Novel NiCo2O4 nanofibers prepared via electrospinning method as host materials for perfect polysulfide inhibition

Abstract

Lithium-sulfur batteries have been widely studied as promising energy storage system due to their high specific capacity and energy density. However, the poor electronic conductivity and severe polysulfide shuttle effect still hinder the practical applications of lithium-sulfur batteries. Therefore, improving the electronic conductivity and inhibiting the polysulfide migration are still the hot research topic in lithium-sulfur batteries. In this work, ternary metal oxide NiCo2O4 nanofibers are designed as novel sulfur host for high-performance lithium-sulfur batteries. On the one hand, the polar NiCo2O4 could provide sufficient active site for anchoring the soluble polysulfide. On the other hand, the high electronic conductivity of NiCo2O4 nanofibers could adequately activate insulated sulfur and improve the specific capacity and rate capability of lithium-sulfur batteries. As a result, the as-prepared NiCo2O4 nanofibers/S (NCO-NFs/S) composite cathodes exhibit initial specific capacity of 1238 mAh g−1 at 0.2 C. Moreover, the specific capacity of 706 mAh g−1 could be obtained after 500 cycles at 1 C for the NCO-NFs/S composites.