Composite current collector with retained weld reservation
By designing a composite current collector with pre-reserved welding tabs, the problems of welding tabs affecting conductivity and increasing battery weight were solved, achieving efficient production and cost reduction, enhancing the current collector's flow capacity, and simplifying the process.
Patent Information
- Application Number
- CN202423159480.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-20
- Publication Date
- 2025-11-28
- Estimated Expiration
- 2034-12-20
AI Technical Summary
When welding tabs, the base film of existing composite current collectors affects the conductivity. Adding additional tabs and adapters increases the weight and cost of the battery, and it is difficult to achieve efficient mass production.
Design a composite current collector with welding pre-reservation, including a conductive substrate and a welding pre-reservation part. The thickness of the welding pre-reservation part is greater than that of the current collector coating part. The lower surface of the coating part is covered with a non-conductive base layer and has a conductive coating. The pre-reservation part is directly welded to devices such as the busbar, reducing the number of processes.
It improved production efficiency, reduced processes, lowered production costs, avoided voids, enhanced flow capacity, and simplified the process flow.
Smart Images
Figure CN223612434U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the field of current collector, especially to a composite current collector with welding reserved. BACKGROUND
[0002] The current collector is one of indispensable electrode materials of the lithium ion battery, has important functions of bearing active material (bearing property) and collecting micro-current (conductivity). Thin type, functionalization are main development directions of the current collector, and the Al foil current collector of 8~9 mu m and the Cu foil current collector of 4~5 mu m almost reach the extreme level of manufacturability of the lithium ion battery, and the further thinning of the current collector leads to the reduction of strength, and it is difficult to be applied in batches. Functionalization current collector such as carbon coating, LFP, ceramic and the like can improve adhesion, internal resistance, safety performance and the like, but still has some negative effects, such as higher process control requirement, cost increase or energy density reduction and the like. The composite current collector integrates the characteristics of light and thin high-safety current collector, and has been widely researched in recent years.
[0003] When the composite current collector is used in the battery, the base film of the composite current collector can wrap the end of the puncture object when being punctured, to prevent the positive and negative electrodes from directly contacting and forming a short circuit. In the current situation of frequent spontaneous combustion of electric vehicles, the application of the composite current collector is accelerated. In the process of preparing the battery by using the composite current collector, the tab needs to be welded, so that the current collected by the composite current collector is led out from the tab to the power device. At present, the tab is welded by clamping the end of the composite current collector with the tab and the adapter piece at the edge of the end of the composite current collector, and then welding. The base film of the composite current collector is not conductive, and the base film will affect the conductive effect after welding. In addition, the additional tab and adapter piece greatly increase the weight and cost of the battery. Therefore, the prior art still needs to be improved and enhanced. SUMMARY
[0004] In view of the above shortcomings of the prior art, the purpose of the utility model is to provide a composite current collector with welding reserved.
[0005] To solve the above technical problems, the utility model adopts the following technical scheme:
[0006] The utility model provides a composite current collector with welding reserved, including conductive base sheet, the conductive base sheet includes current collector coating part and welding reserved part, the thickness of the welding reserved part is greater than the thickness of the current collector coating part, the upper surface of the welding reserved part is flush with the upper surface of the current collector coating part, the lower surface of the welding reserved part is higher than the lower surface of the current collector coating part, the lower surface of the current collector coating part is covered with non-conductive base layer, and the lower surface of the non-conductive base layer and the lower surface of the welding reserved part are provided with conductive coating.
[0007] In a preferred embodiment, the composite current collector with welding reservation, the side of the non-conductive base layer is connected with the welding reservation part, and the lower surface of the non-conductive base layer is flush with the lower surface of the welding reservation part.
[0008] In a preferred embodiment, the composite current collector with welding reservation, the conductive base sheet is a metal foil.
[0009] In a preferred embodiment, the composite current collector with welding reservation, the thickness of the conductive base sheet is 6 µm-20 µm.
[0010] In a preferred embodiment, the composite current collector with welding reservation, the lower surface of the current collector coating part is etched with a notch structure.
[0011] In a preferred embodiment, the composite current collector with welding reservation, the notch structure is a mesh-like notch structure, and the notch depth of the notch structure is 100 nm-1000 nm.
[0012] In a preferred embodiment, the composite current collector with welding reservation, the non-conductive base layer is a polymer film layer.
