A highly efficient absorptive and catalytic self-supporting Fe2O3/CC host for high performance Li-S batteries

Abstract

The lithium-sulfur (Li-S) battery is a promising energy storage system because of its high energy density and low cost. However, the shuttling of lithium polysulfides (LiPSs) and low conductivity of the S cathode are barriers to its practical application. Fe₂O₃ nanorods were grown on a carbon cloth (Fe₂O₃/CC) by a solvothermal reaction and calcination to obtain a cathode for the battery. The mesoporous structure of the Fe₂O₃ and the CC conducting network facilitates lithium-ion and electron transport. Meanwhile, the nanorod arrangement results in the exposure of more Fe₂O₃ active sites, which improves the adsorption and rapid conversion of LiPSs. As a result, a Li–S cell using a Fe₂O₃/CC cathode has a high capacity of 1 250 mAh g⁻¹ at 0.1 C with an excellent life of over 100 cycles with a capacity retention of 67%. It also has a 70% capacity retention after 1 000 cycles at 0.2 C. The excellent electrochemical performance of the Fe₂O₃/CC cathode indicates its potential applications in Li-S batteries.