摘要
采用湿法球磨-喷雾干燥-碳热还原制备纳/微结构LiFePO4/C复合材料。通过XRD、SEM表征材料结构形貌,利用充放电测试循环伏安、交流阻抗测试等表征电化学性能,分别考察不同喷雾干燥条件对其形貌及性能的影响。结果表明:浆料浓度、进风温度、进料速率对材料形貌及性能影响较大,喷嘴口径对性能影响较小,随着浆料浓度的减小,所得样品由碗状结构转变为球形。最佳喷雾干燥条件为浆料浓度200g/L,进风温度200℃,进料速率1.3L/h,喷嘴口径0.5mm。此条件下制备的材料表现出最佳的放电比容量,常温下材料在0.5C倍率下的放电比容量为160mAh·g-1,10C放电比容量为123mAh·g-1,循环100次后容量几乎无衰减。
The nano/micro LiFePO 4/C composite was prepared by a wet milling-spray drying-carbothermal reduction process. The structure and morphology were characterized by X-ray diffraction （XRD） and electron scanning microscope（SEM）, electrochemical properties were characterized by cyclic voltammetry,AC impedance testing with galvanostatic charge-discharge method to investigate the influence under different spray drying conditions. The results show that the morpholoyy and electrochemical performance are significantly influenced by slurry concentration, inlet temperature and feed rate, while are mildly influenced by nozzle diameter. The morphology of the obtained sample is transformed from bowl-like mesoporous structure to spheres with the decrease of the slurry concentration. With a slurry concentration of 200g/L, an inlet temperature of 200℃, a feed rate of 1.3L/h and a spray nozzle diameter of 0.5mm, the obtained sample has the best electrochemical properties. Under that condition, the discharge capacities at 0.5C and 10C under room-temperature are 160mAh·g -1 and 123mAh·g -1 , respectively, and no obvious capacity fading is observed after 100 cycles.
作者
吕奕菊
谭家栩
蒋世权
文衍宣
张淑芬
LYU Yi-ju;TAN Jia-xu;JIANG Shi-quan;WEN Yan-xuan;ZHANG Shu-fen(Guangxi Key Laboratory of Electrochemical and Magneto-chemical Functional Materials,Guilin University of Technology,Guilin 541004,Guangxi,China;School of Chemistry and Chemical Engineering,Guangxi University,Nanning 530004,China;State Key Laboratory of Fine Chemicals,Dalian University of Technology,Dalian 116024,Liaoning,China)
出处
《材料工程》
EI
CAS
CSCD
北大核心
2018年第12期85-94,共10页
Journal of Materials Engineering
基金
广西自然科学基金资助项目(2016GXNSFBA380068)
广西"特聘专家"专项经费资助项目(DT18101293)
