Two-dimensional Co(OH)2/graphene oxide composite as an efficient multifunctional interlayer for high-performance lithium–sulfur batteries

Abstract

The shuttling-effect of soluble lithium-based polysulfides (LiPS) represents one of the main obstacles for practical application of lithium–sulfur (Li–S) batteries. Herein, to address this issue, a flexible Li–S interlayer consisting of a two-dimensional α-Co(OH)2 nano-plate and graphene oxide (GO) is developed using a simple vacuum filtration technique. In the interlayer, the α-Co(OH)2 and GO are assembled into a layered structure forming a physical barrier for the shuttling of LiPS. Additionally, the α-Co(OH)2 offers strong chemical adsorption and efficient catalysis performance towards LiPS conversion, further inhibiting its shuttling. Attributed to these beneficial features of the interlayer, the Li–S battery delivers an initial discharge capacity of 834 mAh g−1 at the current density of 1 C. More importantly, after 300 cycles, a high discharge capacity of 590 mAh g−1 was retained, corresponding to a low capacity fading rate of 0.1% per cycle. This work might be of great interest for the feasible and scalable preparation of multifunctional interlayers in Li–S batteries.