Nickel-cobalt sulfide arrays with different loading densities were fixed on nickel foam via a facile hydrothermal method in ethanol. Their loading densities could be easily adjusted via changing the amount of reactant...Nickel-cobalt sulfide arrays with different loading densities were fixed on nickel foam via a facile hydrothermal method in ethanol. Their loading densities could be easily adjusted via changing the amount of reactants. It was found that the nickel-cobalt sulfide arrays on Ni foam with moderate loading density showed excellent electrochemical performance for supercapacitors. The best sample not only exhibited an outstanding areal capacitance of 4.84 F cm^-2 at 10 mA cm^-2 but also showed the best cycle stability and rate performance compared with the samples with other loading densities.Remarkably, this method to control the loading densities of nickel-cobalt sulfide on nickel foammay provide a new strategy for the investigation of other nanoarrays on various substrates for catalysts and lithium-ion batteries other than supercapacitors.展开更多
Carbon quantum dots(CQDs)as a new class of emerging materials have gradually drawn researchers’concern in recent years.In this work,the graphitic CQDs are prepared through a scalable approach,achieving a high yield w...Carbon quantum dots(CQDs)as a new class of emerging materials have gradually drawn researchers’concern in recent years.In this work,the graphitic CQDs are prepared through a scalable approach,achieving a high yield with more than 50%.The obtained CQDs are further used as structure-directing and conductive agents to synthesize novel N,S-CQDs/NiCo2S4 composite cathode materials,manifesting the enhanced electrochemical properties resulted from the synergistic effect of highly conductive N,S-codoped CQDs offering fast electronic transport and unique micro-/nanostructured NiCo2S4 microspheres with Faradaic redox characteristic contributing large capacity.Moreover,the nitrogen-doped reduced graphene oxide(N-rGO)/Fe2O3 composite anode materials exhibit ultrahigh specific capacity as well as significantly improved rate property and cycle performance originating from the high-capacity prism-like Fe2O3 hexahedrons tightly wrapped by highly conductive N-rGO.A novel alkaline aqueous battery assembled by these materials displays a specific energy(50.2 Wh kg^−1),ultrahigh specific power(9.7 kW kg^−1)and excellent cycling performance with 91.5%of capacity retention at 3 A g^−1 for 5000 cycles.The present research offers a valuable guidance for the exploitation of advanced energy storage devices by the rational design and selection of battery/capacitive composite materials.展开更多
Fiber-supercapacitors(FSCs)are promising power sources for miniature portable and wearable electronic devices.However,the development and practical application of these FSCs have been severely hindered by their low vo...Fiber-supercapacitors(FSCs)are promising power sources for miniature portable and wearable electronic devices.However,the development and practical application of these FSCs have been severely hindered by their low volumetric capacitance and narrow operating voltage.In this work,vertically aligned nickel cobalt sulfide(Ni Co2S4)nanowires grown on carbon nanotube(CNT)fibers were achieved through an in-situ two-step hydrothermal reaction method.The as-prepared Ni Co2S4@CNT fiber electrode exhibits a high volumetric capacitance of 2332 F cm-3,benefiting from its superior electric conductivity,large surface area,and rich Faradic redox reaction sites.Furthermore,a Ni Co2S4@CNT//VN@CNT(vanadium nitride nanosheets grown on CNT fibers)asymmetric fiber-supercapacitor(AFSC)was successfully fabricated.The device exhibits an operating voltage up to 1.6 V and a high volumetric energy density of 30.64m Wh cm-3.The device also possesses outstanding flexibility as evidenced by no obvious performance degradation under various bending angles and maintaining high capacitance after 5000 bending cycles.This work promotes the practical application of flexible wearable energy-storage devices.展开更多
为了进一步提高基于硫化镍钴电极的染料敏化太阳能电池光伏性能,将以自组装形成的二维聚苯乙烯光子晶体为模板,采用反向恒压电沉积技术制备一种具有多孔结构的硫化镍钴薄膜(Ni x Co y S-PC),并直接作为对电极应用于染料敏化太阳能电池...为了进一步提高基于硫化镍钴电极的染料敏化太阳能电池光伏性能,将以自组装形成的二维聚苯乙烯光子晶体为模板,采用反向恒压电沉积技术制备一种具有多孔结构的硫化镍钴薄膜(Ni x Co y S-PC),并直接作为对电极应用于染料敏化太阳能电池中。对比测试结果发现,Ni x Co y S-PC电极展现出了比无多孔结构的硫化镍钴(Ni x Co y S-FTO)电极、铂电极更加优异的电催化性能,这是因为多孔结构有利于提高其电催化活性位点及氧化还原电对I-/I-3的扩散速率。因此,基于Ni x Co y S-PC电极的染料敏化太阳能电池展现出了较高的光电转换效率(5.80%),高于基于Ni x Co y S-FTO电极(5.43%)和铂电极(4.87%)的电池效率。展开更多
基金supported by the National Natural Science Foundation of China(51404103,61376073 and 51574117)Hunan University Fund for Multidisciplinary Developing(2015JCA04)Fundamental Research Funds for the Central Universities
文摘Nickel-cobalt sulfide arrays with different loading densities were fixed on nickel foam via a facile hydrothermal method in ethanol. Their loading densities could be easily adjusted via changing the amount of reactants. It was found that the nickel-cobalt sulfide arrays on Ni foam with moderate loading density showed excellent electrochemical performance for supercapacitors. The best sample not only exhibited an outstanding areal capacitance of 4.84 F cm^-2 at 10 mA cm^-2 but also showed the best cycle stability and rate performance compared with the samples with other loading densities.Remarkably, this method to control the loading densities of nickel-cobalt sulfide on nickel foammay provide a new strategy for the investigation of other nanoarrays on various substrates for catalysts and lithium-ion batteries other than supercapacitors.
