Lithium-ion Battery Waste as a Robust Oxygen Evolution Reaction Electrocatalyst for Seawater Splitting

Electrocatalytic seawater splitting seems to be the most promising and urgent demand strategy for clean hydrogen energy production. Utilizing low-cost electrocatalysts is pivotal in the hydrogen economy, as seawater splitting can be made highly efficient and more economical. To meet these expectations, we proposed using lithium-ion battery waste, the black carbon mass left over from hydrometallurgical metal recovery, as an efficient and stable electrocatalyst for oxygen evolution reaction (OER) performed in alkaline media. The SEM-EDS, XPS, XRD, XRF, and Raman analyses revealed that the composition and structure of the post-leached battery powders depend on the hydrometallurgical waste recycling conditions, which in turn affects their OER electrocatalytic activity. The electrochemical tests proved that Li-ion battery waste has remarkable OER catalytic performance with an overpotential of 344 mV and 239 mV, reaching 10 mA cm ^-2 in water splitting and in seawater splitting, respectively, which is only less than 85 mV and 100 mV higher than for benchmark RuO ₂ in water splitting and seawater splitting, respectively.