Composite current collector pole group structure and battery
By setting an active material layer and a metal foil current collector ear in the conductive layer of the composite liquid collector electrode structure, and using multi-layer ultrasonic welding technology, the composite liquid collector electrode structure in the prior art requires welding using continuous roller equipment, which is solved. The high manufacturing cost and defect rate problems have achieved efficient and low-cost battery production.
Patent Information
- Application Number
- CN202420489082.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-13
- Publication Date
- 2025-02-25
- Estimated Expiration
- 2034-03-13
AI Technical Summary
The existing composite fluid collector pole assembly structure requires welding using continuous roller equipment, resulting in high battery manufacturing cost, high manufacturing efficiency and defect rate.
By setting an active material layer in the conductive layer of the composite liquid collector and forming blank areas on both sides of the conductive layer, metal foil current collector electrodes are provided. When welding, only the electrode ears, the composite liquid collector and extension parts are needed to reduce the welding area Area, multi-layer ultrasonic welding technology is used.
It significantly improves welding efficiency, reduces battery manufacturing costs, improves production efficiency and yield rate, and avoids the problems of high accuracy requirements and high defect rate of continuous roller equipment.
Smart Images
Figure CN222530451U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of batteries, in particular to a composite current collector electrode group structure and a battery. Background Art
[0002] Compared with traditional current collectors, composite current collectors have thinner thickness and lighter weight, which is beneficial to improving the energy density of lithium-ion batteries and improving the safety of lithium-ion batteries.
[0003] The composite current collector includes an intermediate polymer layer and metal layers arranged on both sides of the polymer layer. Since the intermediate polymer layer is an insulating material, the metal layers on both sides thereof cannot be conducted during the charge and discharge process. In the prior art, the conduction of the metal layers on both sides of the composite current collector is achieved by staggered stacking of the composite current collector and the normal metal foil current collector. The composite current collector electrode group structure of this structure requires a large area to be welded, and the composite current collector and the normal metal foil current collector need to be welded by continuous roller equipment, resulting in the need to introduce and use continuous roller equipment during the battery manufacturing process, which increases the manufacturing cost and manufacturing time of the battery; at the same time, the continuous roller welding equipment has high requirements for equipment precision, which increases the defective rate of battery manufacturing. Utility Model Content
[0004] In view of this, the utility model provides a composite current collector electrode group structure and a battery to solve the problem that the composite current collector electrode group structure in the prior art needs to be welded by continuous roller equipment, resulting in high battery manufacturing cost, high manufacturing efficiency and high defect rate.
[0005] In a first aspect, the utility model provides a composite current collector electrode group structure, comprising:
[0006] A plurality of composite current collector pole pieces are stacked; each of the composite current collector pole pieces comprises a composite current collector, an active material layer and a metal foil current collector pole piece; the composite current collector comprises a polymer layer and a conductive layer arranged on both sides of the polymer layer; the active material layer is arranged in the middle area of each conductive layer to form a blank area on the surface of the conductive layer on both sides of the active material layer; one end of the metal foil current collector pole piece is arranged on the blank area of one of the conductive layers, and the other end extends out of the composite current collector to form an extension; the metal foil current collector pole piece is welded to the composite current collector adjacent thereto, and the adjacent extensions are welded;
[0007] A transition metal foil current collector, one end of which is arranged on the blank area at the top or bottom of all the composite current collector pole pieces, and the other end extends out of the composite current collector, and the end of the transition metal foil current collector extending out of the composite current collector is welded to the extension portion.
