Explorations into new electrolytes have highlighted the critical impact of solvation structure on battery performance,Classical molecular dynamics(CMD)using semi-empirical force fields has become an essential tool for...Explorations into new electrolytes have highlighted the critical impact of solvation structure on battery performance,Classical molecular dynamics(CMD)using semi-empirical force fields has become an essential tool for simulating solvation structures.However,mainstream force fields often lack accuracy in describing strong ion-solvent interactions,causing disparities between CMD simulations and experimental observations.Although some empirical methods have been employed in some of the studies to address this issue,their effectiveness has been limited.Our CMD research,supported by quantum chemical calculations and experimental data,reveals that the solvation structure is influenced not only by the charge model but also by the polarization description.Previous empirical approaches that focused solely on adjusting ion-solvent interaction strengths overlooked the importance of polarization effects.Building on this insight,we propose integrating the Drude polarization model into mainstream force fields and verify its feasibility in carbonate,ether,and nitrile electrolytes.Our experimental results demonstrate that this approach significantly enhances the accuracy of CMD-simulated solvation structures.This work is expected to provide a more reliable CMD method for electrolyte design,shielding researchers from the pitfalls of erroneous simulation outcomes.展开更多
The elucidation of the multi-scale transport phenomena of lithium ions in solid electrolyte under working conditions poses huge challenges to both experimental and theoretical realms.Highresolution ab initio molecular...The elucidation of the multi-scale transport phenomena of lithium ions in solid electrolyte under working conditions poses huge challenges to both experimental and theoretical realms.Highresolution ab initio molecular dynamics simulations are severely limited by spatial and temporal scales,hindering direct comparisons with experimental observations under room temperature and applied electric potential.Herein,classical molecular dynamics simulations under constant potential are employed to unveil the migration mechanism of Li-ions in Li_(6)PS_(5)Cl(LPSC)confined by electrode interfaces considering realistic conditions.By sophisticated manipulation of anion compositions in LPSC electrolyte,it is observed that neighboring vacancies provide effective pathways for Li-ions migration and the coordination environments evolves progressively with increasing diffusion coefficient,while the conductivity exhibits a non-monotonic peak in Li_(5.3)PS_(4.3)Cl_(1.7).The semiquantitative agreement with existing experimental resultsdemonstrates the superiority of our constant potential solid electrolytemodel,which weexpect to provide atomistic understanding towards rational design of solid electrolyte.展开更多
Classical molecular dynamics simulation has been widely used to study the rapid cooling process of preparing amorphous alloys.However,the simulated cooling rate is several orders of magnitude higher than the experimen...Classical molecular dynamics simulation has been widely used to study the rapid cooling process of preparing amorphous alloys.However,the simulated cooling rate is several orders of magnitude higher than the experimental cooling rate.In this paper,Zr_(55)Cu_(35)Al_(10)alloy was taken as an example.It is found that adding isothermal annealing at a temperature slightly lower than Tand prolonging isothermal annealing time could effectively reduce the cooling rate.The glassy sample prepared in this way demonstrates significant energetic stability and well-developed short-range and medium-range order.展开更多
基金supported by the Science and Technology Project of State Grid Corporation of China(5419-202199552A-0-5-ZN).
文摘Explorations into new electrolytes have highlighted the critical impact of solvation structure on battery performance,Classical molecular dynamics(CMD)using semi-empirical force fields has become an essential tool for simulating solvation structures.However,mainstream force fields often lack accuracy in describing strong ion-solvent interactions,causing disparities between CMD simulations and experimental observations.Although some empirical methods have been employed in some of the studies to address this issue,their effectiveness has been limited.Our CMD research,supported by quantum chemical calculations and experimental data,reveals that the solvation structure is influenced not only by the charge model but also by the polarization description.Previous empirical approaches that focused solely on adjusting ion-solvent interaction strengths overlooked the importance of polarization effects.Building on this insight,we propose integrating the Drude polarization model into mainstream force fields and verify its feasibility in carbonate,ether,and nitrile electrolytes.Our experimental results demonstrate that this approach significantly enhances the accuracy of CMD-simulated solvation structures.This work is expected to provide a more reliable CMD method for electrolyte design,shielding researchers from the pitfalls of erroneous simulation outcomes.
基金supported by the National Key Research and Development Program of China (No. 2021YFF0500600)Natural Science Foundation of Henan Province (No. 242300421129, 252300421176 and 232301420051)National Natural Science Foundation of China (No. 22478361). The computations were performed at National Supercomputing Center in Zhengzhou, China.
文摘The elucidation of the multi-scale transport phenomena of lithium ions in solid electrolyte under working conditions poses huge challenges to both experimental and theoretical realms.Highresolution ab initio molecular dynamics simulations are severely limited by spatial and temporal scales,hindering direct comparisons with experimental observations under room temperature and applied electric potential.Herein,classical molecular dynamics simulations under constant potential are employed to unveil the migration mechanism of Li-ions in Li_(6)PS_(5)Cl(LPSC)confined by electrode interfaces considering realistic conditions.By sophisticated manipulation of anion compositions in LPSC electrolyte,it is observed that neighboring vacancies provide effective pathways for Li-ions migration and the coordination environments evolves progressively with increasing diffusion coefficient,while the conductivity exhibits a non-monotonic peak in Li_(5.3)PS_(4.3)Cl_(1.7).The semiquantitative agreement with existing experimental resultsdemonstrates the superiority of our constant potential solid electrolytemodel,which weexpect to provide atomistic understanding towards rational design of solid electrolyte.
文摘Classical molecular dynamics simulation has been widely used to study the rapid cooling process of preparing amorphous alloys.However,the simulated cooling rate is several orders of magnitude higher than the experimental cooling rate.In this paper,Zr_(55)Cu_(35)Al_(10)alloy was taken as an example.It is found that adding isothermal annealing at a temperature slightly lower than Tand prolonging isothermal annealing time could effectively reduce the cooling rate.The glassy sample prepared in this way demonstrates significant energetic stability and well-developed short-range and medium-range order.