基金financially supported by National Natural Science Foundation of China(21601057)Hunan Provincial Natural Science Foundation of China(2018JJ3116)Excellent Youth Fund of Hunan Provincial Education Department(18B298)
文摘Carbon quantum dots(CQDs)as a new class of emerging materials have gradually drawn researchers’concern in recent years.In this work,the graphitic CQDs are prepared through a scalable approach,achieving a high yield with more than 50%.The obtained CQDs are further used as structure-directing and conductive agents to synthesize novel N,S-CQDs/NiCo2S4 composite cathode materials,manifesting the enhanced electrochemical properties resulted from the synergistic effect of highly conductive N,S-codoped CQDs offering fast electronic transport and unique micro-/nanostructured NiCo2S4 microspheres with Faradaic redox characteristic contributing large capacity.Moreover,the nitrogen-doped reduced graphene oxide(N-rGO)/Fe2O3 composite anode materials exhibit ultrahigh specific capacity as well as significantly improved rate property and cycle performance originating from the high-capacity prism-like Fe2O3 hexahedrons tightly wrapped by highly conductive N-rGO.A novel alkaline aqueous battery assembled by these materials displays a specific energy(50.2 Wh kg^−1),ultrahigh specific power(9.7 kW kg^−1)and excellent cycling performance with 91.5%of capacity retention at 3 A g^−1 for 5000 cycles.The present research offers a valuable guidance for the exploitation of advanced energy storage devices by the rational design and selection of battery/capacitive composite materials.
基金funding support from the CASQueensland Collaborative Science Fund(121E32KYSB20160032)the National Natural Science Foundation of China(No.21403287,No.21433013,51402345,21773291)+1 种基金the National Key R&D Program of China(2016YFB0100100)the CAS-DOE Joint Research Program(121E32KYSB20150004)。
文摘Fiber-supercapacitors(FSCs)are promising power sources for miniature portable and wearable electronic devices.However,the development and practical application of these FSCs have been severely hindered by their low volumetric capacitance and narrow operating voltage.In this work,vertically aligned nickel cobalt sulfide(Ni Co2S4)nanowires grown on carbon nanotube(CNT)fibers were achieved through an in-situ two-step hydrothermal reaction method.The as-prepared Ni Co2S4@CNT fiber electrode exhibits a high volumetric capacitance of 2332 F cm-3,benefiting from its superior electric conductivity,large surface area,and rich Faradic redox reaction sites.Furthermore,a Ni Co2S4@CNT//VN@CNT(vanadium nitride nanosheets grown on CNT fibers)asymmetric fiber-supercapacitor(AFSC)was successfully fabricated.The device exhibits an operating voltage up to 1.6 V and a high volumetric energy density of 30.64m Wh cm-3.The device also possesses outstanding flexibility as evidenced by no obvious performance degradation under various bending angles and maintaining high capacitance after 5000 bending cycles.This work promotes the practical application of flexible wearable energy-storage devices.
文摘为了进一步提高基于硫化镍钴电极的染料敏化太阳能电池光伏性能,将以自组装形成的二维聚苯乙烯光子晶体为模板,采用反向恒压电沉积技术制备一种具有多孔结构的硫化镍钴薄膜(Ni x Co y S-PC),并直接作为对电极应用于染料敏化太阳能电池中。对比测试结果发现,Ni x Co y S-PC电极展现出了比无多孔结构的硫化镍钴(Ni x Co y S-FTO)电极、铂电极更加优异的电催化性能,这是因为多孔结构有利于提高其电催化活性位点及氧化还原电对I-/I-3的扩散速率。因此,基于Ni x Co y S-PC电极的染料敏化太阳能电池展现出了较高的光电转换效率(5.80%),高于基于Ni x Co y S-FTO电极(5.43%)和铂电极(4.87%)的电池效率。
