Waste to treasure: A sustainable technic to prepare high-performance lithium iron phosphate from laterite nickel tailings

The abundance of laterite nickel tailings after nickel extraction not only generate severe environmental contamination but also result in significant waste of metal resources, particularly iron (Fe). Herein, a promising technic of recycling tailings to high-value Fe-based energy storage materials is developed to address above challenges. The traditional hydrometallurgy is firstly applied to leach Fe source from laterite nickel tailings. By referencing the Eh-pH thermodynamic stability phase diagram of the phosphorus system, Fe could be preferentially precipitated in various metal elements, enabling the effective extraction of Fe as raw iron phosphate (FePO4). Notably, a two-step purification strategy is designed to remove residual impurity and adjust Fe/P ratio, subsequently obtaining the high-purity battery-grade FePO4. Finally, a solid-phase method is conducted to prepare nano lithium iron phosphate (LiFePO4) with outstanding electrochemical performance (1C > 150 mAh/g), meeting rigorous commercial standards. Economic analysis further confirms the significant value of implementing this scalable recycling technic, and the potential industrial application is highly anticipated. Thus, this research proposes a sustainable tailings recovery methodology, offering valuable insights for the recycling of other Fe-containing resources.