Direct Ink Writing of Li1.3Al0.3Ti1.7(PO4)3‐Based Solid‐State Electrolytes with Customized Shapes and Remarkable Electrochemical Behaviors

Abstract All‐solid‐state lithium batteries have received extensive attention due to their high safety and promising energy density and are considered as the next‐generation electrochemical energy storage system. However, exploring solid‐state electrolytes in customized geometries without sacrificing the ionic transport is significant yet challenging. Herein, various 3D printable Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 (LATP)‐based inks are developed to construct ceramic and hybrid solid‐state electrolytes with arbitrary shapes as well as high conductivities. The obtained inks show suitable rheological behaviors and can be successfully extruded into solid‐state electrolytes using the direct ink writing (DIW) method. As‐printed free‐standing LATP ceramic solid‐state electrolytes deliver high ionic conductivity up to 4.24 × 10 −4 S cm −1 and different shapes such as “L”, “T,” and “+” can be easily realized without sacrificing high ionic transport properties. Moreover, using this printing method, LATP‐based hybrid solid‐state electrolytes can be directly printed on LiFePO 4 cathodes for solid‐state lithium batteries, where a high discharge capacity of 150 mAh g −1 at 0.5 C is obtained. The DIW strategy for solid‐state electrolytes demonstrates a new way toward advanced solid‐state energy storage with the high ionic transport and customized manufacturing ability.