Current collector, electrode and secondary battery
By designing a current collector with multiple channels and connecting holes, the problem of uneven dry electrode bonding is solved, the electrode performance and electrolyte infiltration are improved, and a more uniform bonding effect is achieved.
Patent Information
- Application Number
- CN202420013313.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-02
- Publication Date
- 2025-01-21
- Estimated Expiration
- 2034-01-02
AI Technical Summary
There are problems such as cavities, low bonding degree, and insufficient fit uniformity of the bonding of the positive and negative electrode film of the dry electrode and the current collector, which leads to problems such as degradation of the performance of the dry electrode and curling of the current collector.
Design a current collector, which includes a current collector body with multiple channels and connecting holes. The channels extend from the first end face to the second end face. The connecting holes are connected with the channels to form an exhaust network to improve the uniformity of fitting and the infiltration of electrolyte. Spend.
Through the design of the current collector, the cavity between the electrode film and the current collector is reduced, the degree of fit and uniformity are improved, the electrode performance is improved, and the current collector curling problem is solved.
Smart Images
Figure CN222380589U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of new energy batteries, and in particular to a current collector, an electrode and a secondary battery. Background Art
[0002] Lithium-ion batteries have the advantages of high energy density and long cycle life. They are widely used in various electronic products and new energy vehicles. With the rapid development of new energy vehicles, the application of dry electrodes in lithium-ion batteries has become more and more prominent.
[0003] At present, the dry-process electrode preparation technology has outstanding technical advantages for making thick electrodes, which can greatly increase the thickness and surface load of the pole piece, which is beneficial to the improvement of the energy density of lithium-ion batteries. In addition, the dry-process electrode technology also has the characteristics of solvent-free use, low manufacturing cost, and high production efficiency. However, the current mainstream electrode preparation technology generally uses the principle of polytetrafluoroethylene (PTFE) fibrillation to form a fiber network to achieve the fixed film formation of the active substance. However, there are currently problems such as cavities, low degree of fitting, and insufficient uniformity in the bonding of the positive and negative electrode membranes of the dry-process electrode with the current collector, which leads to problems such as decreased performance of the dry-process electrode and curling of the current collector, and the advantages of the dry-process electrode cannot be brought into play.
[0004] Therefore, it is urgent to develop a new type of current collector to solve the bonding problem of dry electrodes and thus improve the performance of dry electrodes.
[0005] In view of this, this application is hereby filed. Utility Model Content
[0006] The utility model aims to provide a current collector, an electrode and a secondary battery, which can solve the lamination problem of dry-process electrodes and make the lamination more uniform.
[0007] The embodiment of the utility model is achieved as follows:
[0008] In a first aspect, the utility model provides a current collector, including a current collector body, the current collector body having a first plate surface, a second plate surface, a first end surface and a second end surface, the first plate surface and the second plate surface are arranged opposite to each other, and the first end surface and the second end surface are arranged opposite to each other;
[0009] The current collector body is provided with a plurality of channels extending from the first end surface to the second end surface, the first plate surface is provided with a plurality of first connection holes, the second plate surface is provided with a plurality of second connection holes, the first connection holes are connected to at least one channel, and the second connection holes are connected to at least one channel.
[0010] In an optional embodiment, the current collector body is in the shape of a rectangular parallelepiped, and the first plate surface and the second plate surface are the two surfaces with the largest areas of the current collector body.
[0011] In an optional embodiment, the plurality of channels are arranged in a matrix.
[0012] In an optional embodiment, the plurality of first connection holes and the plurality of second connection holes are arranged in a matrix.
[0013] In an optional embodiment, the position of each row of first connection holes corresponds to a channel close to the first board surface, and the position of each row of second connection holes corresponds to a channel close to the second board surface.
[0014] In an optional embodiment, the diameter of the first connecting hole is smaller than or equal to the diameter of the channel, and the diameter of the second connecting hole is smaller than or equal to the diameter of the channel.
[0015] In an optional embodiment, the diameter of the channel is 2 μm-30 μm, and the pore diameters of the first connecting hole and the second connecting hole are both 2 μm-30 μm.
[0016] In an alternative embodiment, the thickness of the current collector body is 2 μm-30 μm.
[0017] In a second aspect, the utility model provides an electrode, comprising the current collector of any one of the aforementioned embodiments.
[0018] In a third aspect, the utility model provides a secondary battery, comprising the electrode of the aforementioned embodiment.
[0019] The beneficial effects of the embodiment of the utility model are: by setting a plurality of channels between the first end face and the second end face of the current collector body, setting a first connection hole and a second connection hole on the first plate surface and the second plate surface respectively, and using the first connection hole and the second connection hole to communicate with the channels respectively, an exhaust network is formed, and the cavity formed between the electrode film and the current collector during dry electrode lamination allows gas to be discharged and the electrode film can be embedded in the current collector, thereby improving the degree of lamination. In addition, when the electrolyte is infiltrated, the channel can allow the electrolyte to enter the interior of the current collector, so that the electrode film is more thoroughly infiltrated, thereby improving the degree of electrolyte infiltration. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.
