Melamine Foam Derived 2H/1T MoS as Flexible Interlayer with Efficient Polysulfides Trapping and Fast Li Diffusion to Stabilize Li-S Batteries.

Lithium-sulfur (Li-S) batteries featuring high-energy densities are identified as a hopeful energy storage system but are strongly impeded by shuttle effect and sluggish redox chemistry of sulfur cathodes. Herein, annealed melamine foam loaded 2H/1T MoS (CF@2H/1T MoS) is prepared as a multifunctional interlayer to inhibit the shuttle effect, improve redox kinetics, and reduce the charge-discharge polarization of Li-S batteries. The CF@2H/1T MoS becomes fragmented structures after assembling the cell, which not only benefits to adsorb and catalyze LiPSs but also to significantly buffer the volume expansion due to a large number of gaps between fragmented structures. Meanwhile, the batteries based on CF@2H/1T MoS interlayer delivers high areal capacity of 5.1 mAh cm under high sulfur mass loading of 7.6 mg cm at 0.2 C. Importantly, the experiments of Raman spectra demonstrate that the CF@2H/1T MoS can obviously inhibit the shuttle effect by effectively adsorbing and catalyzing LiPSs. This novel design idea and low-cost melamine foam raw material open up a new way for the application of high-energy density Li-S batteries.