Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Science, Shenyang 110016, China.
Engineering Laboratory for Functionalized Carbon Materials, Shenzhen Key Laboratory for Graphene-based Materials, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, China and Laboratory of Advanced Materials, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China.
Chem Commun (Camb). 2019 Oct 31;55(88):13211-13214. doi: 10.1039/c9cc07092c.
Slowing the dendrite formation process is one way to alleviate the fast capacity fade and safety issues in lithium metal battery systems. We used tetraethylene glycol dimethyl ether (TEGDME) as a complementary solvent to increase the desolvation activation energy of Li+, reduce the speed of lithium electrodeposition kinetics, and suppress dendrite formation. Density functional theory calculations combined with Raman spectroscopy indicate that a stronger coordination interaction is obtained between Li+ and TEGDME than between Li+ and 1,2-dimethoxyethane (DME) or 1,3-dioxolane (DOL). Such a strong coordination leads to a slower electrochemical reaction rate. As a result, uniform lithium electrodeposition morphology and good cycling stability of a Li|Li symmetric cell for more than 500 hours were achieved. Our approach suggests a way in which dendrite formation can be controlled by the electrochemical reaction itself.
减缓枝晶形成过程是缓解锂金属电池系统中快速容量衰减和安全问题的一种方法。我们使用四乙二醇二甲醚（TEGDME）作为补充溶剂，以增加锂离子的去溶剂化活化能，降低锂电镀动力学的速度，并抑制枝晶形成。密度泛函理论计算结合拉曼光谱表明，锂离子与 TEGDME 的配位相互作用强于锂离子与 1,2-二甲氧基乙烷（DME）或 1,3-二氧戊环（DOL）的配位相互作用。这种强配位作用导致电化学反应速率较慢。结果，实现了具有超过 500 小时的均匀锂电镀形态和良好循环稳定性的 Li|Li 对称电池。我们的方法表明，可以通过电化学反应本身来控制枝晶形成。
