Shear-thinning inks for DIW of customizable PEO/Li1.3Al0.3Ti1.7(PO4)3 solid electrolytes: Additive manufacturing toward high-performance solid-state batteries

The application of solid-state electrolytes is one of the effective approaches to address the safety issues of lithium-ion batteries. From a manufacturing perspective, 3D printing based on direct ink writing (DIW) has attracted unprecedented interest due to its high design freedom and convenient fine-scale control. In this study, Li[Formula: see text]Al[Formula: see text]Ti[Formula: see text](PO 4 ) 3 (LATP) electrolyte nanoparticles were dispersed in polyethylene oxide (PEO) polymer to form a printable electrolyte ink, and a composite solid-state electrolyte was subsequently fabricated via DIW. The results show that the composite electrolyte ink containing 2 wt.% LATP exhibits the optimal rheological properties at room temperature. The addition of LATP nanofillers effectively enhances the structural stability, thermal stability, and electrochemical performance of the polymer electrolyte. The ionic conductivity of the printed composite solid-state electrolyte membrane is increased to 5.62 × 10[Formula: see text] S ⋅ cm[Formula: see text]. The NCA/graphite solid-state lithium-ion battery assembled with this electrolyte displays a specific discharge capacity of 236 mAh g[Formula: see text] at a 0.1 C rate, and exhibits excellent electrochemical reversibility and cycle stability. This multi-shaped, printable ink technology opens up new pathways for the manufacturing of scalable energy storage devices.