An ultrafine V2O3 modified hierarchical porous carbon microsphere as a high performance cathode matrix for lithium–sulfur batteries

Abstract

An ultrafine V₂O₃ modified carbon microsphere (VCM) was effectively prepared by a facile wet impregnation method and used as a cathode matrix for lithium–sulfur batteries. This resulting composite presents hierarchical porous frameworks of mesopores together with micropores, effectively restrains soluble polysulfides and enhances mass transport. Moreover, V₂O₃ modification in this mono-dispersed microsphere material can trap polysulfides and mitigate loss of active materials by chemical adsorption. The S/VCM nanocomposites show a high initial discharge capacity of 1177 mA h g⁻¹ at 0.5C and an excellent cycling performance with 921 mA h g⁻¹ after 100 cycles. And it still maintains higher rate capacities of 843 and 719 mA h g⁻¹ at 1C and 2C, respectively, after 100 cycles. These improved electrochemical performances are attributed to the synergistic effects of hierarchical pores and uniformly dispersed vanadium trioxide.