Nanostructured Co3O4 Asymmetrically Deposited on a Single Carbon Cloth for an All-Solid-State Integrated Hybrid Device with Reversible Zinc-Air High-Energy Conversion and Asymmetric Supercapacitive High-Power Delivery

Hybrid energy devices combining multiple energy components based on different mechanisms can provide a more comprehensive output performance than individual ones. However, past attempts of connecting separate parts through additional wire connections have limitations of low energy efficiency and bulky system formation. Herein, we develop a hybrid energy device that integrates a rechargeable zinc-air battery and an asymmetric supercapacitor on a single carbon-cloth-based platform. Nanostructured Co3O4 is asymmetrically deposited in different regions of the carbon cloth to obtain bi-functions as pseudocapacitive positive electrode and catalytic air electrode. A moisturizing gel polymer electrolyte is also used to make the device integrative, compact, and flexible. A working mechanism and an operation strategy of repeated in situ charging of the supercapacitor part by the zinc-air battery part and external recharging of the zinc-air battery part are proposed and evaluated with demonstration of powering a vibration motor. The developed hybrid energy device can be self-charged to 1.15 V in 200 s followed by delivering a peak power density of 7.91 mW cm–2 for 50 repeated cycles and be fully recharged by an external power source again. Thus, both zinc-air high-energy conversion and asymmetric supercapacitive high-power delivery are simultaneously achieved on such a single device, which has a potential use in portable and wearable electronic applications.