Nb-based compounds for rapid lithium-ion storage and diffusion

Exploring electrode materials with rapid, safe, and stable Li-(de)intercalation is of vital importance for developing next-generation lithium-ion batteries (LIBs) and hybrid lithium ion capacitors (LICs). Niobium-based compounds have attracted extensive interest for fast lithium storage due to their unique crystalline structure and high safety. This review provides a comprehensive overview of Nb-based electrode materials and their recent research progress. According to the different constitutions present in Nb-based anode materials, Nb?O, Nb?C, Nb?N and M-Nb-O (M = metal elements) systems are systematically discussed. Their physicochemical features and intrinsic disadvantages including low conductivities and sluggish ion diffusion rates impede the practical application are concluded. Then the design of Nb-based electrode architectures using nanosizing, conductive layer-coating, foreign atom doping, and their synergetic effects are also discussed since they play essential roles in enhancing the intrinsic capabilities. Finally, feasible strategies for improving the electrochemical capabilities of high-rate niobium-based electrodes are also briefly introduced. With this review, we hope to provide reference values for researchers or general readers, and to inspire more explorative work on building effective Nb-based energy storage materials for lithium-ion batteries and hybrid lithium ion capacitors.