副教授
硕士生导师
教师拼音名称:zhangzhonghua
电子邮箱:
所在单位:新能源材料与器件教研室
学历:博士研究生
办公地点:材料学院楼215A
性别:男
联系方式:15092410550
学位:工学博士
职称:副教授
毕业院校:中国科学院大学
学科:材料科学与工程其他专业
材料学移动电话:
邮箱:
2023-09-15 2023 年度山东省优秀研究生导师
2022-12-30 2022年山东省优秀硕士学位论文指导教师
2022-03-01 2021年度校级先进工作者
2020-06-01 2019年度校级先进工作者
最后更新时间:..
关键字:MAGNESIUM; GROWTH; STABILITY; OXIDATION; CATION
摘要:Understanding the electrolyte-metal anode interface passivation mechanism is crucial for the buildup of sustainable and low cost alkali (earth) metal batteries. Trace H2O-assisted Mg2+-anion ion pair decomposition on a model Mg metal electrode is studied here using a nuclear magnetic resonance and cryogenic electron microscopy technique, accompanied by molecular dynamic simulation and density functional theory calculations. The electrolyte chemical species transitions, from [Mg2+(diglyme)(2)](2+) and [Mg2+(diglyme)(2)(TFSI)(-)](+) to [Mg2+(diglyme)(TFSI-)(2)(H2O)](0), [Mg2+(H2O)(n)(TFSI-)](+) (n = 1, 4, 6), and [Mg2+(H2O)(6)](2+), have been unraveled upon introducing trace H2O impurities into the conventional electrolyte. These H2O competitively solvating complexes not only induce the preferential decomposition of anions, but also reduce the cation transference number. The electrodeposits with a primary fractal nano-seaweed morphology and a secondary dendrite-in-ball microstructure were seriously passivated by MgO and Mg(OH)(2) nanocrystals derived from the parasitic reactions of anions and H2O molecules. The reversibility of Mg stripping/plating processes were thus impaired along with the reproducibility of electrochemical experiments. By introducing isobutylamine and trace di-N-butylmagnesium, the ternary electrolytes displayed extra-low overpotential of lower than 0.15 V (similar to 2.0 V for conventional electrolytes) and greatly improved Coulombic efficiency of near 90% (almost irreversible for conventional electrolytes).
卷号:16
期号:3
是否译文:否