New publication explores lithium dendrite formation in solid-state batteries
All-solid-state lithium metal batteries are often limited by lithium dendrite formation at high current densities, which can trigger internal short circuits and sudden voltage collapse. At intermediate current densities, a more subtle failure mode, known as a “soft short”, tends to occur. Unlike a hard short, a soft short does not drive the cell voltage to zero; instead, it produces dynamic voltage fluctuations and prevents further voltage increase during charging, making the phenomenon harder to interpret.
To uncover the electro-chemo-mechanical origins of the soft-short behavior, Xu et al. have studied the cycling of Li₄Ti₅O₁₂ | Li₆PS₅Cl | Li cells in a three-electrode configuration equipped with operando pressure monitoring. A lithiated W/Au reference electrode enabled independent measurement of both working and counter electrode potentials as well as their evolving impedance. During galvanostatic cycling, they directly observed the onset of a soft short and its partial voltage recovery by simultaneously tracking electrode potentials and real-time cell pressure. This was made possible by the three-electrode CompreCell DP in the CompreFrame.
By correlating pressure transients with Faradaic currents, they also demonstrated that the emergence of a soft short fundamentally decouples the internal electrochemical processes from the externally applied current. Impedance spectroscopy further supported this interpretation: after dendritic bridging, the cell’s ohmic resistance dropped markedly, indicating the formation of electronically conductive pathways across the solid electrolyte.
Read the publication in Journal of Energy Chemistry.
Formation of soft short circuits by lithium penetration in solid electrolytes. © Xu, Zhang, Schmidt, El Kazzi 2026 (CC-BY)