High-performance Ni-Co-Mn electrocatalyst recovered from spent lithium-ion battery cathode materials for robust oxygen evolution in acid solution

Recovering valuable metals from spent lithium-ion batteries (LIBs) for high value-added application is beneficial for global energy cycling and environmental protection. In this work, we obtain the high-performance N-doped Ni-Co-Mn (N-NCM) electrocatalyst from waste LIBs, for robust oxygen evolution application. Lithium-rich solution and NCM oxides are effectively separated from ternary cathode materials by sulfation roasting and low-temperature water leaching approach, in which the recovery efficiency of Li metal reaches nearly 100%. By facile NH₃ treatment, the incorporation of N into NCM significantly increases the ratio of low-valence state Co²⁺ and Mn²⁺, and the formed Mn—N bond benefits the surface catalytic kinetics. Meanwhile, the N doping induces lattice expansion of the NCM, triggering tensile stress to favor the adsorption of the reactant. Thus, the optimized N-NCM electrocatalyst exhibits the superior overpotentials of 256 and 453 mV to achieve the current density of 10 and 100 mA/cm², respectively, with a low Tafel slope of 37.3 mV/dec. This work provides a fresh avenue for recycling spent LIBs in the future to achieve sustainable development.