Current collector and winding type battery cell
By creating grooves on the surface of the current collector and coating it with an electrolyte layer, the lithium plating problem caused by insufficient electrolyte in wound lithium batteries is solved, thus extending the battery's lifespan.
Patent Information
- Application Number
- CN202423061810.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-11
- Publication Date
- 2025-12-19
- Estimated Expiration
- 2034-12-11
AI Technical Summary
In the later stages of cycling, wound lithium batteries are prone to lithium plating due to insufficient electrolyte at the corners. Furthermore, the active material on the anode plate closer to the current collector has less electrolyte after cycling compared to the active material closer to the separator, leading to accelerated capacity decay.
Multiple first and second grooves are provided on the surface of the current collector, and first and second electrolyte layers are coated in the grooves to provide additional electrolyte to reduce concentration polarization and enhance the uniformity of electrolyte distribution. An adhesive layer is used to improve the adhesion of the active material layer.
By adding an electrolyte layer, the rate of battery capacity decay is slowed down, thus improving battery lifespan.
Smart Images
Figure CN223693146U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to battery technology field especially relates to a current collector and winding type electric core. BACKGROUND
[0002] In the later period of winding type lithium battery cycle, winding type lithium battery winding type electric core is easy to cause lithium precipitation phenomenon because of the content of electrolyte at the corner, and the active material of anode sheet near the current collector side is less than the active material near the diaphragm side after cycle electrolyte, and it is easy to accelerate the attenuation of battery capacity. SUMMARY
[0003] The utility model discloses at least one of the technical problems existing in the prior art is solved, and for this purpose, the utility model provides a current collector, which can slow down the attenuation rate of battery capacity.
[0004] The utility model further provides a winding type electric core with the current collector.
[0005] The current collector according to the first aspect of the utility model comprises:
[0006] The current collector body has a first surface and a second surface oppositely arranged along the thickness direction of the current collector body, the first surface and / or the second surface is provided with a plurality of first grooves and a plurality of second grooves, a plurality of the first grooves are arranged at intervals along the length direction of the current collector body, a plurality of the second grooves are arranged at intervals along the width direction of the current collector body, the first electrolyte layer is arranged in the first groove, and the second electrolyte layer is arranged in the second groove.
[0007] The current collector according to the first aspect of the utility model has at least the following beneficial effects:
[0008] By arranging a plurality of first grooves and a plurality of second grooves on the first surface, the first electrolyte layer is coated in a plurality of first grooves, and the second electrolyte layer is coated in a plurality of second grooves, the first electrolyte layer and the second electrolyte layer can provide additional electrolyte for the active material of the anode sheet near the current collector side, can reduce the concentration polarization of the active material of the anode sheet near the current collector side compared with the active material near the diaphragm side after battery cycle, can slow down the attenuation rate of battery capacity, thereby improving the service life of the battery.
[0009] According to some embodiments of the utility model, the first groove penetrates to both sides of the width direction of the current collector body, and / or;
[0010] The second groove penetrates to both sides of the length direction of the current collector body.
[0011] According to some embodiments of the present application, the first surface and / or the second surface is provided with an adhesive layer on the outer side of the first groove and the second groove.
[0012] According to some embodiments of the present application, in the first surface or the second surface, the total area of the plurality of first electrolyte layers is S1, the total area of the plurality of second electrolyte layers is S2, and the total area of the adhesive layer is S3, satisfying: 0.1≤(S1+S2) / S3≤0.25.
[0013] According to some embodiments of the present application, the width of the plurality of first grooves increases along the length direction of the current collector body.
[0014] According to some embodiments of the present application, each of the first grooves is in communication with the plurality of second grooves.
[0015] According to some embodiments of the present application, the sum of the widths of the plurality of second grooves is C, and the width of the current collector body is D, satisfying: 0.05≤C / D≤0.4.
[0016] According to some embodiments of the present application, the sum of the lengths of the plurality of first grooves is L1, and the length of the current collector body is L2, satisfying: 0.05≤L1 / L2≤0.4.
