通过两步液相法合成了生长在泡沫镍上的具有多孔结构的纳米Ni3S2,分别用XRD,SEM对材料进行了物相和微观形貌表征,并利用电化学工作站测试了其电化学性能.实验结果表明,利用(NH4)2S2O8氧化泡沫镍时反应温度应在70℃以上,反应时间在3 h以...通过两步液相法合成了生长在泡沫镍上的具有多孔结构的纳米Ni3S2,分别用XRD,SEM对材料进行了物相和微观形貌表征,并利用电化学工作站测试了其电化学性能.实验结果表明,利用(NH4)2S2O8氧化泡沫镍时反应温度应在70℃以上,反应时间在3 h以上,合成的电极材料表面呈多孔薄层的三维结构,孔径大小分布广,并且薄层之间没有互相重叠的现象.循环伏安曲线及恒流充放电曲线显示,Ni3S2电极材料具有良好的可逆性,明显的电池电容特点.当电流密度增大10倍时,比电容只下降了35.5%,具有良好的倍率性能.由交流阻抗谱图可知,高频区电阻率为0.91Ω,低频区直线斜率大,表明材料具有良好的导电性.当电极材料充放电次数从0增加到1 000次时,比电容由1 015.4 F g^-1增加到1 222.7 F g^-1,增加了20.4%,表明制备的Ni3S2具有良好的循环稳定性.展开更多
采用一步固相煅烧工艺制备了碳纳米管原位封装Ni3S2纳米颗粒(Ni3S2@CNT),并研究了其作为钠离子电池(SIBs)负极材料的电化学性能.通过X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、循环伏安测试、恒流充放电以及交流阻抗...采用一步固相煅烧工艺制备了碳纳米管原位封装Ni3S2纳米颗粒(Ni3S2@CNT),并研究了其作为钠离子电池(SIBs)负极材料的电化学性能.通过X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、循环伏安测试、恒流充放电以及交流阻抗等研究了Ni3S2@CNT的物相结构、形貌特征以及电化学性能.电化学测试表明,材料在100 mA·g^(-1)电流密度下,放电容量可以达到541.6 m Ah·g^(-1),甚至在2000 mA·g^(-1)的大电流密度下其放电比容量也可以维持在274.5 m Ah·g^(-1).另外,材料在100 mA·g^(-1)电流密度下,经过120周充放电循环后其放电和充电比容量仍然可以保持在374.5 m Ah·g^(-1)和359.3 m Ah·g^(-1),说明其具有良好倍率性能和循环稳定性能.良好的电化学性能归因于这种独特的碳纳米管原位封装Ni3S2纳米颗粒结构.碳纳米管不但可以提高复合材料的导电性,也可以缓冲Ni3S2纳米颗粒在反复充放电过程中产生的体积膨胀效应,明显改善了Ni3S2@CNT负极复合材料的电化学性能.展开更多
以NH4SCN为硫源,在水溶液中电沉积制备Ni3S2/Ni复合材料.利用EDS、SEM、XRD分别对该复合材料进行组分、形貌、晶体结构的表征与分析,并将所制备的复合材料与Li片组成电池,研究其电化学性能.结果表明NH4SCN的浓度对复合材料的形貌及电性...以NH4SCN为硫源,在水溶液中电沉积制备Ni3S2/Ni复合材料.利用EDS、SEM、XRD分别对该复合材料进行组分、形貌、晶体结构的表征与分析,并将所制备的复合材料与Li片组成电池,研究其电化学性能.结果表明NH4SCN的浓度对复合材料的形貌及电性能有显著的影响.如在NH4SCN浓度为0.1 mol/L时,该复合物由亚微米颗粒组成,此时的电化学性能最好,首次放电比容量达到240.4 m Ah/g,容量保持率为89.35%.展开更多
A binder-free Ni3S2 electrode was prepared directly on a graphene-coated Ni foam （G/Ni） substrate through surface sulfiding of substrate using thiourea as the sulfur source in this work. The Ni3S2 showed a flower-li...A binder-free Ni3S2 electrode was prepared directly on a graphene-coated Ni foam （G/Ni） substrate through surface sulfiding of substrate using thiourea as the sulfur source in this work. The Ni3S2 showed a flower-like morphology and was uniformly distributed on the G/Ni surface. The flower-like Ni3S2 was composed of cross-arrayed nanoflakes with a diameter and a thickness of 1-2 μm and -50 nm, re- spectively. The free space in the flowers and the thin feature of Ni3S2 buffered the volume changes and relieved mechanical strain during re- peated cycling. The intimate contact with the Ni substrate and the fixing effect of graphene maintained the structural stability of the Ni3S2 electrode during cycling. The G/Ni-supported Ni3S2 maintained a reversible capacity of 250 mAh·g^-1 after 100 cycles at 50 mA·g^-1, demon- strating the good cycling stability as a result of the unique microstructure of this electrode material.展开更多
The growing global demands of safe, low-cost and high working voltage energy storage devices trigger strong interests in novel battery concepts beyond state-of-art lithium-ion battery. Herein, a dualion battery based ...The growing global demands of safe, low-cost and high working voltage energy storage devices trigger strong interests in novel battery concepts beyond state-of-art lithium-ion battery. Herein, a dualion battery based on nanostructured Ni_3S_2/Ni foam@RGO(NSNR) composite anode is developed, utilizing