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

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 (Nb 2 O 5 ) 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 Nb 2 O 5 nanoparticle networks to facilitate electronic transport via continuous connection of materials. Additionally, the high surface area of the nanoparticles is maintained. The Nb 2 O 5 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 Nb 2 O 5 material was investigated by cyclic voltammetry. In galvanostatic charge–discharge tests, the synthesized Nb 2 O 5 nanoparticle network electrode exhibited stable cycle performance and remarkable rate capability without carbon incorporation.