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[Display omitted] • E-waste can be strategically converted into energy-storing electrodes. • Interesting core–shell morphology is formed by a facile two-step synthesis process. • The optimized NiSe-120/Cu 4 O x -3 electrode shows an areal capacity of 138.27 µAh cm−2. • Excellent stability is achieved even after 50,000 charge–discharge cycles. • The C-type HSC device exhibits a good areal capacitance of 233.1 mF cm−2. Recently, for energy storage materials, various surfactant-less synthesis methods have been attaining extensive attention from researchers. Herein, we utilized the wasted desoldering copper wicks (E-waste) as the base substrate to synthesize hierarchical core–shell maze-corn-like nickel selenide/copper oxide (NiSe/Cu 4 O x) architectures by a facile two-step synthesis process. Initially, the Cu 4 O x nanorods (NRs) were grown directly over the surface of the flat braided E-waste copper wicks by thermal oxidation, followed by a facile electrodeposition method to coat the pre-existing Cu 4 O x NRs with NiSe nanoparticles. The optimized NiSe-120/Cu 4 O x -3 electrode exhibited superior electrochemical characteristics (138.27 µAh cm−2 at 4 mA cm−2) compared to the other electrodes, owing to the contribution of core and shell materials, and sustained an ultra-long cycling test of 50,000 charge/discharge cycles with an excellent capacity retention of 98.7%. Inspired by commercially available AA battery, the as-synthesized working electrode was coupled with activated carbon-coated nickel foam to fabricate a cylindrical-type (C-type) hybrid supercapacitor (HSC) device, with an areal capacitance of 233.1 mF cm−2 accompanied by an extraordinary cycling efficiency of 99.1%. Furthermore, the C-type HSC device exhibited maximum energy and power densities of 70.9 µWh cm−2 and 14,000 µW cm−2, respectively and it was tested by powering portable electronics for real-time application. [ABSTRACT FROM AUTHOR]