[0008] Beneficial effects: The composite current collector electrode group structure of this structure has an active material layer arranged in the middle area of the conductive layer of the composite current collector, a blank area is formed on the surface of the conductive layer on both sides of the active material layer, and a metal foil current collector electrode ear is arranged on the blank area. During welding, only the metal foil current collector electrode ear and the composite current collector, as well as the extension of the adjacent metal foil current collector electrode ear need to be welded. The welding area required for the composite current collector electrode group structure is small, and all metal foil current collector electrodes and composite current collectors can be welded by multi-layer ultrasonic welding, and all extensions can be directly welded by multi-layer ultrasonic welding, which can significantly improve the welding efficiency and improve the production efficiency of the electrode group and the battery; there is no need to introduce continuous roller equipment during the battery manufacturing process, which is conducive to reducing the manufacturing cost of the electrode group and the battery and improving the yield rate of the electrode group and the battery. At the same time, the active material layer is arranged in the middle area of the conductive layer, and the surface of the active material layer protrudes from the surface of the conductive layer where the blank area is located, so that the metal foil current collector electrode ear is arranged on the blank area. After rolling the active material layer and the metal foil current collector electrode ear, the surface of the active material layer protrudes from the surface of the metal foil current collector electrode ear. The metal foil current collector tab is welded on the composite current collector to conduct the conductive layer through the metal foil current collector tab; multiple composite current collector pole pieces are stacked, and the extensions of adjacent metal foil current collector tabs are welded to conduct the conductive layers of each composite current collector, and the transition metal foil current collector is welded to the outermost composite current collector and the extensions of the metal foil current collector tab, so that the outermost exposed conductive layer conducts the various conductive layers, thereby achieving conduction of all conductive layers.
[0009] In an optional embodiment, one end of the metal foil current collector tab is disposed on a blank area of the conductive layer on top of the polymer layer, and the transition metal foil current collector is disposed on a blank area of the conductive layer at the bottom of all the composite current collector pole pieces.
[0010] Beneficial effect: One end of the metal foil current collector tab is disposed on the blank area of the conductive layer on top of the polymer layer, which facilitates rolling of the metal foil current collector tab to bond the metal foil current collector tab to the blank area.
[0011] In an optional embodiment, all of the metal foil current collector tabs are flush with the end surface of the transition metal foil current collector.
[0012] Beneficial effects: The electrode group structure can be optimized, and the electrode group can be placed in the battery casing, which can improve the battery space utilization.
[0013] In an optional embodiment, the connection direction of the blank areas on both sides of the active material layer is the length direction of the metal foil current collector tab, and the length of the extension portion is L, 5mm≤L≤30mm.
[0014] Beneficial effects: The extension part has a moderate length to prevent it from being too long, which is beneficial to improving space utilization. At the same time, it prevents the extension part from being too short, which can ensure the welding area between adjacent extension parts, ensure the welding firmness between the extension parts, prevent the extension part from loosening, ensure the conductive effect between all conductive layers, and thus ensure the normal output of the electrode group electric energy.
[0015] In an optional embodiment, 8mm≤L≤20mm.
[0016] In an optional embodiment, the width of the welding region between the metal foil current collector tab and the composite current collector is W, and 5 mm ≤ W ≤ 30 mm.
[0017] Beneficial effect: It is ensured that the metal foil current collector tab and the composite current collector have sufficient welding area to ensure the current collection effect.
[0018] In an optional embodiment, 10 mm ≤ W ≤ 20 mm.
[0019] In an optional embodiment, the composite current collector includes a positive composite current collector and a negative composite current collector; the conductive layer of the positive composite current collector includes an aluminum foil conductive layer, and the conductive layer of the negative composite current collector includes a copper foil conductive layer.
[0020] In an optional implementation, the thickness of the aluminum foil conductive layer is 1 μm, and / or the thickness of the copper foil conductive layer is 1 μm.
[0021] In a second aspect, the utility model further provides a battery, comprising any one of the composite current collector electrode group structures described above. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0023] Figure 1 A schematic diagram of a single composite current collector electrode piece in a composite current collector electrode group structure according to an embodiment of the utility model;
[0024] Figure 2 It is a schematic diagram of stacking multiple composite current collectors and metal foil current collector tabs in a composite current collector electrode group structure according to an embodiment of the utility model.
