrusions are arranged on the first cover plate to achieve mutual insulation between the first coating portion and the first cover plate. At the same time, the space between two adjacent first protrusions can be used to accommodate the protruding portion of the first substrate portion relative to the first coating portion. The structure is simple and reliable, and can reduce the difficulty of manufacturing the battery cell to a certain extent.

[0014] In some embodiments, the end cap assembly further includes an insulating connector, which is disposed on a side of the first end cap close to the electrode assembly, and the second electrode plate is insulated from the first cover plate via the insulating connector.

[0015] In the embodiment of the present application, the second pole piece and the first cover plate are spaced apart by an insulating connector to insulate the second pole piece and the first cover plate from each other, thereby preventing the second pole piece and the first cover plate from being conductive and affecting the normal use of the battery cell. At the same time, the insulating connector and the first end cover can be detachably arranged, which is beneficial for subsequent maintenance and inspection.

[0016] In some embodiments, the insulating connector is slidably connected to the first cover plate and can move relative to the first cover plate along the radial direction of the shell to change the distance between the first pole piece and the second pole piece.

[0017] The embodiment of the present application slides the insulating connector to the first cover plate, thereby achieving the insulation setting of the second pole piece and the first cover plate and adjusting the distance between the first pole piece and the second pole piece. The operation is simple and quick, and no additional components are required, which indirectly reduces the size and weight of the battery cell.

[0018] In some embodiments, the electrode assembly further includes a plurality of diaphragms, and the diaphragms are disposed between adjacent first pole pieces and second pole pieces.

[0019] The embodiment of the present application is different from the traditional one in the number and arrangement of diaphragms. By providing multiple diaphragms to separate different first pole pieces from the second pole pieces, this design is beneficial to the maintenance and replacement of internal parts of the electrode assembly to extend the service life of the battery cell.

[0020] In some embodiments, the electrode assembly further includes a support mechanism, the support mechanism extends along a first direction, and the first pole piece and the second pole piece are radially arranged around the outer periphery of the support mechanism along the shell.

[0021] The embodiment of the present application utilizes a lightweight insulating polymer as a supporting structure to avoid the problem of center collapse of a traditional electrode assembly, enhance the stability of the internal structure of the electrode assembly, and ensure the normal use of the battery cell.

[0022] In a second aspect, an embodiment of the present application provides a battery, comprising a box and a battery cell as shown in any of the aforementioned embodiments, wherein the battery cell is accommodated in the box.

[0023] In a third aspect, an embodiment of the present application provides an electrical device, including the battery shown in the aforementioned embodiment, and the battery is used to provide electrical energy.

[0024] In a fourth aspect, an embodiment of the present application provides a method for manufacturing a battery cell, comprising:

[0025] A battery substrate is provided, the battery substrate comprising a shell, a first end cover, a plurality of first substrate parts, a plurality of second substrate parts and a plurality of diaphragms, the first end cover is covered on one end of the shell, the plurality of first substrate parts and the plurality of second substrate parts are alternately nested along the radial direction of the shell, and the diaphragm is arranged between adjacent first substrate parts and second substrate parts;

[0026] Injecting the first slurry between the first substrate portion and the adjacent diaphragm to form a first coating portion, wherein the first substrate portion and the first coating portion together constitute a first pole piece;

[0027] The second slurry is injected between the second substrate portion and the adjacent diaphragm to form a second coating portion, and the second substrate portion and the second coating portion together constitute a second pole piece.

[0028] The embodiment of the present application realizes the production of the electrode assembly by injection molding. Compared with the traditional coating process, the embodiment of the present application realizes the control of the size of the first coating part and the second coating part by adjusting the distance between the diaphragm and the adjacent first substrate part and the second substrate part. And it only needs to inject the first slurry and the second slurry between the diaphragm and the adjacent first substrate part and the second substrate part to ensure that the structure of the first coating part and the second coating part is consistent. The operation is simple and fast, which is conducive to improving production efficiency and also can obtain a higher yield rate.

[0029] In some embodiments, the step of providing a battery substrate comprises:

[0030] Providing a first end cover, the first end cover comprising a first cover plate and first protrusions protruding from the first cover plate and spaced apart from each other, with grooves formed between adjacent first protrusions;

[0031] An insulating connector is formed in a portion of the groove to form a first receiving groove and a second receiving groove alternately distributed in the radial direction of the first end cover, wherein an insulating connector is formed inside one of the first receiving groove and the second receiving groove;

[0032] Fixing the first substrate portion to one of the first receiving groove or the second receiving groove where the insulating connector is not formed;

[0033] The second substrate portion is fixed to the side of the insulating connector away from the first cover plate, and a plurality of first substrate portions and a plurality of second substrate portions are alternately nested along the radial direction of the housing;

[0034] The diaphragm is fixed in a portion of the groove so that the diaphragm is located between the adjacent first substrate portion and the second substrate portion.