[0017] According to some embodiments of the present application, the depth of the first groove is h1, the depth of the second groove is h2, and the thickness of the current collector body is H, satisfying: 0.3≤h1 / H≤0.5, 0.3≤h2 / H≤0.5.
[0018] The winding type battery cell according to the second aspect of the present application comprises an anode pole piece, a cathode pole piece, and a diaphragm arranged between the anode pole piece and the cathode pole piece, and the anode pole piece uses the current collector according to the above embodiments.
[0019] The winding type battery cell according to the second aspect of the present application at least has the following
[0020] Advantages:
[0021] The battery according to the first aspect of the present application is provided with a plurality of first grooves and a plurality of second grooves on the first surface, the plurality of first grooves are coated with a first electrolyte layer, the plurality of second grooves are coated with a second electrolyte layer, the first electrolyte layer and the second electrolyte layer can provide additional electrolyte for the active material on the side of the anode pole piece close to the current collector, can reduce the concentration polarization of the active material on the side of the anode pole piece close to the current collector compared with the active material on the side close to the diaphragm in the later stage of battery cycle, can slow down the decay rate of the battery capacity, and thus improves the service life of the battery.
[0022] The additional aspects and advantages of the present application will be in part apparent and in part pointed out below in the description of the application. BRIEF DESCRIPTION OF DRAWINGS
[0023] The above and / or additional aspects and advantages of the present application will become apparent and be readily appreciated from the following description of embodiments, given by way of example, and with reference to the following drawings, wherein:
[0024] Figure 1 is a top view of the current collector of the first aspect embodiment of the present application;
[0025] Figure 2 is a sectional view along line A-A in Figure 1
[0026] Figure 3 is a sectional view along line A-A in Figure 2
[0027] Figure 4 is a schematic view of the wound type battery cell of the second aspect embodiment of the present application.
[0028] REFERENCE NUMERALS
[0029] current collector body 100, first groove 101, second groove 102, first electrolyte layer 200, second electrolyte layer 300, adhesive layer 400. DETAILED DESCRIPTION
[0030] Embodiments of the present application are described below in detail, examples of which are shown in the drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the drawings are exemplary and are only used to explain the present application, and cannot be understood as a limitation of the present application.
[0031] In the description of the present application, it should be understood that, in relation to the orientation description, for example, the orientation or position relationship indicated by the upper, lower, front, rear, left, right, etc. is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as a limitation of the present application.
[0032] In the description of the utility model, if several means one or more, the meaning of multiple is two or more, greater than, less than, exceed and the like are understood as not including the number, above, below, within and the like are understood as including the number. If it is described to the first, the second is only used for distinguishing the technical features for the purpose, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or implicitly indicating the sequence of indicated technical features.
[0033] In the description of the utility model, unless otherwise explicitly limited, the words such as setting, installation, connection should be understood in a broad sense, and the skilled person in the art can reasonably determine the specific meaning of the above words in the utility model according to the specific content of the technical scheme.
[0034] In the related art, after the cycle of the winding type lithium battery, the winding type lithium battery is prone to lithium precipitation due to the insufficient content of electrolyte at the corner, and the active material on the side of the anode sheet close to the current collector is less than the active material on the side close to the diaphragm after the cycle, which will accelerate the capacity attenuation of the battery in the later cycle.
[0035] Reference Figures 1 to 3 According to the current collector of the first aspect of the utility model, the current collector body 100 has a first surface and a second surface arranged oppositely along the thickness direction of the current collector body 100, the first surface is provided with a plurality of first grooves 101 and a plurality of second grooves 102, the plurality of first grooves 101 are arranged at intervals along the length direction of the current collector body 100, the plurality of second grooves 102 are arranged at intervals along the width direction of the current collector body 100, the first groove 101 is provided with a first electrolyte layer 200, and the second groove 102 is provided with a second electrolyte layer 300. By arranging the first electrolyte layer 200 and the second electrolyte layer 300 in the first groove 101 and the second groove 102 respectively, the attenuation rate of the battery capacity can be slowed down, thereby improving the service life of the battery.
