Surface-controlled Nb2O5 nanoparticle networks for fast Li transport and storage

Abstract

Hybrid supercapacitors are successfully introduced to reduce the gap between high-capacity battery electrodes and high-power capacitor electrodes in case of electrochemical energy storage devices. Niobium pentoxide (Nb2O5) has attracted great interest for hybrid supercapacitors because of its moderate capacity and excellent cycle performance. However, its low electronic conductivity is still a major problem. Carbon is usually incorporated to address this limitation. Here, we report the Nb2O5 nanoparticle networks to facilitate electronic transport via continuous connection of materials. Additionally, the high surface area of the nanoparticles is maintained. The Nb2O5 nanoparticle network was synthesized using a simple solvothermal reaction in organic media. The materials characterization was performed using X-ray diffraction analysis, and scanning and transmission electron microscopies. The charge storage mechanism of the synthesized Nb2O5 material was investigated by cyclic voltammetry. In galvanostatic charge–discharge tests, the synthesized Nb2O5 nanoparticle network electrode exhibited stable cycle performance and remarkable rate capability without carbon incorporation.