| As social development continues to drive innovations in technology and products in the new energy industry,the research and application of lithium-ion batteries in the field of energy storage has also gained great opportunities for development.However,current lithium-ion batteries still have problems,such as poor rate performance of graphite anode materials,poor long-cycle charge and discharge performance,and low area specific capacity and mass specific capacity.These unresolved problems have become an obstacle between the current lithium-ion battery and the actual market demand.Therefore,changing the structure of the current collector to improve the battery performance has become a feasible research idea.This paper mainly studies the preparation method of porous copper foil,and applies it as a current collector to the graphite anode of lithium ion battery for electrochemical performance test.The study found that a porous copper foil can be obtained by using a printing template method to prepare a stainless steel sheet template with discontinuous dot matrix,and then performing a 10 m A/cm2 plating operation with an acid copper sulfate plating solution.With the increase of screen mesh and the introduction of printing mobile platform,the hole density of porous copper foil gradually increased.The minimum hole density obtained from primary and secondary printing from 150 mesh to 300 mesh is 1725 holes/cm2,and the maximum hole density is 13259 holes/cm2.Porous copper foil was used as the current collector of lithium-ion batteries.The effects of pore density,thickness and dripping amount of electrolyte on the performance of lithium-ion batteries were studied.It was found that as the pore density increased,the battery performance improved After lowering.As the thickness increases from 9,10 to 11 ?m,the performance of the battery gradually decreases.When the electrolyte is excessive,the battery performance does not significantly improve.From this,the optimal porous copper foil was optimized as a battery current collector parameter combination: a hole density of 10534 holes/cm2,a thickness of the porous copper foil of 9 ?m,and an electrolyte dripping amount of 140 ?L.At the same time,the battery performance difference between the optimal parameter combination of porous copper foil and continuous copper foil under two loadings of 2 mg cm-2 and 45.8 mg cm-2 was studied.The results show that,compared with continuous copper foil batteries,the advantages of charge and discharge cycles and rate performance of porous copper foil batteries are obvious under the low-load single-sided coating condition of 2 mg cm-2.Under the high load of 45.8 mg cm-2,single-sided and double-sided coating are used.It is found that the performance of single-sided or double-sided coated porous copper foil batteries is far superior to that of coated or double-sided continuous copper foil.Among them,the double-coated porous copper foil battery has the best performance,and the double-coated continuous copper foil battery has the worst performance.The single-sided coating and double-sided coating methods under different loadings have a direct impact on the performance of continuous copper foil and porous copper foil,from the unit load and area specific capacity curves and the unit load and mass ratio of the four batteries The capacity curve reflects two aspects: with the increase of the loading capacity,the performance of single-sided or double-sided coated porous copper foil batteries is superior to that single-sided or double-sided coated continuous copper foil.Under the current of C/30,the area specific capacity of double-sided coated porous copper foil is the largest,with a load of 78.2 mg cm-2 corresponding to the area specific capacity of 20.8 m A h cm-2.The quality specific capacity of double-sided coated porous copper foil is the largest,with a load of 78.2 mg cm-2 corresponding to a mass specific capacity of 265.4 m A h g-1. |
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