[0013] In a preferred embodiment, the composite current collector with welding reservation, the thickness of the non-conductive base layer is 1 µm-4 µm.
[0014] In a preferred embodiment, the composite current collector with welding reservation, a lower coating layer is arranged between the non-conductive base layer and the conductive coating layer, the lower coating layer is an aluminum oxide, silicon nitride, silicon carbide, copper alloy, aluminum alloy, nickel alloy or titanium alloy coating layer, the conductive coating layer is a metal coating layer, the thickness of the conductive coating layer is the same as that of the current collector coating part of the conductive base sheet, the conductive coating layer is an aluminum, copper, titanium, nickel, aluminum alloy, titanium alloy, nickel alloy or aluminum alloy coating layer, and the conductive base sheet is an aluminum, copper, titanium, nickel, aluminum alloy, titanium alloy, nickel alloy or aluminum alloy base sheet.
[0015] The utility model also provides a preparation method of the composite current collector with welding reservation, which comprises:
[0016] The conductive base sheet comprises a current collector coating part and a welding reservation part, and the current collector coating part of the conductive base sheet is subjected to thinning treatment;
[0017] A non-conductive base layer is coated on the lower surface of the current collector coating part;
[0018] A conductive coating layer is plated on the lower surface of the non-conductive base layer and the lower surface of the welding reservation part.
[0019] Compared with the prior art, the utility model provides a kind of composite current collector of retaining welding reservation, wherein the composite current collector of retaining welding reservation, including conductive substrate, the conductive substrate includes current collector coating part and welding reservation part, the thickness of the welding reservation part is greater than the thickness of the current collector coating part, the upper surface of the welding reservation part is flush with the upper surface of the current collector coating part, the lower surface of the welding reservation part is higher than the lower surface of the current collector coating part, the lower surface of the current collector coating part is covered with non-conductive base layer, and conductive coating is arranged on the lower surface of the non-conductive base layer and the lower surface of the welding reservation part.By such setting, the utility model since conductive substrate is pure metal foil, and welding reservation part is also pure metal foil, when preparing battery, it is not necessary to weld pole lug and adapter piece again, can the welding reservation part of composite current collector be cut into strip directly, then and busbar etc.Outside device welding, this is favorable for reducing multiple processes, to improve production efficiency. BRIEF DESCRIPTION OF DRAWINGS
[0020] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or prior art, the drawings needed to be used in the following embodiment or prior art description will be briefly introduced, and obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can be obtained according to the structure shown in these drawings without creative labor.
[0021] Figure 1 The structure diagram of the conductive substrate of the composite current collector of retaining welding reservation provided by the utility model is shown.
[0022] Figure 2 The structure diagram of the composite current collector of retaining welding reservation provided by the utility model is shown.
[0023] Figure 3 The notch structure diagram of the conductive substrate of the composite current collector of retaining welding reservation provided by the utility model is shown.
[0024] Explanation of the drawings:
[0025] Conductive substrate 100
[0026] Current collector coating part 110
[0027] Welding reservation part 120
[0028] Non-conductive base layer 200
[0029] Conductive coating 300 DETAILED DESCRIPTION
[0030] Clearly and completely describe the technical scheme in the embodiments of the utility model with reference to the drawings in the embodiments of the utility model, obviously, the described embodiments are only a part of the embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by the ordinary skill in the art without creative labor belong to the scope of protection of the utility model.
[0031] It should be noted that if the embodiments of the utility model involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement condition, etc. between the components in a certain specific posture (as shown in the drawings), if the specific posture changes, the directional indications also change accordingly.
[0032] In addition, if the embodiments of the utility model involve descriptions such as "first", "second", etc., the descriptions of "first", "second", etc. are only for description purposes and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the fact that the ordinary skill in the art can realize it, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is not within the scope of protection required by the utility model.
[0033] As shown in Figure 1 , Figure 2 and Figure 3 , the utility model provides a kind of composite current collector with welding reservation, wherein the composite current collector with welding reservation includes conductive substrate 100, the conductive substrate 100 includes current collector coating part 110 and welding reservation part 120, the thickness of the welding reservation part 120 is greater than the thickness of the current collector coating part 110, the upper surface of the welding reservation part 120 is flush with the upper surface of the current collector coating part 110, the lower surface of the welding reservation part 120 is higher than the lower surface of the current collector coating part 110, the lower surface of the current collector coating part 110 is covered with non-conductive base layer 200, and conductive coating 300 is provided on the lower surface of the non-conductive base layer 200 and the lower surface of the welding reservation part 120. By such setting, the utility model is pure metal foil material for conductive substrate 100, and the welding reservation part 120 is also pure metal foil material, so that during the preparation of battery, the tab and adapter piece do not need to be welded again, and the welding reservation part 120 of the composite current collector can be directly cut into strip shape and welded with external devices such as bus bar, which is conducive to reducing multiple processes, thereby improving production efficiency.
