Electrode assembly and related battery, device, manufacturing method and manufacturing device

Abstract

The present application discloses an electrode assembly and its related battery, device, manufacturing method and manufacturing device. The electrode assembly according to an embodiment of the present application includes: a first pole piece and a second pole piece with opposite polarities. An active material area of the first pole piece and an active material area of the second pole piece are wound to form a main body part. An inactive material area of the first pole piece or an inactive material area of the second pole piece is wound to form a tab. The tab includes a bent part bent relative to the main body part; a current collector. At least a part of the current collector is located within the bent part and is used to guide electrolyte to flow into the interior of the main body part. The electrode assembly according to the embodiment of the present application improves the wetting effect of the electrolyte on the active material, and can effectively improve the performance of the battery when applied to the battery.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of batteries, and particularly to an electrode assembly and related batteries, devices, manufacturing methods, and manufacturing devices thereof. Background Art

[0002] Batteries such as lithium-ion batteries have the advantages of small volume, high energy density, high power density, many cycle usage times, and long storage time, and are widely used in some electronic devices, electric vehicles, electric toys, and electric equipment. For example, lithium-ion batteries have been widely used in products such as mobile phones, laptop computers, battery cars, electric vehicles, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and electric tools.

[0003] With the continuous development of battery technology, higher requirements are put forward for the performance of batteries. The electrolyte is the carrier of ion transport in lithium-ion batteries. Lithium ions are transported between the positive electrode plate and the negative electrode plate through the electrolyte, so that lithium ions can be normally inserted and extracted between the positive electrode active material region and the negative electrode active material region. Therefore, the wetting effect of the electrolyte on the active materials in the electrode assembly is an important factor to ensure high performance of the battery.

[0004] For a wound electrode assembly, the electrolyte is transported to the inside of the electrode assembly through the gap between adjacent two tabs. However, the tabs of the electrode assembly usually form bent portions after being flattened to reduce the overall space occupied by the electrode assembly. However, the bent portions formed by flattening the tabs will cause the ends of adjacent two tab layers in the laminated structure to be closely adjacent to each other and form a closed structure. Such a closed structure hinders the passage of the electrolyte from the external space of the tab into the main body to a certain extent, resulting in insufficient wetting of the positive and negative electrode active material regions, which has an important impact on the battery performance. Summary of the Invention

[0005] In view of the above problems, the embodiments of the present application propose an electrode assembly and related batteries, devices, manufacturing methods, and manufacturing devices to improve the wetting effect of the electrolyte on the active material region and improve the performance of the battery.

[0006] According to the first aspect of the embodiments of the present application, an electrode assembly is provided, including: a first electrode plate and a second electrode plate with opposite polarities. The active material regions of the first electrode plate and the second electrode plate are wound to form a main body portion. The non-active material region of the first electrode plate or the non-active material region of the second electrode plate is wound to form a tab. The tab includes a bent portion bent relative to the main body portion; a flow guiding member, at least a part of which is located inside the bent portion and is used for guiding the electrolyte to flow into the inside of the main body portion.

[0007] In the electrode assembly according to the embodiments of the present application, by providing a current guide member and arranging at least a part of the current guide member within the bent portion of the tab, the opening size at the end of the bent portion is increased to a certain extent, enabling the electrolyte to smoothly pass through the opening, improving the wetting effect of the electrolyte on the active material region, and effectively enhancing the performance of the battery when applied to the battery.

[0008] In some embodiments, at least one first flow channel is provided in the current guide member and / or the bent portion. One end of the first flow channel communicates with the external space of the electrode assembly, and the other end communicates with the interior of the main body portion. The current guide member guides the electrolyte into the interior of the main body portion through the first flow channel.

[0009] In such embodiments, the electrolyte can enter the interior of the main body portion of the electrode assembly from the external space of the electrode assembly through the first flow channel, enabling the current guide member and / or the bent portion to play a role in guiding the flow by themselves.

[0010] In some embodiments, the current guide member includes at least two current guide units, and a second flow channel is formed between two adjacent current guide units. The current guide member guides the electrolyte into the interior of the main body portion through the second flow channel.

[0011] In such embodiments, the electrolyte can also enter the interior of the main body portion of the electrode assembly from the external space of the electrode assembly through the gaps between the multiple current guide units, increasing the entry path of the electrolyte and further improving the wettability of the electrolyte of the electrode assembly; and the multiple current guide units can be arranged regularly or irregularly, making the design of the current guide member more flexible.

[0012] In some embodiments, the current guide member includes a first portion and a second portion. The first portion is located within the bent portion, and the second portion is connected to the outer end of the first portion and extends to the external space of the electrode assembly.

[0013] In such embodiments, the second portion of the current guide member can also play a role in guiding the flow, enabling the electrolyte located in the external space of the electrode assembly to flow along the second portion of the current guide member into the bent portion of the tab, and then into the interior of the main body portion of the electrode assembly, further improving the wetting effect of the electrolyte on the active material region.

[0014] In some embodiments, the current guide member further includes a third portion. The third portion is connected to the inner end of the first portion and extends between the active material regions of the first electrode plate and the second electrode plate.

[0015] In such an embodiment, the electrolyte can more easily flow into the interior of the main body portion from the bent portion of the tab along the third portion of the flow guide member, further improving the wetting effect of the electrolyte on the active material region.

[0016] In some embodiments, the flow guide member is made of an insulating material and has through holes for ions to pass through in its thickness direction.

[0017] In such an embodiment, the flow guide member can be made of the same or similar material as the separator; moreover, in the case where the flow guide member further includes a third portion, the flow guide member can also function as a separator or be formed by at least a portion of the separator, thereby simplifying the preparation of the electrode assembly.

[0018] In some embodiments, the electrode assembly further includes a separator located between the active material regions of the first electrode sheet and the second electrode sheet, and the flow guide member is attached to the separator or is spaced apart from the separator.

[0019] In such an embodiment, when a separator is further provided in the electrode assembly, the design of the flow guide member is flexible, and it can be attached to or spaced apart from the separator without affecting the function and role of the separator itself.

[0020] In some embodiments, the end face of the bent portion has a drainage area and a connection area. The bent portion is connected to an external member through the connection area, and the bent portion guides the electrolyte to flow into the interior of the main body portion through the flow guide member located in the drainage area.

[0021] In such an embodiment, by dividing the drainage area and the connection area on the end face of the bent portion, it is not only convenient for the connection of external members (such as electrode terminals), but also enables the flow guide member in the drainage area to more effectively guide the electrolyte to flow into the interior of the main body portion.

[0022] According to a second aspect of the embodiments of the present application, there is provided a battery cell, including: the electrode assembly of the above embodiment; a housing for accommodating the electrode assembly; and a terminal assembly provided on the housing for connecting the bent portion to output or input electrical energy.

