含氧化还原活性基团的苯醌衍生物,在水系质子电池里是一种比容量高、资源丰富的理想电极材料,然而其高溶解性和低的工作电压不利于质子电池的循环稳定性和能量密度的提升,引入吸电子基团不仅可以降低其LUMO能量来提升其反应电位,还可以...含氧化还原活性基团的苯醌衍生物,在水系质子电池里是一种比容量高、资源丰富的理想电极材料,然而其高溶解性和低的工作电压不利于质子电池的循环稳定性和能量密度的提升,引入吸电子基团不仅可以降低其LUMO能量来提升其反应电位,还可以一定程度上抑制其溶解来提升稳定性。因此,通过电化学研究并对比了3种不同的苯醌化合物作为质子电池的电极材料,研究了不同氯取代情况造成的影响。其中四氯取代的四氯苯醌(4Cl-BQ)反应电位最高(0.51 V vs.Ag/AgCl),多电子氧化还原反应机制使其在水系质子电池里具有158 mAh/g的出色容量和高的倍率性能,并且氯取代有效抑制了溶解,在1 A/g的电流密度下也能稳定循环超过1200圈,显示出优异的性能。最后通过探究了电荷的快速反应动力学特征解释了出色的倍率性能。该研究表明,通过引入-Cl基团改进的4Cl-BQ,能进一步提升其在电池里综合性能,是一种极具发展潜力的水系质子电池材料。展开更多
Metal-organic frameworks(MOFs)are import-ant as possible energy storage materials.Nitrogen-doped iron-cobalt MOFs were synthesized by a one-pot solvo-thermal method using CoCl_(3)·6H_(2)O and FeCl_(3)·6H_(2)...Metal-organic frameworks(MOFs)are import-ant as possible energy storage materials.Nitrogen-doped iron-cobalt MOFs were synthesized by a one-pot solvo-thermal method using CoCl_(3)·6H_(2)O and FeCl_(3)·6H_(2)O dis-solved in N,N-dimethylformamide,and were converted into Fe-Co embedded in N-doped porous carbon polyhedra by pyrolysis in a nitrogen atmosphere.During pyrolysis,the or-ganic ligands transformed into N-doped porous carbon which improved their structural stability and also their electrical contact with other materials.The Fe and Co are tightly bound together because of their encapsulation by the carbon nitride and are well dispersed in the carbon matrix,and improve the material’s conductivity and stability and provide additional capacity.When used as the anode for lithium-ion batteries,the material gives an initial capacity of up to 2230.7 mAh g^(-1)and a reversible capa-city of 1146.3 mAh g^(-1)is retained after 500 cycles at a current density of 0.5 A g^(-1),making it an excellent candidate for this purpose.展开更多
文摘含氧化还原活性基团的苯醌衍生物,在水系质子电池里是一种比容量高、资源丰富的理想电极材料,然而其高溶解性和低的工作电压不利于质子电池的循环稳定性和能量密度的提升,引入吸电子基团不仅可以降低其LUMO能量来提升其反应电位,还可以一定程度上抑制其溶解来提升稳定性。因此,通过电化学研究并对比了3种不同的苯醌化合物作为质子电池的电极材料,研究了不同氯取代情况造成的影响。其中四氯取代的四氯苯醌(4Cl-BQ)反应电位最高(0.51 V vs.Ag/AgCl),多电子氧化还原反应机制使其在水系质子电池里具有158 mAh/g的出色容量和高的倍率性能,并且氯取代有效抑制了溶解,在1 A/g的电流密度下也能稳定循环超过1200圈,显示出优异的性能。最后通过探究了电荷的快速反应动力学特征解释了出色的倍率性能。该研究表明,通过引入-Cl基团改进的4Cl-BQ,能进一步提升其在电池里综合性能,是一种极具发展潜力的水系质子电池材料。
文摘Metal-organic frameworks(MOFs)are import-ant as possible energy storage materials.Nitrogen-doped iron-cobalt MOFs were synthesized by a one-pot solvo-thermal method using CoCl_(3)·6H_(2)O and FeCl_(3)·6H_(2)O dis-solved in N,N-dimethylformamide,and were converted into Fe-Co embedded in N-doped porous carbon polyhedra by pyrolysis in a nitrogen atmosphere.During pyrolysis,the or-ganic ligands transformed into N-doped porous carbon which improved their structural stability and also their electrical contact with other materials.The Fe and Co are tightly bound together because of their encapsulation by the carbon nitride and are well dispersed in the carbon matrix,and improve the material’s conductivity and stability and provide additional capacity.When used as the anode for lithium-ion batteries,the material gives an initial capacity of up to 2230.7 mAh g^(-1)and a reversible capa-city of 1146.3 mAh g^(-1)is retained after 500 cycles at a current density of 0.5 A g^(-1),making it an excellent candidate for this purpose.
