【作者】 王志国； 彭文杰； 王志兴； 郭华军； 李新海；

【Author】 WANG Zhi-guo PENG Wen-jie WANG Zhi-xing GUO Hua-jun LI Xin-hai (School of Metallurgical Science and Engineering,Central South University,Changsha 410083,China)

【机构】 中南大学冶金科学与工程学院；

【摘要】 采用固相法在锂离子电池正极材料 LiCoO₂表面包覆一层 LiFePO₄;研究了 LiFePO₄包覆量对材料性能的影响:采用 X 射线衍射仪和扫描电镜分析样品的晶体结构和表面形貌。研究结果表明:样品具备 LiCoO₂的α-NaFeO₂型层状结构,但随着包覆量的增加,XRD 衍射谱显示样品存在多种杂相:合成的样品电化学性能良好, 当 LiFePO₄的包覆量为1%时,在室温下以0.1C 倍率充放电,首次放电比容量达145.9 mA·h/g,纯相 LiCoO₂放电比容量为146.2 mA·h/g。样品采用1C 倍率放电时,首次放电比容量达138.9 mA·h/g,循环性能较好,经过20次循环放电比容量仅衰减4.97%。更多还原

【Abstract】 LiCoO₂ cathode materials were coated with LiFePO₄ by the solid state reaction for lithium-ion batteries.The effects of LiFePO₄ coating amount on properties of samples were studied.The crystalline structure and morphology of samples were analyzed by X-ray diffractometry and scanning electron microscopy,respectively.The results show that the samples own the α-NaFeO₂ layered structure of LiCoO₂.But with the increase of coating amount,XRD patterns show more impurity phases.The samples show excellent electrochemical performance.At room temperature,the specific discharge capacity of the sample coated with 1% LiFePO₄ reaches 145.9 mA·h/g at 0.1C,while the specific discharge capacity of pure LiCoO₂ reaches 146.2 mA·h/g.The specific discharge capacity at 1C reaches 138.9 mA·h/g.The materials show better cycle performance.The capacity only losts 4.97% after 20 cycles.更多还原