Nanopowder MnO 2 was prepared with two oxidation reduction methods.XRD,SEM,FT IR and surface area measurement techniques were used to investigate properties of the MnO 2 powder.The results showed that the nano MnO 2 w...Nanopowder MnO 2 was prepared with two oxidation reduction methods.XRD,SEM,FT IR and surface area measurement techniques were used to investigate properties of the MnO 2 powder.The results showed that the nano MnO 2 with an average diameter in 30～50nm and good dispersity and high catalytic activity for H 2O 2 decomposition,can be synthesized with the two methods.With reduced crystal size of the powder,the infrared absorption peak of Mn O bond was blue shifted and fissioned,one shifted 61 19cm -1 and the other shifted 11 15cm -1 ,and the characteristic vibration bands of adsorption water were also blue shifted.展开更多
研究了水系电解液中Li^+、Zn^(2+)和Mn^(2+)阳离子对具有不同晶型结构和形貌的MnO_2正极电化学性能的影响,探讨其储能机理。结果表明,在不含Mn(Ⅱ)离子的水溶液中,MnO_2电极所表现的电化学性能趋同,容量低,衰减快。含有Zn^(2+)离子的水...研究了水系电解液中Li^+、Zn^(2+)和Mn^(2+)阳离子对具有不同晶型结构和形貌的MnO_2正极电化学性能的影响,探讨其储能机理。结果表明,在不含Mn(Ⅱ)离子的水溶液中,MnO_2电极所表现的电化学性能趋同,容量低,衰减快。含有Zn^(2+)离子的水溶液中,MnO_2电极因二价锌离子的嵌入-脱出,容量明显提升,但衰减严重。当溶液中同时含有Zn^(2+)、Mn^(2+)离子时,基于Mn^(2+)和Zn^(2+)离子之间的协同作用和Mn^(2+)离子氧化/还原反应过程的作用,有效抑制MnO_2颗粒的聚集和结构塌陷,削弱碱式硫酸锌杂质不利的影响,保持了锌离子在MnO_2电极中嵌入-脱出的高容量特性(200 m Ah?g^(-1),电流密度:100m A?g^(-1)),及良好的循环稳定性。展开更多
文摘Nanopowder MnO 2 was prepared with two oxidation reduction methods.XRD,SEM,FT IR and surface area measurement techniques were used to investigate properties of the MnO 2 powder.The results showed that the nano MnO 2 with an average diameter in 30～50nm and good dispersity and high catalytic activity for H 2O 2 decomposition,can be synthesized with the two methods.With reduced crystal size of the powder,the infrared absorption peak of Mn O bond was blue shifted and fissioned,one shifted 61 19cm -1 and the other shifted 11 15cm -1 ,and the characteristic vibration bands of adsorption water were also blue shifted.
文摘研究了水系电解液中Li^+、Zn^(2+)和Mn^(2+)阳离子对具有不同晶型结构和形貌的MnO_2正极电化学性能的影响,探讨其储能机理。结果表明,在不含Mn(Ⅱ)离子的水溶液中,MnO_2电极所表现的电化学性能趋同,容量低,衰减快。含有Zn^(2+)离子的水溶液中,MnO_2电极因二价锌离子的嵌入-脱出,容量明显提升,但衰减严重。当溶液中同时含有Zn^(2+)、Mn^(2+)离子时,基于Mn^(2+)和Zn^(2+)离子之间的协同作用和Mn^(2+)离子氧化/还原反应过程的作用,有效抑制MnO_2颗粒的聚集和结构塌陷,削弱碱式硫酸锌杂质不利的影响,保持了锌离子在MnO_2电极中嵌入-脱出的高容量特性(200 m Ah?g^(-1),电流密度:100m A?g^(-1)),及良好的循环稳定性。
