Carbon coated Nb2O5 nanosheets via dopamine-induced phase transition for high-rate lithium-ion battery

Nb 2 O 5 has attracted great attention as a promising anode material for lithium-ion batteries (LIBs) due to relatively high rate-capacity, fast charge/discharge ability and excellent cycling performance. Unfortunately, the poor electron conductivity restricts its application. In this work, we report an effective method to synthesize large-size Nb 2 O 5 nanosheets wrapped within carbon layer (denoted as Nb 2 O 5 @C) by using layered K 4 Nb 6 O 17 (abbreviated as KN) as the templates of dopamine polymerization, followed by the carbonization . It is demonstrated that dopamine not only serves as the carbon source, but also promotes the phase transition and the morphology transition. The obtained Nb 2 O 5 @C nanosheets with enhanced electron conductivity deliver outstanding rate capability (485, 372, 304, 267 and 232 mAh g −1 at the current density of 0.1, 0.2, 0.5, 1 and 2 A g −1 , respectively) with a low capacity fading-rate of about 0.02% after 1000 cycles at 2 A g −1 . This work may provide a helpful strategy in developing the high-rate lithium-ion storage applications for other related materials.