Energy & Fuels, Vol.34, No.3, 3887-3894, 2020
Synthesis of High Reversibility Anode Composite Materials Using T-Nb2O5 and Coal-Based Graphite for Lithium-Ion Battery Applications
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.