<p>Aqueous zinc-ion capacitors are currently drawing attention for advanced energy storage applications, primarily because of their exceptional safety performance, environmental sustainability, and overall economic value. Hydrogel electrolytes are promising candidates for the construction of zinc-ion hybrid supercapacitors. However, most of the previously reported hydrogel electrolytes suffer from insufficient mechanical strength and limited fatigue resistance. In this study, Cu²⁺ modification was introduced into a dual-physically and chemically crosslinked car-boxymethyl cellulose/chitosan (CC) gel polymer electrolyte to yield a Cu²⁺-CC gel. Coordination between Cu²⁺ and functional groups (— OH, —COO⁻, and —NH₂) substantially improved the mechanical properties of the electrolyte, demonstrating a maximum tensile stress of (7.20±0.52) MPa. The resulting Cu²⁺-CC gel possesses a porous architecture, along with high ionic conductivity (31.25±0.76 mS·cm⁻¹ at ambient temperature), a wide electrochemical stability window (2.54 V), and a high exchange current density (1.38 mA·cm⁻²). The zinc-ion hybrid supercapacitor assembled with this electrolyte retained 95.2% over 38000 charge-discharge cycles at 1 A·g⁻¹. Furthermore, the assembled device demonstrated remarkable operational stability even under severe mechanical deformation, including bending from 0° to 180°.</p>