Microstructure-resolved modeling of gyroid structural electrolytes: Mechanical and transport behavior

Structural batteries require structural electrolytes that balance mechanical integrity with efficient ionic transport, a trade-off often controlled through the liquid/solid composition. Additive manufacturing provides another route through microstructure design. In this work, a microstructure design is used to navigate the stiffness-conductivity trade-off in gyroid-structured electrolytes. It is shown that decreasing porosity from 90% to 20% produces an ∼18× increase in stiffness and an ∼7× decrease in ionic conductivity in a conventional gyroid microstructure. Microstructure-resolved simulations isolate the role of geometric anisotropy at fixed porosity, revealing strong directional dependence of multifunctional properties. The elastic moduli vary by up to 28× across different directions between the simulated gyroid structures, while the ionic conductivities vary by ∼5×. The resulting mechanical-transport property maps demonstrate that the microstructure, rather than composition alone, enables the systematic navigation of the stiffness-conductivity trade-off. Geometric anisotropy emerges as a particularly powerful design lever because it influences effective stiffness far more strongly than ionic conductivity, enabling pronounced directional mechanical tuning while preserving substantial ionic transport. These findings establish porosity and anisotropy as key design parameters and provide a pathway toward architected structural electrolytes with directionally improved performance.