High-Performance All-Solid-State Lithium–Sulfur Batteries Enabled by Slurry-Coated Li6PS5Cl/S/C Composite Electrodes
Chao Zheng, Kai Wang, Lujie Li, Hui Huang, Chu Liang, Yongping Gan, Xinping He, Wenkui Zhang, Jun Zhang
Abstract
Among many lithium secondary batteries, lithium–sulfur batteries stand out because of their high theoretical specific energy, low cost, non-toxicity and the fact that they cause no environmental pollution. However, due to poor electronic and ionic conductivity, shuttle effect, lithium dendrites and other defects, it remains a big challenge to achieve large-scale application of lithium-sulfur batteries. Here we report an all-solid-state lithium–sulfur battery based on Li-argyrodite Li 6 PS 5 Cl solid-state electrolytes through a slurry-coating method. Li 6 PS 5 Cl with a high ionic conductivity of 1.3 × 10 –3 S cm −1 at room temperature is used as the solid electrolyte and the ion conductive additive in the electrode. The sulfur-based composite cathode is fabricated through a slurry-coating process by dispersing sulfur, Li 6 PS 5 Cl, ethyl cellulose, and carbon black in 1,3-dioxolane (DOL). This method can disperse the Li 6 PS 5 Cl around sulfur particles well, and the solvent does not react with any component of composite cathodes during preparation. The battery delivers a high discharge capacity of 962 mA h g −1 at room temperature for the first cycle at 80 mA g −1 . While the Coulombic efficiency is approximately 99.5% during 100 cycles. This work provides a new insight into the combination method between the sulfide-type SSEs and sulfur cathodes, which is critical to the electrochemical performance of all-solid-state lithium-sulfur batteries.