Structural Insights Into Aluminum‐Doped Manganese Dioxides as Promising Materials for Direct Lithium Extraction: Modeling and Mechanism Study

• DOI: 10.1002/admi.202400912
• Publication Date: 2025-02-11T05:47:05Z
• Authors: Shuxuan Yan; Shaozhen Pei; Xiaodong Li; Zhongyan Luo; Xiangping Chen; Małgorzata Szlachta; Junhua Xu
• Keywords: Chemical sciences; 218; Modeling; Direct lithium extraction; 216; Mechanism; Al-doped manganese dioxide sieves; 540; 620

Abstract This study aimed to provide new insights into lithium (Li) sorption and extraction mechanisms by systematically investigating the structure, surface properties, defect vacancies of both doped undoped manganese oxide sorbents. HMnO Al‐doped sorbents are successfully synthesized, their formulas vacancy ratios determined using X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, thermal gravimetric analysis (TGA), photoelectron (XPS), inductively coupled plasma‐atomic emission (ICP‐AES) characterization. Among materials tested, HMO‐2.5Al exhibited best performance in batch experiments, enhancing Li⁺ 44.49 mg g −1 reducing Mn loss 3.38%. also demonstrated exceptional selectivity simulated brine test, with separation factors α Li Ca , Na K Mg being 3.33, 353.08, 1327.44, 6552.76, respectively. The sorbent displayed sustained durability before after five cycles sorption‐desorption. ion exchange‐surface complexation model is employed investigate titration behavior, pH effects, isotherms, providing mechanism underlying + sorption. A two‐stage proposed, involving a exchange reaction reaction. Overall, synthesized demonstrate significant potential for direct from solutions high concentrations coexisting ions contribute novel field study.