Synthesis of Double-Shelled Co-LDH@rGO Nanocages through a Spray-Drying Process as an Advanced Sulfur Reservoir for Lithium–Sulfur Batteries

A reasonable design of a sulfur electrode structure is necessary to pursue practical and feasible lithium–sulfur batteries with high performance. Here, double-shelled Co-LDH@rGO (LDH = layered double hydroxide; rGO = reduced graphene oxide) hollow nanocages, through an easy spray-drying process, are developed as advanced sulfur reservoirs. The Co-LDH@rGO microspheres not only maximize the advantages of structure to encapsulate sulfur but also provide excellent conductivity and abundant self-functionalized surfaces to facilitate the adsorption of polysulfides by chemical bonding. Consequently, the obtained Co-LDH@rGO/S electrodes exhibit significantly improved electrochemical performances, such as a high discharge capacity of 1046 mAh g–1 at 0.2 C, excellent rate capability, and stable cycle ability at 1 C with a decay rate of 0.05% per cycle over 500 cycles. This work puts forward a simple and effective method to synthesize double-shelled materials, which is helpful for the architectural design of prospective sulfur host materials.