Structural Power Composites Based on High Mass Loading Zn‐Ion Hybrid Supercapacitors with Metal Mesh Current Collectors and Aramid Nanofiber/Glass Fiber Composite Electrolytes

ABSTRACT A multifunctional electrode design is proposed for structural power composites (SPCs) by integrating high‐mass‐loading Zn‐ion hybrid supercapacitor (ZHSC) components with stainless steel (SS) mesh current collectors. A combined wet–dry processing route was developed to overcome fabrication challenges in thick electrodes, such as compositional inhomogeneity and drying‐induced cracking. The resulting freestanding activated carbon (AC) films were thermally laminated onto SS mesh to form ACSS electrodes with strong interfacial adhesion and improved electrical conductivity. A complementary ZnSS electrode was fabricated by calendering Zn foil onto SS mesh, enhancing mechanical robustness and electrical properties. The electrodes were assembled on opposite sides of an aramid nanofiber/glass fiber (ANFGF) composite electrolyte and subsequently protonated to enable strong interfacial bonding through the ANF network. The resulting ZHSC‐SPC device demonstrates capacitive charge storage, with areal capacitance scaling linearly with electrode stacking while retaining gravimetric performance. The device delivers a specific capacitance of 72.2 F g −1 , areal capacitance of 1284.3 mF cm −2 , energy density of 516 µWh cm −2 , and power density of 6.2 mW cm −2 , with 76% retention after 500 cycles. Mechanical tests confirm high performance, with a tensile strength of 114 MPa and an elastic modulus of 2.8 GPa, demonstrating suitability for structural energy storage applications.