[0023] According to a third aspect of the embodiments of the present application, there is provided a battery including the battery cell of the above embodiment.

[0024] According to a fourth aspect of the embodiments of the present application, there is provided an electrical device including the battery of the above embodiment, wherein the battery is used to provide electrical energy.

[0025] According to a fifth aspect of the embodiments of the present application, a method for preparing an electrode assembly is provided, including: providing a first electrode sheet, a second electrode sheet, and a current collector, wherein the first electrode sheet and the second electrode sheet have opposite polarities, and at least a part of the current collector is disposed between the first electrode sheet and the second electrode sheet; winding the first electrode sheet and the second electrode sheet to form a wound structure, wherein the active material regions of the first electrode sheet and the second electrode sheet form a main body after winding, and the non-active material region of the first electrode sheet or the non-active material region of the second electrode sheet forms a tab after winding; and bending at least a part of the tab relative to the main body to form a bent portion, and at least a part of the current collector is located within the bent portion for guiding electrolyte to flow into the interior of the main body.

[0026] According to a sixth aspect of the embodiments of the present application, a device for preparing an electrode assembly is provided, including: a pole piece placement module configured to provide a first electrode sheet, a second electrode sheet, and a current collector, wherein the first electrode sheet and the second electrode sheet have opposite polarities, and at least a part of the current collector is disposed between the first electrode sheet and the second electrode sheet; a winding module configured to wind the first electrode sheet and the second electrode sheet to form a wound structure, wherein the active material regions of the first electrode sheet and the second electrode sheet form a main body after winding, and the non-active material region of the first electrode sheet or the non-active material region of the second electrode sheet forms a tab after winding; and a flattening module configured to bend at least a part of the tab relative to the main body to form a bent portion, and at least a part of the current collector is located within the bent portion for guiding electrolyte to flow into the interior of the main body.

[0027] The above description is only an overview of the technical solutions of the embodiments of the present application. In order to be able to understand the technical means of the embodiments of the present application more clearly, it can be implemented according to the content of the description. And in order to make the above and other purposes, features and advantages of the embodiments of the present application more obvious and understandable, the specific embodiments of the present application are specifically given below. Description of the Drawings

[0028] By reading the detailed description of the preferred embodiments below, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present application. And in all the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0029] Figure 1 is a three-dimensional structural schematic diagram of an electrode assembly according to some embodiments of the present application;

[0030] Figure 2 is a schematic diagram of a laminated and wound structure of an electrode assembly according to some embodiments of the present application;

[0031] Figure 3 Schematic diagram of the partial sectional structure of an electrode assembly according to some embodiments of the present application;

[0032] Figure 4 Schematic diagram of the structure of an electrode assembly before winding according to some embodiments of the present application;

[0033] Figure 5 Schematic diagram of the partial sectional structure of the end face of the bending portion of an electrode assembly according to some embodiments of the present application;

[0034] Figure 6 Schematic diagram of the structure of an electrode assembly before winding according to some embodiments of the present application;

[0035] Figure 7 Schematic diagram of the partial sectional structure of an electrode assembly according to some embodiments of the present application;

[0036] Figure 8 Schematic diagram of the structure of an electrode assembly before winding according to some embodiments of the present application;

[0037] Figure 9 Schematic diagram of the partial sectional structure of an electrode assembly according to some other embodiments of the present application;

[0038] Figure 10 Schematic diagram of the partial sectional structure of an electrode assembly according to some other embodiments of the present application;

[0039] Figure 11 Schematic diagram of the end face structure of the bending portion of an electrode assembly according to some embodiments of the present application;

[0040] Figure 12 Schematic diagram of the exploded structure of a battery cell according to some embodiments of the present application;

[0041] Figure 13 Schematic diagram of the structure of a battery according to some embodiments of the present application;

[0042] Figure 14 Schematic diagram of the exploded structure of a battery according to some embodiments of the present application;

[0043] Figure 15 Schematic diagram of the structure of an electrical device according to some embodiments of the present application;

[0044] Figure 16 Schematic diagram of the flow of a method for preparing an electrode assembly according to some embodiments of the present application;

[0045] Figure 17 Schematic diagram of the structure of a device for preparing an electrode assembly according to some embodiments of the present application.

[0046] The reference numerals in the specific embodiments are as follows:

[0047] Electrode assembly 100, first electrode tab 110, first active material region 111, first non-active material region 112, second electrode tab 120, second active material region 121, second non-active material region 122, current collector 130, first part 131, second part 132, third part 133, current collection unit 130a, separator 140, main body 150, tab 160, first tab 160a, second tab 160b, bent portion 161, bent layer 161a, connecting portion 162, first current guiding channel 171, current guiding hole 171a, current guiding groove 171b, second current guiding channel 172, connecting region 181, drainage region 182, central drainage region 182a, peripheral drainage region 182b; battery cell 200, outer casing 210, terminal assembly 220, electrode terminal 221, end cap 222; battery 300, box body 310; electrical device 400, motor 401, controller 402; electrode assembly preparation device 600, electrode tab placement module 601, winding module 602, flattening module 603. Detailed implementation manners

[0048] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of this application. Apparently, the described embodiments are some but not all of the embodiments of this application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of this application without making creative efforts shall fall within the protection scope of this application.

[0049] It should be noted that unless otherwise specified, the technical terms or scientific terms used in the embodiments of this application should have the ordinary meanings understood by those skilled in the art to which the embodiments of this application belong.

[0050] In the description of the embodiments of this application, the orientation or positional relationship indicated by technical terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. This is only for the convenience of describing the embodiments of this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the embodiments of this application.

[0051] In addition, technical terms such as "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features, nor are they used to describe a specific order or primary-secondary relationship. In the description of the embodiments of the present application, the meaning of "a plurality of" is more than two, unless otherwise specifically defined.

[0052] Reference to "embodiments" in this document means that specific features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art can understand that the embodiments described herein can be combined with other embodiments.

[0053] The term "and / or" in this document is merely a description of the association relationship of associated objects, indicating that three relationships can exist. For example, "A and / or B" can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. Additionally, the character " / " in this document generally represents an "or" relationship between the associated objects before and after.

[0054] The "a plurality of" mentioned in the present application refers to more than two (including two). Similarly, "a plurality of groups" refers to more than two groups (including two groups), and "a plurality of pieces" refers to more than two pieces (including two pieces).

[0055] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installation", "connection", "coupling", "fixing", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can also be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication 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 specific circumstances.

[0056] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over", and "on top of" the second feature can be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature is at a higher horizontal level than the second feature. The first feature being "under", "beneath", and "underneath" the second feature can be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature is at a lower horizontal level than the second feature.

