【摘要】 本文采用高能球磨法制备了Li VPO4F/C正极材料,并研究了不同球磨时间以及预烧结的次序对Li VPO4F/C晶体结构、物理和电化学性能的影响。实验结果表明,先球磨后预烧结合成的Li VPO4F/C的颗粒细小、均匀,形貌为类球形;Li VPO4F/C的颗粒大小随着球磨时间的增加先减小后团聚长大;Li VPO4F/C在0.1 C下的首次放电比容量和50次循环后的容量保持率随着球磨时间的增加先增大后减少;球磨后预烧结和球磨前预烧结两种方式合成的Li VPO4F/C正极材料在0.1 C下的首次放电容量分别为133.2 m Ah/g和128.3 m Ah/g,库伦效率分别为97.5%、94.7%,50次循环后,容量衰减率分别为1.8%、4.6%。更多还原

【Abstract】 Carbon-coated Li VPO4 F cathode material was prepared by ball-milling activation and subsequent solid state reaction,with glucose as carbon precursor.The effect of different ball milling time and order of ball-milling and presintering on crystal structure,physical property and electrochemical performance of Li VPO4 F / C composites were studied.The results show that Li VPO4 F / C can be synthesized with ball-milling before sintering and the particles are near-spherical with a fine and uniform morphology.The particles size of Li VPO4 F / C decrease firstly and then aggregate gradually with a longer ball-milling time.And at the rate of 0.1 C,the discharge specific capacity of Li VPO4 F / C and the capacity retention ratio after 50 cycles first increase then decrease with milling time.The initial discharge specific capacity of Li VPO4 F / C cathode material synthesized with presintering after and before ball-milling are 138.9 m Ah / g and 128.3 m Ah / g,the coulomb efficiency are 98.6% and 94.7%,the capacity fading rate after 50 cycles are 1.8% and 4.6%,respectively.更多还原