超导电碳基涂层铝箔制备及对高能量磷酸铁锂电池的影响

Preparation of carbon-coated aluminum foil with highly conductivity and the effect on high energy density LiFePO4 battery

动力电池用超导电碳基涂层铝箔首先被制备出来,并以此为基础制备出电性能优异、能量密度达到138Wh/kg的高能量磷酸铁锂18650电池。研究表明,碳基涂层铝箔在磷酸铁锂和铝箔集流体之间形成一个良好的电子导电层区域,使得充放电过程中电子转移更为便利,改善了放电平台,倍率性能和低温性均得到明显提升。碳基涂层良好的热导性可及时带出热量,提高了电池的循环寿命。涂层铝箔相对普通铝箔,电阻从9.4mΩ降至8.5mΩ,0.2C发挥克容量提升0.9mAh/g,1C/1C充放循环2000周后,循环性能提升从82.2%提升至88.9%。

Carbon-coated aluminum foil was firstly synthesized,and 18650 LiFePO4 batteries with the excellent electrochemical performance was assembled,which energy density reached 138 Wh/kg.The results showed that the foil can form a good electron conductive layer between lithium iron phosphate and aluminum foil collector,making the electron transmission more convenient and lead to the improvement discharge platform,rate discharge performance and low temperature performance of the battery.Besides,the foil with desired thermal conductivity would improve heat dissipation and benefit cycling performance.Compared with the ordinary aluminum foil,using coated aluminum foil can reduce the resistance of 18650 LiFePO4 batteries from 9.4 mΩto 8.5 mΩ,the discharge capacity of 0.2 Cincreased 0.9 mAh/g.The efficiency increased from 82.2%to 88.9%after cycling 2000 th at 1 C/1 C.