Flexible, compressible, versatile biomass-derived freestanding carbon monoliths as binder- and substrate-free tri-functional electrodes for solid-state zinc-air batteries and overall water splitting

Highly flexible and compressible biomass-derived freestanding monoliths are directly utilized as binder-and substrate-free tri-functional electrodes for the wearable electronic devices. The introduction of Co nanoparticles, nanoclusters, and single atoms onto biomass-derived monoliths leads to the additional growth of CNTs for ensuring the interconnectivity of 3D cellulose-derived carbon network. Thus, superb flexibility and/or compressibility as well as high-efficiency tri-functional activity are achieved simultaneously. The alkaline water electrolyzer with monolithic electrodes requires only a potential of 1.56 V to generate hydrogen at a current density of 50 mA cm(-2) for over 120 h. Furthermore, the quasi-solid-state zinc-air batteries(ZABs) exhibit a high peak power density of 175.5 mW cm(-2), and an optimal charge-discharge overpotential with a remarkably small voltage gap (delta V) of 0.27 V at 5 mA cm(-2). The excellent charge-discharge cycle stability even under bending and compression conditions demonstrates its high potential for emerging next-generation electronics devices.

Automated summary

This study utilizes highly flexible and compressible biomass-derived freestanding monoliths as binder-and substrate-free tri-functional electrodes. The introduction of Co nanoparticles, nanoclusters, and single atoms onto the monoliths leads to the additional growth of CNTs, ensuring the interconnectivity of 3D cellulose-derived carbon network. The monolithic electrodes demonstrate excellent performance in alkaline water electrolyzer and quasi-solid-state zinc-air batteries, indicating their high potential for emerging next-generation electronics devices.