An electrochemical strategy to fabricate MnOx thin film from spent batteries for pseudocapacitive applications

Nanoscale design of 1D metal oxides derived from mixed Ni-MH battery/transition metal dust

Controllable recycling of End-of-life rechargeable nickel-metal hydride (Ni-MH) batteries and by-products of steelmaking to added-value functional nanostructures is desired but challenging. The present work introduces an innovative and high-yield microrecycling strategy to simultaneous synthesis of TM alloy (i.e., Ni-based superalloy) and RE oxide (REO) nanostructures from obsolete Ni-MH batteries mixed with zinc-rich electric arc furnace dust (EAFD). This strategy involves integration of high-temperature thermal isolation followed by thermal nanowiring techniques. The impure thermally-isolated REOs were purified and transformed into one dimensional (1D) nanorods of hybrid REOs. Besides, during high-temperature thermal isolation, defect-rich ZnO with tailored structures of nanorods and nanoribbons were fabricated using controllable vapour deposition. The electrochemical performance of ZnO nanoribbons for oxygen evolution reaction (OER) revealed a considerable overpotential reduction of 131 mV (18%) compared to pure commercial nano-ZnO. This approach is transformational in providing a scalable and cost-effective pathway to facilitate recycling of the challenging, yet critical, waste materials into functional nanostructures for energy and environmental applications.