graphite as cathode material and LiPF6-VC-based solvent as electrolyte. The battery operates at high working voltage of 4.2–4.5 V, with superior discharge capacity of ～90 m A h g^(-1) at 100 mA g^(-1), outstanding rate performance, and long-term cycling stability over 500 cycles with discharge capacity retention of ～85.6%. Moreover, the composite simultaneously acts as the anode material and the current collector, and the corrosion phenomenon can be greatly reduced compared to metallic Al anode. Thus, this work represents a significant step forward for practical safe, low-cost and high working voltage dual-ion batteries,showing attractive potential for future energy storage application.展开更多
The development of low-cost semiconductor photocatalysts for highly efficient and durable photocatalytic H2 evolution under visible light is very challenging.In this study,we combine low-cost metallic Ni3C cocatalysts...The development of low-cost semiconductor photocatalysts for highly efficient and durable photocatalytic H2 evolution under visible light is very challenging.In this study,we combine low-cost metallic Ni3C cocatalysts with twin nanocrystal Zn0.5Cd0.5S(ZCS)solid solution homojunctions for an efficient visible-light-driven H2 production by a simple approach.As-synthesized Zn0.5Cd0.5S-1%Ni3C(ZCS-1)heterojunction/homojunction nanohybrid exhibited the highest photocatalytic H2-evolution rate of 783μmol h‒1 under visible light,which is 2.88 times higher than that of pristine twin nanocrystal ZCS solid solution.The apparent quantum efficiencies of ZCS and ZCS-1 are measured to be 6.13%and 19.25%at 420 nm,respectively.Specifically,the homojunctions between the zinc blende and wurtzite segments in twin nanocrystal ZCS solid solution can significantly improve the light absorption and separation of photogenerated electron-hole pairs.Furthermore,the heterojunction between ZCS and metallic Ni3C NP cocatalysts can efficiently trap excited electrons from ZCS solid solution and enhance the H2-evolution kinetics at the surface for improving catalytic activity.This study demonstrates a unique one-step strategy for constructing heterojunction/homojunction hybrid nanostructures for a more efficient photocatalytic H2 evolution compared to other noble metal photocatalytic systems.展开更多
文摘通过两步液相法合成了生长在泡沫镍上的具有多孔结构的纳米Ni3S2,分别用XRD,SEM对材料进行了物相和微观形貌表征,并利用电化学工作站测试了其电化学性能.实验结果表明,利用(NH4)2S2O8氧化泡沫镍时反应温度应在70℃以上,反应时间在3 h以上,合成的电极材料表面呈多孔薄层的三维结构,孔径大小分布广,并且薄层之间没有互相重叠的现象.循环伏安曲线及恒流充放电曲线显示,Ni3S2电极材料具有良好的可逆性,明显的电池电容特点.当电流密度增大10倍时,比电容只下降了35.5%,具有良好的倍率性能.由交流阻抗谱图可知,高频区电阻率为0.91Ω,低频区直线斜率大,表明材料具有良好的导电性.当电极材料充放电次数从0增加到1 000次时,比电容由1 015.4 F g^-1增加到1 222.7 F g^-1,增加了20.4%,表明制备的Ni3S2具有良好的循环稳定性.
文摘采用一步固相煅烧工艺制备了碳纳米管原位封装Ni3S2纳米颗粒(Ni3S2@CNT),并研究了其作为钠离子电池(SIBs)负极材料的电化学性能.通过X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、循环伏安测试、恒流充放电以及交流阻抗等研究了Ni3S2@CNT的物相结构、形貌特征以及电化学性能.电化学测试表明,材料在100 mA·g^(-1)电流密度下,放电容量可以达到541.6 m Ah·g^(-1),甚至在2000 mA·g^(-1)的大电流密度下其放电比容量也可以维持在274.5 m Ah·g^(-1).另外,材料在100 mA·g^(-1)电流密度下,经过120周充放电循环后其放电和充电比容量仍然可以保持在374.5 m Ah·g^(-1)和359.3 m Ah·g^(-1),说明其具有良好倍率性能和循环稳定性能.良好的电化学性能归因于这种独特的碳纳米管原位封装Ni3S2纳米颗粒结构.碳纳米管不但可以提高复合材料的导电性,也可以缓冲Ni3S2纳米颗粒在反复充放电过程中产生的体积膨胀效应,明显改善了Ni3S2@CNT负极复合材料的电化学性能.