[0021] Figure 1 A schematic diagram of the structure of the current collector provided in an embodiment of the utility model;
[0022] Figure 2 for Figure 1Enlarged view of area A in the middle;
[0023] Figure 3 This is a real picture after bonding with common carbon-coated copper negative electrode;
[0024] Figure 4 This is a real picture of the current collectors provided by the embodiment of the utility model after bonding.
[0025] Icon: 100 - current collector; 110 - current collector body; 111 - first plate surface; 112 - second plate surface; 113 - first end surface; 114 - second end surface; 115 - channel; 116 - first connecting hole; 117 - second connecting hole. DETAILED DESCRIPTION
[0026] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Generally, the components of the embodiments of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.
[0027] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the present invention to be protected, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0028] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.
[0029] In the description of the present utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate the orientation or position relationship based on the orientation or position relationship shown in the accompanying drawings, or the orientation or position relationship in which the utility model product is usually placed when in use, which is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.
[0030] In addition, the terms "horizontal", "vertical" and the like do not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.
[0031] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0032] like Figure 1 As shown, an embodiment of the utility model provides a current collector 100, including a current collector body 110. The current collector body 110 can be in the shape of a rectangular parallelepiped with six faces, including a first plate face 111, a second plate face 112, a first end face 113 and a second end face 114, and the other two faces are not marked.
[0033] Furthermore, please combine Figure 1 and Figure 2 , the first plate surface 111 and the second plate surface 112 are arranged opposite to each other, the first end surface 113 and the second end surface 114 are arranged opposite to each other, and there are two other surfaces that are not marked. The current collector body 110 is provided with a plurality of channels 115 extending from the first end surface 113 to the second end surface 114, the first plate surface 111 is provided with a plurality of first connection holes 116, and the second plate surface 112 is provided with a plurality of second connection holes 117. The first connection holes 116 are connected to at least one channel 115, and the second connection holes 117 are connected to at least one channel 115. In this way, a channel structure is formed inside the current collector body 110, the first end surface 113 shows the channel opening, the plurality of first connection holes 116 on the first plate surface 111 are all connected to at least one channel 115, and similarly, the plurality of second connection holes 117 on the second plate surface 112 are all connected to at least one channel 115.
[0034] It should be noted that the first connection hole 116 and the second connection hole 117 on the surface are both connected to the internal channel, so that the surface passage is connected to the internal pipeline network to form an exhaust network, so that a cavity is formed between the electrode film and the current collector when the dry electrode is bonded, so that the gas can be discharged and the electrode film can be embedded in the current collector to improve the degree of bonding. At the same time, when the electrolyte is infiltrated, the channel 115 can allow the electrolyte to enter the interior of the current collector, so that the electrode film is more thoroughly infiltrated, and the degree of electrolyte infiltration is improved.
[0035] In some embodiments, the first plate surface 111 and the second plate surface 112 are the two surfaces with the largest area of the current collector body 110, that is, the four sides of the first plate surface 111 and the second plate surface 112 include length sides and width sides, but do not include sides representing the thickness direction.
[0036] Furthermore, the channel 115 may extend in the length direction or in the width direction. To reduce the difficulty of processing, the channel 115 may extend in the width direction.
[0037] In some embodiments, the plurality of channels 115 are arranged in a matrix, that is, in multiple rows and columns, but the present invention is not limited thereto. The matrix arrangement is convenient for processing and design.
[0038] Similarly, the plurality of first connection holes 116 and the plurality of second connection holes 117 may also be arranged in a matrix. That is, the first connection holes 116 are arranged in multiple rows and columns on the first board surface 111 , and the second connection holes 117 are also arranged in multiple rows and columns on the second board surface 112 .
[0039] Furthermore, the position of each row of first connection holes 116 corresponds to a channel 115 close to the first plate surface 111, that is, each row of first connection holes 116 is located along Figure 1 The positions of the second connection holes 117 in each row correspond to a channel 115 close to the second plate surface 112, that is, the second connection holes 117 in each row are arranged in a direction of the top channel 115. Figure 1 The first connection holes 116 and the second connection holes 117 are arranged in a spaced relationship in the direction of the bottom channel 115. The first connection holes 116 and the second connection holes 117 both have a certain depth to communicate with the corresponding channel 115.
[0040] Furthermore, the diameter of the first connection hole 116 is smaller than or equal to the diameter of the channel 115, and the diameter of the second connection hole 117 is smaller than or equal to the diameter of the channel 115. The first connection holes 116 and the second connection holes 117 of smaller sizes are spaced apart to better discharge the gas.
