Realizing High Utilization of High-Mass-Loading Sulfur Cathode via Electrode Nanopore Regulation

One main challenge of realizing high-energy-density lithium-sulfur batteries is low active materials utilization, excessive use of inert components, high electrolyte intake, and mechanical instability of high-mass-loading sulfur cathodes. Herein, chunky sulfur/graphene particle electrodes were designed, where active sulfur was confined in vertically aligned nanochannels (width similar to 12 nm) of chunky graphene-based particles (similar to 70 mu m) with N, O-containing groups. The short charge transport distance and low tortuosity enabled high utilization of active materials for high-mass-loading chunky sulfur/graphene particle electrodes. The intermediate polysulfide trapping effect by capillary effect and heteroatoms-containing groups, and a mechanically robust graphene framework, helped to realize stable electrode cycling. The as-designed electrode showed high areal capacity (10.9 mAh cm(-2)) and high sulfur utilization (72.4%) under the rigorous conditions of low electrolyte/active material ratio (similar to 2.5 mu L mg(-1)) and high sulfur loading (9.0 mg cm(-2)), realizing high energy densities (520 Wh kg(-1), 1635 Wh L--(1)).

Automated summary

The study presents the design of chunky sulfur/graphene particle electrodes, which achieve stable electrodes and high utilization of active materials through the vertical alignment of active sulfur and the inclusion of heteroatoms in chunky graphene particles.