[0025] Description of reference numerals:
[0026] 1. Composite current collector pole piece; 101. Composite current collector; 1011. Polymer layer; 1012. Conductive layer; 102. Active material layer; 103. Metal foil current collector pole ear; 2. Transfer metal foil current collector; 3. Ultrasonic welding head. DETAILED DESCRIPTION
[0027] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.
[0028] Combine the following Figure 1 to Figure 2 , describing an embodiment of the utility model.
[0029] According to an embodiment of the present invention, on one hand, a composite current collector electrode group structure is provided, which includes a plurality of composite current collector electrode sheets 1 and a transition metal foil current collector 2 .
[0030] Among them, multiple composite current collector pole pieces 1 are stacked; each composite current collector pole piece 1 includes a composite current collector 101, an active material layer 102 and a metal foil current collector pole piece 103; the composite current collector 101 includes a polymer layer 1011 and a conductive layer 1012 arranged on both sides of the polymer layer 1011; the active material layer 102 is arranged in the middle area of each conductive layer 1012 to form a blank area on the surface of the conductive layer 1012 on both sides of the active material layer 102; one end of the metal foil current collector pole piece 103 is arranged on the blank area of one of the conductive layers 1012, and the other end extends out of the composite current collector 101 to form an extension; the metal foil current collector pole piece 103 is welded to the composite current collector 101 adjacent to it, and the adjacent extensions are welded; one end of the transition metal foil current collector 2 is arranged on the blank area at the top or bottom of all composite current collector pole pieces 1, and the other end extends out of the composite current collector 101, and one end of the transition metal foil current collector 2 extending out of the composite current collector 101 is welded to the extension.
[0031] In the composite current collector electrode group structure of this structure, an active material layer 102 is arranged in the middle area of the conductive layer 1012 of the composite current collector 101, a blank area is formed on the surface of the conductive layer 1012 on both sides of the active material layer 102, and a metal foil current collector pole ear 103 is arranged on the blank area. During welding, only the metal foil current collector pole ear 103 and the composite current collector 101, and the extension of the adjacent metal foil current collector pole ear 103 need to be welded. The welding area required for the composite current collector electrode group structure is small, and all the metal foil current collector pole ears 103 and the composite current collector 101 can be welded by multi-layer ultrasonic welding, and all the extensions can be directly welded by multi-layer ultrasonic welding, which can significantly improve the welding efficiency and improve the production efficiency of the electrode group and the battery; in the battery manufacturing process, there is no need to introduce continuous roller equipment, which is conducive to reducing the manufacturing cost of the electrode group and the battery and improving the yield rate of the electrode group and the battery. At the same time, the active material layer 102 is arranged in the middle area of the conductive layer 1012, and the surface of the active material layer 102 protrudes from the surface of the conductive layer 1012 where the blank area is located, so that the metal foil current collector tab 103 can be arranged on the blank area. After the active material layer 102 and the metal foil current collector tab 103 are rolled, the surface of the active material layer 102 protrudes from the surface of the metal foil current collector tab 103. The metal foil current collector tab 103 is welded on the composite current collector 101 to conduct the conductive layer 1012 through the metal foil current collector tab 103; multiple composite current collector pole pieces 1 are stacked, and the extensions of adjacent metal foil current collector tabs 103 are welded to conduct the conductive layers 1012 of each composite current collector 101, and the transition metal foil current collector 2 is welded to the outermost composite current collector 101 and the extension of the metal foil current collector tab 103, so that the outermost exposed conductive layer 1012 conducts to each conductive layer 1012, thereby achieving conduction of all conductive layers 1012.
[0032] like Figure 1 and Figure 2 As shown, when the composite current collector electrode 1 is placed horizontally, its upper side is called the upper part of the polymer layer 1011, and its lower side is called the lower part of the polymer layer 1011.
