Nanostructured T-Nb2O5-based composite with reduced graphene oxide for improved performance lithium-ion battery anode

Nb2O5 has attracted much attention in various research filed such as hybrid capacitors, photo/electrocatalysis, and especially Li-ion batteries (LIBs) due to stable structure and high safety. Nevertheless, its low electronic conductivity (~ 3×10−6 S cm−1) degrades Li-storage performance that limits the practical use in LIBs. Here, we present a facile method for synthesis of T-Nb2O5 nanospheres/reduced graphene oxide composites by using niobium oxalate and bituminous coal as raw materials via a solvothermal method and subsequent calcination to enhance the conductivity of Nb2O5. In this work, the prepared Nb2O5 particles have excellent crystallinity that can be uniformly distributed onto the surface of the rGO layer to form Nb2O5/rGO composites. The electrochemical properties indicate that Nb2O5/rGO electrodes exhibit outstanding capacity, excellent reversibility, and superior cycle stability compared to other transition metal oxide-based electrodes. Notably, the initial capacities of the Nb2O5/rGO electrode at 0.02 A g−1 are 603 and 1104 mAh g−1, and the capacity still maintained 332 mAh g−1 after 100 cycles at 0.2 A g−1. Our synthetic approach provides a viable route to produce anode materials in a composite form facilitating nanostructured Nb2O5 with rGO exfoliated from bituminous coal for excellent performance in LIBs.