Three-Dimensionally Printed Ionogel-Coated Ceramic Electrolytes for Solid-State Lithium Batteries

Stereolithography three-dimensional (3D) printing technology enables the customization of ceramic-based solid electrolyte structures with desired electrochemical properties; however, formulating slurries that both are highly ceramic-loaded and have low viscosity for printing poses a challenge. Here, we propose an ionogel-coated ceramic approach to prepare a shear-thinning fast-ion conductor ceramic (Li_6.5La₃Zr_1.5Ta_0.5O₁₂) slurry, which possesses both a high ceramic content of 50 wt % and a low viscosity of 1.53 Pa·s. Utilizing this slurry, 3D symmetric honeycomb briquette-like electrolyte films are printed, and solid-state lithium batteries are easily fabricated by filling the cathode and anode slurries into the respective symmetric honeycombs. The atomic-level interaction between ceramic/ionogel interfaces and the integrated electrode/electrolyte interface facilitates rapid Li⁺ transport across multiscale interphases in batteries. Additionally, the interactions of ceramic nanoparticles and ionic liquids with Li salt substantially increase the concentration of free Li⁺, both of which enhance the ionic conductivity and ensure stable Li⁺ transport efficiency. Solid-state lithium batteries can cycle stably 500 times without obvious degradation at 0.5 C and 50 °C. The strategy offers a feasible solution for printing customized solid-state ceramic-based electrolytes.