摘要
Currently,the iron chromium redox flow battery(ICRFB)has become a research hotspot in the energy storage field owing to its low cost and easily-scaled-up.However,the activity of electrolyte is still ambiguous due to its complicated solution environment.Herein,we performed a pioneering investigation on the coordination behavior and transformation mechanism of Cr^(3+)in electrolyte and prediction of impurity ions impact through quantum chemistry computations.Based on the structure and symmetry of electrostatic potential distribution,the activity of different Cr^(3+)complex ions is confirmed as[Cr(H2O)5Cl]^(2+)>[Cr(H2O)4Cl2]+>[Cr(H2O)6]^(3+).The transformation mechanism between[Cr(H2O)6]^(3+)and[Cr(H2O)5Cl]^(2+)is revealed.We find the metal impurity ions(especially Mg^(2+))can exacerbate the electrolyte deactivation by reducing the transformation energy barrier from[Cr(H2O)5Cl]^(2+)(24.38 kcal mol^(−1))to[Cr(H2O)6]^(3+)(16.23 kcal mol^(−1)).The solvent radial distribution and mean square displacement in different solvent environments are discussed and we conclude that the coordination configuration limits the diffusivity of Cr^(3+).This work provides new insights into the activity of electrolyte,laying a fundamental sense for the electrolyte in ICRFB.
基金
Fundamental Research Funds for the Central Universities(2023MS125)。
作者简介
Xiaojun Zhao received his Ph.D.degree from North China Electric Power University(NCEPU)in 2011 and was a visiting scholar at Griffith University and Graz University of Technology.Since 2021,he has been working at the Department of Electrical Engineering of NCEPU as a professor.His major research focuses on key materials of high-performance flow batteries and lithium batteries and energy storage technology applications in new energy power systems;Corresponding author:Hao Li received his Ph.D.degree from the University of Texas at Austin in 2019 and then was a postdoctoral researcher at the Catalysis Theory Center at the Technical University of Denmark.Since 2022,he has been working at the Advanced Institute for Materials Research(WPI-AIMR)of Tohoku University as an associate professor and group leader.His major research focuses on the development of materials theory and the development of computation methods based on artificial intelligence.E-mail:li.hao.b8@tohoku.ac.jp;Corresponding author:Weijie Yang received his Ph.D.degree from North China Electric Power University(NCEPU)in 2019.Since 2022,he has been working at the Department of Energy Power and Mechanical Engineering of NCEPU as an associate professor.He became the director of the Teaching and Research Section of Hydrogen Energy Science and Engineering in 2022.He was selected for 2023 Stanford's List of World's Top 2%Scientists.His major research focuses on DFT and ML for hydrogen storage materials and advanced catalysis,E-mail:yangwj@ncepu.edu.cn。
