【摘要】 以过渡金属乙酸盐原料,通过溶胶-凝胶法制备了两种富锂锰基正极材料Li[Li0.13Co0.61Mn0.26]O2和Li[Li0.2Co0.4-Mn0.4]O2,采用XRD、SEM和电化学技术对所得样品的结构、形貌及电化学性能进行了表征和分析。结果表明富锂锰基材料为层状固熔体,且一次颗粒粒径为纳米级。采用恒电流法研究充电过程中材料电荷转移阻抗的变化,结果表明:在充电过程中富锂锰基正极材料电荷转移阻抗先增大后减小,当SOC大约在30%~50%时Rct达到最大,分别约为2 164~4 341Ω和4 254~6 741Ω,而在其余状态下Rct相对较低。更多还原

【Abstract】 Two kinds of lithium rich manganese based cathode materials Li [Li0.13Co0.26Mn0.61]O2and Li[Li0.2Co0.4Mn0.4]O2were successfully synthesized via sol-gel method by using transition metal acetate as raw material.The as-prepared materials were characterized by XRD, SEM and electrochemical performance tests. The result proves the structure of lithium rich manganese based cathode materials are layered solid-solution, and the size of primary particles of materials are nanoscale.The change of charge transfer Rctimpedance(Rct) of lithium rich manganese based cathode materials during charging in the same cycle was studied through chronopotentiometry. The results indicate that during charging process, reaches maximum values about 2 164~4 341 Ω and 4 254~6 741 Ω respectively, at scope of state-of-charge(SOC) form 30% to 50% and a lower relative value at rest scope of SOC.更多还原