λ-MnO2/PPy复合电极的制备及其电化学辅助锂离子选择性吸附性能  

Preparation and Investigation on Electrochemical Assisted Lithium Recovery Ability of λ-MnO_2/PPy Composite Electrode

作　　者：周游 许鑫 冯志文 梁敏楠 唐阳[1] 孙艳芝[1] 陈咏梅[1] 万平玉[1] ZHOU You;XU Xin;FENG Zhiwen;LIANG Minnan;TANG Yang;SUN Yanzhi CHEN Yongmei;WAN Pingyu(Institute of Applied Electrochemistry, Faculty of Science, Beijing University of Chemical Technology, Beijing 100029, China)

机构地区：[1]北京化工大学理学院,应用电化学研究所,北京100029

出　　处：《河南大学学报（自然科学版）》2018年第3期357-364,共8页Journal of Henan University:Natural Science

基　　金：北京市自然科学基金(2182046)

摘　　要：λ-MnO_2是锂离子选择性吸附材料,适用于从成分复杂锂含量低的盐湖卤水中提取锂,然而这种方法依然存在着吸附平衡时间长、因锰溶损而导致的重复使用性差等问题.将λ-MnO_2制作成电极,通过电化学辅助MnⅢ/MnⅣ转换被认为是提高锂吸附速率的途径之一.为了减少电化学辅助提锂过程中锰溶损现象、提高电极重复使用性能,本研究提出聚吡咯(PPy)包覆λ-MnO_2颗粒制作λ-MnO_2/PPy复合电极.电化学研究结果表明,PPy的包覆提高了LiMn_2O_4颗粒间及其与基体电极之间的导电性,加之PPy包覆层的物理阻隔作用,显著改善了电极中活性物质的提锂效率和重复使用性能.研究结果表明,利用λ-MnO_2/PPy电极进行电化学辅助锂离子提取的效率可达到17.1mg·g^(-1)·h^(-1).λ-MnO2 as a lithium-ion selective adsorbent is suitable for lithium recovery from brine which contains various impurity ions and low concentration of lithium.However,Lithium recovery withλ-MnO2 has suffered from long adsorption equilibrium and poor recyclability caused by manganese loss.The electrochemically assisted MnⅢ/MnⅣconversion is considered as one of the ways to accelerate the process of lithium extracting/releasing by usingλ-MnO2 electrode in a battery system.In order to reduce the manganese loss during electrochemically assisted extraction of lithium and improve the recyclability of the electrode,we introduced polypyrrole（PPy）coated on the surface ofλ-MnO2 and applied this composite on to the electrode.Electrochemical studies show that the PPy coating,improving the electrical conductivity between the LiMn2O4 particles and substrate and the physical barrier effect of the PPy coating,significantly improving the lithium extraction efficiency and reusability of the electrode.It shows that the efficiency of electrochemical assisted lithium ion extraction withλ-MnO2/PPy electrode can reach 17.1 mg·g^-1·h^-1.

关 键 词：λ-MnO2/PPy复合电极 电化学辅助提锂 聚吡咯包覆 盐湖提锂 Mn^Ⅲ/Mn^Ⅳ转化 

分 类 号：O657.1[理学—分析化学]