Premium
Revealing the Magnesium‐Storage Mechanism in Mesoporous Bismuth via Spectroscopy and Ab‐Initio Simulations
Author(s) -
Xu Xin,
Chao Dongliang,
Chen Biao,
Liang Pei,
Li Huan,
Xie Fangxi,
Davey Kenneth,
Qiao ShiZhang
Publication year - 2020
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.202009528
Subject(s) - bismuth , materials science , mesoporous material , raman spectroscopy , xanes , electrolyte , lithium (medication) , chemical physics , chemical engineering , inorganic chemistry , spectroscopy , chemistry , electrode , organic chemistry , catalysis , medicine , physics , quantum mechanics , engineering , optics , metallurgy , endocrinology
We present mesoporous bismuth nanosheets as a model to study the charge‐storage mechanism of Mg/Bi systems in magnesium‐ion batteries (MIBs). Using a systematic spectroscopy investigation of combined synchrotron‐based operando X‐ray diffraction, near‐edge X‐ray absorption fine structure and Raman, we demonstrate a reversible two‐step alloying reaction mechanism Bi↔MgBi↔Mg 3 Bi 2 . Ab‐initio simulation methods disclose the formation of a MgBi intermediate and confirm its high electronic conductivity. This intermediate serves as a buffer for the significant volume expansion (204 %) and acts to regulate Mg storage kinetics. The mesoporous bismuth nanosheets, as an ideal material for the investigation of the Mg charge‐storage mechanism, effectively alleviate volume expansion and enable significant electrochemical performance in a lithium‐free electrolyte. These findings will benefit mechanistic understandings and advance material designs for MIBs.