文献类型：期刊文献

英文题名：Revealing the pH-dependent dissolution mechanism of LiMn2O4/λ-MnO2 redox couple for selective electrochemical lithium extraction

作者：Wang, Penglin[1,2,3];Zhou, Shiyu[1,2,3];Qi, Chenyu[1,2,3];Yao, Xiao[4];Gu, Shuai[1,2,3];Yu, Jianguo[1,2,3]

机构：[1]East China Univ Sci & Technol, Natl Engn Res Ctr Integrated Utilizat Salt Lake Re, Shanghai 200237, Peoples R China;[2]East China Univ Sci & Technol, Engn Res Ctr Salt Lake Resources Proc Engn, Minist Educ, Shanghai 200237, Peoples R China;[3]East China Univ Sci & Technol, Jo l Lab Potassium & Lithium Strateg Resources, Shanghai 200237, Peoples R China;[4]East China Univ Sci & Technol, Sch Chem Engn, Shanghai 200237, Peoples R China

年份：2025

卷号：372

外文期刊名：SEPARATION AND PURIFICATION TECHNOLOGY

收录：;EI(收录号：20251918401179);WOS:【SCI-EXPANDED(收录号:WOS:001492018500002)】；

基金：This work was supported by the National Natural Science Foundation of China [grant number 52304422] , the Major Research Plan of the National Natural Science Foundation of China [grant number 92475207] , Shanghai Rising-Star Program [grant number 24QA2702000] , and the Nature Science Foundation of Shanghai [grant number 22ZR1415800] .

语种：英文

外文关键词：Selective electrochemical lithium extraction; In-situ detector EQCM; Dissolution mechanism; Selective electrochemical lithium extraction; Intrinsic manganese dissolution potentials; LiMn2O4/lambda-MnO2 redox couple; In-situ detector EQCM; Dissolution mechanism

摘要：The selective electrochemical lithium extraction process based on the LiMn2O4/lambda-MnO2 redox couple demonstrated exceptional potential for recovering Li+ from salt-lake brines. However, manganese dissolution remains a critical challenge. This study employs in situ electrochemical quartz crystal microbalance (EQCM) to elucidate intrinsic manganese dissolution potentials (E-i) and pH-dependent manganese dissolution mechanisms. At pH < 5, manganese dissolution occurred spontaneously through H+-induced structural destabilization and spontaneous disproportionation reaction of Mn3+ to Mn2+ and Mn4+, and potential is not the critical parameter, while at pH >= 5 manganese dissolution is dominated by the potential-driven external electron-induced Mn3+ reduction reaction. Two reduction peaks are observed in the voltammetry curves within the pH range of 3-7 and at pH 5 and 7 both peaks are induced exclusively by lithium intercalation, while at pH 3 only the first reduction peak is solely corresponding to lithium intercalation. This research laid the foundation for understanding the manganese dissolution mechanism systematically, thus paving the way for securing the long-term stability, durability, and scalability of the LiMn2O4/lambda-MnO2 redox couple.