Rationally Design a Sulfur Cathode with Solid-Phase Conversion Mechanism for High Cycle-Stable Li-S Batteries

Solid-solid reactions are very effective for solving the main challenges of lithium-sulfur (Li-S) batteries, such as the shuttle effect of polysulfides and the high dependence of electrolyte consumption. However, the low sulfur content and sluggish redox kinetics of such cathodes dramatically limit the practical energy density of Li-S batteries. Here a rationally designed hierarchical cathode to simultaneously solve above-mentioned challenges is reported. With nanoscale sulfur as the core, selenium-doped sulfurized polyacrylonitrile (PAN/S7Se) as the shell and micron-scale secondary particle morphology, the proposed cathode realizes excellent solid-solid reaction kinetics in a commercial carbonate electrolyte under high active species loading and a relatively low electrolyte/sulfur ratio. Such an approach provides a promising solution toward practical lithium sulfur batteries.

Automated summary

The study introduces a hierarchically designed cathode to address the main challenges faced by lithium-sulfur batteries, achieving excellent solid-solid reaction kinetics through optimizing nanoscale sulfur core and selenium-doped sulfurized polyacrylonitrile shell. This approach provides a promising solution towards practical lithium sulfur batteries with high active species loading and a relatively low electrolyte/sulfur ratio.