Activation mechanism of conventional electrolytes with amine solvents:Species evolution and hydride-containing interphase formation  

作　　者：Jinlei Zhang Ning Yuan Jing Liu Xiaosong Guo Xi Chen Zhenfang Zhou Zhonghua Zhang Guicun Li 

机构地区：[1]College of Materials Science and Engineering,Qingdao University of Science and Technology,Qingdao 266042,Shandong,China [2]School of Materials Science and Engineering,Tongji University,Shanghai 201804,China [3]Department of Pharmacy,Jining Medical University,Rizhao 276826,Shandong,China [4]Department of Physics,Xi’an Jiaotong-Liverpool University,Suzhou 215123,Jiangsu,China [5]Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education),Nankai University,Tianjin 300071,China

出　　处：《Journal of Energy Chemistry》2024年第11期615-622,共8页能源化学（英文版）

基　　金：National Natural Science Foundation of China (22279068, 51972187);Natural Science Foundation of Shandong Province (ZR2021QE166);Qingdao New Energy Shandong Laboratory Open Project (QNESL OP202312)。

摘　　要：Rechargeable magnesium(Mg)-metal batteries have brought great expect to overcome the safety and energy density concerns of typical lithium-ion batteries.However,interracial passivation of the Mgmetal anode impairs the reversible Mg plating/stripping chemistries,resulting in low Coulombic efficiency and large overpotential.In this work,a facile isobutylamine(IBA)-assisted activation strategy has been proposed and the fundamental mechanism has been unveiled in a specific way of evolving active species and forming MgH_(2)-based solid-electrolyte interphase.After introducing IBA into a typical electrolyte of magnesium bis(trifluoromethanesulfo nyl) imide(Mg(TFSI)_(2)) in diglyme(G2) solvents,electrolyte species of [Mg^(2+)(IBA)5]^(2+) and protonated amine-based cations of [(IBA)H]^(+) have been detected by nuclear magnetic resonance and mass spectra.This not only indicates direct solvation of IBA toward Mg^(2+)but also suggests its ionization,which is central to mitigating the decomposition of G2 and TFSI anions by forming neutrally charged [(IBAH^(+))(TFSI^(-))]~0 and other complex ions.A series of experiments,including cryogenic-electron microscopy,D_(2)O titration-mass spectra,and time of flight secondary ion mass spectrometry results,reveal a thin,non-passivated,and MgH_(2)-containing interphase on the Mg-metal anode.Besides,uniform and dendrite-free Mg electrodeposits have been revealed in composite electrolytes.Benefiting from the activation effects of IBA,the composite electrolyte displays superior electrochemical performance(overpotential is approximately 0.16 V versus 2.00 V for conventional electrolyte;Coulombic efficiency is above 90% versus <10% for conventional electrolyte).This work offers a fresh direction to advanced electrolyte design for next-generation rechargeable batteries.

关 键 词：Rechargeable magnesium batteries Amine solvents IONIZATION MgH_(2)-based solid-electrolyte interphase 

分 类 号：TM912[电气工程—电力电子与电力传动] O646[理学—物理化学]