EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

With the advancing electrification of the automotive sector, the demand for safer lithium-ion batteries with higher energy densities is getting louder. Both, increased safety and elevated energy density are envisioned to be achieved by replacing the flammable liquid electrolyte with a solid electrolyte. Liquid electrolytes degrade in contact with most anode materials and form a solid electrolyte interphase (SEI), that protects against further decomposition and exothermic reactions. However, the SEI offers only limited thermal stability and insufficient protection from Li-dendrite formation during charging. Solid ceramic electrolytes with their superior thermal stability and high mechanical rigidity are expected to solve these problems. The prevention of the formation of lithium dendrites enables the use of the high-capacity anode metallic lithium ( > $3.8$ $ A$ $ h $ $g^-$$^1$), which significantly increases the energy density. Without Li-dendrite formation, internal short-circuits, which can cause a thermal runaway, are prevented.
Whether solid electrolytes enable all-solid-state batteries that meet their expectations is critically assessed on the basis of a few representative studies.