[0041] In some embodiments, the diameter of the channel 115 is 2 μm-30 μm, and the interval between two adjacent channels 115 is not limited and can be 2 μm-30 μm. The apertures of the first connection holes 116 and the second connection holes 117 are both 2 μm-30 μm, the interval between two adjacent first connection holes 116 is 2 μm-30 μm, the interval between two adjacent second connection holes 117 is 2 μm-30 μm, the thickness of the current collector body 110 is 2 μm-30 μm, and the diameter of the control channel 115 is slightly smaller than the thickness.
[0042] It should be noted that the length and width of the current collector body 110 are not limited and can be set as needed. For example, the width can be 10mm-20000mm, and the length is not limited (a current collector roll has a length of several hundred meters, and the length can be designed as needed).
[0043] The material of the current collector body 110 is not limited, and may be copper foil, aluminum foil, nickel foil, steel foil, etc.
[0044] It should be noted that the melting point of pure copper is about 1000°C and the melting point of silicon dioxide is about 1700°C. It is possible to place an extremely fine optical fiber in molten copper metal and finally extract the optical fiber to form a hole. The surface can be polished or punctured with a micron-level steel needle to form holes, but is not limited to this.
[0045] The embodiment of the utility model further provides an electrode, comprising the above-mentioned current collector 100, on which an active material layer is arranged, and the current collector 100 can be a positive electrode or a negative electrode.
[0046] It should be noted that the electrode can be manufactured by a conventional dry method, and the specific process is not limited.
[0047] The embodiment of the utility model provides a secondary battery, comprising the above-mentioned electrode, and also comprising an electrolyte, a diaphragm, etc., to form a complete secondary battery.
[0048] Example 1
[0049] This embodiment provides a method for preparing an electrode, wherein the structure of the current collector used is as follows: Figure 1 and Figure 2 As shown, the material is copper foil, and the specific preparation process is as follows:
[0050] (1) Mixing
[0051] Using a mixing shearing device, the weighed active material (LiFePO4), conductive agent (conductive carbon black) and dry binder (PTFE) are placed in the shearing device in a mass ratio of 80:10:10. After sealing, start low-speed mixing to premix the materials and make their particles evenly dispersed. After a period of time, turn off the device; then turn on the high speed to shear the material, and stop shearing for 2 hours.
[0052] (2) Material collection
[0053] After the high-speed shearing is completed, the equipment is turned off, the high-speed shearing chamber is opened, and the product is collected.
[0054] (3) Film formation
[0055] The material is put into a roller press to be rolled into a film.
[0056] (4) Fitting
[0057] The electrode film is placed on both sides of the current collector (the first plate surface and the second plate surface), and an automatic unwinding operation is performed, and the film is laminated by a hot roller (temperature 50-200° C.).
[0058] The results show that if ordinary carbon-coated copper negative electrode is used, curling is likely to occur after bonding (such as Figure 3 As shown), but the current collector provided by the embodiment of the utility model shows uniform and flat (as shown Figure 4 shown).
[0059] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may be subject to various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
Claims
1. A current collector, characterized in that: The current collector body comprises a first plate surface, a second plate surface, a first end surface and a second end surface, wherein the first plate surface and the second plate surface are arranged opposite to each other, and the first end surface and the second end surface are arranged opposite to each other; The current collector body is provided with a plurality of channels extending from the first end surface to the second end surface, the first plate surface is provided with a plurality of first connecting holes, the second plate surface is provided with a plurality of second connecting holes, the first connecting hole is connected to at least one of the channels, and the second connecting hole is connected to at least one of the channels.
2. The current collector according to claim 1, characterized in that: The current collector body is in a rectangular parallelepiped shape, and the first plate surface and the second plate surface are two surfaces of the current collector body with the largest areas.
3. The current collector according to claim 1 or 2, characterized in that: The plurality of channels are arranged in a matrix.
4. The current collector according to claim 3, characterized in that: The plurality of first connection holes and the plurality of second connection holes are arranged in a matrix.
5. The current collector according to claim 4, characterized in that: The position of each row of the first connection holes corresponds to one of the channels close to the first board surface, and the position of each row of the second connection holes corresponds to one of the channels close to the second board surface.
6. The current collector according to claim 1, characterized in that: The diameter of the first connecting hole is smaller than or equal to the diameter of the channel, and the diameter of the second connecting hole is smaller than or equal to the diameter of the channel.
7. The current collector according to claim 6, characterized in that: The diameter of the channel is 2 μm-30 μm, and the diameters of the first connecting hole and the second connecting hole are both 2 μm-30 μm.
8. The current collector according to claim 1, characterized in that: The thickness of the current collector body is 2 μm-30 μm.
9. An electrode, characterized in that: The present invention comprises the current collector according to any one of claims 1 to 8.
10. A secondary battery, characterized in that: Comprising the electrode according to claim 9.