Anode Interlayers and Composite Cathodes at Low Stack-Pressures in All-Solid-State Batteries

Lithium-free so-called anodeless solid-state batteries are attractive for manufacturing. However, at charge rates on the order of 1 mA cm^-2 and above, plating of Li at the current collector/solid electrolyte interface can be inhomogeneous, and dendrites (filaments of Li metal) are observed to penetrate through the solid electrolyte resulting in cell failure. Recent work has suggested that introduction of an interlayer between the solid electrolyte and current collector can protect the solid electrolyte against dendrite growth whilst promoting more homogeneous deposition of Li metal. We investigate a carbon-based interlayer, revealing the structural changes within the interlayer and Li deposition behaviour during the processes of charge and discharge. We identify the origin of the failure of the interlayer at high rates.<br/><br/>It is a practical requirement that solid-state batteries operate under low stack pressures (≤ 2MPa), presenting challenges for performance including of the composite cathode. We investigate a composite cathode composed of a solid electrolyte, NMC811 active material, and carbon nanofibers at low stack pressures.