Ether-based electrolytes with relatively high stability are widely used in Li-O_(2) batteries (LOBs) with high energy density.However,they are still prone to be attacked by reactive oxygen species.Understanding the de...Ether-based electrolytes with relatively high stability are widely used in Li-O_(2) batteries (LOBs) with high energy density.However,they are still prone to be attacked by reactive oxygen species.Understanding the degradation chemistry of ether-based solvent induced by reactive oxygen species is significant importance toward selection of stable electrolytes for LOBs.Herein,we demonstrate that a great amount of H_(2) gas evolves on the Li anode during the long-term discharge process of LOBs,which is due to the electrolyte decomposition at the oxygen cathode.By coupling with in-situ and ex-situ characterization techniques,it is demonstrated that O_(2)^(-) induces the H-abstraction of tetraethylene glycol dimethyl ether(TEGDME) to produce a large amount of H_(2)O at cathode,and this H_(2)O migrates to Li anode and produce H_(2) gas.Based on the established experiments and spectra,a possible decomposition pathway of TEGDME caused by O_(2)^(-)at the discharge process is proposed.And moreover,three types of strategies are discussed to inhibit the decomposition of ether-based electrolytes,which should be highly important for the fundamental and technical advancement for LOBs.展开更多
Eight species, HRgX （Rg = He, Ne, Ar, Kr; X = Cl, Br）, are predicted to have bending transition states at B3PW91/AUG-cc-PVTZ level, leading to 2-body decomposition pathway like H-Rg-X→Rg＋HX. The reaction path has ...Eight species, HRgX （Rg = He, Ne, Ar, Kr; X = Cl, Br）, are predicted to have bending transition states at B3PW91/AUG-cc-PVTZ level, leading to 2-body decomposition pathway like H-Rg-X→Rg＋HX. The reaction path has been obtained with Intricate Reaction Coordinates （IRC） method on identical theoretical level. Additionally, the linear transition states of HArCl, HArBr, HKrCl and HKrBr were obtained at MP2/6-311 ＋＋G （2d, 2p） level, resulting in 3-body dissociation channel as H-Rg-X→H ＋ Rg＋ X.展开更多
Recent advancements have led to the synthesis of various new metal-containing explosives,particularly energetic metal-organic frameworks(EMOFs),which feature high-energy ligands within well-ordered crystalline structu...Recent advancements have led to the synthesis of various new metal-containing explosives,particularly energetic metal-organic frameworks(EMOFs),which feature high-energy ligands within well-ordered crystalline structures.These explosives exhibit significant advantages over traditional compounds,including higher density,greater heats of detonation,improved mechanical hardness,and excellent thermal stability.To effectively evaluate their detonation performance,it is crucial to have a reliable method for predicting detonation heat,velocity,and pressure.This study leverages experimental data and outputs from the leading commercial computer code to identify suitable decomposition pathways for different metal oxides,facilitating straightforward calculations for the detonation performance of alkali metal salts,and metal coordination compounds,along with EMOFs.The new model enhances predictive reliability for detonation velocities,aligning more closely with experimental results,as evi-denced by a root mean square error(RMSE)of 0.68 km/s compared to 1.12 km/s for existing methods.Furthermore,it accommodates a broader range of compounds,including those containing Sr,Cd,and Ag,and provides predictions for EMOFs that are more consistent with computer code outputs than previous predictive models.展开更多
基金the National Natural Science Foundation of China (21773055, U1604122, 22005085)。
文摘Ether-based electrolytes with relatively high stability are widely used in Li-O_(2) batteries (LOBs) with high energy density.However,they are still prone to be attacked by reactive oxygen species.Understanding the degradation chemistry of ether-based solvent induced by reactive oxygen species is significant importance toward selection of stable electrolytes for LOBs.Herein,we demonstrate that a great amount of H_(2) gas evolves on the Li anode during the long-term discharge process of LOBs,which is due to the electrolyte decomposition at the oxygen cathode.By coupling with in-situ and ex-situ characterization techniques,it is demonstrated that O_(2)^(-) induces the H-abstraction of tetraethylene glycol dimethyl ether(TEGDME) to produce a large amount of H_(2)O at cathode,and this H_(2)O migrates to Li anode and produce H_(2) gas.Based on the established experiments and spectra,a possible decomposition pathway of TEGDME caused by O_(2)^(-)at the discharge process is proposed.And moreover,three types of strategies are discussed to inhibit the decomposition of ether-based electrolytes,which should be highly important for the fundamental and technical advancement for LOBs.
基金This work was supported by the Foundation of Education Committee of Liaoning Province (990321076)
文摘Eight species, HRgX （Rg = He, Ne, Ar, Kr; X = Cl, Br）, are predicted to have bending transition states at B3PW91/AUG-cc-PVTZ level, leading to 2-body decomposition pathway like H-Rg-X→Rg＋HX. The reaction path has been obtained with Intricate Reaction Coordinates （IRC） method on identical theoretical level. Additionally, the linear transition states of HArCl, HArBr, HKrCl and HKrBr were obtained at MP2/6-311 ＋＋G （2d, 2p） level, resulting in 3-body dissociation channel as H-Rg-X→H ＋ Rg＋ X.
基金the research committee at Malek Ashtar University of Technology (MUT) for their invaluable support of this project
文摘Recent advancements have led to the synthesis of various new metal-containing explosives,particularly energetic metal-organic frameworks(EMOFs),which feature high-energy ligands within well-ordered crystalline structures.These explosives exhibit significant advantages over traditional compounds,including higher density,greater heats of detonation,improved mechanical hardness,and excellent thermal stability.To effectively evaluate their detonation performance,it is crucial to have a reliable method for predicting detonation heat,velocity,and pressure.This study leverages experimental data and outputs from the leading commercial computer code to identify suitable decomposition pathways for different metal oxides,facilitating straightforward calculations for the detonation performance of alkali metal salts,and metal coordination compounds,along with EMOFs.The new model enhances predictive reliability for detonation velocities,aligning more closely with experimental results,as evi-denced by a root mean square error(RMSE)of 0.68 km/s compared to 1.12 km/s for existing methods.Furthermore,it accommodates a broader range of compounds,including those containing Sr,Cd,and Ag,and provides predictions for EMOFs that are more consistent with computer code outputs than previous predictive models.
