Overcoming polarization and dissolution of manganese-based electrodes to enhance stability in electrochemical lithium extraction

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2024-10, Vol.497, p.155009, Article 155009
• Main Authors: Qiao, Yingjun, Ran, Yonggan, Qian, Zhiqiang, Zhao, Bing, Li, Chengpeng, Liu, Zhong
• Format: Article
• Language: English
• Subjects: Disproportionation reactions; Electrochemistry stability; Li+ extraction; Lithium manganese oxide; Polarization; Salt lake
• ISSN: 1385-8947
• DOI: 10.1016/j.cej.2024.155009

[Display omitted] •rGO reduces electrode polarization and enhances surface properties.•−SO3- in Nafion efficiently captures dissolved Mn2+, inhibiting further reactions.•The synergy of rGO and Nafion significantly enhances the lifespan of Mn-based electrodes. The Mn dissolution issue in manganese-based materials (LMO) represents one of the most challenging barriers to further commercial development of electrochemical lithium extraction, which is an efficient and clean way of extracting Li from liquid resources. Here, by leveraging the advantages of composite materials, a novel combination of reduced graphene oxide (rGO) and sulfonated ionic polymers (Nafion) is introduced to relieve the issues of electrode polarization and manganese dissolution, critical factors limiting the durability of LMO electrodes. By modifying with rGO to enhance electronic conductivity and surface characteristics, and capturing dissolved Mn2+ through Nafion, the modified electrode showed significant improvement in cycling stability and lithium adsorption capacity. Experimental results confirm that this synergistic approach effectively mitigates polarization effects and controls disproportionation reactions, thereby enhancing the stability of the lithium extraction process, revealing a notable increase in electrode capacity retention from 79.04 % to 94.64 % after 30 cycles. Additionally, through DFT calculations and XPS analysis, the effectiveness of the manganese capture strategy is validated. This work presents an effective new strategy to extend the lifespan of manganese-based electrodes and enhance their adsorption performance.