铝箔涂碳对LiFePO_4/C电池性能的影响

研究涂碳铝箔作为集流体对磷酸铁锂(LiFePO_4)/C正极材料及电池性能的影响。铝箔涂碳可抑制电极材料的极化,提高材料与集流体的粘附效果,降低两者间的电荷转移电阻,提高Li+的扩散速率。以涂碳铝箔为集流体的半电池,在10 C倍率下的中值电压仍在3.10 V以上,活性材料与集流体之间的电荷转移电阻比光铝箔低65%以上,Li+扩散速率是光铝箔的3倍以上。涂碳铝箔作为集流体,可降低组装的全电池的内阻,与光铝箔相比,内阻降幅在25%以上,功率密度涨幅大于35%;在4 C倍率下全电池的中值电压仍在3.00 V以上,在3.65~2.00 V放电,4.00 C/0.33 C容量比在99%以上。

Effect of aluminum foil coating carbon on performance of LiFePO4/C battery

Effect of carbon coated aluminum(Al) foil as current collector on lithium iron phosphate (LiFePO4)/C cathode materials and battery performance were studied.Coating carbon on Al foil could suppress the polarization and improve the cohesiveness between the cathode powder and the current collector,reduce the charge transfer resistance and improve the Li + diffusion coefficient.The mean voltage of half cell using carbon coated Al foil as current collector was kept above 3.10 V at 10 C rate,the charge transfer resistance reduced by 65 ％ and the Li + diffusion coefficient increased by more than three times compared with common Al foil.Carbon coated Al foil as current collector could reduce the internal resistance of assembled full battery,the internal resistance was reduced more than 25 ％ and the power density increased more than 35 ％ compared with common Al foil.At 4 C discharge rate,the mean voltage of full batteries was above 3.00 V.When discharged in 3.65-2.00 V,the ration of capacity between 4.00 C and 0.33 C was above 99 ％.