Composite Cathode Architectures for High Performance All-Solid-State Lithium Sulfur Batteries

Future electric aircraft will require novel energy storage systems with the best achievable safety and extraordinary energy and power performance. The all-solid-state lithium-sulfur (Li-S) battery is an attractive solution to achieve both safety and specific energy requirements. The power performance is expected to be enhanced by the use of conductive fillers such as advanced carbon nanomaterials as well as electrochemical additives such as selenium (Se). However, grand challenges remain in every aspect of this battery system, including the Li metal anode, solid electrolyte, cathode composition, and the various interfaces and interphases encountered where two or multiple components meet. Here, we will discuss the various fabrication strategies to create composite S cathode architectures to achieve high mass loadings (> 5 – 10 mg cm^-2) using solid sulfide electrolytes in solvent-free processes. It is demonstrated that while the Li metal anode and solid electrolyte interface characteristics may dominate the cycling properties, the cathode composition and architecture from optimized fabrication processes is also essential to achieve high S utilization and thus the needed energy density. The results from various advanced carbon additives, such as holey graphene, will also be discussed.