[0035] The embodiment of the present application specifically designs the first end cover, and a first protrusion is provided on the first end cover. The positions of the first pole piece and the second pole piece are controlled by the grooves formed between adjacent first protrusions. At the same time, the diaphragm is fixed to the first cover plate, and the injection positions of the first slurry and the second slurry are restricted by the diaphragm, thereby ensuring that the electrode assembly structure is stable and reliable.

[0036] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0038] Figure 1 A simplified schematic diagram of a vehicle provided in an embodiment of the present application;

[0039] Figure 2 is an exploded schematic diagram of a battery provided in an embodiment of the present application;

[0040] Figure 3 is a structural schematic diagram of a battery module provided in an embodiment of the present application;

[0041] Figure 4 is a schematic diagram of the structure of a battery cell provided in an embodiment of the present application;

[0042] Figure 5 yes Figure 4A schematic diagram of the internal structure of a battery cell is shown;

[0043] Figure 6 yes Figure 5 A schematic structural diagram of a battery cell from another perspective;

[0044] Figure 7 yes Figure 6 Schematic diagram of the cross-sectional structure at AA in the middle;

[0045] Figure 8 is a flow chart of a method for manufacturing a battery cell provided in an embodiment of the present application;

[0046] Figures 9a to 9c is a schematic diagram of a manufacturing process of a battery cell manufacturing method provided in an embodiment of the present application;

[0047] Fig.10 is a flow chart of step S100;

[0048] Figures 11a to 11e This is another schematic diagram of the manufacturing process of the battery cell manufacturing method provided in the embodiment of the present application.

[0049] In the attached figure:

[0050] Vehicles 1000;

[0051] Battery 100; controller 200; motor 300; housing 400; battery module 500;

[0052] A first box body 41; a second box body 42; a receiving space 43;

[0053] Battery cell 10; housing 11; end cap assembly 12; electrode assembly 13;

[0054] First end cover 121; second end cover 122; insulating connector 123;

[0055] First pole piece 131; second pole piece 132; diaphragm 133; support mechanism 134;

[0056] First cover plate 1211; first protrusion 1212; second protrusion 1213; groove 1214; first receiving groove 1215; second receiving groove 1216; third receiving groove 1217;

[0057] A first substrate portion 1311; a first coating portion 1312; a second substrate portion 1321; a second coating portion 1322;

[0058] The first direction X. DETAILED DESCRIPTION

[0059] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0060] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0061] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0062] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0063] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0064] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0065] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0066] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0067] In the description of the embodiments of the present application, the battery cells may include lithium-ion secondary battery cells, lithium-ion primary battery cells, lithium-sulfur battery cells, sodium-lithium-ion battery cells, sodium-ion battery cells or magnesium-ion battery cells, etc., and the embodiments of the present application do not limit this. The battery cells may be cylindrical, flat, rectangular or other shapes, etc., and the embodiments of the present application do not limit this. Battery cells are generally divided into three types according to the packaging method: cylindrical battery cells, square battery cells and soft-pack battery cells, and the embodiments of the present application do not limit this.

[0068] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity. For example, the battery mentioned in the present application may include a battery module or a battery pack. The battery generally includes a box for encapsulating one or more battery cells. The box can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cells.

[0069] The battery cell includes an electrode assembly and an electrolyte. The electrode assembly is composed of a positive electrode sheet, a negative electrode sheet and a separator. The battery cell mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. The positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode current collector. The current collector not coated with the positive electrode active material layer protrudes from the current collector coated with the positive electrode active material layer. The current collector not coated with the positive electrode active material layer serves as the positive electrode tab. Taking lithium-ion batteries as an example, the material of the positive electrode current collector may be aluminum, and the positive electrode active material may be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode current collector. The current collector not coated with the negative electrode active material layer protrudes from the current collector coated with the negative electrode active material layer. The current collector not coated with the negative electrode active material layer serves as the negative electrode tab. The material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon or silicon, etc. In order to ensure that a large current can be passed without melting, the number of positive electrode tabs is multiple and stacked together, and the number of negative electrode tabs is multiple and stacked together. The material of the diaphragm can be PP or PE.

[0070] The battery cell further includes a housing for accommodating the electrode assembly and the electrolyte. The housing includes a shell and an end cap connected to the shell, and the shell and the end cap form a receiving cavity to accommodate the electrode assembly and the electrolyte. In some embodiments, the battery cell further includes a current collecting member for electrically connecting the electrode assembly to the electrode terminal on the end cap.

[0071] The applicant found that in the related art, a battery cell is composed of a single positive electrode sheet and a single negative electrode sheet, which are wound together to form an electrode assembly. This design requires first preparing positive and negative electrode sheets of larger size, and the structures of the positive electrode sheet and the negative electrode sheet must be consistent. At the same time, during preparation, it is also necessary to ensure that the positive and negative electrode sheets are wound along a specific path to form an electrode assembly, which has a high processing difficulty.

