Rational Design of High-Loading Sulfur Cathodes with a Poached-Egg-Shaped Architecture for Long-Cycle Lithium-Sulfur Batteries

A high-loading electrode is essential for establishing high-energy-density lithium-sulfur (Li-S) batteries, but it is confronted with critical challenges. Herein, we present a freestanding poached-egg-shaped architecture through a facile template supported vacuum-filtration strategy and employ it as an efficient sulfur host for Li-S batteries. This unique architecture guarantees an effective encapsulation of the "sulfur yolk" inside the fully vacuum sealed framework, effectively limiting the active material loss and polysulfide diffusion. Also, the conductive and porous framework serves as an interlinked electron pathway and electrolyte channel, greatly facilitating fast electric/ionic transport along with active material reactivation and reutilization during cycling. A high peak discharge capacity (1200 mA h g(-1)), a low capacity-fade rate (0.09% cycle(-1)) for 500 cycles, and excellent rate capability (C/5-1C rates) are accomplished. Moreover, with such an advantageous architecture, the sulfur loading is successfully increased to 32 mg cm(-2) to achieve an areal capacity of up to 16 mA h cm (-2). This work provides guidelines for realizing optimized high-loading Li-S batteries.