Lithium-sulfur(Li-S)batteries are anticipated as one of the most promising candidates for the highenergy-density storage systems.However,the insulating nature and shuttling effect of sulfur severely limits their perfo...Lithium-sulfur(Li-S)batteries are anticipated as one of the most promising candidates for the highenergy-density storage systems.However,the insulating nature and shuttling effect of sulfur severely limits their performance.The incorporation of sulfur with carbon materials has been deemed as one of the most powerful strategies to improve electrical conductivity and suppress soluble polysulfide shuttling.Herein,a novel three-dimensional carbon framework(3DCF)is prepared and employed as a sulfur host(3DCF@S)for Li-S batteries.The 3DCF not only supplies abundant paths for lithium ion diffusion and electron transport,but also strengthens polysulfide immobilization during the lithium/sulfur conversion reactions.As a result,the 3DCF@S with high sulfur content of 90%exhibits a high capacity of 1366 mA h/g at 0.1 C and excellent cycling stability with a satisfactory capacity of 601 mA h/g after 600 cycles at 2.0 C.The resultant Li-S button battery based 3DCF@S electrode could power a light-emitting diode for 2 h.The acquired 3DCF@S is expected to be widely used in Li-S batteries and this study will promote developments of carbon/sulfur composites for Li-S batteries.展开更多
Nickel selenide electrocatalysts for hydrogen evolution reaction(HER)with a high efficiency and a lowcost have a significant potential in the development of water splitting.However,the inferiority of the high overpote...Nickel selenide electrocatalysts for hydrogen evolution reaction(HER)with a high efficiency and a lowcost have a significant potential in the development of water splitting.However,the inferiority of the high overpotential and poor stability restricts their practical applications.Herein,a composite nanostructure consists of ultrasmall NiSe_(2) nanocrystals embedded on graphene by microwave reaction is reported.The prepared NiSe_(2)/reduced graphite oxide(rGO)electrocatalyst exhibited a high HER activity with an overpotential of 158 mV at a current density of 10 mA/cm^(2) and a corresponding moderate Tafel slope of 56 mV/dec in alkaline electrolyte.In addition,a high retention of electrochemical properties(approximately 100%)was demonstrated with an unchangeable microstructure after 100 h of continuous operation.展开更多
基金financially supported by the National Postdoctoral Science Foundation(2016YFA0200100)the Project of Education Department of Jiangxi Province(Grant No.GJJ160649)Doctoral startup fund of Jiangxi University of Science and Technology(Grant No.3401223242)。
文摘Lithium-sulfur(Li-S)batteries are anticipated as one of the most promising candidates for the highenergy-density storage systems.However,the insulating nature and shuttling effect of sulfur severely limits their performance.The incorporation of sulfur with carbon materials has been deemed as one of the most powerful strategies to improve electrical conductivity and suppress soluble polysulfide shuttling.Herein,a novel three-dimensional carbon framework(3DCF)is prepared and employed as a sulfur host(3DCF@S)for Li-S batteries.The 3DCF not only supplies abundant paths for lithium ion diffusion and electron transport,but also strengthens polysulfide immobilization during the lithium/sulfur conversion reactions.As a result,the 3DCF@S with high sulfur content of 90%exhibits a high capacity of 1366 mA h/g at 0.1 C and excellent cycling stability with a satisfactory capacity of 601 mA h/g after 600 cycles at 2.0 C.The resultant Li-S button battery based 3DCF@S electrode could power a light-emitting diode for 2 h.The acquired 3DCF@S is expected to be widely used in Li-S batteries and this study will promote developments of carbon/sulfur composites for Li-S batteries.
基金supported by the National Key Research and Development Program of China(No.5007041901)the Natural Science Research Project of Anhui Provincial Education Department(KJ2020A0736 and KJ2019A0671)+2 种基金the Academic Funding Project for Top Talents in Disciplines of Anhui universities(gxbjZD2021082)Doctoral Research Foundation(No.2019jb23)Scientific Research Key Project(No.2020yzd10)of Suzhou University.
文摘Nickel selenide electrocatalysts for hydrogen evolution reaction(HER)with a high efficiency and a lowcost have a significant potential in the development of water splitting.However,the inferiority of the high overpotential and poor stability restricts their practical applications.Herein,a composite nanostructure consists of ultrasmall NiSe_(2) nanocrystals embedded on graphene by microwave reaction is reported.The prepared NiSe_(2)/reduced graphite oxide(rGO)electrocatalyst exhibited a high HER activity with an overpotential of 158 mV at a current density of 10 mA/cm^(2) and a corresponding moderate Tafel slope of 56 mV/dec in alkaline electrolyte.In addition,a high retention of electrochemical properties(approximately 100%)was demonstrated with an unchangeable microstructure after 100 h of continuous operation.
