氢化TiO_(2)包覆核壳C/Fe_(3)O_(4)@rGO锂离子电池阳极材料

Hydrogenated TiO_(2) coated core-shell structure C/Fe_(3)O_(4)@rGO lithium battery anodes

通过一种简便的方法制备氧空位缺陷的氢化TiO_(2)包覆核壳结构C/Fe_(3)O_(4)@rGO(H-TiO_(2)/C/Fe_(3)O_(4)@rGO)复合材料,作为锂离子电池(lithium-ion batteris,LIBs)高性能阳极材料。TiO_(2)在Li+脱嵌过程中体积膨胀系数约为4%,可缓解Fe_(3)O_(4)在充放电过程中的体积膨胀,提高阳极材料结构的稳定性。同时,通过氢化处理改善TiO_(2)较低的电导率(约1×10^(-12) S·m^(-1))。H-TiO_(2)/C/Fe_(3)O_(4)@rGO在0.3 A·g^(-1)的电流密度下循环200周次后比容量为867 mAh·g^(-1),在1 A·g^(-1)的电流密度下循环700周次的比容量为505 mAh·g^(-1),这些结果远大于石墨的理论容量(372 mAh·g^(-1)),表明H-TiO_(2)/C/Fe_(3)O_(4)@rGO复合材料具有用作LIBs阳极材料的前景。

The hydrogenated TiO_(2) coated core-shell structure C/Fe_(3)O_(4)@rGO(H-TiO_(2)/C/Fe_(3)O_(4)@rGO)composite material with oxygen vacancy defects was prepared by a simple method as high-performance anode material for lithium-ion batteries(LIBs).The volume expansion coefficient of TiO_(2) in the process of Li+deintercalation is about 4%,which can alleviate the volume expansion of Fe_(3)O_(4) during charging and discharging,and improve the stability of the anode material structure.At the same time,the lower conductivity of TiO_(2)(about 1×10^(-12) S·m^(-1))is improved by hydrogenation.After 200 cycles,the H-TiO_(2)/C/Fe_(3)O_(4)@rGO specific capacity is 867 mAh·g^(-1) at a current density of 0.3 A·g^(-1),and the specific capacity is 505 mAh·g^(-1) after 700 cycles at a current density of 1 A·g^(-1),these results is far greater than the theoretical capacity of graphite(372 mAh·g^(-1)).These findings indicate that the H-TiO_(2)/C/Fe_(3)O_(4)@rGO composite materials may be used as a suitable anode material for LIBs.