Vat photopolymerization of tantalum-doped Li7La3Zr2O12 electrolytes: a new Frontier in solid-state battery design

Abstract

The advancement of all-solid-state lithium batteries (ASSLBs) necessitates the development of high-performance solid electrolytes that can meet stringent requirements for ionic conductivity, chemical stability, and structural integrity. This study focuses on the design and fabrication of 3D-customized ceramic-based solid electrolytes using Vat Photopolymerization (VPP) 3D printing, with a specific emphasis on tantalum-doped Li₇La₃Zr₂O₁₂ (LLZO). LLZO, known for its superior ionic conductivity, chemical stability, and inherent safety, is an ideal candidate for next-generation battery technologies. The 3D-printed tantalum-doped LLZO electrolytes were engineered to integrate a porous structure for facilitating lithium-ion transport and a non-porous structure to ensure effective ion conduction and mechanical stability. Through the optimization of debinding and sintering processes, the printed electrolytes achieved high density and a refined microstructure, critical factors for enhancing electrochemical performance. Structural and morphological analyses using X-ray diffraction (XRD) and scanning electron microscopy (SEM) confirmed phase purity and detailed microstructural features, respectively. Electrochemical impedance spectroscopy (EIS) demonstrated a significant ionic conductivity of 3.15 × 10⁻⁵ S cm⁻¹, highlighting the potential of these materials for deployment in high-performance ASSLBs. The results underscore the feasibility of VPP 3D printing as a transformative approach for fabricating complex, high-performance solid electrolytes tailored to the demanding specifications of next-generation energy storage systems.