Open AccessLithiation and Magnesiation Mechanism of VOCl: First-Principles Moleculardynamics Simulation
Author(s) -
Dan mei Gao,
Jingren Dong,
Yuan Yuan,
Renchao Xiao,
Liu Yu-ping,
danmei yu,
Changguo Chen,
Aitao Tang,
Dingfei Zhang,
Fusheng Pan
Publication year - 2022
Publication title -
journal of the electrochemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.258
H-Index - 271
eISSN - 1945-7111
pISSN - 0013-4651
DOI - 10.1149/1945-7111/ac682e
Subject(s) - diffusion , electrochemistry , intercalation (chemistry) , cathode , kinetic energy , ion , battery (electricity) , lithium (medication) , metal , range (aeronautics) , chemistry , materials science , thermodynamics , electrode , inorganic chemistry , metallurgy , physics , organic chemistry , quantum mechanics , composite material , medicine , power (physics) , endocrinology
The layered metal oxide VOCl is a kind of promising electrode material for rechargeable batteries. It is the first time that the thermodynamic, electronic, and kinetic properties of lithiated and magnesiated VOCl were systematically investigated. The upper limit of Li and Mg topological intercalation into VOCl is x Li = 1 and x Mg = 0.5, respectively. Beyond the critical value, further lithiation and magnesiation will cause the phase evolution of layered VOCl. Upon lithiation, four discharge plateaus are observed at 2.10, 2.23, 1.62 and 1.23 V vs Li + /Li in the concentration range of 0 ≤ x Li ≤ 1. Upon magnesiation, the average voltage reaches 1.10 V vs Mg 2+ /Mg in the concentration range of 0 ≤ x Mg ≤ 0.25, which are consistent with the experimental values. The pair correlation function (PCF) diagrams display the formation of V metal at high concentration of x Li and x Mg , proving the occurrence of conversion reaction. The diffusion energy barriers of Li ions and Mg ions in VOCl are 0.22 and 0.72 eV, respectively, which are much lower than those of other intercalation materials. The layered VOCl bulk is a high-rate capability cathode material for lithium-ion battery. Based on the thermodynamic/kinetic properties and the AIMD simulation results, the electrochemical mechanism of layered VOCl is an intercalation-conversion reaction during the lithiated and magnesiated processes. The conversion-type cathodes have the potential to circumvent the sluggish solid-state Mg diffusion and improves the performance of Mg rechargeable batteries with high-energy density and high-rate capability.