[0072] Based on the above-mentioned problems discovered by the applicant, the present application provides a battery cell, which adopts an integrated structural design, including multiple first pole pieces and multiple second pole pieces. The multiple first pole pieces and the multiple second pole pieces are alternately nested along the radial direction of the shell to form an electrode assembly. By changing the specific structure of the electrode assembly, the size of a single first electrode and a single second electrode is reduced, the processing difficulty is reduced, and the yield rate of the battery cell is improved.

[0073] The technical solutions described in the embodiments of the present application are applicable to batteries and electrical devices using batteries, such as mobile phones, portable devices, laptop computers, electric vehicles, electric cars, ships, spacecraft, electric toys and electric tools, etc., wherein spacecrafts include airplanes, rockets, space shuttles and spacecrafts, etc., electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys and electric airplane toys, etc., and electric tools include metal cutting power tools, grinding power tools, assembly power tools and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators and electric planers.

[0074] The battery cells described in the embodiments of the present application are not limited to being applicable to the electrical devices described above, but for the sake of simplicity, the following embodiments are described using electric vehicles as examples.

[0075] See also Figure 1 , Figure 1 A simple schematic diagram of a vehicle 1000 provided in an embodiment of the present application. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 may be provided inside the vehicle 1000, and specifically, for example, the battery 100 may be provided at the bottom, front or rear of the vehicle 1000. The battery 100 may be used to power the vehicle 1000, for example, the battery 100 may be used as an operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300, and the controller 200 is used, for example, to control the battery to power the motor 300. The battery may be used for starting and navigating the vehicle 1000, and of course, the battery 100 may also be used to drive the vehicle 1000, replacing or partially replacing fuel or natural gas to provide drive for the vehicle 1000.

[0076] Figure 2 Schematic diagram of an explosion of a battery provided in some embodiments of the present application. Figure 2 As shown, the battery 100 includes a housing 400 and a battery cell ( Figure 2 (not shown), the battery cells are accommodated in the box body 400.

[0077] The box 400 is used to accommodate battery cells, and the box 400 can be a variety of structures. In some embodiments, the box 400 may include a first box portion 41 and a second box portion 42, the first box portion 41 and the second box portion 42 cover each other, and the first box portion 41 and the second box portion 42 jointly define a storage space 43 for accommodating battery cells. The second box portion 42 may be a hollow structure with one end open, the first box portion 41 is a plate-like structure, and the first box portion 41 covers the open side of the second box portion 42 to form a box 400 with a storage space 43; the first box portion 41 and the second box portion 42 may also be a hollow structure with one side open, and the open side of the first box portion 41 covers the open side of the second box portion 42 to form a box 400 with a storage space 43. Of course, the first box portion 41 and the second box portion 42 may be in a variety of shapes, such as a cylinder, a cuboid, etc.

[0078] In order to improve the sealing performance after the first box body 41 and the second box body 42 are connected, a sealing member, such as a sealant, a sealing ring, etc., may also be provided between the first box body 41 and the second box body 42 .

[0079] Assuming that the first box body portion 41 covers the top of the second box body portion 42 , the first box body portion 41 can also be referred to as an upper box cover, and the second box body portion 42 can also be referred to as a lower box.

[0080] In the battery 100, there can be one or more battery cells. If there are multiple battery cells, the multiple battery cells can be connected in series, in parallel, or in mixed connection. Mixed connection means that multiple battery cells are connected in series and in parallel. Multiple battery cells can be directly connected in series, in parallel, or in mixed connection, and then the whole formed by the multiple battery cells is accommodated in the box 400; of course, multiple battery cells can also be connected in series, in parallel, or in mixed connection to form a battery module 500, and multiple battery modules 500 are then connected in series, in parallel, or in mixed connection to form a whole, and accommodated in the box 400.

[0081] Figure 3 for Figure 2 The schematic diagram of the battery module is shown in FIG. Figure 3 As shown, in some embodiments, there are multiple battery cells 10, and the multiple battery cells 10 are first connected in series, in parallel, or in mixed series to form a battery module 500. The multiple battery modules 500 are then connected in series, in parallel, or in mixed series to form a whole, and are accommodated in a box.

[0082] The multiple battery cells 10 in the battery module 500 are electrically connected through a busbar component to achieve parallel connection, series connection, or mixed connection of the multiple battery cells 10 in the battery module 500 .

[0083] Figure 4 is a schematic diagram of the structure of a battery cell provided in an embodiment of the present application, Figure 5 for Figure 4 Schematic diagram of the internal structure of a battery cell shown.

[0084] See also Figure 4 and Figure 5 The battery cell of the embodiment of the present application includes a shell 11, an end cap assembly 12 and an electrode assembly 13. The shell 11 is a hollow structure with two ends open and a receiving portion; the end cap assembly 12 includes a first end cap 121 and a second end cap 122 respectively covering the two ends of the shell 11; the electrode assembly 13 is arranged in the receiving portion, including a plurality of first pole pieces 131 and a plurality of second pole pieces 132 with opposite polarities, the first pole piece 131 is electrically connected to the first end cap 121, the second pole piece 132 is electrically connected to the second end cap 122, and the orthographic projections of the first pole piece 131 and the second pole piece 132 on the first end cap 121 are both closed shapes, wherein the plurality of first pole pieces 131 and the plurality of second pole pieces 132 are alternately nested along the radial direction of the shell 11.