[0057] Existing batteries generally include a housing and an electrode assembly accommodated within the housing, and an electrolyte is filled within the housing. The electrode assembly is mainly formed by stacking a positive electrode sheet and a negative electrode sheet, and a separator is usually provided between the positive electrode sheet and the negative electrode sheet. The portions of the positive electrode sheet and the negative electrode sheet having active materials constitute the main body of the electrode assembly, and the portions of the positive electrode sheet and the negative electrode sheet without active materials respectively constitute the positive electrode tab and the negative electrode tab. In the case of a lithium-ion battery, the positive electrode sheet includes a positive electrode current collector and positive electrode active material layers provided on both sides of the positive electrode current collector. The material of the positive electrode current collector can be, for example, aluminum, and the positive electrode active material can be, for example, lithium cobaltate, lithium iron phosphate, ternary lithium, or lithium manganate, etc.; the negative electrode sheet includes a negative electrode current collector and negative electrode active material layers provided on both sides of the negative electrode current collector. The material of the negative electrode current collector can be, for example, copper, and the negative electrode active material can be, for example, carbon or silicon, etc. The positive electrode tab and the negative electrode tab can be located together at one end of the main body or respectively at both ends of the main body.

[0058] During the charge and discharge process of the battery, the positive electrode active material and the negative electrode active material in the main body react with the electrolyte, and the tabs are connected to the electrode terminals to form a current loop. If the wetting effect of the electrolyte on the active material is insufficient, it may cause the positive electrode or negative electrode active material not to fully participate in the reaction, affecting the efficiency of the electrode assembly and the performance of the battery. Therefore, the wetting effect of the electrolyte on the active material in the electrode assembly is an important factor to ensure high performance of the battery.

[0059] Currently, the improvement measures for the wetting effect of the electrolyte on the active material in the battery mainly focus on coating a material to improve the wetting effect on the surface of the electrode sheet, or changing the material or hierarchical structure of the separator. However, such design solutions lead to a further increase in the cost of the electrode assembly and a more complex manufacturing process.

[0060] In the processing and assembly procedures of the electrode assembly, it is often necessary to flatten the tabs to cause the tabs to bend and deform, so as to facilitate the connection of the tabs to the electrode terminals and the assembly of the battery cells. The inventors of the present application found in practice that flattening the tabs will cause the ends of two adjacent tab layers in the stacked structure to be closely adjacent to each other and form a closed structure. Such a closed structure to a certain extent hinders the passage of the electrolyte from the external space of the tabs into the main body, has an adverse effect on the wetting effect of the electrolyte on the active material in the electrode assembly, and thus affects the performance of the battery.

[0061] Based on the discovery of the above problems, the inventors of the present application improved the structural design of the electrode assembly to enhance the wetting effect of the electrolyte on the active material in the electrode assembly and improve the performance of the battery. The following will further describe each embodiment of the present application with reference to the accompanying drawings.

[0062] According to the first aspect of the embodiments of the present application, an electrode assembly 100 is provided. Please refer toFigure 1 and Figure 2 , wherein Figure 1 schematically shows a three-dimensional structure of the electrode assembly 100 according to some embodiments of the present application; Figure 2 schematically shows a laminated winding structure of the electrode assembly 100 according to some embodiments of the present application.

[0063] As shown in the figure, the electrode assembly 100 includes a first electrode tab 110, a second electrode tab 120, and a current collector 130. The first electrode tab 110 and the second electrode tab 120 have opposite polarities. For example, the first electrode tab 110 is a positive electrode tab, and the second electrode tab 120 is a negative electrode tab, or vice versa. The first electrode tab 110 and the second electrode tab 120 are wound about a winding axis to form a winding structure.

[0064] The first electrode tab 110 is provided with a first active material region 111 (i.e., a region provided with a first active material) and a first non-active material region 112 (i.e., a region not provided with a first active material); the second electrode tab 120 is provided with a second active material region 121 (i.e., a region provided with a second active material) and a second non-active material region 122 (i.e., a region not provided with a first active material). The first active material and the second active material can be a positive electrode active material and a negative electrode active material, respectively.

[0065] In the winding structure, the first active material region 111 of the first electrode tab 110 and the second active material region 121 of the second electrode tab 120 are wound to form a main body portion 150, and the first non-active material region 112 of the first electrode tab 110 is wound to form a first electrode ear 160a, and the second non-active material region 122 of the second electrode tab 120 is wound to form a second electrode ear 160b. At least a part of the current collector 130 is located within a bent portion 161 of an electrode ear (such as the first electrode ear 160a or the second electrode ear 160b) after winding, and is used to guide the electrolyte to flow into the interior of the main body portion 150.

[0066] Please further refer to Figure 3 , Figure 3 schematically shows a partial cross-sectional structure of the electrode assembly according to some embodiments of the present application, specifically showing a partial cross-sectional structure of one end where the first electrode ear 160a is located in the winding structure of the electrode assembly. Those skilled in the art should understand that the other end where the second electrode ear 160b is located may also have a similar structure.

[0067] As shown in the figure, the first tab 160a includes a bent portion 161 that is bent relative to the main body portion 150. At least a part of the current collector 130 is located within the bent portion 161. The current collector 130 can be spaced between adjacent bent layers 161a in the bent portion 161. To some extent, the current collector increases the opening size at the end of the bent portion 161, enabling the electrolyte to pass through the opening smoothly, and improving the wetting effect of the electrolyte on the first active material region 111 and the second active material region 121. When such an electrode assembly 100 is applied to a battery cell or a battery, the performance of the battery can be effectively improved.

[0068] In the specific embodiment shown in the figure, the first tab 160a and the second tab 160b are respectively located at two ends of the main body portion 150. Those skilled in the art should understand that the figure shown is only an example. In other embodiments, the first tab 160a and the second tab 160b can also be located at different positions at the same end of the main body portion 150 to form two tab regions of the first tab 160a and the second tab 160b on one end face of the main body portion 150.

[0069] In the specific embodiment shown in the figure, after the first electrode sheet 110 and the second electrode sheet 120 of the electrode assembly 100 are wound, a cylindrical laminated winding structure is formed, and the first tab 160a and the second tab 160b are respectively located on two circular end faces of the main body portion 150. Those skilled in the art should understand that the figure shown is only an example. In other embodiments, the electrode assembly 100 can also be a flat cylindrical or cuboid laminated winding structure. Correspondingly, the first tab 160a or the second tab 160b can be located on the flat circular end face or the rectangular end face at one end or both ends of the main body portion 150.

