The search of electrode materials with high electrochemical activity is one of key solutions to actualize both high energy density and high power density in a supercapacitor. Recently, we have developed one novel kind...The search of electrode materials with high electrochemical activity is one of key solutions to actualize both high energy density and high power density in a supercapacitor. Recently, we have developed one novel kind of rare earth and transitional metal colloidal supercapacitors, which can deliver higher specific capacitance than electrical double-layer capacitors(EDLC) and traditional pseudocapacitors. The electrode materials in colloidal supercapacitors are in-situ formed electroactive colloids, which were transformed from commercial rare earth and transitional metal salts in alkaline electrolyte by chemical and electrochemical assisted coprecipitation. In these colloidal supercapacitors, multiple-electron Faradaic redox reactions can be utilized, which can deliver ultrahigh specific capacitance often larger than one-electron capacitance. Multiple-valence metal cations used in our designed colloidal supercapacitors mainly include Ce3+, Yb3+, Er3+, Fe3+, Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Sn2+ and Sn4+. The colloidal supercapacitors can be served as the promising next-generation high performance supercapacitors.展开更多
The components and their concentration ratio of surfactant mixture in aqueous solution of gelatin and sodium carboxymethylcellulose (NaCMC) are very important during the preparation of stable microcapsules for electro...The components and their concentration ratio of surfactant mixture in aqueous solution of gelatin and sodium carboxymethylcellulose (NaCMC) are very important during the preparation of stable microcapsules for electrophoretic display.In this work,hydrocarbon/fluorocarbon composite surfactant was introduced for the first time into the capsule wall to improve the chemical resistance and barrier property of the microcapsules.By investigating surface tension and zeta potential of NaCMC with the mixture of sodium dodecyl sulfate (SDS)/perfluoro-nonene oxy benzene sulfonate (OBS),we found that both the presence of hydrophobic interaction and the hydrogen bonding between NaCMC and SDS/OBS enhanced the adsorption of NaCMC at the oil/water interface and thus facilitated the formation of capsule wall.The morphology,particle size,surface free energy and thermal stability of the obtained microcapsules were characterized.The results showed that optically transparent microcapsules with uniform size,smooth surface and compact wall can be obtained by adjusting the pH value of the reaction system and the concentration ratio of SDS/OBS.Based on the prepared microcapsules,a matrix display prototype operated at 9 V direct current in static driven mode was fabricated.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.51125009&91434118)the National Natural Science Foundation for Creative Research Group(Grant No.21221061)+1 种基金the External Cooperation Program of BIC,Chinese Academy of Sciences(Grant No.121522KYS820150009)the Hundred Talents Program of the Chinese Academy of Sciences
文摘The search of electrode materials with high electrochemical activity is one of key solutions to actualize both high energy density and high power density in a supercapacitor. Recently, we have developed one novel kind of rare earth and transitional metal colloidal supercapacitors, which can deliver higher specific capacitance than electrical double-layer capacitors(EDLC) and traditional pseudocapacitors. The electrode materials in colloidal supercapacitors are in-situ formed electroactive colloids, which were transformed from commercial rare earth and transitional metal salts in alkaline electrolyte by chemical and electrochemical assisted coprecipitation. In these colloidal supercapacitors, multiple-electron Faradaic redox reactions can be utilized, which can deliver ultrahigh specific capacitance often larger than one-electron capacitance. Multiple-valence metal cations used in our designed colloidal supercapacitors mainly include Ce3+, Yb3+, Er3+, Fe3+, Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Sn2+ and Sn4+. The colloidal supercapacitors can be served as the promising next-generation high performance supercapacitors.
基金supported by the National High-Tech Research & Development Program of China (863 Program,2008AA03A331)partly supported by the Science & Research Program of Zhejiang Province (2009C21024)
文摘The components and their concentration ratio of surfactant mixture in aqueous solution of gelatin and sodium carboxymethylcellulose (NaCMC) are very important during the preparation of stable microcapsules for electrophoretic display.In this work,hydrocarbon/fluorocarbon composite surfactant was introduced for the first time into the capsule wall to improve the chemical resistance and barrier property of the microcapsules.By investigating surface tension and zeta potential of NaCMC with the mixture of sodium dodecyl sulfate (SDS)/perfluoro-nonene oxy benzene sulfonate (OBS),we found that both the presence of hydrophobic interaction and the hydrogen bonding between NaCMC and SDS/OBS enhanced the adsorption of NaCMC at the oil/water interface and thus facilitated the formation of capsule wall.The morphology,particle size,surface free energy and thermal stability of the obtained microcapsules were characterized.The results showed that optically transparent microcapsules with uniform size,smooth surface and compact wall can be obtained by adjusting the pH value of the reaction system and the concentration ratio of SDS/OBS.Based on the prepared microcapsules,a matrix display prototype operated at 9 V direct current in static driven mode was fabricated.