Confined sulfidation strategy toward cobalt sulfide@nitrogen, sulfur co-doped carbon core-shell nanocomposites for lithium-ion battery anodes

Abstract A confined sulfidation strategy is developed for the preparation of cobalt sulfide@nitrogen, sulfur co-doped carbon composites (CoS@NSC) with a unique core-shell structure. The as-fabricated CoS@NSC composites are beneficial for efficient lithium ion diffusion, fast electron transfer and improved structural integrity. As a demonstration, the CoS@NSC, as an anode material for lithium-ion battery, exhibits a high initial stable discharge capacity of 754 mA h g-1 and high capacity retention by maintaining 635 mA h g-1 at 1 A g-1 after 100 charge/discharge cycles. This confined sulfidation strategy can be readily extended to a large-scale and cost-effective production of other transition metal sulfide@carbon core-shell nanocomposites.