[0070] In the specific embodiment shown in the figure, the first tab 160a or the second tab 160b can include a bent portion 161 and a connecting portion 162. Among them, the bent portion 161 is bent relative to the main body portion 150, and the connecting portion 162 is connected between the main body portion 150 and the bent portion 161 and is generally vertically arranged relative to the main body portion 150. It can be understood that the connecting portion 162 can also not be vertically arranged relative to the main body portion 150, but has an inclination angle relative to the main body portion 150 and is inclined towards the center of the winding axis. Those skilled in the art should understand that the figure shown is only an example. In other embodiments, the first tab 160a or the second tab 160b may not include the connecting portion 162, but the bent portion 161 is directly connected to the main body portion 150; in some other embodiments, the first tab 160a or the second tab 160b may further include other parts in addition to the bent portion 161 and the connecting portion 162.

[0071] In the specific embodiment shown in the figure, the electrode assembly 100 further includes a separator 140. The separator 140 is located in the main body portion 150 and is spaced between the first active material region 111 of the first electrode sheet 110 and the second active material region 121 of the second electrode sheet 120, so that the separator 140 can be spaced from the current collector 130. Those skilled in the art should understand that the figure shown is only an example. In other embodiments, the separator 140 can also abut against the current collector 130, or be attached to the current collector 130, partially overlap with it, or form a part of the current collector 130.

[0072] Please further refer to Figure 4 , Figure 4 which schematically shows the structure of the electrode assembly 100 before winding according to some embodiments of the present application.

[0073] As shown in the figure, in the electrode assembly 100 before winding, the first active material region 111 of the first electrode sheet 110 and the second active material region 122 of the second electrode sheet 120 are stacked, and the separator 140 is spaced therebetween. The non-active material regions 112 of the first electrode sheet 110 and 122 of the second electrode sheet 120 extend out at the upper and lower ends respectively, so as to form a first electrode tab 160a and a second electrode tab 160b respectively in the winding structure after winding. The current collector 130 is disposed at the portions of the first electrode sheet 110 and the second electrode sheet 120 corresponding to the bending portion 161, so that in the winding structure after winding, the current collector 130 is located between the adjacent bending layers 161a within the bending portion 161. Such a design enables the arrangement of the current collector 130 during the winding operation of the electrode assembly 100, simplifying the manufacturing process of the electrode assembly 100.

[0074] In the specific embodiment shown in the figure, the current collector 130 is of a one-piece structure and is entirely within the bending portion 161. In such an embodiment, during the manufacturing process of the electrode assembly 100, the one-piece current collector 130 can be placed between the first electrode sheet 110 and the second electrode sheet 120 and wound together with the first electrode sheet 110 and the second electrode sheet 120 to form a winding structure. At least a part of the current collector 130 overlaps with a part of the first non-active material region 112 or a part of the second non-active material region 122, so that after winding and flattening operations, at least a part of the current collector 130 is located within the bending portion 161.

[0075] Those skilled in the art should understand that the figure shown is only an example. In other embodiments, the current collector 130 can also be composed of multiple parts and can also include parts located outside the bending portion 161.

[0076] In the electrode assembly 100 according to some embodiments of the present application, at least one first diversion channel 171 is provided in the bent portion 161 of the current collector 130 and / or the tab 160. One end of the first diversion channel 171 communicates with the external space of the electrode assembly 100, and the other end communicates with the inside of the main body portion 150. Thus, the electrolyte can be guided through the first diversion channel 171 to flow from the external space of the bent portion 161 of the tab 160 into the inside of the main body portion 150.

[0077] Please refer to Figure 5 , which schematically shows a partial cross-sectional structure of the electrode assembly 100 at the bent portion 161 according to some embodiments of the present application.

[0078] As shown in the figure, diversion holes 171a may be provided in the current collector 130, or diversion grooves 171b may be provided on the side wall of the current collector 130. When the current collector 130 is disposed in the bent portion 161 of the tab 160 of the electrode assembly 100, the diversion holes 171a and the gaps between the diversion grooves 171b and the bent layer 161a may form the first diversion channel 171, communicating the external space of the bent portion 161 with the inside of the main body portion 150. Bent grooves 171c may also be provided on the bent portion 161, so that the gaps between the bent grooves 171c and the current collector 130 may also form the first diversion channel 171 communicating the external space of the bent portion 161 with the inside of the main body portion 150. Among them, the bent groove 171c may be a groove structure provided on the tab 160 of the first electrode sheet 110 or the second electrode sheet 120, or may be formed by the wrinkles generated during the flattening process of the tab 160.

[0079] By providing the first diversion channel 171, after the electrolyte in the external space enters the bent portion 161 from the end opening of the bent portion 161 of the tab 160, it can more easily enter the inside of the main body portion 150 of the electrode assembly 100 along the first diversion channel 171, further improving the wetting effect of the electrolyte on the active material in the electrode assembly 100.

[0080] In the specific embodiment shown in the figure, the diversion holes 171a, the diversion grooves 171b, and the bending grooves 171c are all circular or semi-circular structures. Those skilled in the art should understand that the figure shown is only an example. In other embodiments, the diversion holes 171a, the diversion grooves 171b, and the bending grooves 171c may also have other regular or irregular cross-sectional shapes, and the formed first diversion channel 171 may have a regular straight or arc-shaped channel, or may have an irregular channel path, and the direction of the first diversion channel 171 is consistent with the local bending direction of the bending layer 161a, or may have other directions, or a disorderly direction, as long as one end of the first diversion channel 171 communicates with the external space of the electrode assembly 100 and the other end communicates with the inside of the main body 150. For example, the diversion member 130 may be provided with through holes inside, or may be a porous structure with pores.

[0081] Those skilled in the art should understand that in other embodiments, the diversion holes 171a, the diversion grooves 171b, and the bending grooves 171c do not have to exist simultaneously, but may be a combination of any one or more of them. For example, a diversion hole 171a may be provided inside the diversion member 130, and a diversion groove 171b may be provided on the side wall at the same time; or only a diversion hole 171a may be provided on the diversion member 130.

[0082] In the electrode assembly 100 of some embodiments of the present application, the diversion member 130 may further include at least two diversion units 130a, and a second diversion channel 172 is formed between two adjacent diversion units 130a. The second diversion channel 172 communicates the inside of the main body 150 with the external space of the bending part 161, so that the electrolyte can be guided into the inside of the main body 150 through the second diversion channel 172.

[0083] Please continue to refer to Figure 5 and please further refer to Figure 6 where Figure 6 schematically shows the structure of the electrode assembly 100 according to some embodiments of the present application before winding.

[0084] As Figure 5 shown in, the diversion member 130 may include several diversion units 130a, and the diversion units 130a are arranged at intervals, so as to form a second diversion channel 172 between the diversion units 130a. The second diversion channel 172 communicates the external space of the bending part 161 with the inside of the main body 150, so that the electrolyte outside the bending part 161 can flow into the inside of the main body 150 through the second diversion channel 172.

