较低的体积能量密度限制了当前电化学电容器的应用,而提高体积能量密度的关键在于发展具有致密化储能特性的多孔炭材料。目前,毛细致密化已成为平衡多孔炭密度和孔隙率从而提高材料体积比电容的主要方法,但仍在孔结构的精细调控方面存...较低的体积能量密度限制了当前电化学电容器的应用,而提高体积能量密度的关键在于发展具有致密化储能特性的多孔炭材料。目前,毛细致密化已成为平衡多孔炭密度和孔隙率从而提高材料体积比电容的主要方法,但仍在孔结构的精细调控方面存在不足,制约了毛细致密化多孔炭与高电压离子液体的兼容性。本文提出了碘化钾(KI)辅助的毛细致密化策略,通过在石墨烯网络中预载KI来控制毛细致密化过程,实现了对孔结构的有效调控。同时电化学性能表征结果表明KI具有增加离子到达表面积和提供赝电容的作用。基于此,所制碘化钾/石墨烯材料的密度达到0.96 g cm^(-3),在离子液体中的体积比电容为115Fcm^(-3)。由该材料所组装的电化学电容器可以提供19.6WhL^(-1)的体积能量密度。展开更多
A novel strategy, which is better-suited for preparing materials with a very microscopic structure, is described and the whisker-like composite of Co(OH) 2/HY was prepared by using this strategy. In addition, the mech...A novel strategy, which is better-suited for preparing materials with a very microscopic structure, is described and the whisker-like composite of Co(OH) 2/HY was prepared by using this strategy. In addition, the mechanism by which the growth proceeds is not very rigorously worked out. Due to the high dispersed capability of HY towards to Co(OH) 2 resulting in loose whisker-like microstructure of Co(OH) 2, small channels become available for the diffusion of OH - electrolyte ions through all Co(OH) 2 thin layer. Consequentially, the prepared composite shows a very high specific capacitance (483 F/g) and utilization (93%) of effective electroactive composition of composite.展开更多
A series of ordered mesoporous carbons have been synthesized via a simple template method using mesopore silica molecular sieve SBA-15 as template and commercial available phenol-formaldehyde resin as carbon precursor...A series of ordered mesoporous carbons have been synthesized via a simple template method using mesopore silica molecular sieve SBA-15 as template and commercial available phenol-formaldehyde resin as carbon precursor. The samples were characterized by X-ray diffraction(XRD), transmission electron microscopy (TEM) and nitrogen adsorption. The order and the specific surface area of the mesoporous carbon can be adjusted by the concentration of the resin. When the concentration was fixed at 0.15 g·mL-1, the highest order and the largest specific surface area of 1 017 m2·g-1 were obtained. The Cyclic Voltammetry(CV)test result shows that the specific capacitance of C0.15 sample is 222 F·g-1, when the scanning rate is 2 mV·s-1; and 159 F·g-1 when the scanning rate increases to 50 mV·s-1. Due to the differences of the pore structure, the ordered mesoporous carbons have better electrochemical capacitance than the activated carbon.展开更多
CoAl LDHs with different molar ratio of Ni have been prepared by chemical co -precipitation method.XRD results show that these materials have layered struc tures.Electrochemical tests show that Co(Ni)Al LDHs as electr...CoAl LDHs with different molar ratio of Ni have been prepared by chemical co -precipitation method.XRD results show that these materials have layered struc tures.Electrochemical tests show that Co(Ni)Al LDHs as electrode material hav e typical capacit ive properties in a wide voltage range of0.0to0.6V;Co(Ni)Al LDH(Ni∶Co =4∶6)as an electrode material has the highest capacitance of960F · g -1 and good cycling performance.But the poor capacitive properties of NiAl LDH electrode are showed in a narrow voltage range of0.3to0.55V.展开更多
文摘较低的体积能量密度限制了当前电化学电容器的应用,而提高体积能量密度的关键在于发展具有致密化储能特性的多孔炭材料。目前,毛细致密化已成为平衡多孔炭密度和孔隙率从而提高材料体积比电容的主要方法,但仍在孔结构的精细调控方面存在不足,制约了毛细致密化多孔炭与高电压离子液体的兼容性。本文提出了碘化钾(KI)辅助的毛细致密化策略,通过在石墨烯网络中预载KI来控制毛细致密化过程,实现了对孔结构的有效调控。同时电化学性能表征结果表明KI具有增加离子到达表面积和提供赝电容的作用。基于此,所制碘化钾/石墨烯材料的密度达到0.96 g cm^(-3),在离子液体中的体积比电容为115Fcm^(-3)。由该材料所组装的电化学电容器可以提供19.6WhL^(-1)的体积能量密度。
文摘A novel strategy, which is better-suited for preparing materials with a very microscopic structure, is described and the whisker-like composite of Co(OH) 2/HY was prepared by using this strategy. In addition, the mechanism by which the growth proceeds is not very rigorously worked out. Due to the high dispersed capability of HY towards to Co(OH) 2 resulting in loose whisker-like microstructure of Co(OH) 2, small channels become available for the diffusion of OH - electrolyte ions through all Co(OH) 2 thin layer. Consequentially, the prepared composite shows a very high specific capacitance (483 F/g) and utilization (93%) of effective electroactive composition of composite.
文摘A series of ordered mesoporous carbons have been synthesized via a simple template method using mesopore silica molecular sieve SBA-15 as template and commercial available phenol-formaldehyde resin as carbon precursor. The samples were characterized by X-ray diffraction(XRD), transmission electron microscopy (TEM) and nitrogen adsorption. The order and the specific surface area of the mesoporous carbon can be adjusted by the concentration of the resin. When the concentration was fixed at 0.15 g·mL-1, the highest order and the largest specific surface area of 1 017 m2·g-1 were obtained. The Cyclic Voltammetry(CV)test result shows that the specific capacitance of C0.15 sample is 222 F·g-1, when the scanning rate is 2 mV·s-1; and 159 F·g-1 when the scanning rate increases to 50 mV·s-1. Due to the differences of the pore structure, the ordered mesoporous carbons have better electrochemical capacitance than the activated carbon.
文摘CoAl LDHs with different molar ratio of Ni have been prepared by chemical co -precipitation method.XRD results show that these materials have layered struc tures.Electrochemical tests show that Co(Ni)Al LDHs as electrode material hav e typical capacit ive properties in a wide voltage range of0.0to0.6V;Co(Ni)Al LDH(Ni∶Co =4∶6)as an electrode material has the highest capacitance of960F · g -1 and good cycling performance.But the poor capacitive properties of NiAl LDH electrode are showed in a narrow voltage range of0.3to0.55V.
基金Program for New Century Excellent Talents in U.,China M inistry of Edn.(NCET-10-0768,NCET-13-0643)National Natural Science Foundation of China(U1361110,51172285,51372277)~~
