▎ 摘　　要

High electromagnetic interference (EMI) shielding but relatively low cost is highly desired due to the severe electromagnetic pollution and cost restriction. However, no existing research can provide the optimal microstructure to these competing goals in nanocomposite foams. The present paper concentrates on the multi-objective optimization of high-efficient EMI shielding in porous graphene-reinforced nanocomposites. First, a two-scale electromagnetic constitutive model of EMI shielding effectiveness (SE) and cost is established through the effective-medium approximation with tunneling and Maxwell-Wagner-Sillars polarization effects. Then, a NSGA-II-based multi-objective optimization is developed for high EMI SE and low cost with the assistance of crowding distance and elite strategy. Compared to the experimental data of graphene/PDMS nanocomposite foam, the effective EMI SE of Pareto-optimal solutions increases by 78% while maintaining the identical cost. On the contrary, the optimal cost decreases by 76% while achieving the same EMI SE. The optimal EMI SE per unit cost is demonstrated to enhance by 405% with the experiment. The significant promotion of Pareto-optimal solutions in EMI shielding performance and efficiency is ascribed to the appropriate choice of microstructural parameters based on the multi-objective optimization. This research provides accurate instructions for the multi-objective optimal design in porous graphene-reinforced nanocomposites.