Hierarchically decorated ZnO/CoOx nanoparticles on carbon fabric for high energy-density and flexible supercapacitors

Exploring the electrochemical performance of metal/metal oxide nanoparticle composites is vital for enhancing the charge storage capability of supercapacitors. Herein, electrodes coated with ZnO/CoOx x are fabricated by soaking cotton fabric seeded with 2-methylimidiazole in an ethylene glycol-based solution containing Zn and Co salts. The use of cotton fabric can reduce textile industrial waste while achieving high capacitance and sustainable energy for wearable electronics. In addition, the three-dimensional network of conductive flexible carbon derived from cotton fabric facilitates rapid ion transport kinetics at interlayers. The concentrations of Zn and Co salts are varied to produce ZnO/CoOx x samples and determine the optimal salt ratio for superior electrochemical performance. The optimal sample exhibits a capacitance of 1.95 F cm-- 2 at 5 mA cm-2 and an energy density of 725 mu Wh & sdot;cm-- 2 over a wide potential window of 1.6 V. The long-term stability test results of the symmetric cells indicate 94 % capacitance retention after 12,000 charge-discharge cycles, emphasizing the advantages of mixed metallic oxides with cellulose-derived carbon fabric for supercapacitor electrodes. This study offers valuable insights into the fabrication of high-performance, flexible, and binder-free supercapacitor electrodes as a scalable alternative for practical applications.