摘要
Li-Mg合金作为锂电池负极材料在新能源领域中具有广阔的应用前景,熔盐电解法制备Li-Mg合金极具优势。本文采用三电极体系研究了Mg2+在LiCl-KCl-MgCl_(2)熔体中钨电极上的电化学行为及Li-Mg共沉积机理,探究了MgCl_(2)浓度对电解共沉积Li-Mg的影响。方波伏安法与计时电流法实验结果表明:Mg2+在钨电极上一步两电子还原为金属Mg,属于瞬时成核过程,不受温度的影响。计时电位法实验结果表明:随着MgCl_(2)浓度的增加,LiCl-KCl-MgCl_(2)熔体电解共沉积Li-Mg所需的阴极电流密度逐渐增大。当LiCl-KCl-MgCl_(2)熔体中MgCl_(2)浓度为5%时,实现Li-Mg共沉积的最小阴极电流密度为0.287 A/cm^(2)。恒电流电解结果表明:当MgCl_(2)浓度≤5%时,Li-Mg产品中金属Mg含量随着熔体中MgCl_(2)浓度的增加而增大,当MgCl_(2)浓度达到10%时,电解仅得到金属Mg。
Li-Mg alloys,as cathode materials for lithium batteries,have broad application prospects in the field of new energy,and the preparation of Li-Mg alloys by molten salt electrolysis has great advantages.The electrochemical behavior of Mg^(2+)on a tungsten electrode in LiCl-KCl-MgCl_(2)melt and the Li-Mg co-deposition process were studied by a three-electrode system,respectively.The effect of MgCl_(2)concentration on electrolytic co-deposition of Li-Mg was also investigated.The experimental results of square wave voltammetry and timing current method show that the one-step two electrons reduction of Mg^(2+)to metallic Mg on the tungsten electrode is an instantaneous nucleation process,which is not affected by temperature.The results of the timing potentiometric experiment show that with the increasing concentration of MgCl_(2),the cathodic current density required for the electrolytic co-deposition of Li-Mg from LiCl-KCl-MgCl_(2)melt is gradually increased.When the MgCl_(2)concentration in the LiCl-KCl-MgCl_(2)melt is 5%,the minimum cathodic current density to achieve Li-Mg co-deposition is 0.287 A/cm^(2).The galvanostatic electrolysis results show that when the MgCl_(2)concentration is less than or equal to 5%,the metal Mg content in the Li-Mg product increases with MgCl_(2)concentration in the melt.When the MgCl_(2)concentration reaches 10%,electrolysis only obtains metal Mg.
作者
张远景
刘兆庭
朱实贵
路贵民
ZHANG Yuanjing;LIU Zhaoting;ZHU Shigui;LU Guimin(National Engineering Research Center for Integrated Utilization of Salt Lake Resources,East China University of Science andTechnology,Shanghai 200237,China;Joint International Laboratory for Potassium and Lithium Strategic Resources,Shanghai200237,China;Fengxin Ganfeng Lithium Industry Co.,Ltd.,Yichun 336000,Jiangxi,China)
出处
《有色金属科学与工程》
CAS
北大核心
2023年第3期311-317,共7页
Nonferrous Metals Science and Engineering
基金
国家自然科学基金资助项目(U20A20147)。
