Synthesis of High Reversibility Anode Composite Materials Using T-Nb<sub>2</sub>O<sub>5</sub> and Coal-Based Graphite for Lithium-Ion Battery Applications
Xiaoxiao Qu, Yuhao Liu, Binbin Li, Baolin Xing, Guangxu Huang, Chuanxiang Zhang, Suck Won Hong, Jianglong Yu, Yijun Cao
Abstract
Nb2O5, as a potential electrochemical material, has been studied extensively due to its superior volumetric stability and safety. In the paper, we report a novel method for the synthesis of a T-Nb2O5/coal-based graphite (CBG) composite via a solvothermal method combined with calcination to overcome the limited low level of the ionic diffusivity and electric conductivity of Nb2O5. The homogeneous distribution of the Nb2O5 nanoparticles on the coal-based graphite surface can suppress the accumulation of Nb2O5 and reduce the internal resistance. As an anode material for Li-ion batteries, the T-Nb2O5/CBG-2 composite presents a high capacity, outstanding cyclic stability, and superior reversibility. The newly developed composite of T-Nb2O5/CBG-2 indicates an initial specific capacity of 378 and 661 mAh g–1 at 0.02 A g–1 in the charge/discharge process. At a current density of 0.2 A g–1, the T-Nb2O5/CBG-2 composite materials can maintain a stable capacity of 216 mAh g–1 after 100 cycles. Moreover, after the current density has returned to 0.02 A g–1, it is possible to recover a large capacity of 416 mAh g–1, which represents the excellent reversibility of T-Nb2O5/CBG-2.