Ordered mesoporous tungsten oxide–carbon nanocomposite for use as a highly reversible negative electrode in lithium-ion batteries

Abstract

In the present study, a tungsten oxide–carbon nanocomposite (WOx–C) is synthesized and employed as the negative electrode in lithium-ion batteries. The prepared material exhibited an ordered mesoporous carbon structure uniformly embedded by tungsten oxide nanoparticles. Also, it is composed of about 90% highly reduced tungsten W5+ fraction. The conversion of WOx to W0 and Li2O is proven to be the major lithiation mechanism of WOx–C negative electrode. From electrochemical analysis, a distinct improvement in the delithiation resistance of tungsten oxide within the composite electrode is observed. This improvement in polarization is a result of the high electrical conductivity of the mesoporous carbon matrix and the uniform distribution of tungsten species. The lower delithiation polarization leads to a WOx-C electrode with very stable cycleability, which has been rarely observed in typical conversion-type negative electrodes. © 2020 Elsevier B.V.