[0033] In one embodiment, one end of the metal foil current collector pole tab 103 is arranged on the blank area of the conductive layer 1012 at the top of the polymer layer 1011, and the transfer metal foil current collector 2 is arranged on the blank area of the conductive layer 1012 at the bottom of all composite current collector pole pieces 1. When making the composite current collector pole piece 1, firstly, a conductive glue is coated on the blank area of the composite current collector 101, and the metal foil current collector pole tab 103 is placed on the blank area, and the metal foil current collector pole tab 103 is rolled to make it bonded to the conductive layer 1012 of the composite current collector 101. One end of the metal foil current collector pole tab 103 is arranged on the blank area of the conductive layer 1012 at the top of the polymer layer 1011, so as to facilitate rolling the metal foil current collector pole tab 103 to bond the metal foil current collector pole tab 103 to the blank area.
[0034] Since the upper surface of the active material layer 102 protrudes from the upper surface of the metal foil current collector tab 103, during the rolling stage, the roller rolls the active material layer 102, and an auxiliary rolling structure protruding downward from the roller is provided on the side of the roller. The auxiliary rolling structure rolls the metal foil current collector tab 103 region, so as to synchronously roll the active material layer 102 and the metal foil current collector tab 103 during the rolling process.
[0035] In other embodiments, one end of the metal foil current collector tab 103 may also be set on the blank area of the conductive layer 1012 at the bottom of the polymer layer 1011. In this case, the conductive layer 1012 of the composite current collector 101 at the top of the composite current collector electrode group structure is exposed, and the transition metal foil current collector 2 is set on the blank area of the top conductive layer 1012.
[0036] like Figure 2 As shown, in one embodiment, all metal foil current collector tabs 103 are flush with the end faces of the transition metal foil current collector 2. After welding, the ends of all extensions are flush with the ends of the transition metal foil current collector 2, which can optimize the electrode group structure, place the electrode group in the battery casing, and improve the battery space utilization.
[0037] like Figure 1 As shown, blank areas are formed on the surface of the conductive layer 1012 on the left and right sides of the active material layer 102, and the connecting direction of the blank areas on both sides of the active material layer 102 is the length direction of the metal foil current collector tab 103 (i.e. Figure 2 The left and right directions are the length directions of the metal foil current collector pole ear 103), and the length of the extension portion is L, 5mm≤L≤30mm. The length of the extension portion is moderate, preventing it from being too long, which is beneficial to improving the space utilization rate, and preventing the extension length from being too short, which can ensure the welding area between adjacent extension portions, ensure the welding firmness between the extension portions, prevent the extension portion from loosening, ensure the conductive effect between all conductive layers 1012, and thus ensure the normal output of the electrode group electric energy.
[0038] Preferably, in one embodiment, 8 mm ≤ L ≤ 20 mm, so as to further optimize the length of the extension portion, ensure the welding effect of adjacent extension portions, and further improve the space utilization of the electrode group and the battery.
[0039] Figure 1 Shown and Figure 2 The left and right directions are the length directions of the metal foil current collector tab 103 and the composite current collector 101. In the plane where the composite current collector 101 is located, the direction perpendicular to the length of the metal foil current collector tab 103 is its width direction, that is, Figure 2 The front-to-back direction is the width direction of the metal foil current collector tab 103 and the composite current collector 101. The width of the welding area between the metal foil current collector tab 103 and the composite current collector 101 is W, 5mm≤W≤30mm, which can ensure that the metal foil current collector tab 103 and the composite current collector 101 have sufficient welding area to ensure the current collection effect.
[0040] Optionally, in one embodiment, 10 mm≤W≤20 mm, so as to further optimize the width of the welding region between the metal foil current collector tab 103 and the composite current collector 101 .
[0041] Optionally, in the width direction of the composite current collector 101 (i.e. Figure 2 In the front-to-back direction), the metal foil current collector tabs 103 are all located inside the composite current collector 101, that is, the width of the metal foil current collector tabs 103 is smaller than the width of the composite current collector 101.
