Tailoring Mg 2+ Solvation Structure in a Facile All-Inorganic [Mg x Li y Cl 2x+y · n THF] Complex Electrolyte for High Rate and Long Cycle-Life Mg Battery

Energy & Environmental Materials

article

Haiyan Fan¹  Xinxin Zhang¹  Yuxing Zhao¹  Jianhua Xiao¹  Hua Yuan¹  Guang Wang¹  Yitao Lin¹  Jifang Zhang¹  Ludi Pan¹  Ting Pan¹  Yang Liu¹  Yuegang Zhang¹ 

[1] State Key Laboratory of Low-Dimensional Quantum Physics, Department of Physics, Tsinghua University

关键词: cycle life;    electrolyte;    Mg battery;    solvation structure;   

DOI  :  10.1002/eem2.12327

来源: Wiley

【 摘 要 】

A high-performance all-inorganic magnesium–lithium chloride complex (MLCC) electrolyte is synthesized by a simple room-temperature reaction of LiCl with MgCl2 in tetrahydrofuran (THF) solvent. Molecular dynamics simulation, density functional theory calculation, Raman spectroscopy, and nuclear magnetic resonance spectroscopy reveal that the formation of [MgxLiyCl2x+y·nTHF] complex solvation structure significantly lowers the coordination number of THF in the first solvation sheath of Mg2+, which significantly enhances its de-solvation kinetics. The MLCC electrolyte presents a stable electrochemical window up to 3.1 V (vs Mg/Mg2+) and enables reversible cycling of Mg metal deposition/stripping with an outstanding Coulombic efficiency up to 99% at current densities as high as 10 mA cm−2. Utilizing the MLCC electrolyte, a Mg/Mo6S8 full cell can be cycled for over 10 000 cycles with a superior capacity retention of 85 mA h g−1 under an ultrahigh rate of 50 C (1 C = 128.8 mA g−1). The facile synthesis of high-performance MLCC electrolyte provides a promising solution for future practical magnesium batteries.

【 授权许可】

Unknown