AbstractPotassium metal anode solid-state cells with a K-beta”-alumina ceramic electrolyte are found to have relatively high critical currents for dendrite penetration on charge of approximately 4.8 mA/cm², and voiding on discharge of approximately 2.0 mA/cm², at 20 °C under 2.5 MPa stack-pressure. These values are higher than generally reported in the literature under comparable conditions for Li and Na metal anode solid-state batteries. The higher values for potassium are attributed to its lower yield strength and its readiness to creep under relatively low stack-pressures. The high critical currents of potassium anode solid-state batteries help to confirm the importance of the metal anode mechanical properties in the mechanisms of dendrite penetration and voiding.