Lithium-sulfur (Li-S) batteries are attractive candidates for next-generation rechargeable batteries. With the steady development of sulfur cathodes, the recent revival of research on dendrite-free Li metal anodes offers opportunities to improve the stabilities and safety of Li-S batteries. However, the low capacities and low Li utilizations of current Li anodes hinder the improvement of the energy densities of Li-S batteries. Here, we present a facile approach to fabricate lithiophilic three-dimensional porous current collectors by modifying commercial metal foams with yolk-shell structured N-doped porous carbon nanosheets. Benefiting from the structure-based rational design, this current collector is able to generate dendrite-free Li anodes with improved Coulombic efficiencies and life spans, enabling carbon/sulfur cathodes to exhibit significantly enhanced stabilities (e.g., 78.1% of capacity retention after 1400 cycles). More importantly, we successfully constructed a high-areal-capacity Li-S full cell (9.84 mAh cm-2) with 82% Li utilization. This work provides a promising route toward high-energy-density Li-S batteries.
Keywords: Li−S batteries; carbon nanosheets; current collectors; high sulfur loading; lithium metal anodes.