Blacklight Sintering of Garnet-Based Composite Cathodes

Garnet-structured Li7La3Zr2O12 (LLZO) is an attractive electrolyte for lithium solid-state batteries (SSBs), but its processing requires long sintering at temperatures above 1000 degrees C to achieve sufficient ionic conductivity. Such sintering is not only time and energy consuming, but also leads to undesirable material interactions. Therefore, a significant reduction of the sintering time is very important for the future development of garnet-based batteries. A promising method is the recently introduced photonic blacklight sintering with light sources in the UV spectrum, which enables energy-efficient sintering of ceramic layers within seconds. In this work, blacklight sintering of garnet-based SSBs is validated using a model cell consisting of LLZO and LiCoO2 (LCO) composite cathode layers printed on dense LLZO pellets. An optimized sintering program allowed the production of working cells in only 20 s. This study demonstrates the suitability of blacklight sintering for processing garnet-based SSBs and provides guidance for future process optimization.