Melamine Foam Derived 2H/1T MoS2 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 MoS2 (CF@2H/1T MoS2) 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 MoS2 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 MoS2 interlayer delivers high areal capacity of 5.1 mAh cm-2 under high sulfur mass loading of 7.6 mg cm-2 at 0.2 C. Importantly, the experiments of in situ Raman spectra demonstrate that the CF@2H/1T MoS2 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.