[0034] The composite current collector provided by the utility model comprises a non-conductive base layer 200, the non-conductive base layer 200 is generally a high polymer film layer, the composite current collector provided by the utility model further comprises upper and lower surfaces arranged in the thickness direction of the high polymer film layer, a metal layer is arranged on the upper and lower surfaces of the high polymer film layer, and the metal layer is respectively a conductive base sheet 100 and a conductive coating layer 300; in the embodiment, a metal conductive base sheet 100 and a metal conductive coating layer 300 are adopted. The metal conductive base sheet 100 is provided with a welding reserved part 120 and a current collector coating part 110. The welding reserved part 120 is located at one side in the width direction of the composite current collector, and the remaining part of the current collector is the current collector coating part 110. The thickness of the welding reserved part 120 for tab welding of the metal conductive base sheet 100 is higher than that of the current collector coating part 110, a high polymer film layer is arranged on the current collector coating part 110, and the thickness of the high polymer film layer can be the same as the difference between the thickness of the welding reserved part 120 and the thickness of the current collector coating part 110. The metal conductive coating layer 300 is arranged on the high polymer film layer and the welding reserved part 120, and the metal conductive base sheet 100 is a pure metal foil. Through the arrangement, since the metal conductive base sheet 100 is a pure metal foil, the welding reserved part 120 is also a pure metal foil, and when the battery is prepared, the tab and the adapter plate do not need to be welded again, the welding reserved part 120 is directly cut into a strip shape and then welded with a bus bar and other devices, so that the process is greatly reduced, and the production efficiency is improved. The high polymer film layer of the embodiment can be a film made of any non-conductive material. The high polymer film layer of the embodiment of the utility model can be a film formed by one or more of polyamide, polyimide, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyethylene, polypropylene, polypropylene, acrylonitrile-butadiene-styrene copolymer, polyvinyl alcohol, polystyrene, polyvinyl chloride, polyvinylidene fluoride, polytetrafluoroethylene, polystyrene sulfonate sodium, polyacetylene, silicone rubber, polyformaldehyde, polyphenylene ether, polyphenylene sulfide, polyethylene glycol, polyazothiophene high molecular material, polyphenyl, polypyrrole, polyaniline, polythiophene, poly pyridine, cellulose, starch, protein, epoxy resin and phenolic resin.
[0035] Further, the composite current collector provided by the utility model retains the welding reserved part, the side surface of the non-conductive base layer 200 is connected with the welding reserved part 120, and the lower surface of the non-conductive base layer 200 is flush with the lower surface of the welding reserved part 120. Further, the composite current collector provided by the utility model retains the welding reserved part, the conductive base sheet 100 is a metal foil. Further, the composite current collector provided by the utility model retains the welding reserved part, the thickness of the conductive base sheet 100 is 6µm-20µm, and the thickness of the conductive base sheet 100 can be selected as 12µm of the metal foil.
[0036] Further, the composite current collector provided by the utility model reserves welding, the lower surface of the current collector coating part 110 is etched with a notch structure. Further, the composite current collector provided by the utility model reserves welding, the notch structure is a mesh-like notch structure, and the notch depth of the notch structure is 100nm-1000nm. That is to say, in the utility model, the notch structure can also be etched on the conductive substrate 100, that is, on the side of the pure metal foil facing the polymer film layer mentioned above, and the notch depth is 100nm-1000nm. Then, the polymer film layer is formed on the side of the conductive substrate 100 provided with the notch structure. In this way, the polymer material is partially formed on the conductive substrate 100, thereby improving the bonding force between the conductive substrate 100 and the polymer film layer. The notch structure is preferably a mesh-like structure, and the bonding force is better, and the mass of the composite current collector can be reduced.
