3D-printed polydimethylsiloxane separators with triply periodic minimal surface structure enable uniform zinc deposition

Aqueous zinc-ion batteries are promising candidates for large-scale energy storage due to their low cost and high safety. However, their development is restricted by uncontrolled zinc dendrite growth. To address this, this study developed a novel photocurable polydimethylsiloxane (PDMS) resin for 3D printed separators to guide zinc deposition. 3D printing enabled the one-step fabrication of tailored 3D structured PDMS separators with zinc-philic functional groups (–COO–, C–O–C) as well as uniform pores (triply periodic minimal surface (TPMS 3D-dia) and simple cubic pore (3D-sc)). These separators facilitated uniform zinc deposition. Finite element analysis revealed that the 3D-dia separator exhibited more uniform current density, superior fluid dynamics, and higher mechanical strength than the 3D-sc. In electrochemical tests, the Zn||Zn symmetric battery with the 3D-dia separator proved a stable cycling life of 520 cycles at 1 mA cm −2 , significantly outperforming the glass fiber separator (101 cycles). This work presents a novel strategy for preparing and modifying separators, as well as a facile, effective approach to protecting metal anodes.