[0085] The shell 11 can be in various shapes, such as a cylinder, a cuboid, etc. The shape of the shell 11 can be determined according to the specific shape of the electrode assembly 13. For example, if the electrode assembly 13 is a cylindrical structure, a cylindrical shell 11 can be selected; if the electrode assembly 13 is a cuboid structure, a cuboid shell 11 can be selected. It should be noted that when the shell 11 is in the shape of a cylinder, the radial direction of the shell 11 is the extension direction of any radius in the cross section of the shell 11; when the shell 11 is in the shape of a polygon such as a cuboid or other irregular shapes, the radial direction of the shell 11 is the extension direction of the longest side in the cross section of the shell 11.

[0086] In addition to accommodating the electrode assembly 13, the housing 11 can also be used to accommodate electrolytes, such as electrolytes. The first end cap 121 and the second end cap 122 in the end cap assembly 12 are relatively arranged on both sides of the housing 11 along the first direction X and form a sealed connection. The housing 11 and the end cap assembly 12 can be in various structural forms, for example, the first end cap 121 is directly welded to the housing 11, and the second end cap 122 is insulated and separated from the housing 11 by a sealing member. Or the first end cap 121 itself is integrated with the housing 11, and the second end cap 122 is sealed at one end of the housing 11, which is not limited in the embodiment of the present application.

[0087] The first pole piece 131 is electrically connected to the first end cap 121, and the second pole piece 132 is electrically connected to the second end cap 122. The first pole piece 131 is one of the positive pole piece and the negative pole piece, and the second pole piece 132 is the other of the two. The first end cap 121 and the second end cap 122 can respectively serve as the positive and negative electrode terminals of the battery cell to output the electric energy generated by the electrode assembly 13.

[0088] See also Figure 5 and Figure 6 The number of the first pole piece 131 and the number of the second pole piece 132 are both multiple, the sizes of different first pole pieces 131 and different second pole pieces 132 are different, and the orthographic projections of a single first pole piece 131 and a single second pole piece 132 on the first end cover 121 are both closed shapes. Optionally, the orthographic projections of a single first pole piece 131 and a single second pole piece 132 on the first end cover 121 are both circular structures, and the multiple circular structures are staggered and nested.

[0089] The embodiment of the present application changes the internal structure of the electrode assembly 13, splits the traditional single first pole piece 131 and the single second pole piece 132 into multiple first pole pieces 131 and multiple second pole pieces 132, and makes the multiple first pole pieces 131 and the multiple second pole pieces 132 alternately nested along the radial direction of the shell 11, thereby reducing the size of the single first pole piece 131 and the single second pole piece 132, reducing the processing difficulty of the electrode assembly 13, and improving the yield rate, ensuring mass production processing.

[0090] See also Figure 7 In some embodiments, the first pole piece 131 includes a first substrate portion 1311 and a first coating portion 1312 disposed on a side of the first substrate portion 1311 close to the second pole piece 132 . The first substrate portion 1311 protrudes from the first coating portion 1312 along the first direction X and is electrically connected to the first end cover 121 .

[0091] When the first electrode sheet 131 is a positive electrode sheet, the first substrate portion 1311 is a positive electrode current collector, and the first coating portion 1312 is a positive electrode active material layer; when the first electrode sheet 131 is a negative electrode sheet, the first substrate portion 1311 is a negative electrode current collector, and the first coating portion 1312 is a negative electrode active material layer. The length of the first substrate portion 1311 in the first direction X is greater than the length of the first coating, so that the first substrate portion 1311 protrudes from the first coating portion 1312 along the first direction X, and the protruding portion is electrically connected to the first end cover 121 as the pole ear portion of the first electrode sheet 131. It can be understood that the structure of the second electrode sheet 132 can be similar to that of the first electrode sheet 131, including a second substrate portion 1321 and a second coating portion 1322 located on at least one side of the second substrate portion 1321, and the embodiments of the present application will not be repeated.

[0092] In the embodiment of the present application, the length of the first substrate portion 1311 in the first direction X is greater than the length of the first coating so that the first substrate portion 1311 protrudes from the first coating portion 1312. The protruding portion of the first substrate portion 1311 can be directly electrically connected to the first end cover 121 as a pole ear portion, thereby realizing an integrated design of the first pole piece 131 and the first end cover 121, and the structure is simple and reliable.

[0093] Please continue reading Figure 7In some embodiments, the first end cover 121 includes a first cover plate 1211 and a first protrusion 1212 protruding from the first cover plate 1211 along a first direction X, wherein the first coating portion 1312 abuts against the first protrusion 1212 and is insulated from the first cover plate 1211 through the first protrusion 1212.

