Recycling spent battery components into highly efficient hydrogen and oxygen evolution electro-nano-catalysts

Inspired by the 'waste-to-resource' strategic theme for environmental recovery, here we present the recycling of spent dry cells and spent Lithium-ion batteries aiming to achieve the preparation of cheap and efficient electrocatalysts for Proton Exchange membrane electrolyzers instead of the precious-based electrocatalysts. Graphite doped with manganese (IV) oxide nanoparticles, graphite doped with manganese (IV) oxide and aluminum oxide nanoparticles, lithium cobalt oxide doped with copper oxide nanoparticles, and lithium cobalt oxide doped with copper oxide and zinc oxide nanoparticles synthesis procedures are done via hydrothermal method at a pressure of 4.5 Mpa at 180 ^○C. Electrochemical characterization is done to determine overpotential, tafel slope, and electrocatalytic stability via a three-electrode system. The optimum results are observed by the graphite doped with manganese (IV) oxide nanoparticles, which show -55.06 mV and -41.33 mV/dec as overpotential and tafel slope at -10 mA/cm² for hydrogen evolution reaction with surface area of 40.87 m²/g and 21.05 nm as crystal size and Graphite doped with manganese oxide and aluminum oxide nanoparticles, which show 321.58 mV and 174.14 mV/dec as overpotential and Tafel slope for oxygen evolution reaction at 10 mA/cm² with surface area of 7.64 m²/g and 44.43 nm as crystal size.