Upcycling of spent LiFePO4 cathodes to efficient oxygen evolution electrocatalysts in anion exchange membrane water electrolysis

Abstract

An efficient oxygen evolution reaction electrocatalyst LFP₁G₁₃Ni_0.5Urea_1.5 was innovatively developed by upgrading waste LiFePO₄ and graphite. LFP₁G₁₃Ni_0.5Urea_1.5 showed an overpotential of 283 mV at 10 mA cm⁻² and a Tafel slope of 38.9 mV dec⁻¹, outperforming IrO₂. It achieved 1 A cm⁻² at 1.847 V and 800 h stability at 0.5 A cm⁻² in anion exchange membrane water electrolysis, providing a dual-benefit strategy that simultaneously achieved battery waste valorization and low-cost green hydrogen production.