[0042] The composite current collector 101 includes a positive composite current collector and a negative composite current collector; the conductive layer 1012 of the positive composite current collector includes an aluminum foil conductive layer, and the conductive layer 1012 of the negative composite current collector includes a copper foil conductive layer. When the composite current collector electrode group structure is manufactured, the positive active material is coated on the conductive layer 1012 of the positive composite current collector, and the aluminum foil current collector pole ear is arranged on the blank area of the positive composite current collector, and the positive composite current collector pole piece is formed after rolling; the negative active material is coated on the conductive layer 1012 of the negative composite current collector, and the copper foil current collector pole ear is arranged on the blank area of the negative composite current collector, and the negative composite current collector pole piece is formed after rolling; the positive composite current collector pole piece and the negative composite current collector pole piece are alternately stacked, and each layer of the composite current collector 101 and the pole ear, as well as each layer of the extension part, are welded to obtain the pole group.
[0043] Optionally, in one embodiment, the thickness of the aluminum foil conductive layer 1012 is 1 μm, and / or the thickness of the copper foil conductive layer 1012 is 1 μm.
[0044] The positive electrode composite current collector uses PET, PP, and PI as polymer substrates. A 1 μm thick aluminum film is prepared on both sides of the polymer layer 1011 by thermal evaporation to form a positive electrode composite current collector. A 30-nanometer to 50-nanometer continuous copper seed layer is evaporated on the polymer layer 1011 by magnetron sputtering or thermal evaporation, and then the copper thickness is thickened to 1 μm by water electroplating to form a negative electrode composite current collector.
[0045] like Figure 2 As shown, the ultrasonic welding head 3 for welding the composite current collector 101 includes a horizontal portion and a boss portion arranged on one side of the horizontal portion, and the welding surface of the boss portion protrudes from the welding surface of the horizontal portion. During welding, the horizontal portion corresponds to the metal foil current collector pole ear 103 on the blank area, and the boss portion corresponds to the extension portion of the metal foil pole ear, so that the metal foil current collector pole ear 103 and the composite current collector 101, as well as all the extension portions, are welded simultaneously by the ultrasonic welding head 3.
[0046] The preparation process of the composite current collector electrode group structure is as follows:
[0047] Coating active materials on the conductive layer 1012 and applying conductive glue to the blank area of the composite current collector 101;
[0048] Placing the metal foil current collector tab 103 on the blank area, rolling the active material layer 102 and the metal foil current collector tab 103 so that the metal foil current collector tab 103 is bonded to the blank area of the composite current collector 101 to form a composite current collector electrode sheet 1;
[0049] Cutting the composite current collector electrode sheet 1 and stacking layers of the composite current collector electrode sheets 1 up and down;
[0050] The transition metal foil current collector 2 is disposed on the conductive layer 1012 of the bottom composite current collector electrode sheet 1, and each layer of metal foil current collector electrode tabs 103 and the composite current collector 101, as well as each layer of extension portions, are ultrasonically welded.
[0051] The following describes the manufacturing process of the composite current collector electrode group structure in combination with two specific embodiments:
[0052] Example 1
[0053] NCM811:SP; CNT; PVDF = 95:2:1:2 were mixed evenly in NMP solvent to prepare positive electrode active material slurry, the positive electrode active material slurry was coated on the surface of 6 (PET) + 1 (Al) + 1 (Al) composite aluminum foil, and 10 mm blank areas were reserved on both sides of the composite aluminum foil, and polyacrylic conductive adhesive was coated on the blank areas; while rolling the electrode sheets, an aluminum foil current collector pole ear with a width of 30 mm and a thickness of 15 μm was adhered to the blank area of the composite aluminum foil; the electrode sheets were cut; the electrode sheets were stacked, a 15 μm thick transfer aluminum foil current collector was added to the bottom of the stacked electrode group, and the aluminum foil current collector pole ear and the composite aluminum foil were ultrasonically welded.
