Solvent-free quasi-solid polymer electrolyte with a high dielectric constant for stable lithium metal anodes

Developing Li-metal batteries (LMBs) requires stability and uniform deposition of lithium during operation. However, lithium dendrites and the extremely low conductivity of the quasi-solid polymer electrolyte (qSPE) limit their performance. A high-throughput screen has been carried out here with the assistance of artificial intelligence (AI) to find a promising electrolyte material – Lithium stearate, which is first used to prepare and form qSPE. The qSPE is named as lithium stearate electrolyte (LST) possessing high Li+ ionic transference number (0.67) and conductivity (8.08 × 10−4 S cm−1) at 25 °C, which is attributed to the lithium stearate interweaving and poly(tetrafluoroethylene) (PTFE) fibrilization. Furthermore, the ultrahigh dielectric properties (ε = 792 @ 100 Hz) of LST fixed the anti-ion pair, (stable anion) minimized the space charge region on the surface of the anode. At the same time, the higher LUMO value of LST inhibits the Li-dendrite growth effectively. The excellent properties of quasi-solid polymer electrolytes make them suitable to be used in solid LMBs.