[0037] Further, the composite current collector provided by the utility model reserves welding, the non-conductive base layer is a polymer film layer. Further, the composite current collector provided by the utility model reserves welding, the thickness of the non-conductive base layer 200 is 1µm-4µm. Further, the composite current collector provided by the utility model reserves welding, a lower coating layer is arranged between the non-conductive base layer 200 and the conductive coating layer 300, the lower coating layer is an aluminum oxide, silicon nitride, silicon carbide, copper alloy, aluminum alloy, nickel alloy or titanium alloy coating layer, the conductive coating layer 300 is a metal coating layer, the thickness of the conductive coating layer 300 is the same as that of the current collector coating part 110 of the conductive substrate 100, the conductive coating layer 300 is an aluminum, copper, titanium, nickel, aluminum alloy, titanium alloy, nickel alloy or aluminum alloy coating layer, and the conductive substrate 100 is an aluminum, copper, titanium, nickel, aluminum alloy, titanium alloy, nickel alloy or aluminum alloy substrate. The thickness of the polymer film layer can be 1µm-4µm, and the polymer film layer with a thickness of 3µm can be arranged. A lower coating layer can also be arranged between the conductive coating layer 300 and the polymer film layer. For example, the lower coating layer is an aluminum oxide, silicon nitride, silicon carbide, copper alloy, aluminum alloy, nickel alloy, titanium alloy or the like, and the function of the lower coating layer is to improve the bonding force between the lower metal layer and the polymer film layer (that is, the polymer material). The material of the conductive coating layer 300 can be aluminum, copper, titanium, nickel, or an aluminum alloy, a titanium alloy, a nickel alloy or an aluminum alloy or the like. Preferably, the material of the conductive base layer and the material of the conductive coating layer 300 are consistent.
[0038] The utility model also provides a preparation method of the composite current collector which reserves welding as mentioned above, comprising:
[0039] S100, take a conductive substrate 100, the conductive substrate 100 includes a current collector coating part 110 and a welding reserved part 120, the current collector coating part 110 of the conductive substrate 100 is thinned;
[0040] S200, a layer of non-conductive base layer 200 is coated on the lower surface of the current collector coating part 110;
[0041] S300, a layer of conductive coating 300 is plated on the lower surface of the non-conductive base layer 200 and the lower surface of the welding reserved part 120.
[0042] Specifically, the composite current collector with retained welding reserved in the utility model is prepared as follows: firstly, a metal foil (that is, the conductive substrate 100) is taken, and the thickness thereof can be 6 µm-20 µm, for example, 12 µm; then, a part of the metal foil is thinned, and the etching method, electroplating method or other existing thinning methods can be adopted, so that one side of the metal foil in the width direction is not thinned, and other positions are thinned, and the thickness of the thinned part is 1 µm-3 µm, for example, 3 µm. At this time, the thinned part is the current collector coating part 110, and the position without thinning is the welding reserved part 120 of the current collector; then, a layer of non-conductive polymer material is sprayed or coated on the current collector coating part 110, to form the above-mentioned polymer film layer. The polymer material adopted by the polymer film layer can be PP material, PET material or PI material, and the thickness of the polymer material is equal to the thickness by which the welding reserved part 120 is higher than the current collector coating part 110; the formed polymer material is waited to solidify; after solidification, the above-mentioned material is vacuum evaporated once to form the above-mentioned conductive coating 300. The thickness of the conductive coating 300 is equal to the thickness of the current collector coating part 110 after thinning.
[0043] In the utility model, the surface of the polymer material can also be subjected to roughness treatment to improve the roughness of the surface of the polymer material, and specifically, the plasma treatment method or the like can be adopted, and then the conductive coating 300 is formed on the surface of the polymer material, and the main purpose is also to improve the bonding force between the lower metal layer and the polymer material.
[0044] The composite current collector prepared in this way has the following advantages which are not available in the prior production methods: first, the process of welding the tab can be reduced; second, the welding reserved part 120 of the current collector is pure metal, which can improve the flow capacity of this part and reduce heat generation; third, the production cost of the composite current collector can be reduced, and a single vacuum coating equipment costs up to several million, and a single vacuum pumping and operation also consumes a considerable cost; fourth, the problem of voids in the production of the composite current collector can be completely solved, and the voids are mostly caused by the burning of the film by high-temperature particles when the metal layer is formed on the film for the first time. However, the conductive base sheet 100 is not formed by vacuum coating, so there will be no pinholes (also known as holes); fifth, since the conductive base sheet 100 and the conductive coating 300 are not formed by the same process, the conductive base sheet 100 and the conductive coating 300 will not stick together in the final composite current collector, such as after winding, thus solving the outstanding problem; sixth, the polymer film layer of the composite current collector can be adjusted in thickness according to the actual situation, so that the thickness of the film can be reduced, and the production of an ultrathin composite current collector can be realized.
