Ultrathin 2D–2D MXene-LDH Interlayer with High Polysulfide Adsorption Ability for Advanced Li–S Batteries

Lithium–sulfur (Li–S) batteries are considered as promising energy storage systems due to the high energy density of 2600 W h kg–1. However, the practical application of Li–S batteries is hindered by the inadequate conductivity of sulfur and Li2S, as well as the shuttle effect caused by polysulfides during the charge–discharge process. Introducing a conductive interlayer between the cathode and the separator to physically resist polysulfides represents an effective and straightforward approach to mitigate the shuttle effect in Li–S batteries. In this paper, an ultrathin (<1 μm) 2D–2D MXene-LDH interlayer with high polysulfide adsorption ability was introduced to Li–S batteries. The synergistic effect between MXene and layered double hydroxide greatly improved the adsorption effect of the interlayers: the conductive Ti3C2Tx MXene chemically adsorbs polysulfides and promotes their fast transfer, and the NiCo-LDH alleviates the restack of MXene and facilitates Li+ diffusion. After inserting the MXene-LDH interlayer, the Li–S batteries exhibit an enhanced specific capacity of 1137.6 mA h g–1 at 0.1 C and retain 622.6 mA h g–1 after 100 cycles. The ultrathin 2D–2D interlayer offers a feasible way for the development of highly efficient and lightweight interlayers in Li–S batteries.