[0094] The first substrate portion 1311 is directly connected to the first cover plate 1211 by welding or other methods. The first protrusion 1212 is arranged on the first cover plate 1211. There are multiple first protrusions 1212, the number of which is the same as the number of the first coating portion 1312. The two are arranged correspondingly and abuttingly. The multiple first protrusions 1212 are arranged in sequence. A recessed portion is formed between two adjacent first protrusions 1212. The first substrate portion 1311 is located in the recessed portion and is electrically connected to the first cover plate 1211. The first protrusion 1212 and the first cover plate 1211 are insulated from each other, so that the first coating portion 1312 can be insulated from the first cover plate 1211.

[0095] During the preparation of the battery cell, a first protrusion 1212 can be firstly provided on the first cover plate 1211, and the manufactured first end cover 121 is sealed and fixed to the shell 11, and then the first substrate portion 1311 in the manufactured first pole piece 131 is inserted between two adjacent first protrusions 1212 along the first direction X until the first substrate portion 1311 is in direct contact with the first cover plate 1211, at which time the first coating portion 1312 is in contact with the first protrusion 1212, and finally the first substrate portion 1311 and the first cover plate 1211 are fixed by welding or the like, so that the position of the first pole piece 131 in the shell 11 is fixed.

[0096] In the embodiment of the present application, a plurality of first protrusions 1212 are arranged on the first cover plate 1211 to achieve mutual insulation between the first coating portion 1312 and the first cover plate 1211. At the same time, the space between two adjacent first protrusions 1212 can be used to accommodate the protruding portion of the first substrate portion 1311 relative to the first coating portion 1312. The structure is simple and reliable, and can reduce the difficulty of manufacturing the battery cell to a certain extent.

[0097] like Figure 7As shown, in some embodiments, a second protrusion 1213 is further provided on the first cover plate 1211, and the second protrusion 1213 is arranged in contact with the second coating portion 1322 in the second electrode 132, so that the second coating portion 1322 is insulated from the first cover plate 1211. It should be noted that when the first electrode 131 is a negative electrode and the second electrode 132 is a positive electrode, the length of the first coating portion 1312 in the first direction X is greater than the length of the second coating portion 1322 in the second direction, so the height of the first protrusion 1212 in the first direction X can be set to be less than the height of the second protrusion 1213 in the first direction X, so that the dimensions of the first electrode 131, the second electrode 132 and the first end cover 121 match.

[0098] like Figure 7 As shown, in some embodiments, the end cover assembly further includes an insulating connector 123 , which is disposed on a side of the first end cover 121 close to the electrode assembly 13 , and the second electrode sheet 132 is insulated from the first cover plate 1211 by the insulating connector 123 .

[0099] As can be seen from the foregoing, the second pole piece 132 is electrically connected to the second end cover, and the second pole piece 132 is insulated from the first end cover 121. The second protrusion 1213 on the first end cover 121 insulates the second coating portion 1322 in the second pole piece 132 from the first cover plate 1211. The insulating connector 123 is disposed between adjacent second protrusions 1213, and is used to insulate the second substrate portion 1321 in the second pole piece 132 from the first cover plate 1211. The insulating connector 123 and the first end cover 121 may be detachably connected, and the second pole piece 132 can be first connected to the insulating connector 123, and then both are installed on the first end cover 121 together.

[0100] In the embodiment of the present application, the second pole piece 132 and the first cover plate 1211 are spaced apart by the insulating connector 123, so that the second pole piece 132 and the first cover plate 1211 are insulated from each other, and the second pole piece 132 and the first cover plate 1211 are prevented from being conductive and affecting the normal use of the battery cell. At the same time, the insulating connector 123 and the first end cover 121 can be detachably arranged, which is beneficial to subsequent maintenance and inspection.

[0101] It should be noted that the structure of the second end cover 122 may be the same as that of the first end cover 121 , or may be different from that of the first end cover 121 , and this embodiment of the present application does not limit this.

[0102] In some embodiments, the insulating connector 123 is slidably connected to the first cover plate 1211 and can move relative to the first cover plate 1211 along the radial direction of the housing 11 to change the distance between the first pole piece 131 and the second pole piece 132 .

[0103] The second pole piece 132 is connected to the insulating connector 123. The position of the second pole piece 132 can be adjusted by changing the position of the insulating connector 123 to change the distance between the first pole piece 131 and the second pole piece 132. The connection method between the insulating connector 123 and the first cover plate 1211 includes but is not limited to magnetic connection. The distance between the first pole piece 131 and the second pole piece 132 refers to the distance between the first substrate portion 1311 and the second substrate portion 1321 in the radial direction of the housing 11.

[0104] In the embodiment of the present application, the insulating connector 123 is slidably connected to the first cover plate 1211, and while the second pole piece 132 is insulated from the first cover plate 1211, the distance between the first pole piece 131 and the second pole piece 132 is adjusted. The operation is simple and quick, and no additional components are required, which indirectly reduces the size and weight of the battery cell.

[0105] See also Figure 7 In some embodiments, the electrode assembly 13 further includes a plurality of diaphragms 133 , and the diaphragms 133 are disposed between adjacent first electrode sheets 131 and second electrode sheets 132 .

