氯化镁-氯化铝-EMImBF_(4)/有机醚可充镁电池电解液  

MgCl_(2)-AlCl_(3)-EMImBF_(4)/Organic Ether for Rechargeable Magnesium Battery Electrolytes

作　　者：文家新[1] 叶俊镠 魏鑫 杨京东 尹雪娇 李凌杰[3] WEN Jiaxin;YE Junliu;WEI Xin;YANG Jingdong;YIN Xuejiao;LI Lingjie(School of Architectural and Engineering,Chongqing Industry Polytechnic College,Chongqing 401120,China;College of Materials Science and Engineering,Hunan University of Science and Technology,Xiangtan 411201,China;School of Chemistry and Chemical Engineering,Chongqing University,Chongqing 400044,China)

机构地区：[1]重庆工业职业技术学院建筑工程学院,重庆401120 [2]湖南科技大学材料科学与工程学院,湘潭411201 [3]重庆大学化学化工学院,重庆400044

出　　处：《高等学校化学学报》2024年第5期120-128,共9页Chemical Journal of Chinese Universities

基　　金：重庆市教委科学技术研究项目(批准号:KJQN202103202,KJQN202103210,KJZD-K202203203);重庆工业职业技术学院博士研究基金(批准号:2022GZYBSZK2-11)资助.

摘　　要：可充镁电池(RMBs)是下一代最具潜力的储能体系之一,电解液对RMBs的性能具有重要影响.本文通过将1-乙基-3-甲基咪唑鎓四氟硼酸盐(EMImBF_(4))添加到MgCl_(2)+AlCl_(3)电解液(MACC)中,构建了一种MACC-EMImBF_(4)/有机醚(MACCE)可充镁电池电解液体系;采用循环伏安(CV)、线性扫描伏安(LSV)、电化学交流阻抗谱(EIS)和恒流充放电曲线(GCD)等方法测试了MACCE电解液的电化学性能及全电池性能;并通过场发射扫描电子显微镜(FESEM)、X射线衍射仪(XRD)和X射线光电子能谱仪(XPS)对循环后的电极表面进行了分析.结果表明,EMImBF_(4)的添加有效改善了电解液的性能,MgCl_(2)-AlCl_(3)与EMImBF_(4)的最佳摩尔比为5∶1.MACCE电解液的离子电导率为3.94 mS/cm,Mg^(2+)沉积-溶出过电位为59 mV,库仑效率达97.5%以上,氧化稳定电位可达2.8 V(vs.Mg/Mg^(2+))且循环时间超过500 h.MACCE电解液在循环过程中可在Mg负极表面形成一层纳米颗粒层,有助于改善循环稳定性.MACCE电解液与正极材料Mo6S8的兼容性好,Mo6S8|MACCE|Mg全电池的放电平均比容量可达64.4mA∙h/g(12.88mA/g,0.1C),100次循环后比容量保持率可达73.2%.Rechargeable magnesium batteries(RMBs)are considered to be one of the next most promising energy storage systems.The electrolyte has an important influence on the performance of RMBs.The RMBs electrolyte system of MACC-EMImBF_(4)/organic ether(MACCE)was prepared by the addition of 1-ethyl-3-methyl-1H-imidazol-3-ium tetrafluoroborate(EMImBF_(4))into the magnesium aluminum chloride complex(MACC)electrolyte.The electro-chemical performance and full cell performance of the MACCE electrolyte were tested by cyclic voltammetry(CV),linear scanning voltammetry(LSV),electrochemical impedance spectroscopy(EIS),and galvanostatic charge-discharge curves(GCD).The surface of the electrodes with MACCE electrolyte after circulation was analyzed by field emission scanning electron microscopy(FESEM),X-ray powder diffractometry(XRD)and X-ray photoelectron spectroscopy(XPS).The results show that the addition of EMImBF_(4) can effectively improve the electrolyte performance,and the optimum molar ratios of MgCl_(2)-AlCl_(3) to EMImBF_(4) is 5∶1.MACCE electrolyte has superior electrochemical performances with a high ionic conductivity(ca.3.94 mS/cm),a low overpotential(ca.59 mV),a high Coulombic efficiency(more than 97.5%),a high anodic stability[ca.2.8 V(vs.Mg/Mg^(2+))],and a long-term(more than 500 h)cycling stability.The analysis results demonstrate that a nanoparticles layer can be formed on the surface of Mg anode during cycling,which is helpful to improve the cycling stability.Moreover,MACCE displays good compatibility with the Mo6S8 cathode material.The Mo6S8|MACCE|Mg full cell delivers a discharge specific capacity of 64.4 mA∙h/g(12.88 mA/g,0.1C),which can retain ca.73.2%even after 100 cycles.MACCE electrolyte is simple to be prepared,low cost,and can be applied to RMBs,which is of great significance to accelerate the commercial application of RMBs.

关 键 词：可充镁电池 MgCl_(2)+AlCl_(3)电解液 1-乙基-3-甲基咪唑鎓四氟硼酸盐 电化学性能 兼容性 

分 类 号：O646[理学—物理化学]