Improving Solid State Battery Materials Testing through Active Pressure and Temperature Control

Solid-state battery materials characterization poses several practical challenges related to sample preparation and measurement conditions. For example, Ohno et al highlighted this fact in a round-robin study in 2020, where ionic conductivities measured for several inorganic solid electrolyte samples were found to deviate by as much as one order of magnitude. Parameters such as pelletization pressure, measurement temperature and measurement pressure greatly affect the obtained results, and it is therefore necessary to control and monitor the experimental conditions throughout measurements. In this talk, characterization of solid electrolytes as well as full solid-state battery cells under active pressure and temperature control is described. A force sensor below the test cell is connected to a servo motor in a feedback loop, giving accurate and responsive pressure control. This kind of active pressure control has been shown to yield the optimal performance of all solid-state batteries. The implications for materials characterization and device performance testing will be discussed.