Ultrathin CoNi-layered double hydroxide grown on nickel foam as high-performance current collector for lithium-sulfur batteries

This work designed and synthesized a novel cobalt-nickel-layered double hydroxide flake grown on nickel foam (CoNi LDH@NF) as a high-performance current collector in lithium-sulfur batteries. The nickel foam has a three-dimensional hierarchical architecture, which can provide enough space for sulfur hosting and restrain its volumetric effect during the charge and discharge process. Meanwhile, the CoNi LDH flakes provide sufficient hydroxyl active sites to improve the strong chemical adsorption of polysulfides. Moreover, the CoNi LDH flakes grow on nickel foam significantly increase the electrochemically active surface area, providing abundant active centers and sufficient space to promote the rapid conversion of lithium polysulfides and benefiting the electrochemical performance of the cell. Accordingly, the cell equipped with the CoNi LDH@NF current collector shows outstanding cycling stability performance with a high capacity of 793 mAh g-1 at 0.2 C after 100 cycles. At 1.0 C, the capacity of the cell was maintained at 493 mAh g-1 after 500 continuous cycles with an attenuation rate of 0.067% per cycle. This study provides a feasible method to develop an efficient current collector for lithium-sulfur batteries.