Because of a remarkably high theoretical energy density, the lithium-sulfur (Li-S) battery has attracted significant attention as a candidate for next-generation batteries. While employing solid electrolytes can provide a new avenue for high-capacity Li-S cells, all-solid-state batteries have unique failure mechanisms such as chemomechanical failure due to the volume changes of active materials. In this study, we investigate all-solid-state Li-S model cells with differently processed cathode composites and elucidate a typical failure mechanism stemming from irreversible Li 2 S formation in the cathode composites. Reducing the particle size is key to minimizing the influence of volume changes, and a capacity of >1000 mAh g sulfur -1 is achieved by ball milling of the cathode composites. In addition, the long-term stability of the ball-milled cathode is investigated by varying the upper and lower cutoff potentials for cycling, which results in the unveiling of the significantly detrimental role of the lower cutoff potential. Preventing a deep discharge leads to a reversible capacity of 800 mAh g sulfur -1 over 50 cycles in the optimized cell. This work highlights the importance of mitigating chemomechanical failure using microstructural engineering as well as the influence of the cutoff potentials in all-solid-state Li-S batteries.
All Science Journal Classification (ASJC) codes
- General Chemistry
- General Chemical Engineering
- Materials Chemistry