Autonomous Exploration of an Unexpected Electrode Material for Lithium Batteries

Significant improvements in experimental efficiency are required to explore new lithium-ion-conducting materials. Autonomous research based on robotic experiments exploring a vast chemical space is expected to resolve this problem. This study demonstrates the autonomous exploration of inorganic films with improved lithium ionic conductivity. The system successfully generated a phase diagram and found a new amorphous Li-ion conductor, Li 1.8 Al 0.03 Ge 0.05 PO 3.3, exhibiting lithium ionic conductivity of approximately 3.4 × 10 –6 S cm –1 at room temperature, showing one order of magnitude higher conductivity than the starting material. Furthermore, we unexpectedly found a mixed conductor, Li 0.81 Al 0.24 Ge 0.61 PO 4.2, which is an electrode material for lithium batteries. The exploration of a large chemical space using an autonomous system enables the discovery of unexpected new materials. We discuss the possibilities of using the autonomous system for further materials exploration.