[0085] As Figure 6As shown, before the first electrode tab 110 and the second electrode tab 120 of the electrode assembly 100 are wound, a plurality of current guiding units 130a can be disposed at positions corresponding to the bent portion 161 of the tab 160. For example, the current guiding units 130a can be attached to the tab 160. During the winding operation, the current guiding units 130a will be wound together with the first electrode tab 110, and in the formed winding structure, the current guiding units 130a are within the bent portion 161. A gap between the current guiding units 130a will form a second current guiding channel 172 within the bent portion 161. The second current guiding channel 172 communicates the external space of the bent portion 161 with the inside of the main body portion 150 to allow the electrolyte to enter the inside of the main body portion 150 from outside the bent portion 161 via the second current guiding channel 172.

[0086] In the specific embodiment shown in the figure, the current guiding units 130a are square structures arranged at uniform intervals. Those skilled in the art should understand that what is shown in the figure is only an example. In other embodiments, these current guiding units 130a can also be of other shapes, such as regular or irregular block-shaped or strip-shaped structures; the individual current guiding units 130a can be arranged in a regular array or scattered; and the individual current guiding units 130a can have the same or different shapes and arrangement manners, as long as a second current guiding channel 172 can be formed between two adjacent current guiding units 130a. In addition, those skilled in the art should also understand that it is not necessary for there to be an interval arrangement between any two current guiding units 130a, and some of the current guiding units 130a can be adjacent to each other without a gap.

[0087] Setting the current guiding member 130 to include a plurality of current guiding units 130a increases the design flexibility of the current guiding member 130. For example, during the preparation of the electrode assembly 100, at least two current guiding units 130a can be disposed on the surface of the first electrode tab 110 or at least two current guiding units 130a can be disposed on the surface of the second electrode tab 120 before the first electrode tab 110 and the second electrode tab 120 are wound. Among them, at least a part of the current guiding units 130a can be disposed in the first non-active material region 112 or the second non-active material region 122, so that after the winding and flattening operations, at least a part of the current guiding member 130 formed by the plurality of current guiding units 130a will be within the bent portion 161.

[0088] Those skilled in the art should also understand that in some embodiments, the first diversion channel 171 and the second diversion channel 172 may also exist simultaneously to increase the path for the electrolyte to enter the interior of the main body 150 from the external space of the bent portion 161, and further improve the wetting effect of the electrolyte on the active material in the electrode assembly 100. For example, when the diversion member 130 includes at least two diversion units 130a and a second diversion channel 172 is formed between the diversion units 130a, the diversion unit 130a may also be provided with diversion holes 171a or diversion grooves 171b, or the diversion unit 130a may also be made of a material having a pore structure, so that a first diversion channel 171 is further formed within the bent portion 161 of the tab 160.

[0089] In the electrode assembly 100 of some embodiments of the present application, the diversion member 130 may be entirely within the bent portion 161 of the tab 160; in some other embodiments, in addition to the portion located within the bent portion 161 of the tab 160, the diversion member 130 may further include a portion located outside the bent portion 161.

[0090] In the electrode assembly 100 of some embodiments of the present application, the diversion member 130 may include a first portion 131 and a second portion 132. Among them, the first portion 131 is located within the bent portion 161 of the tab 160, the second portion 132 is connected to the outer end of the first portion 131, and extends to the external space of the electrode assembly 100.

[0091] Please refer to the attached Figure 7 and Figure 8 , in which Figure 7 schematically shows a partial cross-sectional structure of the electrode assembly 100 according to some embodiments of the present application, specifically showing the partial cross-sectional structure of one end of the first tab 160a in the winding structure of the electrode assembly 100; Figure 8 schematically shows the structure of the electrode assembly 100 before winding according to some embodiments of the present application.

[0092] As Figure 7 shown, the diversion member 130 includes a first portion 131 and a second portion 132. The first portion 131 is located within the bent portion 161; the second portion 132 is connected to the outer end of the first portion 131 and extends outward to the external space of the electrode assembly 100. The second portion 132 of the diversion member 130 can play a role in guiding the flow, enabling the electrolyte in the external space of the electrode assembly 100 to flow along the second portion 132 of the diversion member 130, flow into the opening at the end of the bent portion 161 of the tab 160, and then enter the interior of the main body 150 of the electrode assembly 100 along the first portion 131 of the diversion member 130. Such a design helps to further improve the wetting effect of the electrolyte on the active material in the electrode assembly 100 and provides convenience for the electrolyte to enter the opening at the end of the bent portion 161.

[0093] As shown Figure 8 Figure 8

[0094] In the specific embodiment shown in the figure, the second part 132 of the current collector 130 can be formed by die-cutting. Such an embodiment does not limit the material used for the current collector 130. In the die-cut part, the bent part 161 of the tab 160 is exposed to ensure that the bent part 161 of the tab 160 can be attached to an external component such as an electrode terminal. Those skilled in the art should understand that the figure shown is only an example. In other embodiments, the current collector 130 may not require die-cutting. At this time, the second part 132 can cover. In such an embodiment, the current collector 130 can be set to be partially or entirely made of a conductive material (such as a conductive metal), or a conductive material can be coated on all or part of the outer surface of the current collector 130, so that an external component such as an electrode terminal can be attached to the second part 132 of the current collector 130 extending beyond the bent part 161, and thus be electrically connected to the bent part 161 of the tab 160.

[0095] In the specific embodiment shown in the figure, the first part 131 and the second part 132 of the current collector 130 are attached, and the current collector 130 is an integral structure. Those skilled in the art should understand that the figure shown is only an example. In other embodiments, when the current collector 130 includes the first part 131 and the second part 132, the current collector 130 can also be a multi-piece structure. For example, it can include at least two current collector units 130a, and at least one current collector unit 130a can include a part extending into the external space of the electrode assembly 100 to form the second part 132 of the current collector 130.

[0096] In the electrode assembly 100 of some embodiments of the present application, the current collector 130 may further include a third part 133 connected to the inner end of the first part 131, and the third part 133 extends into the main body part 150, that is, extends between the first active material area 111 of the first electrode sheet 110 and the second active material area 121 of the second electrode sheet 120.

[0097] Please continue to refer to the appendix Figure 8 and please further refer to the appendix Figure 9 and Figure 10 wherein Figure 9 and Figure 10Schematically shows a partial cross-sectional structure of the electrode assembly 100 according to some embodiments of the present application, specifically showing the partial cross-sectional structure of one end of the electrode assembly 100 winding structure where the first tab 160a is located.

[0098] As shown in the figure, the current collector 130 may further include a third portion 133. The third portion 133 may be connected to the inner end of the first portion 131 and extend into the main body portion 150, so as to extend and be spaced between the first active material region 111 of the first electrode sheet 110 and the second active material region 121 of the second electrode sheet 120.

