A thin composite polymer electrolyte with high room-temperature conductivity enables mass production for solid-state lithium-metal batteries

Researchers pursue mass production of thin solid electrolytes with high room-temperature (RT) conductivity for solid state batteries with high energy and safety. A novel solid-state composite polymer electrolyte (CPE) with high room-temperature conductivity is obtained by UV-polymerization method and applied for solid-state Li-metal batteries. A commercial PE separator is used as a framework to straighten the CPE. The thickness of this CPE is only 16 µm, which is consist with the thickness of the PE film. It shows a high ionic conductivity of 1.11 × 10⁻⁴ S cm⁻¹ at RT. Li//Li cell can stably cycle for more than 1000 h at 0.1 mA cm⁻² current density at RT, and LiCoO₂//Li solid-state batteries possess excellent rate performance and cycling stability with a capacity retention of 76.1% after 385 cycles from 145.3 mAh g⁻¹ to 110.6 mAh g⁻¹ with a 0.2 C rate at RT.