Reduced graphene oxide wrapped ZnCo layered double hydroxides microsphere as efficient sulfur host in lithium-sulfur batteries

Abstract

The practical application of lithium-sulfur (Li-S) batteries is impeded by the shuttling of the polysulfide and slow sulfur electrochemical reaction. In this study, a reduced graphene oxide (rGO) wrapped hollow ZnCo layered double hydroxides (ZnCo-LDH) microsphere is fabricated as sulfur host material. The rGO nanosheets offer efficient charge transportation pathways. Meanwhile, the porous rGO and hollow ZnCo-LDH provide sufficient space for sulfur storage and mitigates the volume variation during battery charging and discharging. In addition, ZnCo-LDH exhibits excellent chemical adsorption capacity for polysulfides, and promotes their electrochemical conversion reactions. Benefited from these advantages, the S/ZnCo-LDH@rGO cathode delivers a high rate performance of 796.5 mAh g−1 at 5.0 C, and excellent stability performance with a capacity decay of 0.036 % per cycle after 500 cycles at 1.0 C. This study shows that the porous microsphere design of rGO wrapped layered double hydroxides has excellent application prospects as efficient sulfur host for Li-S batteries.