[0036] Specifically, the first surface and the second surface are the surfaces with the largest surface area of the current collector body 100, a plurality of first grooves 101 and a plurality of second grooves 102 are arranged on the first surface, the plurality of first grooves 101 are coated with a first electrolyte layer 200, the plurality of second grooves 102 are coated with a second electrolyte layer 300, the first electrolyte layer 200 and the second electrolyte layer 300 can provide additional electrolyte for the active material on the side of the anode sheet close to the current collector, can reduce the concentration polarization of the active material on the side of the anode sheet close to the current collector compared with the active material on the side close to the diaphragm after the cycle of the battery, can slow down the attenuation rate of the battery capacity, thereby improving the service life of the battery.
[0037] It should be noted that the current collector body 100 is a copper foil, the first groove 101 and the second groove 102 can be etched on the current collector body 100 by laser etching, and since the first electrolyte layer 200 and the second electrolyte layer 300 are coated in the first groove 101 and the second groove 102 respectively, the first electrolyte layer 200 and the second electrolyte layer 300 do not occupy the space of the active material layer and do not cause loss of battery energy density.
[0038] As another embodiment, the second surface of the current collector body 100 can be provided with a plurality of first grooves 101 and a plurality of second grooves 102, and the first electrolyte layer 200 and the second electrolyte layer 300 can be coated in the first grooves 101 and the second grooves 102 respectively, which can slow down the decay rate of the battery capacity, and details are not described here.
[0039] As another embodiment, the first surface and the second surface of the current collector body 100 can be provided with a plurality of first grooves 101 and a plurality of second grooves 102, and the first electrolyte layer 200 and the second electrolyte layer 300 can be coated in the first grooves 101 and the second grooves 102 respectively, which can slow down the decay rate of the battery capacity, and details are not described here.
[0040] In some embodiments of the present application, the first groove 101 penetrates to both sides of the width direction of the current collector body 100, which can promote the uniform distribution of the electrolyte.
[0041] Specifically, the first groove 101 is a long strip structure, the slot of the first groove 101 is located on the first surface or the second surface, one end of the first groove 101 penetrates to one side of the width direction of the current collector body 100, and the other end of the first groove 101 penetrates to the other side of the width direction of the current collector body 100, and after the battery is injected with electrolyte, the electrolyte can seep into the active material on the anode sheet from both ends of the first groove 101, which can promote the uniform distribution of the electrolyte.
[0042] In some embodiments of the present application, the second groove 102 penetrates to both sides of the length direction of the current collector body 100, which can promote the uniform distribution of the electrolyte.
[0043] Specifically, the second groove 102 is a long strip structure, the slot of the second groove 102 is located on the first surface or the second surface, one end of the second groove 102 penetrates to one side of the length direction of the current collector body 100, and the other end of the second groove 102 penetrates to the other side of the length direction of the current collector body 100, and after the battery is injected with electrolyte, the electrolyte can seep into the active material on the anode sheet from both ends of the second groove 102, which can promote the uniform distribution of the electrolyte.
[0044] In some embodiments of the utility model, the region of the first surface or the second surface outside the first groove 101 and the second groove 102 is provided with an adhesive layer 400, the adhesive layer 400 improves the adhesion of the active material layer to improve the quality of the battery.
[0045] Specifically, the adhesive layer 400 is a carbon black coating, the adhesive layer 400 is arranged on the region of the first surface or the second surface outside the first groove 101 and the second groove 102 by coating, on the one hand, the adhesive layer 400 improves the adhesion of the active material layer, on the other hand, the impedance of the battery can be reduced.
[0046] As another embodiment, the region of the first surface and the second surface outside the first groove 101 and the second groove 102 can also be provided with an adhesive layer 400, which is not limited here.
