A template-free synthesis via alkaline route for Nb2O5/carbon nanotubes composite as pseudo-capacitor material with high-rate performance

•A simple four-step method to prepare T-Nb2O5/CNTs composite.•The composite is with well-dispersed CNTs in the Nb2O5 phase.•The composite has excellent large-current discharge property.•The composite has a high energy storage property at high current density.

In this paper, we report a facile template-free method to prepare the T-Nb2O5/CNTs composite. The addition of ammonia induces the electrostatic interaction between functionalized CNTs and niobic acid colloids during hydrothermal process, resulting in CNTs homogeneously distributed in the T-Nb2O5 phase. The obtained T-Nb2O5/CNTs composite shows high rate Li+ storage ability with typical intercalation capacitive behaviour. The presence of well-dispersed CNTs in Nb2O5 can apparently reduce the limitation from diffusion process and increase the high rate charge-discharge capability. From the galvanostatic tests, a capacity of ∼180 mAh g−1 at 1 A g−1 and ∼130 mAh g−1 at 5 A g−1 is attained.

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