Ascorbic acid treatment of laterite nickel ore to prepare a spinel-structured lithium-ion battery anode

Abstract

The concentrated sulfuric acid leachate of laterite nickel ore was treated with ascorbic acid as the leaching agent to regulate the valence states of metals. Ascorbic acid treatment was combined with component separation and a regulatory strategy to prepare a multi-metallic spinel-structured lithium-ion battery anode, G-FNMMA, directly. The anode material consisted of multiple spinel phases, as represented by (Fe, Ni, Mn, Mg, and Al)O₄. It had a stable microspherical structure with a gradient architecture. Characterization by XRD, SEM, TEM, and XPS indicated that this structure and crystal defects of the anode material favored electrochemical activity. Electrochemical tests proved that upon the first discharge, the specific capacity of the optimal sample G-FNMMA[Fe5] reached 1121.2 mAh g⁻¹. The material still maintained a reversible capacity of 740.2 mAh g⁻¹ after 500 cycles at a current density of 1000 mA g⁻¹, indicating excellent cycling stability and rate performance. The anode's exceptional performance was mainly attributed to the high stability of the spinel structure and the dominance of pseudo-capacitive lithium-ion storage. The direct transformation of laterite nickel ore into a high-performance lithium-ion battery anode was studied in detail to substantiate a new, feasible pathway for the high-value, green utilization of laterite nickel ore and smelting solid waste.