采用溶胶-凝胶法合成富锂锰基(Li1.2Ni0.2Mn0.6O2)正极材料,考察反应pH对材料结构、形貌及电化学性能的影响。X射线衍射(XRD)分析结果表明,制备的材料(Li1.2Ni0.2Mn0.6O2)结晶良好,均为理想层状结构的富锂锰基材料。扫描电子显微镜(SEM)分析结果显示,pH 7.0时制得的材料颗粒细小,分散均匀。充放电性能测试结果显示,pH 7的样品具有良好的电化学性能,在2.04.8 V以0.05 C充放电时,首次容量达到263 m Ah/g。同时具有良好的倍率性能,1.0 C放电容量达到200 m Ah/g。
Li-rich Mn-based cathode materials( Li1.2Ni0.2Mn0.6O2) have been synthesized by a sol-gel method. The influence of reaction pH on the structure,morphology and electrochemical performance respectively of Li1.2Ni0.2Mn0.6O2 has been studied. XRD results show that the prepared Li1.2Ni0.2Mn0.6O2 crystallizes well and exhibits ideal laminated structure of Li-rich Mn-based cathode materials. SEM results indicate that the particles of sample material synthesized at pH = 7 displays more dispersed and smaller than other samples. Electrochemical charge/discharge measurements in lithium-ion cells indicate that the material synthesized at pH = 7 exhibits excellent electrochemical performance. Its first capacity can reach 263 m Ah/g when charging/discharging at 2. 0-4. 8V,0. 05 C,and its discharge capacity at 1. 0 C can reach 200 m Ah/g,1. 0 C,showing a good doubling performance.