The present study provides detailed experimental results on the synthesis and characterization of carbonized lithium titanate spinel（LTO） composites as electrode materials for lithium ion capacitor.The LTO particles...The present study provides detailed experimental results on the synthesis and characterization of carbonized lithium titanate spinel（LTO） composites as electrode materials for lithium ion capacitor.The LTO particles were grafted with a porous carbon layer obtained from the pyrolysis of camphor.The graphitic nature of the carbon was confirmed through Raman spectroscopy.The relative contributions from the capacitive and diffusion controlled processes underlying these electrodes were mathematically modeled.Electron transport mechanism underlying these electrodes was determined by measuring the work functions（φ） of LTO and carbon grafted LTO using ultraviolet photoelectron spectroscopy.These carbon grafted LTO composites exhibited an energy density of 330 m Wh L-1and a peak power density of 2.8 k W L-1,when employed as electrodes in coin cells with excellent cycling stability at the end of 4000 cycles.展开更多
In this paper,the SiC fiber-reinforced SiC matrix composites with a 0.15μm thick pyrocarbon interphase(noted as SiC/PyC/SiC) were prepared by chemical vapor infiltration(CVI).The SiCf/PyC/SiC were oxidized in air at9...In this paper,the SiC fiber-reinforced SiC matrix composites with a 0.15μm thick pyrocarbon interphase(noted as SiC/PyC/SiC) were prepared by chemical vapor infiltration(CVI).The SiCf/PyC/SiC were oxidized in air at950 "C for 50 h.The dielectric properties after this high temperature oxidation were investigated in X-band from room temperature(RT) to 700℃.Results suggested that:ε′ of the SiC_f/PyC/SiC after oxidation increased at first then decreased with temperature elevating;ε″ increased with temperature raising in the temperature range studied.展开更多
基金Indian Space Research Organization (ISRO),Government of India is gratefully acknowledged for their financial support
文摘The present study provides detailed experimental results on the synthesis and characterization of carbonized lithium titanate spinel（LTO） composites as electrode materials for lithium ion capacitor.The LTO particles were grafted with a porous carbon layer obtained from the pyrolysis of camphor.The graphitic nature of the carbon was confirmed through Raman spectroscopy.The relative contributions from the capacitive and diffusion controlled processes underlying these electrodes were mathematically modeled.Electron transport mechanism underlying these electrodes was determined by measuring the work functions（φ） of LTO and carbon grafted LTO using ultraviolet photoelectron spectroscopy.These carbon grafted LTO composites exhibited an energy density of 330 m Wh L-1and a peak power density of 2.8 k W L-1,when employed as electrodes in coin cells with excellent cycling stability at the end of 4000 cycles.
基金supported by the National Natural Science Foundation under Grant(51072165)the fund of the State Key Laboratory of Solidification Processing in Northwestern Polytechnical University(NPU)(KP201307 and SKLSP201313)
文摘In this paper,the SiC fiber-reinforced SiC matrix composites with a 0.15μm thick pyrocarbon interphase(noted as SiC/PyC/SiC) were prepared by chemical vapor infiltration(CVI).The SiCf/PyC/SiC were oxidized in air at950 "C for 50 h.The dielectric properties after this high temperature oxidation were investigated in X-band from room temperature(RT) to 700℃.Results suggested that:ε′ of the SiC_f/PyC/SiC after oxidation increased at first then decreased with temperature elevating;ε″ increased with temperature raising in the temperature range studied.