[0099] In such an embodiment, the third portion 133 can continue the infiltration path of the electrolyte, so that the electrolyte entering the bent portion 161 can more easily enter the interior of the main body portion 150 of the electrode assembly 100 along the third portion 133 of the current collector 130 and infiltrate the active materials in the first active material region 111 and the second active material region 121. Thus, during the charge and discharge process of the battery, the electrode active materials can come into contact with the electrolyte more fully and participate in the reaction sufficiently, which is beneficial to further improving the battery performance.

[0100] In the specific embodiment shown in the figure, the third portion 133 is spaced in all regions between the first active material region 111 and the second active material region 121. Such an embodiment is beneficial for the full infiltration of the electrolyte into the electrode assembly. However, those skilled in the art should understand that what is shown in the figure is only an example. In other embodiments, the third portion 133 of the current collector 130 may also only extend to some regions between the first active material region 111 and the second active material region 121.

[0101] It should be noted that in the electrode assembly 100 of some embodiments of the present application, the second portion 132 and the third portion 133 of the current collector 130 do not have to exist simultaneously. That is, in some embodiments, the current collector 130 may only include the first portion 131; in some embodiments, the current collector 130 may include the first portion 131 and the second portion 132; in some embodiments, the current collector 130 may include the first portion 131 and the third portion 133; in some embodiments, the current collector 130 may include the first portion 131, the second portion 132 and the third portion 133.

[0102] The electrode assembly 100 generally further includes a separator. The separator is an insulating material and is usually located in the main body portion 150 of the electrode assembly 100 and is spaced between the active material regions of the first electrode sheet 110 and the second electrode sheet 120 for insulating and isolating the first electrode sheet 110 and the second electrode sheet 120. The separator is usually made of PP (polypropylene) material or PE (polyethylene) material and has micron-level or nano-level micropores inside for allowing metal ions to pass through during the charge and discharge process of the battery.

[0103] In the electrode assembly 100 of some embodiments of the present application, the current collector 130 can also be made of an insulating material, and through holes for ions to pass through can be provided in its thickness direction. In this way, the current collector 130 can be made of the same material as the separator membrane. This is particularly advantageous for simplifying the manufacturing process of the electrode assembly 100 and reducing costs.

[0104] Please continue to refer to Figure 8 and Figure 9 , in the specific embodiment shown in the figure, when the current collector 130 is made of an insulating material and through holes for ions to pass through are provided in its thickness direction, the third part 133 of the current collector 130 can also act as a separator membrane. Thus, the current collector 130 has the dual functions of guiding current and acting as a separator, which is particularly advantageous for simplifying the manufacturing process of the electrode assembly 100 and reducing costs.

[0105] Those skilled in the art should understand that the current collector 130 can be made of an insulating material, such as polypropylene (PP), polyethylene (PE), etc., and the scheme of providing through holes for ions to pass through in its thickness direction does not mean that a separate separator membrane will not be additionally provided in the electrode assembly 100 of these embodiments. Therefore, the third part 133 of the current collector 130 in the electrode assembly 100 can act as a separator membrane, or a separate separator 140 can be provided in the electrode assembly 100.

[0106] In the electrode assembly 100 of some embodiments of the present application, the electrode assembly 100 can further include a separator 140, and the separator 140 is located between the first active material region 111 of the first electrode sheet 110 and the second active material 121 of the second electrode sheet 120. The current collector 130 can be attached to the separator 140, or the current collector 130 can be spaced apart from the separator 140.

[0107] Please return to refer to the attached Figures 2 to 4 , and the attached Figure 6 and Figure 7 , in the specific embodiment shown in the figure, the electrode assembly 110 further includes a separator 140, and the separator 140 is spaced apart from the current collector 130; please return to refer to Figure 10 , in the specific embodiment shown in the figure, the current collector 130 in the electrode assembly 110 is attached to the separator 140. In such an embodiment, the current collector 130 and the separator 140 can be made of the same material or different materials, and the shape and structure of the current collector 130 can also be designed according to needs without affecting the separator 140, improving the design flexibility of the current collector 130 and the electrode assembly 100.

[0108] In the electrode assembly 100 of some embodiments of the present application, the end face of the bent portion 161 of the electrode assembly 100 may have a connection region 181 and a drainage region 182. The bent portion 161 is connected to an external component through the connection region 181; the bent portion 161 guides the electrolyte to flow into the interior of the main body portion 150 through the flow guiding member 130 located in the drainage region 182.

[0109] Please refer to Figure 11 , which schematically shows several structures of the electrode assembly 100 according to some embodiments of the present application on the end face of the bent portion 161.

[0110] As shown in the figure, in order to facilitate the connection of the bent portion 161 in the tab 160 of the electrode assembly 100 to an external component such as an electrode terminal, a connection region 181 may be provided on the end face of the bent portion 161. The surface of the connection region 181 is made of a conductive material to facilitate the conductive connection of the electrode terminal. Those skilled in the art should understand that the bent portion 161 may also be connected to the electrode terminal through an adapter member. For example, the bent portion 161 of the connection region 181 is directly welded to the adapter member, and the adapter member is directly welded to the electrode terminal. The remaining part of the end face of the bent portion 161 may constitute the drainage region 182, and the flow guiding member 130 in the drainage region 182 is used to guide the electrolyte to flow into the interior of the main body portion 150.

[0111] Since the connection region 181 may not participate in the drainage of the electrolyte, the end of the adjacent bent layer 161a of the connection region 181 located on the end face of the bent portion 161 may be a closed structure. For example, the flow guiding member 130 may not be provided in the bent portion 161 of these connection regions 181.

[0112] Those skilled in the art should understand that in other embodiments, the end of the adjacent bent layer 161a of the connection region 181 portion may also be an open structure, that is, the flow guiding member 130 may also be provided in the bent portion 161 of these portions. The flow guiding member 130 may be made of an insulating material, a conductive material, or a surface coated with a conductive material, so as to facilitate the conductive connection of the connection region 181 with an external component.

[0113] Those skilled in the art should also understand that in some other embodiments, the flow guiding member 130 in the bent portion 161 of the connection region 181 portion may also include a second portion 132 extending into the external space of the bent portion 161. In such an embodiment, the flow guiding member 130 is preferably made of a conductive material or a surface coated with a conductive material to facilitate the conductive connection with an external component. In some embodiments, the flow guiding member 130 in the bent portion 161 of the drainage region 182 portion may only have a first portion 131, or may also have a second portion 132.

