Porous structured niobium pentoxide/carbon complex for lithium-ion intercalation pseudocapacitors

A facile soft-templated synthesis of the niobium pentoxide/carbon (Nb2O5/C) from the polymerization of resorcinol with formaldehyde under the hydrothermal condition is introduced. This material has been characterized by X-ray diffraction (XRD), transmission electron microscope (TEM) and energy dispersive spectrometer (EDS) techniques. The carbon is well-dispersed in the nanostructure along with Nb2O5 and the material is porous. The intimate contact between Nb2O5 and carbon improves its conductivity. The electrochemical studies revealed that the porous Nb2O5/C displayed good pseudocapacitive response. The specific capacitance of the Nb2O5/C was 387 F g−1 at 0.1 A g−1 and 210 F g−1 at 5 A g−1. The Nb2O5/C exhibits superior cycling performance, which can remain about 96% of its initial capacitance after 1000 cycles at 5 A g−1.