锂硫电池宿主材料的成份与结构区别,是引起电池性能差异的重要原因。经济性好且环保的碳基宿主材料是实现锂硫电池实用化的最有效策略之一。本研究利用油棕树叶柄为原料,采用尿素浸泡和化学活化的方法,制备出具有堆叠纳米片层结构的氮...锂硫电池宿主材料的成份与结构区别,是引起电池性能差异的重要原因。经济性好且环保的碳基宿主材料是实现锂硫电池实用化的最有效策略之一。本研究利用油棕树叶柄为原料,采用尿素浸泡和化学活化的方法,制备出具有堆叠纳米片层结构的氮掺杂多孔炭材料(NPPCNs)用作硫正极宿主材料,显著提高了电池的性能。N-PPCNs实现了N元素的均匀掺杂,作为硫的宿主材料,增加了对多硫化物的吸附能,加速了多硫化物的转化动力学。复合多孔结构和氮的有效掺杂共同作用,抑制了“穿梭效应”,使复合电极达到1257 mAh g^(−1)的高比容量,在1 C倍率下循环500圈仍可保持490 mA h g^(−1)的比容量。这项工作充分证明了废弃生物质再利用的潜力。展开更多
Siderite,as an abundant iron ore,has not been effectively utilized,with a low utilization rate.In this study,the in-situ kinetics and mechanism of siderite during suspension magnetization roasting(SMR)were investigate...Siderite,as an abundant iron ore,has not been effectively utilized,with a low utilization rate.In this study,the in-situ kinetics and mechanism of siderite during suspension magnetization roasting(SMR)were investigated to improve the selective conversion of siderite to magnetite and CO,enriching the theoretical system of green SMR using siderite as a reductant.According to the gas products analyses,the peak value of the reaction rate increased with increasing temperature,and its curves presented the feature of an early peak and long tail.The mechanism function of the siderite pyrolysis was the contraction sphere model(R_(3)):f(α)=3(1−α)2/3;E_(α)was 46.4653 kJ/mol;A was 0.5938 s^(−1);the kinetics equation was k=0.5938exp[−46.4653/(RT)].The in-situ HT-XRD results indicated that siderite was converted into magnetite and wüstite that exhibited a good crystallinity in SMR under a N_(2) atmosphere.At 620℃,the saturation magnetization(M_(s)),remanence magnetization(Mr),and coercivity(Hc)of the product peaked at 53.63×10^(-3)A·m^(2)/g,10.23×10^(-3)A·m^(2)/g,and 12.40×10^(3)A/m,respectively.Meanwhile,the initial particles with a smooth surface were transformed into particles with a porous and loose structure in the roasting process,which would contribute to reducing the grinding cost.展开更多
文摘锂硫电池宿主材料的成份与结构区别,是引起电池性能差异的重要原因。经济性好且环保的碳基宿主材料是实现锂硫电池实用化的最有效策略之一。本研究利用油棕树叶柄为原料,采用尿素浸泡和化学活化的方法,制备出具有堆叠纳米片层结构的氮掺杂多孔炭材料(NPPCNs)用作硫正极宿主材料,显著提高了电池的性能。N-PPCNs实现了N元素的均匀掺杂,作为硫的宿主材料,增加了对多硫化物的吸附能,加速了多硫化物的转化动力学。复合多孔结构和氮的有效掺杂共同作用,抑制了“穿梭效应”,使复合电极达到1257 mAh g^(−1)的高比容量,在1 C倍率下循环500圈仍可保持490 mA h g^(−1)的比容量。这项工作充分证明了废弃生物质再利用的潜力。
基金Projects(51874071,52022019,51734005)supported by the National Natural Science Foundation of ChinaProject(161045)supported by the Fok Ying Tung Education Foundation for Yong Teachers in the Higher Education Institutions of China。
文摘Siderite,as an abundant iron ore,has not been effectively utilized,with a low utilization rate.In this study,the in-situ kinetics and mechanism of siderite during suspension magnetization roasting(SMR)were investigated to improve the selective conversion of siderite to magnetite and CO,enriching the theoretical system of green SMR using siderite as a reductant.According to the gas products analyses,the peak value of the reaction rate increased with increasing temperature,and its curves presented the feature of an early peak and long tail.The mechanism function of the siderite pyrolysis was the contraction sphere model(R_(3)):f(α)=3(1−α)2/3;E_(α)was 46.4653 kJ/mol;A was 0.5938 s^(−1);the kinetics equation was k=0.5938exp[−46.4653/(RT)].The in-situ HT-XRD results indicated that siderite was converted into magnetite and wüstite that exhibited a good crystallinity in SMR under a N_(2) atmosphere.At 620℃,the saturation magnetization(M_(s)),remanence magnetization(Mr),and coercivity(Hc)of the product peaked at 53.63×10^(-3)A·m^(2)/g,10.23×10^(-3)A·m^(2)/g,and 12.40×10^(3)A/m,respectively.Meanwhile,the initial particles with a smooth surface were transformed into particles with a porous and loose structure in the roasting process,which would contribute to reducing the grinding cost.