[0045] In summary, the composite current collector with a welding reserved part provided by the utility model has the following advantages: the conductive base sheet is pure metal foil, and the welding reserved part is also pure metal foil, so that the welding reserved part of the composite current collector can be directly cut into strips and then welded with external devices such as busbars during the preparation of the battery, which is conducive to reducing the number of processes and improving the production efficiency.
[0046] And, the composite current collector thus prepared has a plurality of benefits that existing production methods do not have. First, the process of welding the tab can be reduced; second, the welding reserved part of the current collector is pure metal, which can improve the flow capacity of the part and reduce heat generation; third, the production cost of the composite current collector can be reduced, and a current vacuum coating equipment is as high as several million, and a vacuum extraction operation also consumes a lot of cost; fourth, the problem of voids in the production of the composite current collector can be completely eliminated. The voids are mostly caused by the burning of the film by high-temperature particles when the metal layer is formed on the film for the first time. The conductive base plate of the present application is not formed by vacuum coating, so there will be no pinholes (also known as holes); fifth, because the conductive base plate and the conductive coating are not formed by the same process, there will be no sticking between the conductive base plate and the conductive coating in the final composite current collector formed, such as after winding, thus solving the outstanding problem; sixth, the polymer film layer of the composite current collector of the present application can be adjusted in thickness according to actual conditions because it is coated, so the thickness of the film can be reduced to realize the production of ultra-thin composite current collectors.
[0047] The above only describes the preferred embodiments of the present application, and does not limit the patent scope of the present application, and any equivalent structural transformation made by using the content of the present application specification and drawings, or direct / indirect application in other related technical fields is included in the patent protection scope of the present application.
Claims
1. A composite current collector retaining a welding reservation, characterized by, The conductive substrate comprises a current collector coating part and a welding reserved part, the thickness of the welding reserved part is greater than the thickness of the current collector coating part, the upper surface of the welding reserved part is flush with the upper surface of the current collector coating part, the lower surface of the welding reserved part is higher than the lower surface of the current collector coating part, the lower surface of the current collector coating part is covered with a non-conductive base layer, and a conductive coating layer is arranged on the lower surface of the non-conductive base layer and the lower surface of the welding reserved part.
2. The retention-weld-reserving composite current collector of claim 1, wherein, The side surface of the non-conductive base layer is connected with the welding reserved part, and the lower surface of the non-conductive base layer is flush with the lower surface of the welding reserved part.
3. The retention-weld-reserving composite current collector of claim 1, wherein, The conductive substrate is a metal foil.
4. The tabbed current collector retaining a weld reservation of claim 2, wherein, The thickness of the conductive substrate is 6 µm-20 µm.
5. The retention-weld-reserving composite current collector of claim 1, wherein, The lower surface of the current collector coating part is etched with a notch structure.
6. The tab-composite current collector retaining a weld reservation of claim 5, wherein, The notch structure is a mesh-like notch structure, and the notch depth of the notch structure is 100 nm-1000 nm.
7. The retention-weld-reserving composite current collector of claim 1, wherein, The non-conductive base layer is a polymer film layer.
8. The retention-weld-reserving composite current collector of claim 7, wherein, The thickness of the non-conductive base layer is 1 µm-4 µm.
9. The tab-composite current collector retaining a welding reservation according to any one of claims 1 to 8, characterized in that, A lower coating layer is arranged between the non-conductive base layer and the conductive coating layer.
10. The tab-composite current collector retaining a weld reservation of claim 9, wherein, The lower coating layer is an aluminum oxide, silicon nitride, silicon carbide, copper alloy, aluminum alloy, nickel alloy or titanium alloy coating layer, the conductive coating layer is a metal coating layer, the thickness of the conductive coating layer is the same as that of the current collector coating part of the conductive substrate, the conductive coating layer is an aluminum, copper, titanium, nickel, aluminum alloy, titanium alloy, nickel alloy or aluminum alloy coating layer, and the conductive substrate is an aluminum, copper, titanium, nickel, aluminum alloy, titanium alloy, nickel alloy or aluminum alloy substrate.