[0047] In some embodiments of the utility model, in the first surface or the second surface, the total area of the plurality of first electrolyte layers 200 is S1, the total area of the plurality of second electrolyte layers 300 is S2, and the total area of the adhesive layer 400 is S3, which satisfies: 0.1≤(S1+S2) / S3≤0.25, on the one hand, the structural strength of the current collector body 100 can be ensured, on the other hand, the first electrolyte layer 200 and the second electrolyte layer 300 can provide sufficient electrolyte for the active material.
[0048] It should be noted that if (S1+S2) / S3 is less than 0.1, the content of the first electrolyte layer 200 and the second electrolyte layer 300 is too small to provide sufficient electrolyte for the active material; if (S1+S2) / S3 is greater than 0.25, the first groove 101 and the second groove 102 occupy too large an area of the current collector body 100, affecting the structural strength of the current collector body 100.
[0049] It should be noted that the value of (S1+S2) / S3 can be 0.1, 0.12, 0.14, 0.16, 0.18, 0.19, 0.20, 0.22, 0.24, 0.25.
[0050] In this embodiment, the sum of the widths of the plurality of second grooves 102 is C, the width of the current collector body 100 is D, which satisfies: 0.05≤C / D≤0.4, so that the second electrolyte layer 300 can provide sufficient electrolyte for the active material.
[0051] In this embodiment, the sum of the lengths of the plurality of first grooves 101 is L1, and the length of the current collector body is L2, which satisfies: 0.05≤L1 / L2≤0.4, so that the first electrolyte layer 200 can provide sufficient electrolyte for the active material.
[0052] In the embodiment, the depth of the first groove 101 is h1, the depth of the second groove 102 is h2, and the thickness of the current collector body 100 is H, and the following conditions are met: 0.3≤h1 / H≤0.5 and 0.3≤h2 / H≤0.5, so that the structural strength of the current collector body 100 can be ensured.
[0053] In the embodiment, along the length direction of the current collector body 100, the width of each first groove 101 is greater than or equal to 50 μm and less than or equal to 100 μm.
[0054] In the embodiment, along the width direction of the current collector body 100, the width of each second groove 102 is greater than or equal to 50 μm and less than or equal to 100 μm.
[0055] In some embodiments of the utility model, along the length direction of the current collector body 100, the width of the plurality of first grooves 101 increases, and when the winding cell is wound, the winding is started from the first groove 101 closest to the current collector body 100 with the smallest width to form a wound cell, the corner area of the wound cell has a plurality of different layers, the length of the current collector in the inner corner area is less than the length of the current collector in the outer corner area, by increasing the width of the first groove 101, the width of the first groove 101 on the outside is greater than the width of the first groove 101 on the inside in the corner area, which can provide sufficient electrolyte for the active material at different positions to reduce the concentration polarization and reduce the amount of lithium precipitation of the battery.
[0056] In some embodiments of the utility model, each first groove 101 is communicated with a plurality of second grooves 102, so that the first groove 101 and the second groove 102 have continuity, the first groove 101 and the second groove 102 can be used as a channel for the electrolyte to flow on the side of the active material close to the current collector body 100, which can promote the uniform distribution of the electrolyte.
[0057] In some embodiments of the utility model, the first electrolyte layer 200 and the second electrolyte layer 300 are solid-state electrolyte, gel polymer electrolyte or composite polymer electrolyte, which can provide additional electrolyte for the side of the active material close to the current collector body 100.
[0058] It should be noted that the gel electrolyte is composed of electrolyte and polymer matrix, and the polymer matrix can be natural polymer (such as chitosan, cellulose, etc.), synthetic polymer (such as polyethylene oxide, polyacrylonitrile, polyurethane, etc.).
[0059] It should be noted that the solid-state electrolyte can be oxide solid-state electrolyte or sulfide solid-state electrolyte.
[0060] It should be noted that the composite polymer electrolyte is composed of an electrolyte and a composite polymer matrix, which is a mixture of natural and synthetic polymers.
