Organic cathode materials exhibit higher energy storage capacity,their poor cyclability due to dissolution in liquid organic electrolytes remains a challenge.However,recently,the electrochemical behavior of organopoly...Organic cathode materials exhibit higher energy storage capacity,their poor cyclability due to dissolution in liquid organic electrolytes remains a challenge.However,recently,the electrochemical behavior of organopolysulfides incorporating N-heterocycles unveils promising cathode materials with stable cycling performance.Herein,the integration of organosulfides salt as cathodes with solid electrolytes,exemplified by sodium allyl(methyl)carbamodithioate and sodium diethylcarbamodithioate with a polymer solid electrolyte of polyethylene oxide and LiTFSI,addresses the poor electrochemical stability of organic electrodes.Comparative analysis highlights sodium allyl(methyl)carbamodithioate's superior electrochemical performance and stability compared with sodium diethylcarbamodithioate,emphasizing the efficacy of periphery aliphatic modification in enhancing electrode capacity,rate performance,and electrochemical stability for organosulfide materials within all-solid-state lithium organic batteries.We also explore the origin of periphery aliphatic modification in these enhancing electrochemical performances by kinetic analysis and thermodynamic analysis.Furthermore,employing density functional theory calculations and ex situ FTIR experiments elucidates the critical role of the N-C=S structure in the energy storage mechanism.This research advances organic cathode design within organosulfide materials,unlocking the potential of allsolid-state lithium organic batteries with enhanced cyclability,propelling the development of next-generation energy storage systems.展开更多
As dielectric polymers are confined to nanoscale dimensions;anomalous enhancements in electrical resistivity have been widely inferred and exploited in nanocomposites and multilayered structures—yet direct experiment...As dielectric polymers are confined to nanoscale dimensions;anomalous enhancements in electrical resistivity have been widely inferred and exploited in nanocomposites and multilayered structures—yet direct experimental validation of the mechanisms remains elusive.Herein;we unveil the physical origins of this abnormal resistivity at the nanoscale through a model polymer approach.Direct experimental observations on ultrathin polymer films(down to 5 nm)reveal that the size-dependent enhancement in electrical resistivity primarily originates from confined localβ-relaxation processes;complementing conventional explanations based on changed molecular packing and density.With this insight;we(i)rationalize the temperature-dependent effects of nanofilling in polymer-nanocomposite dielectrics and(ii)engineer a commercial polymer film with a bulk glass transition temperature of 237℃that retains stable insulating performance up to 300℃.These findings provide a unified framework for molecular-dynamics-driven charge transport and offer a strategy to design thermally robust dielectrics for next-generation electronics;power modules;and harsh-environment applications.展开更多
基金supported by the National Natural Science Foundation of China(52272088,52072273 and 51972239)the Zhejiang Provincial Natural Science Foundation of China(LZ21E020001)the Key Lab of Advanced Energy Storage and Conversion(2021HZSY0051)。
文摘Organic cathode materials exhibit higher energy storage capacity,their poor cyclability due to dissolution in liquid organic electrolytes remains a challenge.However,recently,the electrochemical behavior of organopolysulfides incorporating N-heterocycles unveils promising cathode materials with stable cycling performance.Herein,the integration of organosulfides salt as cathodes with solid electrolytes,exemplified by sodium allyl(methyl)carbamodithioate and sodium diethylcarbamodithioate with a polymer solid electrolyte of polyethylene oxide and LiTFSI,addresses the poor electrochemical stability of organic electrodes.Comparative analysis highlights sodium allyl(methyl)carbamodithioate's superior electrochemical performance and stability compared with sodium diethylcarbamodithioate,emphasizing the efficacy of periphery aliphatic modification in enhancing electrode capacity,rate performance,and electrochemical stability for organosulfide materials within all-solid-state lithium organic batteries.We also explore the origin of periphery aliphatic modification in these enhancing electrochemical performances by kinetic analysis and thermodynamic analysis.Furthermore,employing density functional theory calculations and ex situ FTIR experiments elucidates the critical role of the N-C=S structure in the energy storage mechanism.This research advances organic cathode design within organosulfide materials,unlocking the potential of allsolid-state lithium organic batteries with enhanced cyclability,propelling the development of next-generation energy storage systems.
基金National Natural Science Foundation of China,Grant/Award Numbers:52237001,51922056。
文摘As dielectric polymers are confined to nanoscale dimensions;anomalous enhancements in electrical resistivity have been widely inferred and exploited in nanocomposites and multilayered structures—yet direct experimental validation of the mechanisms remains elusive.Herein;we unveil the physical origins of this abnormal resistivity at the nanoscale through a model polymer approach.Direct experimental observations on ultrathin polymer films(down to 5 nm)reveal that the size-dependent enhancement in electrical resistivity primarily originates from confined localβ-relaxation processes;complementing conventional explanations based on changed molecular packing and density.With this insight;we(i)rationalize the temperature-dependent effects of nanofilling in polymer-nanocomposite dielectrics and(ii)engineer a commercial polymer film with a bulk glass transition temperature of 237℃that retains stable insulating performance up to 300℃.These findings provide a unified framework for molecular-dynamics-driven charge transport and offer a strategy to design thermally robust dielectrics for next-generation electronics;power modules;and harsh-environment applications.
