MIT News November 18, 2022
Whether dendrites are driven by mechanical failure or electrochemical degradation of solid electrolytes remains an open question. If internal mechanical forces drive failure, superimposing a compressive load that counters internal stress may mitigate dendrite penetration. A team of researchers in the US (MIT, Brown University) investigated this hypothesis by dynamically applying mechanical loads to growing dendrites in Li6.6La3Zr1.6Ta0.4O12 solid electrolytes. Operando microscopy revealed marked deflection in the dendrite growth trajectory at the onset of compressive loading. Sufficient loading the deflection averted cell failure. They quantified the impact of stack pressure and in-plane stresses on dendrite trajectory, charted the residual stresses required to prevent short-circuit failure, and proposed design approaches to achieve such stresses. For the materials they studied the dendrite propagation was dictated by electrolyte fracture, with electronic leakage playing a negligible role…read more. TECHNICAL ARTICLEÂ
…applying a compression force across a solid electrolyte material (gray disk) caused the dendrite (dark line at left) to stop moving… Credit: MIT