[0061] Reference Figure 1 , Figure 2 According to a second aspect of the present invention, a wound battery cell includes an anode plate, a cathode plate, and a separator disposed between the anode plate and the cathode plate. The anode plate uses a current collector according to the first aspect of the present invention, which can slow down the rate of battery capacity decay and thus improve the battery's service life.
[0062] The current collector of the first aspect embodiment of this utility model has multiple first grooves 101 and multiple second grooves 102 on a first surface. Each of the multiple first grooves 101 is coated with a first electrolyte layer 200, and each of the multiple second grooves 102 is coated with a second electrolyte layer 300. The first electrolyte layer 200 and the second electrolyte layer 300 can provide additional electrolyte to the active material on the side of the anode plate near the current collector. This can reduce the concentration polarization of the active material on the side of the anode plate near the current collector compared to the active material on the side near the separator in the later stages of battery cycling, thereby slowing down the rate of battery capacity decay and improving battery life.
[0063] In this embodiment, from the inner side of the wound cell to the outer side of the wound cell, the number of the first grooves 101 of the current collector located in the corner region gradually increases, so as to provide sufficient electrolyte for the active material located in the corner region.
[0064] Reference Figure 4 In this embodiment, the maximum thickness of the wound cell is G, and the sum of the widths of all the first grooves 101 in each corner region is greater than or equal to 50 μm and less than or equal to π*G / 2, so as to provide sufficient electrolyte for the active material located in the corner region.
[0065] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0066] The present invention has been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the invention.
Claims
1. A current collector for a wound cell, characterized by, The application relates to a current collector body (100) having a first surface and a second surface oppositely arranged along the thickness direction of the current collector body (100), wherein the first surface and / or the second surface is provided with a plurality of first grooves (101) and a plurality of second grooves (102), the plurality of first grooves (101) are arranged at intervals along the length direction of the current collector body (100), the plurality of second grooves (102) are arranged at intervals along the width direction of the current collector body (100), the first grooves (101) are provided with a first electrolyte layer (200), and the second grooves (102) are provided with a second electrolyte layer (300). The first grooves (101) extend to both sides of the width direction of the current collector body (100); and / or 2. The current collector of claim 1, wherein The second grooves (102) extend to both sides of the length direction of the current collector body (100). The area of the first surface and / or the second surface outside the first grooves (101) and the second grooves (102) is provided with an adhesive layer (400).
3. The current collector of claim 1, wherein In the first surface or the second surface, the total area of the plurality of first electrolyte layers (200) is S1, the total area of the plurality of second electrolyte layers (300) is S2, and the total area of the adhesive layer (400) is S3, and the following condition is met: 0.1<= (S1+S2) / S3 <= 0.
25.
4. The current collector of claim 3, wherein Along the length direction of the current collector body (100), the width of the plurality of first grooves (101) increases or decreases.
5. The current collector of claim 1, wherein Each of the first grooves (101) communicates with the plurality of second grooves (102).
6. The current collector of claim 1, wherein The sum of the widths of the plurality of second grooves (102) is C, the width of the current collector body (100) is D, and the following condition is met: 0.05<= C / D <= 0.
4.
7. The current collector of claim 1, wherein The sum of the lengths of the plurality of first grooves (101) is L1, the length of the current collector body (100) is L2, and the following condition is met: 0.05<= L1 / L2 <= 0.
4.
8. The current collector of claim 1, wherein The depth of the first grooves (101) is h1, the depth of the second grooves (102) is h2, and the thickness of the current collector body (100) is H, and the following conditions are met: 0.3<= h1 / H <= 0.5 and 0.3<= h2 / H <= 0.
5.
9. The current collector of claim 1, wherein The application further relates to an anode pole piece, a cathode pole piece and a separator arranged between the anode pole piece and the cathode pole piece, wherein the anode pole piece uses the current collector body according to any one of claims 1 to 9.
10. A wound cell, characterized by,