Li[Li_(0.2)Ni_(0.15)Mn_(0.55)Co_(0.1-x)Cr_x]O_(2-y)Cl_y富锂正极材料的合成及电化学性能研究

Synthesis and Electrochemical Performance of Lithium-rich Layered Cathode Material Li[Li_(0.2)Ni_(0.15)Mn_(0.55)Co_(0.1-x)Cr_x]O_(2-y)Cl_y

采用溶胶-凝胶法合成富锂正极材料,900℃煅烧12 h得到产物Li[Li0.2Ni0.15Mn0.55Co0.1-xCrx]O2-yCly。X射线衍射光谱（XRD）测试表明,材料均具有层状α-NaFeO2结构;扫描电镜（SEM）观察材料颗粒均匀,粒径达到纳米范围;充放电测试显示,Cl-、Cr3＋共掺材料在2~4.8 V电压范围及0.1 C倍率下,20℃时,首次放电比容量达到239.8 mAh·g-1,首次库伦效率为81.2%;55℃时,首次放电比容量和首次库伦效率分别为308.3 mAh·g-1和92.7%。并且40个循环之后在1 C倍率下,材料在20和55℃时放电比容量仍分别达到173.5和207.7 mAh·g-1。

Lithium-rich cathode material was synthesized by a sol-gel method,and the product Li[Li0.2Ni0.15Mn0.55Co0.1-xCrx]O2-yCly was calcined at 900 oC for 12 h.X-ray diffraction（XRD） spectroscopy tests present the α-NaFeO2 layered structure of the material.Scanning electron microscopy（SEM） indicates that its particle size is uniform and can reach nano-range; electrochemical testing shows that for the material with Cl- and Cr3＋ co-doping in 2~4.8 V voltage and 0.1 C rate,its initial discharge specific capacity reaches 239.8 mAh·g-1 and coulombic efficiency is 81.2% at 20 oC; while at 55 oC,in the same conditions,the initial discharge specific capacity and the first coulombic efficiency are 308.3 mAh·g-1 and 92.7%,respectively.After 40 cycles,at the rate of 1 C,the specific capacities retain 173.5 mAh·g-1 at 20 oC and 207.7 mAh·g-1 at 55 oC.