[0114] In the embodiment where the electrode assembly 100 is a cylinder and the end face of the electrode assembly 100 is circular as shown in the figure, the connection area 181 or the diversion area 182 can be fan-shaped as shown in (a) and (b) in the figure; or rectangular as shown in (e) in the figure; or annular fan-shaped as shown in (c) and (d) in the figure; or other shapes. In addition, the connection area 181 or the diversion area 182 can each have one or more areas, and each area can be symmetrically distributed or asymmetrically distributed.

[0115] In some embodiments shown in the figure, as shown in (c), (d) and (e) in the figure, the diversion area 182 can further include a central diversion area 182a and / or a peripheral diversion area 182b. Among them, the central diversion area 182a is located in the central area of the end face, and the peripheral diversion area 182b is located in the peripheral area of the end face. Such an embodiment is particularly advantageous for the case where the current collector 130 further includes a third part 133, or the current collector 130 also serves as a separator membrane. This is because, generally, the first electrode tab 110 and / or the second electrode tab 120 are not present at the positions corresponding to the central diversion area 182a and the peripheral diversion area 182b. By arranging the current collector 130 and the diversion area 182 at such positions, the electrolyte can enter the area where the first electrode tab 110 or the second electrode tab 120 is missing in the electrode assembly 100, so that the electrode active material in the main body 150 of the electrode assembly 100 can be fully immersed in the electrolyte, further improving the wetting effect.

[0116] According to the second aspect of the embodiments of the present application, a battery cell 200 is further provided. Please refer to the attached Figure 12 , which schematically shows the exploded structure of the battery cell 200 according to some embodiments of the present application.

[0117] As shown in the figure, the battery cell 200 includes the electrode assembly 100, the housing 210 and the terminal assembly 220 of the above embodiments. The housing 210 is used to accommodate the electrode assembly 100; the terminal assembly 220 is provided on the housing 210 and is used to connect the electrode tabs 160a and 160b, especially the bent part 161 of the electrode tab, to output or input electric energy.

[0118] In the specific embodiment shown in the figure, the battery cell 200 includes an electrode assembly 100, a housing 210 and a terminal assembly 220 provided on the housing 210. The housing 210 is a hollow structure and is used to accommodate the electrode assembly 100 therein. Those skilled in the art should understand that only the scope is shown in the figure. In other embodiments, the battery cell 200 can also include a plurality of electrode assemblies 100, and the terminal assembly 200 can also be designed according to the number and arrangement of the electrode assemblies 100. In addition, according to the shape and placement method of the electrode assembly 100, and the combination method of a plurality of electrode assemblies 100, the housing 210 can be a cylinder, a flat body, a cuboid or other shapes.

[0119] In some embodiments, the outer casing 210 may be a hollow housing having an open face. For example, when the outer casing 210 is a hollow cylinder, its circular end face may be the open face and has no shell wall, such that the inner and outer spaces of the outer casing 210 communicate at this open face, facilitating placing at least one electrode assembly 100 into the hollow space inside the outer casing 210 through this opening; when the outer casing 210 is a hollow cuboid, one of its side edges may be the open face and has no shell wall, such that the inner and outer spaces of the outer casing 210 communicate at this open face, facilitating placing at least one electrode assembly 100 into the hollow space inside the outer casing 210 through this opening.

[0120] In such an embodiment, the terminal assembly 220 may be disposed at the opening of the outer casing 210, connected to the outer casing 210 and form a closed housing for placing the electrode assembly 100, and an electrolyte is filled in this closed housing. The terminal assembly 220 may include an end cap 222 and terminals 221 provided on the end cap 222. The terminals 221 are used to connect to the bent portions 161 of the tabs 160 of the first electrode tab 110 and the second electrode tab 120.

[0121] According to the shape of the outer casing 210 and actual needs, the battery cell 200 may be cylindrical, flat, cuboid or other shapes. The battery cell 200 may be, for example, a lithium-ion secondary battery, a lithium-ion primary battery, a lithium-sulfur battery, a sodium-lithium-ion battery or a magnesium-ion battery, and so on.

[0122] According to the third aspect of the embodiments of the present application, there is also provided a battery 300, and the battery 300 includes the battery cell 200 of the above embodiments.

[0123] Please refer to the attac Figure 13 and Figure 14 , which schematically show the overall structure and exploded structure of the battery 300 according to some embodiments of the present application, respectively.

[0124] In the specific embodiments shown in the figures, the battery 300 may include one or more battery cells 200, and the plurality of battery cells 200 may be connected in series, in parallel or in a hybrid connection to meet different electrical energy usage requirements. The battery 300 may further include a box body 310, and the interior of the box body 310 is hollow and used to accommodate one or more battery cells 200. According to the shape, quantity, combination mode and other requirements of the accommodated battery cells 200, the box body 310 may also have different shapes and dimensions. Similar to the description of the outer casing 21 of the battery cell 200 above, the box body 310 of the battery 300 may be formed by buckling two parts to form a closed structure.

[0125] According to a fourth aspect of the embodiments of the present application, an electrical device 400 is further provided. The device includes the battery 300 of the above embodiments, and the battery 300 is used to provide electrical energy for the electrical device 400. Please refer to the appendix Figure 15 , which schematically shows the structure of the electrical device 400 according to some embodiments of the present application.

[0126] In the specific embodiment shown in the figure, the electrical device 400 may be, for example, a vehicle, which may be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. The battery 300 is arranged inside the vehicle, or the battery 300 is arranged at the bottom, the front or the rear of the vehicle. The vehicle may have a motor 401, a controller 402 and a battery 300. The battery 300 is used to provide electrical energy for the vehicle, and the controller 402 controls the battery 300 to supply power to the motor 401 to make the motor 401 operate, thereby driving the wheels or other components of the vehicle to work.

[0127] Those skilled in the art should understand that the figure shown is only an example. In other embodiments, the electrical device 400 may also be other devices that include a battery 300 and are powered by the battery 300, such as mobile phones, portable devices, laptop computers, battery cars, electric vehicles, ships, spacecrafts, electric toys and electric tools, etc. Spacecrafts include airplanes, rockets, space shuttles and spaceships, etc.; Electric toys include fixed or mobile electric toys, such as game consoles, electric vehicle toys, electric ship toys and electric airplane toys, etc.; Electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact electric drills, concrete vibrators and electric planers.

[0128] In other embodiments, the battery 300 may also be used as an operating power source for the electrical device 400, for the circuit system of the electrical device 400. For example, it is used for the working power requirements during the start, navigation and operation of an automobile; or it may also be used as a driving power source for the electrical device 400 to replace or partially replace fuel or natural gas to provide driving power for the electrical device.

[0129] According to a fifth aspect of the embodiments of the present application, a method for preparing an electrode assembly is further provided. Please refer to the appendix Figure 16 , which schematically shows the method flow for preparing an electrode assembly according to some embodiments of the present application.

