Ordered hierarchical architectures are attractive candidates for electrochemical energy storage applications.Herein,a facile self-template strategy is applied to prepare Fe7Se8 architectures with a monolithic structur...Ordered hierarchical architectures are attractive candidates for electrochemical energy storage applications.Herein,a facile self-template strategy is applied to prepare Fe7Se8 architectures with a monolithic structure via a self-synthesized single precursor and subsequent calcination at high temperature.With the support of oleylamine,the precursor is structurally targeted to engineer the Fe7Se8 microstructure,featuring nanorod bundles arranged along the longitudinal direction.Because of their ordered hierarchical structure,the Fe7Se8 nanorod bundles deliver a high reversible capacity of 300 m Ah g^-1 at 0.5 A g^-1,along with exceptional rate capability up to 20 A g^-1 and long-term cycle life over 8000 cycles,which represents the highest stability of Fe7Se8 anodes for sodium-ion batteries reported to date.The feasibility of the present strategy to prepare metal selenide structures highlights its promising potential for the rational and effective engineering of electrode materials responsible for the electrochemical performance of energy storage systems.展开更多
A newly grown Ba Ga4Se7 crystal has been synthesized via the Bridgman-Stockbarger technique.This new crystal has advantages of high nonlinear optics（NLO） coefficients,high laser damage thresholds,and wide transparen...A newly grown Ba Ga4Se7 crystal has been synthesized via the Bridgman-Stockbarger technique.This new crystal has advantages of high nonlinear optics（NLO） coefficients,high laser damage thresholds,and wide transparent regions.The Ba Ga4Se7 crystal has bright application prospects as a nonlinear gain medium in mid-infrared and terahertz regions.In this paper,the crystalline structure and synthetic method of the Ba Ga4Se7 crystal are introduced.The refractive indices and absorption coefficients along three dielectric axes between 0.1 THz and 1.0 THz are also obtained.The terahertz difference frequency generation（THz-DFG） characteristics based on the BaG a4Se7 crystal in the frequency range of 0.1 THz to 1.0 THz are analyzed theoretically and the phase-matching conditions are calculated.The application of Ba Ga4Se7 crystals in terahertz wave generation is also discussed.展开更多
基金the National Natural Science Foundation of China(21871164)the Natural Science Foundation of Shandong Province(ZR2019MB024)the Taishan Scholar Project of Shandong Province(no.ts201511004).
文摘Ordered hierarchical architectures are attractive candidates for electrochemical energy storage applications.Herein,a facile self-template strategy is applied to prepare Fe7Se8 architectures with a monolithic structure via a self-synthesized single precursor and subsequent calcination at high temperature.With the support of oleylamine,the precursor is structurally targeted to engineer the Fe7Se8 microstructure,featuring nanorod bundles arranged along the longitudinal direction.Because of their ordered hierarchical structure,the Fe7Se8 nanorod bundles deliver a high reversible capacity of 300 m Ah g^-1 at 0.5 A g^-1,along with exceptional rate capability up to 20 A g^-1 and long-term cycle life over 8000 cycles,which represents the highest stability of Fe7Se8 anodes for sodium-ion batteries reported to date.The feasibility of the present strategy to prepare metal selenide structures highlights its promising potential for the rational and effective engineering of electrode materials responsible for the electrochemical performance of energy storage systems.
基金supported by the National Basic Research Program of China(973)under Grant No.2015CB755403 and No.2014CB339802National High Technology Research and Development Program(863)under Grant No.2011AA010205+6 种基金National Natural Science Foundation of China under Grant No.61107086No.61172010and No.61471257Natural Science Foundation of Tianjin under Grant No.14JCQNJC02200Science and Technology Support Program of Tianjin under Grant No.14ZCZDGX00030Specialized Research Fund for the Doctoral Program of Higher Education under Grant No.20120032110053CAEP THz Science and Technology Foundation under Grant No.CAEPTHZ201304
文摘A newly grown Ba Ga4Se7 crystal has been synthesized via the Bridgman-Stockbarger technique.This new crystal has advantages of high nonlinear optics（NLO） coefficients,high laser damage thresholds,and wide transparent regions.The Ba Ga4Se7 crystal has bright application prospects as a nonlinear gain medium in mid-infrared and terahertz regions.In this paper,the crystalline structure and synthetic method of the Ba Ga4Se7 crystal are introduced.The refractive indices and absorption coefficients along three dielectric axes between 0.1 THz and 1.0 THz are also obtained.The terahertz difference frequency generation（THz-DFG） characteristics based on the BaG a4Se7 crystal in the frequency range of 0.1 THz to 1.0 THz are analyzed theoretically and the phase-matching conditions are calculated.The application of Ba Ga4Se7 crystals in terahertz wave generation is also discussed.
