Li4Ti5O12/(Cu+C)复合材料的制备及电化学性能

以Li₄Ti₅O₁₂，Cu(CH₃COO)₂·H₂O和C₆H₁₂O₆为前驱体，化学沉积与热分解结合合成锂离子电池负极材料Li₄Ti₅O₁₂/(Cu+C)。采用X-射线衍射(XRD)、扫描电子显微镜(SEM)、恒流充放电、循环伏安和电化学阻抗方法表征样品的结构、形貌和电化学性能。结果表明，Li₄Ti₅O₁₂表面包覆的Cu与C提高了Li₄Ti₅O₁₂电极材料的导电率，其循环性能和倍率性能得到有效地改善。在0.5C、1C和3C倍率下，经过50次充放电循环，放电比容量分别为168.2、160、140.6 mAh·g^-1，其容量保持率分别为88.7%、84.4%、71.2%。电化学阻抗测试表明，表面包覆的Cu与C使其电荷转移阻抗大幅度减少。

Synthesis and Electrochemical Performance of Li4Ti5O12/(Cu+C) Composite Electrode Material

Li₄Ti₅O₁₂/(Cu+C) composite as anode material for lithium-ion batteries was synthesized by chemical deposition combined with thermal decomposition of a mixture of Cu(CH₃COO)₂·H₂O, C₆H₁₂O₆ and Li₄Ti₅O₁₂. The structure, morphology and electrochemical performance of samples were characterized by X-ray diffractometry(XRD), scanning electron microscopy(SEM), galvanostatic charge-discharge test, cyclic voltammeter(CV) and electrochemical impedance spectroscopy(EIS). The results showed that surface coating of Cu and C on Li₄Ti₅O₁₂ particle improved its electronic conductivity and therefore enhanced the performance of the circulation and rate capability. The discharge capacity of the composite were 168.2, 160 and 140.6 mAh·g^-1 at 0.5C, 1C and 3C rate after 50 cycles, and the corresponding capacity retention were 88.7%, 84.4% and 71.2%, respectively. EIS test proved that surface coating of Cu and C on Li₄Ti₅O₁₂ particle could decrease its charge transfer resistance greatly.