Stable Cycling of Solid-State Lithium Metal Batteries at Room Temperature via Reducing Electrode/Electrolyte Interfacial Resistance

Solid-state lithium batteries using solid-state electrolytes (SSE) improve both thermal stability and energy density compared with organic liquid electrolytes lithium-ion batteries (LIBs). However, their usage is still challenged by low lithium-ion conductivity and high interfacial resistance between SSE and electrodes, as well as difficulties running at room temperature (RT). Herein, we demonstrate an electrode/solid-state electrolyte interface, in which poly(ether-acrylate) (PEA) network was introduced on the surface of ceramic electrolytes via photo-polymerization, thus dramatically reducing the SSE/Li interfacial resistance from 4822 to 122 Ω cm². As a result, the Li/Li cells can cycle over 500 h at 0.3 mA cm⁻², LiFePO₄/Li delivers 200 cycles with capacity retention of 91.1% at RT, respectively. This research provides a method to improve the interface contact between SSE and electrodes, and offers possibilities for application of solid-state Li metal batteries under ambient condition.