Fabrication of environmentally benign cathode materials from cellulose-supported copper oxides for aqueous rechargeable zinc ion batteries

In modern times to meet the energy crisis, cathode material preparation and fabrication is one of the most challenging issues for energy storage devices. In this research, an ecofriendly cellulose template based on a simple route has been adopted to prepare copper oxide nanoparticles (NPs) for the cathode material of aqueous researchable zinc ion batteries (ARZIBs). The formation of CuO NPs has been ascertained by FTIR, XRD, EDX, FESEM, XPS, and TEM. The stoichiometry of the prepared CuO NPs has been found near the standard as confirmed by EDX and XRD analyses. The phase of CuO having a monoclinic unit cell structure and the detailed composition have been established by XRD and XPS, respectively. The cashew nut shape and morphology have been confirmed by FESEM and TEM. The Cu–O bonds in CuO NPs have successfully been assigned from the vibrational spectra of FTIR. The specific surface area, pore size, and volume distribution of porous CuO NPs calcined at 750 °C were estimated by BET analysis. Along with additives, prepared CuO NPs have been used as cathode materials to fabricate CR-2032 coin cells of ARZIBs. The reversible cyclic voltammogram (CV) exhibited better zinc ion storage performance. The fabricated coin cell has offered a high specific discharge capacity of 253.03 mA h/g at 100 mA/g current density and columbic efficiency of 98.28 %. The battery offered a capacity retention of 86.46 and 40.18 % after 100 and 800 charge-discharge cycles, respectively. Low cell resistance has also been evidenced by electrochemical impedance spectroscopy (EIS). This research work offered an eco-friendly, simple, and frugal approach for the preparing cathode material of ARZIBs.