文摘以NH4SCN为硫源,在水溶液中电沉积制备Ni3S2/Ni复合材料.利用EDS、SEM、XRD分别对该复合材料进行组分、形貌、晶体结构的表征与分析,并将所制备的复合材料与Li片组成电池,研究其电化学性能.结果表明NH4SCN的浓度对复合材料的形貌及电性能有显著的影响.如在NH4SCN浓度为0.1 mol/L时,该复合物由亚微米颗粒组成,此时的电化学性能最好,首次放电比容量达到240.4 m Ah/g,容量保持率为89.35%.
基金financially supported by the Scientific and Technological Project of State Grid Corporation of China
文摘A binder-free Ni3S2 electrode was prepared directly on a graphene-coated Ni foam （G/Ni） substrate through surface sulfiding of substrate using thiourea as the sulfur source in this work. The Ni3S2 showed a flower-like morphology and was uniformly distributed on the G/Ni surface. The flower-like Ni3S2 was composed of cross-arrayed nanoflakes with a diameter and a thickness of 1-2 μm and -50 nm, re- spectively. The free space in the flowers and the thin feature of Ni3S2 buffered the volume changes and relieved mechanical strain during re- peated cycling. The intimate contact with the Ni substrate and the fixing effect of graphene maintained the structural stability of the Ni3S2 electrode during cycling. The G/Ni-supported Ni3S2 maintained a reversible capacity of 250 mAh·g^-1 after 100 cycles at 50 mA·g^-1, demon- strating the good cycling stability as a result of the unique microstructure of this electrode material.
基金supported by the National Natural Science Foundation of China (No. 51725401)the Fundamental Research Funds for the Central Universities (FRF-TP-15-002C1 and FRF-TP17-002C2)
文摘The growing global demands of safe, low-cost and high working voltage energy storage devices trigger strong interests in novel battery concepts beyond state-of-art lithium-ion battery. Herein, a dualion battery based on nanostructured Ni_3S_2/Ni foam@RGO(NSNR) composite anode is developed, utilizing graphite as cathode material and LiPF6-VC-based solvent as electrolyte. The battery operates at high working voltage of 4.2–4.5 V, with superior discharge capacity of ～90 m A h g^(-1) at 100 mA g^(-1), outstanding rate performance, and long-term cycling stability over 500 cycles with discharge capacity retention of ～85.6%. Moreover, the composite simultaneously acts as the anode material and the current collector, and the corrosion phenomenon can be greatly reduced compared to metallic Al anode. Thus, this work represents a significant step forward for practical safe, low-cost and high working voltage dual-ion batteries,showing attractive potential for future energy storage application.
文摘The development of low-cost semiconductor photocatalysts for highly efficient and durable photocatalytic H2 evolution under visible light is very challenging.In this study,we combine low-cost metallic Ni3C cocatalysts with twin nanocrystal Zn0.5Cd0.5S(ZCS)solid solution homojunctions for an efficient visible-light-driven H2 production by a simple approach.As-synthesized Zn0.5Cd0.5S-1%Ni3C(ZCS-1)heterojunction/homojunction nanohybrid exhibited the highest photocatalytic H2-evolution rate of 783μmol h‒1 under visible light,which is 2.88 times higher than that of pristine twin nanocrystal ZCS solid solution.The apparent quantum efficiencies of ZCS and ZCS-1 are measured to be 6.13%and 19.25%at 420 nm,respectively.Specifically,the homojunctions between the zinc blende and wurtzite segments in twin nanocrystal ZCS solid solution can significantly improve the light absorption and separation of photogenerated electron-hole pairs.Furthermore,the heterojunction between ZCS and metallic Ni3C NP cocatalysts can efficiently trap excited electrons from ZCS solid solution and enhance the H2-evolution kinetics at the surface for improving catalytic activity.This study demonstrates a unique one-step strategy for constructing heterojunction/homojunction hybrid nanostructures for a more efficient photocatalytic H2 evolution compared to other noble metal photocatalytic systems.
