铌掺杂锌离子电池正极材料的制备及电化学性能研究

摘要

Nb-doped manganese dioxides were prepared by doping niobium oxalate solution into KMnO4 and Mn(CH3COO)2?4H2O solution during the process of reaction using a liquid-phase co-precipitation method. X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) were used to characterize the synthesized material, it's found that doping Nb ions into manganese dioxide could make the particle size smaller, but the structure of manganese dioxide kept all the same. By using this material as cathode for zinc-ion batteries and assembling coin cells, it's found that doping Nb ions could enhance the electrochemical performance of zinc ion batteries. Under 1A/g current density, the capacity could reach 165.3mAh/g with Nb-doped material, while the maximum capacity of pure material was only 146.6mAh/g under the same condition. Both the rate capability and cycling stability were excellent in this work.%以高锰酸钾和乙酸锰为原料,在利用液相共沉淀法合成二氧化锰的过程中加入草酸铌溶液来合成掺有Nb的二氧化锰.通过粉末X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)等手段对合成的二氧化锰进行表征,发现掺杂Nb能够使粉末颗粒的粒径变小,但不改变材料的结构.通过将粉末材料制成锌离子电池的正极材料并组装扣式电池进行电化学测试,发现掺杂Nb离子能够提高锌离子电池的容量,在1 A/g的电池密度下掺杂Nb离子的电池放电比容量最高达到165.3 mA·h/g,相同条件下未掺杂Nb的电池放电比容量最高为146.6 mA·h/g,并且掺杂后电池的倍率性能和循环稳定性都比较优异.