Co改性LiFe1-xCoxPO4材料的结构与性能

采用液相碳热还原法合成了Co改性的锂离子电池正极材料LiFe1-xCoxPO4（X=0，0．02，0．05，0．08），采用XRD、SEM、循环充放电、电化学阻抗和循环伏安方法研究了材料的结构和电化学性能，结果表明：掺杂适量的Co^3^＋可以减小晶胞体积，提高LiFePO4的循环性能和比容量。其中LiFe0.95Co0.05PO4在0．2C下的首次放电比容量可达到128．84mAh／g，40次循环充放电容量仍保持在93．3％以上。循环伏安和电化学阻抗测试表明材料具有良好的充放电可逆性和较小的阻抗。

Structure and performance of LiFe1-xCoxPO4 modified with Co

The positive material made of olivine-type LiFe1-xCoxPO4(X=0,0.02,0.05,0.08) was prepared by carbon thermal reduction method. The structure and electrochemical performance were investigated by XRD, SEM, cycle charge/discharge, electrochemical impedance and cyclic voltammetry. The results showed that low concentration Co3 doping could decrease the lattice volume and increase the capacity and performance of LiFePO4. The specific capacity of LiFe0.95Co0.05PO4 could reach 128.84 mAh/g at 0.2C rate, after 40 cycles capacity retention was above 93.3% . Electrochemical impedance and cyclic voltammetry showed that the sample had lower impedance and good cycle reversibility.