Zr-modified LiMn₂O₄-based film electrode with enhanced electrical conductivity and structural stability for electrochemical lithium extraction from brine lakes

Abstract

The limited structural stability and intrinsic electronic conductivity of LiMn₂O₄ (LMO) remain key challenges hindering its application in electrochemically switched ion-exchange (ESIX)-based lithium extraction. In this study, a zirconium- modified LiMn₂O₄ (LZMO) film electrode was developed for selective lithium extraction from brine. Combined experimental and density functional theory analyses revealed that Zr modification simultaneously enhanced electronic conductivity and structural stability by tuning the electronic structure and strengthening Mn-O hybridization. The modulation of the electronic structures accelerated charge transfer and elevated the electrochemical kinetics. In addition. the optimized local coordination of Mn-O lowered the proportion of Mn³⁺ and strengthened metal-oxygen bonding, which effectively suppressed Mn dissolution and improved structural integrity. For treating the real brine (Qarhan Salt Lake), the lithium intercalation capacity of the optimized LZMO-0.03 film electrode reached 22.16 mg·g^–1, and the energy consumption for lithium extraction was only 3.61 Wh·mol^–1 under constant current-constant voltage mode. The calculated separation factor for Li/Mg is as high as 685.43. After 20 successive intercalation-deintercalation cycles, Mn dissolution decreased to approximately 51.8% of that of the pristine LMO electrode. This study provides a feasible strategy for balancing the structural stability and electrochemical kinetics of LMO-based electrodes, thereby guiding the design of advanced electrochemical lithium extraction materials.

Keywords

zirconium modification / LiMn₂O₄ / electrochemically switched ion exchange / modified film electrode / lithium extraction

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Higher Education Press 2026

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