[0054] Example 2
[0055] Gr:SP; CMC; SBR = 96:1:1:2 were mixed evenly in an aqueous solvent to prepare a negative electrode active slurry, and the negative electrode active slurry was coated on the surface of a 3(PP)+1(Cu)+1(Cu) composite copper foil, and a 15mm blank area was reserved on both sides of the composite copper foil, and a polyacrylic conductive adhesive was coated on the blank area; while rolling the electrode sheet, a copper foil current collector pole ear with a width of 30mm and a thickness of 4.5 microns was adhered to the blank area of the composite copper foil; the electrode sheet was cut; the electrode sheets were stacked, and a 4.5μm thick transfer copper foil current collector was added to the bottom of the stacked electrode group, and the copper foil current collector pole ear and the composite copper foil were ultrasonically welded.
[0056] According to an embodiment of the present invention, on the other hand, a battery is provided, comprising the above-mentioned composite current collector electrode group structure and a shell, wherein the composite current collector electrode group structure is arranged in the shell.
[0057] For the battery of this structure, when welding the electrode group, it is only necessary to weld the metal foil current collector electrode ear 103 and the composite current collector 101, as well as the extension of the adjacent metal foil current collector electrode ear 103. The composite current collector electrode group structure requires a small welding area, and all the metal foil current collector electrode ears 103 and the composite current collector 101 can be welded by multi-layer ultrasonic welding, as well as all the extensions can be directly welded, which can significantly improve the welding efficiency and improve the production efficiency of the battery. There is no need to introduce continuous roller equipment in the battery manufacturing process, which is conducive to reducing the manufacturing cost of the battery and improving the yield rate of the battery.
[0058] Although the embodiments of the present invention are described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.
Claims
1. A composite current collector electrode group structure, characterized in that: include: A plurality of composite current collector pole pieces are stacked; each of the composite current collector pole pieces comprises a composite current collector, an active material layer and a metal foil current collector pole ear; The composite current collector comprises a polymer layer and a conductive layer arranged on both sides of the polymer layer; the active material layer is arranged in the middle area of each conductive layer to form a blank area on the surface of the conductive layer on both sides of the active material layer; one end of the metal foil current collector tab is arranged on the blank area of one of the conductive layers, and the other end extends out of the composite current collector to form an extension; the metal foil current collector tab is welded to the composite current collector adjacent to it, and the adjacent extensions are welded; A transition metal foil current collector, one end of which is arranged on the blank area at the top or bottom of all the composite current collector pole pieces, and the other end extends out of the composite current collector, and the end of the transition metal foil current collector extending out of the composite current collector is welded to the extension portion.
2. The composite current collector electrode structure according to claim 1, characterized in that: One end of the metal foil current collector pole ear is arranged on the blank area of the conductive layer on the top of the polymer layer, and the transition metal foil current collector is arranged on the blank area of the conductive layer at the bottom of all the composite current collector pole pieces.
3. The composite current collector electrode structure according to claim 1 or 2, characterized in that: All the metal foil current collector tabs are flush with the end surface of the transition metal foil current collector.
4. The composite current collector electrode group structure according to claim 1 or 2, characterized in that: The connecting direction of the blank areas on both sides of the active material layer is the length direction of the metal foil current collector tab, and the length of the extension portion is L, 5mm≤L≤30mm.
5. The composite current collector electrode group structure according to claim 4, characterized in that: 8mm≤L≤20mm.
6. The composite current collector electrode group structure according to claim 1 or 2, characterized in that: The width of the welding area between the metal foil current collector tab and the composite current collector is W, 5mm≤W≤30mm.
7. The composite current collector electrode group structure according to claim 6, characterized in that: 10mm≤W≤20mm.
8. The composite current collector electrode group structure according to claim 1 or 2, characterized in that: The composite current collector comprises a positive composite current collector and a negative composite current collector; the conductive layer of the positive composite current collector comprises an aluminum foil conductive layer, and the conductive layer of the negative composite current collector comprises a copper foil conductive layer.
9. The composite current collector electrode group structure according to claim 8, characterized in that: The thickness of the aluminum foil conductive layer is 1 μm, and / or the thickness of the copper foil conductive layer is 1 μm.
10. A battery, characterized in that: A composite current collector electrode group structure comprising any one of claims 1 to 9.