All-solid-state batteries get record-high density with new method

Researchers at the Korea Research Institute of Standards and Science (KRISS) have developed a breakthrough material technology that significantly advances the commercialization of all-solid-state batteries (ASSBs). ASSBs replace the flammable liquid electrolytes used in conventional lithium-ion batteries with non-flammable solid electrolytes, greatly enhancing battery safety by eliminating fire and explosion risks. This innovation addresses long-standing challenges in the fabrication of oxide-based ASSBs, which use garnet-type solid electrolytes known for their high ionic conductivity and chemical stability but require costly, high-temperature sintering processes. The team overcame a major production barrier by creating a novel fabrication method that involves thinly coating solid electrolyte powders with lithium–aluminum–oxide (Li–Al–O) multifunctional compounds. This coating supplies lithium during sintering, prevents lithium evaporation, and improves particle bonding, resulting in electrolyte membranes with a record-high density exceeding 98.2%. Unlike conventional methods that discard large amounts of expensive lithium-containing "mother powder," this approach eliminates the