Solid-State Li Batteries via Masked-SLA 3D Printing

Solid-state and quasi-solid-state lithium metal batteries are widely regarded as a promising solution to overcome the energy density and safety limitations of conventional lithium-ion technology. However, their practical implementation is critically hindered by the lack of scalable manufacturing strategies capable of producing thin, uniform, and lithium-compatible solid (or gel polymer) electrolyte layers with excellent interfacial contact. Here, a paradigm shift is demonstrated by using stereolithography (SLA) 3D printing to directly print a ready-to-use gel polymer electrolyte without any post-processing. The proposed approach enables the fabrication of dense, nonporous electrolyte layers with precisely controlled thickness and conformal deposition onto substrates such as lithium metal and LiFePO₄ cathodes. Unlike previously reported SLA-based strategies limited to ceramic precursors or sacrificial templates, the printed electrolyte is immediately functional and compatible with battery assembly. This area-parallel, solvent-free manufacturing route offers intrinsic scalability and eliminates material waste associated with conventional processing methods. Beyond the specific demonstrations reported here, the printing procedure provides a versatile platform adaptable to other polymer electrolytes and polymer-inorganic composites, opening new opportunities for additive manufacturing of advanced energy storage devices.