Shuttle effect is one of the most serious disadvantages in lithium-sulfur battery which results in poor cycle performance and hinders the commercialization of Li-S battery.To reduce the dissolution of polysulfides int...Shuttle effect is one of the most serious disadvantages in lithium-sulfur battery which results in poor cycle performance and hinders the commercialization of Li-S battery.To reduce the dissolution of polysulfides into the electrolyte and prolong the cycling stability,nanoparticle-stacked metal nitride derived from layered double hydroxides(LDHs)as an interlayer was inserted between sulfur cathode and separator to confine polysulfides by physical and chemical interactions.Meanwhile,the surface of metal nitride will form an oxide passivation layer.The passivation layer possesses hydrophilic metal-O group and provides a polar surface for strong binding with polysulfide.What’s more,the nanoparticlesstacked structure could immerge and retain electrolyte well,which could enhance the ability of promoting the electron exchange rate.The sulfur electrode with nanoparticle-stacked metal nitride interlayer has an excellent cycle performance owing to the interactions between metal nitride and polysulfides.The battery delivered an initial capacity of 764.6 m Ahg^(-1) and still possesses a capacity of 477.5 mAhg^(-1) with the retention of 62.4% after 800 cycles.展开更多
A terahertz bandpass filter with the sandwich structure consisting of thermally tunable vanadium dioxide(VO2) thin film,silica substrate and subwavelength rectangular Cu hole arrays is designed and theoretically analy...A terahertz bandpass filter with the sandwich structure consisting of thermally tunable vanadium dioxide(VO2) thin film,silica substrate and subwavelength rectangular Cu hole arrays is designed and theoretically analyzed.The results show that the transmittance of the filter can be actively tuned by controlling the temperature of VO2,the narrow band terahertz(THz) waves with the transmittance from 85.2% to 10.5% can be well selected at the frequency of 1.25 THz when the temperature changes from 50 ℃ to 80 ℃,and the maximum modulation depth of this terahertz bandpass filter can achieve 74.7%.展开更多
基金supported by the National Natural Science Foundation of China(21701043,51402100,50702020,21573066 and 81171461)the Provincial Natural Science Foundation of Hunan(2016JJ1006,2016TP1009 and 11JJ4013)+1 种基金the Fundamental Research Funds for the Central Universitiesthe Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province
文摘Shuttle effect is one of the most serious disadvantages in lithium-sulfur battery which results in poor cycle performance and hinders the commercialization of Li-S battery.To reduce the dissolution of polysulfides into the electrolyte and prolong the cycling stability,nanoparticle-stacked metal nitride derived from layered double hydroxides(LDHs)as an interlayer was inserted between sulfur cathode and separator to confine polysulfides by physical and chemical interactions.Meanwhile,the surface of metal nitride will form an oxide passivation layer.The passivation layer possesses hydrophilic metal-O group and provides a polar surface for strong binding with polysulfide.What’s more,the nanoparticlesstacked structure could immerge and retain electrolyte well,which could enhance the ability of promoting the electron exchange rate.The sulfur electrode with nanoparticle-stacked metal nitride interlayer has an excellent cycle performance owing to the interactions between metal nitride and polysulfides.The battery delivered an initial capacity of 764.6 m Ahg^(-1) and still possesses a capacity of 477.5 mAhg^(-1) with the retention of 62.4% after 800 cycles.
基金supported by the National High Technology Research and Development Program of China(No.2011AA010205)the National Natural Science Foundation of China(Nos.61171027 and 10904076)the Tianjin City High School Science&Technology Fund Planning Project(No.20120706)
文摘A terahertz bandpass filter with the sandwich structure consisting of thermally tunable vanadium dioxide(VO2) thin film,silica substrate and subwavelength rectangular Cu hole arrays is designed and theoretically analyzed.The results show that the transmittance of the filter can be actively tuned by controlling the temperature of VO2,the narrow band terahertz(THz) waves with the transmittance from 85.2% to 10.5% can be well selected at the frequency of 1.25 THz when the temperature changes from 50 ℃ to 80 ℃,and the maximum modulation depth of this terahertz bandpass filter can achieve 74.7%.
