3D printing of self-supported solid electrolytes made of glass-derived Li1.5Al0.5Ge1.5P3O12 for all-solid-state lithium-metal batteries

Abstract

Additive manufacturing (AM) techniques using advanced functional materials are attracting strong attention in the field of all solid-state lithium batteries (ASSBs) since they are considered as innovative approaches that will pave the way for cheaper, safer, and customizable batteries with exceptional volumetric energy density. In the present work, stereolithography (SLA) is presented as a suitable technique to produce complex-shaped Li_1.5Al_0.5Ge_1.5P₃O₁₂ (LAGP) full-ceramic electrolytes from glass feedstock. Printed electrolytes showed an ionic conductivity in good agreement with LAGP fabricated by conventional techniques (σ = 6.42 × 10⁻⁵ S cm⁻²). Moreover, 3D printed LAGP corrugated membranes with interfacial area increased by 15% were fabricated showing an equivalent reduction of the area specific resistance. Symmetrical cells with lithium metal electrodes were used to study the stripping and plating behaviour of LAGP printed electrolytes coated with a germanium protective interlayer deposited via thermal evaporation. The symmetric cells showed a stable cycling performance over 250 hours demonstrating the stability of the designed cells. The innovative approach reported here represents the first step for the next generation of ASSBs based on LAGP, offering new degrees of freedom for the manufacturing of full ceramic electrolytes with a complex shape.