[0106] The material of the diaphragm 133 can be PP or PE, etc., and is used to transport metal ions between the first pole piece 131 and the second pole piece 132. The structure of the diaphragm 133 is similar to that of the first pole piece 131 and the second pole piece 132. The orthographic projection of the diaphragm 133 on the first end cover 121 is also a closed structure, and multiple diaphragms 133 are nested in sequence along the radial direction of the housing 11, and are respectively located between adjacent first pole pieces 131 and second pole pieces 132.

[0107] The embodiment of the present application is different from the traditional one in the number and arrangement of the diaphragms 133. By providing multiple diaphragms 133 to separate different first pole pieces 131 from the second pole pieces 132, this design is beneficial to the maintenance and replacement of the internal parts of the electrode assembly 13, so as to extend the service life of the battery cell.

[0108] In some embodiments, the electrode assembly 13 further includes a support mechanism 134 , which extends along the first direction X. The first pole piece 131 and the second pole piece 132 are radially arranged around the outer periphery of the support mechanism 134 along the shell 11 .

[0109] The structure of the support mechanism 134 can be a light insulating polymer, which is arranged at the center of the electrode assembly 13. The first pole piece 131 and the second pole piece 132 are arranged around the support mechanism 134, so as to enhance the stability of the internal structure of the electrode assembly 13 without affecting the weight of the battery cell, and avoid the problem of central collapse. Optionally, the support mechanism 134 is a cylindrical structure and is arranged in a close fit with the adjacent first pole piece 131 or the second pole piece 132.

[0110] The embodiment of the present application utilizes a lightweight insulating polymer as a supporting structure to avoid the problem of center collapse of the traditional electrode assembly 13, enhance the stability of the internal structure of the electrode assembly 13, and ensure the normal use of the battery cell.

[0111] On the other hand, the present application also provides a method for manufacturing a battery cell. Figure 8 to Figure 1 1 The manufacturing method provided in the embodiment of the present application is described in detail.

[0112] In the battery manufacturing process, the coating process is often used to prepare battery cells. There are many difficulties in the preparation process. Problems such as coating cracking, coating leakage, scratches, and wrinkles greatly affect production efficiency and quality rate. In addition, the subsequent preparation of positive and negative electrodes also involves cold pressing, pre-slitting, die-cutting, and striping. The requirements for factory buildings and human resources are high. The continuous processing of multiple processes further leads to the loss of quality rate.

[0113] To address this problem, an embodiment of the present application provides a manufacturing method, which includes:

[0114] S100. Provide a battery substrate, which includes a shell 11, a first end cover 121, a plurality of first substrate portions 1311, a plurality of second substrate portions 1321 and a plurality of diaphragms 133. The first end cover 121 covers one end of the shell 11, the plurality of first substrate portions 1311 and the plurality of second substrate portions 1321 are alternately nested along the radial direction of the shell 11, and the diaphragm 133 is arranged between adjacent first substrate portions 1311 and second substrate portions 1321.

[0115] S110 , injecting a first slurry between the first substrate portion 1311 and the adjacent diaphragm 133 to form a first coating portion 1312 ; the first substrate portion 1311 and the first coating portion 1312 together constitute the first pole piece 131 .

[0116] S120 , injecting the second slurry between the second substrate portion 1321 and the adjacent diaphragm 133 to form a second coating portion 1322 . The second substrate portion 1321 and the second coating portion 1322 together constitute the second pole piece 132 .

[0117] See also Figure 9aThe shell 11, the first end cover 121, the first substrate portion 1311, the second substrate portion 1321 and the diaphragm 133 in step S100 are the shell 11, the first end cover 121, the first substrate portion 1311, the second substrate portion 1321 and the diaphragm 133 described in any of the aforementioned embodiments. The first substrate portion 1311 and the second substrate portion 1321 are fixed on the first end cover 121, and the two are alternately nested along the radial direction of the shell 11. The diaphragm 133 is arranged between adjacent first substrate portions 1311 and second substrate portions 1321, and there is a certain gap between the adjacent first substrate portions 1311 and second substrate portions 1321, which is used for injection molding of the first slurry or the second slurry, and the size of the gap is determined according to the size of the first coating portion 1312 and the second coating portion 1322. Among them, the materials of the first substrate portion 1311 and the second substrate portion 1321 are aluminum and copper, respectively, and this embodiment of the present application is not limited to this.

[0118] See also Figure 9b The first slurry in step S110 is used to form the first coating portion 1312, and the first substrate portion 1311 and the first coating portion 1312 together form the first pole piece 131. During production, the first slurry is injected into the gap between the first substrate portion 1311 and the diaphragm 133, and then the housing 11 is electrically heated to directly dry the first slurry to form the first coating portion 1312.

[0119] See also Fig.9c The second slurry in step S120 is used to form the second coating portion 1322, and the second substrate portion 1321 and the second coating portion 1322 together form the second pole piece 132. During the manufacturing process, the second slurry is injected into the gap between the second substrate portion 1321 and the diaphragm 133, and then the housing 11 is electrically heated to directly dry the second slurry to form the second coating portion 1322.