[0130] In the specific embodiment shown in the figure, the method for preparing an electrode assembly includes:

[0131] S501. Provide a first electrode tab, a second electrode tab, and a current collector. The first electrode tab and the second electrode tab have opposite polarities, and at least a part of the current collector is disposed between the first electrode tab and the second electrode tab; S502. Wind the first electrode tab and the second electrode tab to form a wound structure. Among them, the active material regions of the first electrode tab and the second electrode tab form a main body after winding, and the non-active material region of the first electrode tab or the non-active material region of the second electrode tab forms an electrode ear after winding; and S503. Bend at least a part of the electrode ear relative to the main body to form a bent portion. At least a part of the current collector is located within the bent portion and is used to guide the electrolyte to flow into the interior of the main body.

[0132] In some embodiments, in step S501, the current collector can be provided as a separate component or pre-set on the surface of the first electrode tab and / or the second electrode tab. For example, in the case where the current collector includes a third part and also functions as a separator, the current collector can be provided as a separate component. And according to needs, the current collector, the first electrode tab, or the second electrode tab can be pre-die cut to obtain a specific shape of the current collector and the electrode ear. In some embodiments, in the case where the current collector includes at least two current collector units, the current collector units can be pre-set on the surface of the first electrode tab and / or the second electrode tab.

[0133] In some embodiments, in the winding operation of step S502, the wound structure can be a cylindrical wound structure, an oblate wound structure, or a rectangular wound structure.

[0134] In some embodiments, during the bending operation of step S503, due to the presence of the current collector within the bent portion, the opening size at the end of the bent portion is increased to a certain extent, enabling the electrolyte to pass through the opening smoothly and enhancing the wetting effect of the electrolyte on the active material region.

[0135] According to the sixth aspect of the embodiments of the present application, a device for preparing an electrode assembly is also provided. Please refer to the attached Figure 17 , which schematically shows the structure of a device for preparing an electrode assembly according to some embodiments of the present application.

[0136] In the specific embodiment shown in the figure, the electrode assembly preparation device 600 includes: a pole piece placement module 601 configured to provide a first pole piece, a second pole piece, and a current collector. The first pole piece and the second pole piece have opposite polarities, and at least a part of the current collector is disposed between the first pole piece and the second pole piece; a winding module 602 configured to wind the first pole piece and the second pole piece to form a wound structure, wherein the active material regions of the first pole piece and the second pole piece form a main body after winding, and the non-active material region of the first pole piece or the non-active material region of the second pole piece forms a tab after winding; and a flattening module 603 configured to bend at least a part of the tab relative to the main body to form a bent portion, and at least a part of the current collector is located within the bent portion for guiding electrolyte to flow into the interior of the main body.

[0137] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be covered by the scope of the claims and the description of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. An electrode assembly, characterized in that, Comprising: A first electrode tab and a second electrode tab with opposite polarities. The active material regions of the first electrode tab and the second electrode tab form a main body portion after winding. The non-active material region of the first electrode tab or the non-active material region of the second electrode tab forms an electrode ear after winding. The electrode ear includes a bent portion bent relative to the main body portion. A current collector, at least a part of which is located within the bent portion and is used to guide electrolyte to flow into the interior of the main body portion.

2. The electrode assembly according to claim 1, wherein At least one first flow channel is provided in the current collector and / or the bent portion. One end of the first flow channel communicates with the external space of the electrode assembly, and the other end communicates with the interior of the main body portion. The current collector guides electrolyte to flow into the interior of the main body portion through the first flow channel.

3. The electrode assembly according to claim 1 or 2, characterized in that, The current collector includes at least two current collector units, and a second flow channel is formed between two adjacent current collector units. The current collector guides electrolyte to flow into the interior of the main body portion through the second flow channel.

4. The electrode assembly according to claim 1 or 2, characterized in that The current collector includes a first part and a second part. The first part is located within the bent portion, and the second part is connected to the outer end of the first part and extends to the external space of the electrode assembly.

5. The electrode assembly according to claim 4, wherein, The current collector further includes a third part, which is connected to the inner end of the first part and extends between the active material regions of the first electrode tab and the second electrode tab.

6. The electrode assembly according to claim 1 or 2, characterized in that, The current collector is made of an insulating material, and through holes for ions to pass through are provided in its thickness direction.

7. The electrode assembly according to claim 1 or 2, wherein The electrode assembly further includes a separator, which is located between the active material regions of the first electrode tab and the second electrode tab. The current collector is attached to the separator, or the current collector is arranged at intervals with the separator.

8. The electrode assembly according to claim 1 or 2, characterized in that, The end face of the bent portion has a drainage area and a connection area. The bent portion is connected to an external component through the connection area, and the bent portion guides electrolyte to flow into the interior of the main body portion through the current collector located in the drainage area.

9. A battery cell, characterized in that, Comprising: The electrode assembly according to any one of claims 1 to 8; A housing for accommodating the electrode assembly; A terminal assembly provided on the housing, and the terminal assembly is used to connect the bent portion to output or input electrical energy.

10. A battery, characterized in that, Comprising a battery cell according to claim 9.

11. An electrical device, characterized in that, Comprising a battery according to claim 10, and the battery is used to provide electrical energy.

12. A method for preparing an electrode assembly, characterized in that, Comprising: Providing a first electrode tab, a second electrode tab, and a current collector. The first electrode tab and the second electrode tab have opposite polarities, and at least a part of the current collector is arranged between the first electrode tab and the second electrode tab; Winding the first electrode tab and the second electrode tab to form a winding structure, wherein the active material regions of the first electrode tab and the second electrode tab form a main body portion after winding, and the non-active material region of the first electrode tab or the non-active material region of the second electrode tab forms an electrode ear after winding; And Bending at least a part of the electrode ear relative to the main body portion to form a bent portion, and at least a part of the current collector is located within the bent portion and is used to guide electrolyte to flow into the interior of the main body portion.

13. An apparatus for preparing an electrode assembly, characterized in that, Comprising: The electrode sheet placement module is configured to provide a first electrode sheet, a second electrode sheet, and a current collector. The first electrode sheet and the second electrode sheet have opposite polarities, and at least a part of the current collector is disposed between the first electrode sheet and the second electrode sheet; The winding module is configured to wind the first electrode sheet and the second electrode sheet to form a wound structure. After winding, the active material regions of the first electrode sheet and the second electrode sheet form a main body portion, and the non-active material region of the first electrode sheet or the non-active material region of the second electrode sheet forms an electrode tab after winding; and The flattening module is configured to bend at least a part of the electrode tab relative to the main body portion to form a bent portion. At least a part of the current collector is located within the bent portion for guiding electrolyte to flow into the interior of the main body portion.

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