Self-supporting scaffolds with lithiophilic gradient and polar functional groups for stable Li-S full batteries

Given the poor conductivity of reactants/products and the serious lithium polysulfide shuttle effect, chemical kinetic inhibition, as well as indisciplinable growth of lithium metal dendrites, the design of lithiophilicity-sulfiphilicity hosts is key to solving the problems associated with both sulfur and lithium electrodes in practical Li-S batteries. Herein, a multifunctional self-supporting scaffold (PVDF/C fiber/BN) composed of different electrospun fibers is rationally designed, which can simultaneously address the challenges of Li anodes and S cathodes. The 3D integrated scaffold has a highly promising lithiophilic-lithiophobic gradient interfacial layer, which can efficiently restrain Li dendrites growth and guarantee ultralong and stable Li plating/stripping. Furthermore, the abundant polar functional groups can provide synergistic functions such as physical restraint, chemical adsorption, and excellent electrocatalysis for LiPSs conversion. Combining these advantages, the Li-S full battery (S/PVDF/C fiber/BN || Li/PVDF/C fiber/BN) exhibits remarkable electrochemical performance, including an excellent discharge capacity of 953.3 mAh g⁻¹ after 200 cycles at 0.5 A g⁻¹. The designed full battery also delivers significant areal capacity (4.37 mAh cm⁻² at 0.1 A g⁻¹) even with a high loading of 6 mg cm⁻². This work lays down new design ideas for making dendrite-free, high-performance Li-S full batteries.