[0120] It is understandable that the order between step S110 and step S120 is adjusted and exchanged, and the specific operation process is determined according to the actual situation, and the embodiment itself does not limit this. In addition, during the injection molding process, a slightly negative pressure atmosphere needs to be maintained throughout the process. Specifically, if the vacuum degree is too high, the first slurry or the second slurry is easily extracted, and if the vacuum degree is too low, the bubbles generated during injection molding are difficult to discharge, and the first pole piece 131 or the second pole piece 132 obtained will have a bubble leakage metal problem. Optionally, the pressure range is -30 to -40Kpa.

[0121] The embodiment of the present application realizes the manufacture of the electrode assembly 13 by injection molding. Compared with the traditional coating process, the embodiment of the present application realizes the control of the size of the first coating part 1312 and the second coating part 1322 by adjusting the distance between the diaphragm 133 and the adjacent first substrate part 1311 and the second substrate part 1321. And it is only necessary to inject the first slurry and the second slurry between the diaphragm 133 and the adjacent first substrate part 1311 and the second substrate part 1321 to ensure that the structures of the first coating part 1312 and the second coating part 1322 are consistent at all places. The operation is simple and fast, which is conducive to improving production efficiency and also can obtain a higher yield rate.

[0122] In some embodiments, step S100 includes:

[0123] S101, providing a first end cover 121, the first end cover 121 comprising a first cover plate 1211 and first protrusions 1212 protruding from the first cover plate 1211 and spaced apart from each other, with grooves 1214 formed between adjacent first protrusions 1212;

[0124] S102, forming an insulating connector 123 in a portion of the groove 1214 to form a first receiving groove 1215 and a second receiving groove 1216 alternately distributed in the radial direction of the first end cover 121, wherein the insulating connector 123 is formed inside one of the first receiving groove 1215 and the second receiving groove 1216;

[0125] S103, fixing the first substrate portion 1311 to one of the first receiving groove 1215 and the second receiving groove 1216 where the insulating connector 123 is not formed;

[0126] S104, fixing the second substrate portion 1321 to the side of the insulating connector 123 away from the first cover plate 1211, and the plurality of first substrate portions 1311 and the plurality of second substrate portions 1321 are alternately nested along the radial direction of the housing 11;

[0127] S105 , fixing the diaphragm 133 in a portion of the groove 1214 , so that the diaphragm 133 is located between the adjacent first substrate portion 1311 and the second substrate portion 1321 .

[0128] See also Fig.11aThe first cover plate 1211 and the first protrusion 1212 in step S101 are the same as the first cover plate 1211 and the first protrusion 1212 in any of the above-mentioned embodiments, and the present embodiment will not be repeated. A groove 1214 is formed between adjacent first protrusions 1212, and the groove 1214 includes alternately distributed first receiving grooves 1215 and second receiving grooves 1216. The first receiving grooves 1215 and the second receiving grooves 1216 are used to receive the first substrate part and the second substrate part, respectively. The present embodiment is described by taking the first receiving groove 1215 as a first substrate part and the second receiving groove 1216 as a second substrate part.

[0129] See also Fig.11b In step S102, the insulating connector 123 is located in the second receiving groove 1216 to fix the second substrate 1321. The insulating connector 123 and the first cover plate 1211 are insulated from each other, so that the second substrate 1321 and the first cover plate 1211 are insulated from each other.

[0130] It is understandable that the first end cover 121 may also include a second protrusion 1213, which protrudes from the first cover plate 1211, is located in the second receiving groove 1216, and a third receiving groove 1217 is formed between adjacent second protrusions 1213, and the insulating connector 123 is arranged in the third receiving groove 1217.

[0131] See also Fig.11c In step S103, the first substrate portion 1311 is located in the first receiving groove 1215 and fixed to the first cover plate 1211, and the connection method includes but is not limited to welding. There are multiple first substrate portions 1311, and the multiple first substrate portions 1311 are correspondingly arranged with the multiple first receiving grooves 1215.

[0132] See also Fig.11d In step S104, the second substrate portion 1321 is disposed corresponding to the insulating connector 123, the second substrate portion 1321 is fixed to the side of the insulating connector 123 away from the first cover plate 1211, and the second substrate portion 1321 is insulated from the first cover plate 1211 by the insulating connector 123. Optionally, the insulating connector 123 can move relative to the first cover plate 1211 along the radial direction of the housing 11 to adjust the distance between the adjacent first substrate portion 1311 and the second substrate portion 1321.

[0133] It is understandable that the order of steps S103 and S104 can be adjusted and swapped, and the embodiment of the present application is not limited to this.

