Résumé
Anode-less lithium (Li) metal batteries promise higher energy density but require robust solid electrolyte interfaces. In this regard, sulfide electrolytes are attractive due to their high room-temperature Li-ion conductivity and mechanical softness that maintains good interfacial contact under low pressure. However, their intrinsic reactivity towards Li can drive non-uniform deposition, dendrite growth and progressive interfacial and electrolyte degradation, underscoring the need for interfacial engineering. Here we show that an ultrathin sputtered indium (In) interlayer on a copper (Cu) current collector mitigates such failure modes in Cu | In | Li6PS5Cl | Li cells. Using laboratory X‑ray micro‑computed tomography (µ‑CT), we track the three‑dimensional evolution of interfaces and crack networks in thick sulfide pellets in both ex situ and in situ mode. The In interlayer suppresses the nucleation spike, promotes fine and conformal Li deposits and prevents cracking of electrolyte observed with bare Cu cells. These results establish nanoscale In interlayers as a practical route to stabilize anodeless sulfide cells and demonstrate laboratory µ-CT as a nondestructive tool to visualize buried interface mechanics in realistic solid-state architectures.