锂离子电池正极材料xLi2MnO3·(1-x)Li[Ni(1/3)Mn(1/3)Co(1/3)]O2的制备及表征

Preparation and Characterization of xLi_2MnO_3·(1-x)Li[Ni_(1/3)Mn_(1/3)Co_(1/3)]O_2 Cathode Materials for Lithium-Ion Batteries

以过渡金属乙酸盐和乙酸锂为原料,柠檬酸为螯合剂,通过溶胶-凝胶法结合高温煅烧法制备了锂离子电池富锂锰基正极材料xLi2MnO3·(1-x)Li[Ni1/3Mn1/3Co1/3]O2,采用X射线衍射(XRD),扫描电子显微镜(SEM)和电化学性能测试对所得样品的结构,形貌及电化学性能进行了表征.结果表明:x=0.5时,在900°C下煅烧12h得到颗粒均匀细小的层状xLi2MnO3·(1-x)Li[Ni1/3Mn1/3Co1/3]O2材料,并具有良好的电化学性能,在室温下以20mA·g-1的电流密度充放电,2.0-4.8V电位范围内首次放电比容量高达260.0mAh·g-1,循环40次后放电比容量为244.7mAh·g-1,容量保持率为94.12%.

The lithium rich cathode materials xLi2MnO3·（1-x）Li[Ni1/3Mn1/3Co1/3]O2 （x=0.4,0.5,0.6）were successfully synthesized via sol-gel method with calcination in air.The transition metal acetate,lithium acetate,and citric acid were used as raw materials.The as-prepared materials were characterized by X-ray diffraction（XRD）,scaning electron microscopy（SEM）,and electrochemical tests.The material 0.5Li2MnO3·0.5LiNi1/3Mn1/3Co1/3]O2 ,which was obtained after calcination at 900°C for 12 h,exhibited fine microstructures and good electrochemical performance.When cycled at 2.0-4.8 V with a current density of 20 mA·g^-1 at room temperature,0.5Li2MnO3·0.5LiNi1/3Mn1/3Co1/3]O2 delivered a initial discharge specific capacity of 260.0 mAh·g^-1 ,and maintained a capacity of 244.7 mAh·g^-1 after 40 cycles（capacity retention 94.12%）.