Design Principles for Current Collectors in Anode-Free All-Solid-State Batteries with Argyrodite LPSCl Electrolytes

An anode-free all-solid-state battery (AF-ASSB) configuration emerges as a promising architecture, where all the active Li is originally stored in the cathode while the anode only consists solely of a current collector with zero access Li. AF-ASSBs have the potential to offer over 50% higher volumetric energy density compared to conventional cells using rolled Li metal sheets. Argyrodite-based solid-state electrolytes (SSEs), such as Li₆PS₅Cl (LPSCl) have drawn great research interest due to their favorable combination of ionic conductivity (>10^-3 S cm^-1 at room temperature) and mechanical softness that enhances interfacial contact with Li metal foils and with ceramic cathode particles. However, achieving long-term electrochemical stability in sulfide-based AF-ASSBs remains a significant challenge.
In this presentation, I will discuss the design principles for current collectors that enable stable cycling in AF-ASSBs employing LPSCl SSE. I will focus on the critical roles of metal wetting behaviors and the stability of metal-electrolyte and current collector-electrolyte interfaces. Additionally, I will demonstrate how advanced characterization techniques, such as cryogenic electron microscopy and multiscale modeling, aid in understanding the composition and dynamics at these interfaces. Finally, I will highlight key insights that can potentially guide the design of AFBs with better performance.