水热辅助法制备富锂材料Li1.2Co0.13Ni0.13Mn0.54O2及性能表征

摘要

以LiAc和Li2CO3为锂源,使用水热辅助草酸盐共沉淀法制备出富锂锰基正极材料Li1.2Co0.13Ni0.13Mn0.54O2.采用X射线衍射分析(XRD)、扫描电子显微镜(SEM)、交流阻抗法(EIS)和恒流充放电测试对材料的结构,形貌和电化学性能进行表征.研究表明,以LiAc为锂源制备的材料在20 mNg、2.0～4.8V电位区间内比容量最高达265 mAh/g,首圈效率达到79.3％而使用Li2CO3为锂源制备的材料拥有较好的循环性能,在0.5C和1.0C下经过50圈循环后比容量仍有192和183 mAh/g.%Li-rich manganese-based cathode material was synthesized by a hydrothermal assisted oxalate co-precipitation method using LiAc and Li2CO3 as lithium source,respectively.The structure,morphology and electrochemical performance of both synthesized materials were investigated by X-ray diffraction (XRD),scanning electron microscopy (SEM),electrochemical impedance spectroscopy (EIS) as well as galvanostatic charging and discharging test.The research results show that the sample prepared using LiAc can exhibit a reversible specific capacity of 265 mAh/g at a current density of 20 mA/g between 2.0 and 4.8 V,with a coulombic efficiency of 79.3％.In contrast,the sample prepared with Li2CO3 has a superior cyclic performance,retaining discharged specific capacities of 192 and 183 rnAh/g after 50 charge-discharge cycles under 0.5C and 1C.