A Hybrid Dual-Type Sulfur Cathode and a Lithiated Si/SiOx Nanosphere Anode for Li-Sulfur Full Cells

Lithium−sulfur batteries could become an excellent alternative to replace the currently used lithium-ion batteries. ¹ The natural abundance and low cost of sulfur, coupled with the high theoretical energy density of sulfur-based cathodes, namely, 1675 mAh g^-1 and 2600 Wh kg^-1, are the major advantages of this sulfur battery.² However, commercialization of lithium−sulfur batteries has so far been limited due to the cyclability problems associated with both the sulfur cathode and the lithium−metal anode.³ Herein, we demonstrate a highly reliable lithium−sulfur battery showing cycle performance comparable to that of lithium-ion batteries; our design uses a highly reversible hybrid dual-type sulfur cathode (solid sulfur electrode and polysulfide catholyte) and a lithiated Si/SiO_x nanosphere anode. Our result shows superior battery performance in terms of high specific capacity, excellent charge−discharge efficiency, and notable cycle life, delivering a specific capacity of ∼750 mAh g⁻¹ over 500 cycles (85% of the initial capacity). These promising behaviors may arise from a synergistic effect of the enhanced electrochemical performance of the newly designed anode and the optimized layout of the cathode.

References

1. B. Scrosati, J. Hassoun, Y-K. Sun, Energy Environ. Sci., 4, 3287 (2011).

2. E. Peled, A. Gorenshtein, M. Segal, Y. Sternberg, J. Power Sources, 26, 269 (1989).

3. Y-V. Mikhaylik, J. R. Akridge, J. Electrochem. Soc., 151, A1969 (2004).