Nucleation of voids at second phase particles at lithium–ceramic interface degrades cell performance

We show that foreign second phase particles incorporated into the lithium metal-ceramic-electrolyte interface catalyze nucleation of voids, which, at first, lead to higher voltage and then to voltage collapse in constant current experiments. Voltage increases because voids grow the area-specific resistance. The collapse is caused by dendrites. Cell manufacture in high class clean room environments is recommended for the sake of reliability and increased performance. Graphical abstract