[0134] See also Fig.11eIn step S105, the diaphragm 133 is disposed between the adjacent first substrate portion 1311 and the second substrate portion 1321, and is fixed to the first cover plate 1211. The diaphragm 133 is disposed in the second receiving groove 1216, and is located between the adjacent first protrusion portion 1212 and the second protrusion portion 1213. During the manufacturing process, the diaphragm 133 restricts the injection of the first slurry and the second slurry, ensuring that the first slurry can be located between the diaphragm 133 and the first substrate portion 1311, and the second slurry is located between the diaphragm 133 and the second substrate portion 1321, thereby forming a first pole piece and a second pole piece with reliable structures.

[0135] The embodiment of the present application specifically designs the first end cover 121, and a first protrusion 1212 is provided on the first end cover 121. The positions of the first pole piece and the second pole piece are controlled by the groove 1214 formed between adjacent first protrusions 1212. At the same time, the diaphragm 133 is fixed on the first cover plate 1211, and the injection positions of the first slurry and the second slurry are restricted by the diaphragm 133, thereby ensuring that the electrode assembly structure is stable and reliable.

[0136] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, characterized in that: include: The shell is a hollow structure with openings at both ends and a receiving portion; An end cover assembly comprises a first end cover and a second end cover respectively covering two ends of the shell; an electrode assembly, disposed in the accommodating portion, comprising a plurality of first pole pieces and a plurality of second pole pieces with opposite polarities, wherein the first pole piece is electrically connected to the first end cover, and the second pole piece is electrically connected to the second end cover, and the orthographic projections of the first pole piece and the second pole piece on the first end cover are both closed shapes; Wherein, a plurality of the first pole pieces and a plurality of the second pole pieces are alternately nested along the radial direction of the shell.

2. The battery cell according to claim 1, characterized in that: The first pole piece includes a first substrate portion and a first coating portion provided on a side of the first substrate portion close to the second pole piece, the first substrate portion protruding from the first coating portion along a first direction and being electrically connected to the first end cap; Wherein, the first end cover and the second end cover are arranged opposite to each other along the first direction.

3. The battery cell according to claim 2, characterized in that: The first end cover comprises a first cover plate and a first protrusion protruding from the first cover plate along the first direction; The first coating portion is in contact with the first protrusion and is insulated from the first cover plate through the first protrusion.

4. The battery cell according to claim 3, characterized in that: The end cover assembly further includes an insulating connector, which is disposed on a side of the first end cover close to the electrode assembly, and the second pole piece is insulated from the first cover plate via the insulating connector.

5. The battery cell according to claim 4, characterized in that: The insulating connector is slidably connected to the first cover plate, and can move relative to the first cover plate along the radial direction of the shell to change the distance between the first pole piece and the second pole piece.

6. The battery cell according to claim 1, characterized in that: The electrode assembly further includes a plurality of diaphragms, and the diaphragms are disposed between adjacent first pole pieces and second pole pieces.

7. The battery cell according to claim 1, characterized in that: The electrode assembly further includes a support mechanism, the support mechanism extends along a first direction, and the first pole piece and the second pole piece are arranged around the outer periphery of the support mechanism along the radial direction of the shell; Wherein, the first end cover and the second end cover are arranged opposite to each other along the first direction.

8. A battery, characterized in that: include: A box body and a battery cell according to any one of claims 1 to 7, wherein the battery cell is accommodated in the box body.

9. An electrical device, characterized in that: Comprising a battery as claimed in claim 8, the battery is used to provide electrical energy.

10. A method for manufacturing a battery cell, characterized in that: include: A battery substrate is provided, the battery substrate comprising a shell, a first end cover, a plurality of first substrate parts, a plurality of second substrate parts and a plurality of diaphragms, wherein the first end cover is covered on one end of the shell, a plurality of the first substrate parts and a plurality of the second substrate parts are alternately nested along the radial direction of the shell, and the diaphragm is arranged between adjacent first substrate parts and second substrate parts; Injecting a first slurry between the first substrate portion and the adjacent diaphragm to form a first coating portion, wherein the first substrate portion and the first coating portion together constitute a first pole piece; Injecting a second slurry between the second substrate portion and the adjacent diaphragm to form a second coating portion, wherein the second substrate portion and the second coating portion together constitute a second pole piece; The orthographic projections of the first pole piece and the second pole piece on the first end cover are both closed shapes.

11. The manufacturing method according to claim 10, characterized in that: The step of providing a battery substrate comprises: Providing a first end cover, the first end cover comprising a first cover plate and first protrusions protruding from the first cover plate and spaced apart from each other, with grooves formed between adjacent first protrusions; An insulating connector is formed in part of the groove to form a first accommodating groove and a second accommodating groove alternately distributed in the radial direction of the first end cover, wherein the insulating connector is formed inside one of the first accommodating groove and the second accommodating groove; Fixing the first base material portion to one of the first receiving groove or the second receiving groove where the insulating connector is not formed; The second substrate portion is fixed to the side of the insulating connector away from the first cover plate, and a plurality of the first substrate portions and a plurality of the second substrate portions are alternately nested along the radial direction of the housing; The diaphragm is fixed in a portion of the groove so that the diaphragm is located between the adjacent first substrate portion and the second substrate portion.

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