文献类型：期刊文献

英文题名：Effects of Kinetic Dielectric Decrement on Ion Diffusion and Capacitance in Electrochemical Systems

作者：Qing, Leying[1,2];Lei, Jun[1,2];Zhao, Teng[1,2];Qiu, Genlong[3];Ma, Manman[4];Xu, Zhenli[5,6];Zhao, Shuangliang[1,2,3]

机构：[1]East China Univ Sci & Technol, State Key Lab Chem Engn, Shanghai 200237, Peoples R China;[2]East China Univ Sci & Technol, Sch Chem Engn, Shanghai 200237, Peoples R China;[3]Guangxi Univ, Guangxi Key Lab Petrochem Resource Proc & Proc In, Nanning 530004, Peoples R China;[4]Tongji Univ, Sch Math Sci, Shanghai 200092, Peoples R China;[5]Shanghai Jiao Tong Univ, Sch Math Sci, Inst Nat Sci, Shanghai 200240, Peoples R China;[6]Shanghai Jiao Tong Univ, MoE Key Lab Sci & Engn Comp, Shanghai 200240, Peoples R China

年份：2020

卷号：36

期号：15

起止页码：4055

外文期刊名：LANGMUIR

收录：;EI(收录号：20202108674742);WOS:【SCI-EXPANDED(收录号:WOS:000527781700008)】；

基金：This work is supported by the National Natural Science Foundation of China (Nos. 91934302, 11571236, 21773165, and 11701428). M.M. acknowledges the "Chen Guang" project by the Shanghai Municipal Education Commission and Shanghai Education Development Foundation and the Fundamental Research Funds for the Central Universities. L.Q. is grateful to the China Scholarship Council.

语种：英文

外文关键词：Ions - Density functional theory - Diffusion - Electrolytes

摘要：Diffusion of ionic components in electrolytes not only eliminates the gradients of ionic concentrations but also alters the local dielectric environment, and the coupling effect between kinetic dielectric decrement and ionic concentration gradient on the diffusion dynamics is not well understood. Herein, taking the charging process in electrical double layer systems as a case study, we conduct a multiscale investigation of ion diffusions in aqueous electrolytes by combining the dynamic density functional theory and an ion-concentration-dependent dielectric constant model. By properly considering the time evolutions of local dielectric constant coupled with ion density, we report an interesting phenomenon on the suppression of surface charge density that is not captured by conventional models. In addition, we show that the usage of aqueous electrolyte with small dielectric decrement coefficients promotes the capacitance, in quantitative agreement with experimental measurements.