<p>Metal-incorporated oxy-carbide nanostructures are pondered as a potential material for future-generation energy storage, conversion, and harvesting devices. Here, we proposed the synthesis of porous boron-oxy-carbide (PBOC) nanosheets via a hydrothermal-assisted annealing process and revitalized their utilization in wearable electrochemical supercapacitor devices. Physiochemical analysis, such as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET), and high-resolution transmission electron microscopy (HR-TEM) analysis, revealed the formation of PBOC nanosheets and further coating on carbon cloth (CC) electrodes for wearable supercapacitor (WESC) fabrication. The fabricated WESC using PBOC nanosheets exhibited better capacitive behavior with superior device capacitance of (121.82 F g⁻¹ and 304.56 mF cm⁻²), excellent energy density (43.31 Wh kg⁻¹ and 0.16 mWh cm⁻²) with better cyclic life over 10,000 prolonged cycles. Further, the PBOC-CC WESC revealed an extraordinary rate capacity with excellent self-discharge behavior and high-power density of (16,000 W kg⁻¹ and 1.6 mW cm⁻²) compared to state-of-the-art WESCs. In addition, we displayed a self-powered energy system by integrating solar cells with the PBOC-CC WESC to prove its ability in wearable devices. These cumulative results suggest the priority of PBOC nanosheets as a potential electrode material that may be suitable for application in upcoming electrochemical wearable technology.</p> Graphical Abstract <p></p>