Preparation and sodium storage of NaNi0.4Fe0.2Mn0.4O2 cathode material for sodium ion batteries
Sodium ion batteries have unique advantages as the next generation batteries that could replace lithium ion batteries,however,the development of electrode materials with low cost,good reversibility and long cycle life still remains many technical difficulties.NaNi0.4 Fe0.2 Mn0.4 O2 cathode material for sodium ion batteries was prepared by a simple co-precipitation synthesis of NiⅡ0.4 FeⅡ0.2 MnⅡ0.4(OH)2 precursor,which was then annealed with Na2 CO3 in air atmosphere.The structure and morphologies of the as-prepared materials were characterized by X-ray diffraction(XRD)and scanning electron microscope(SEM).The results showed that the NaNi0.4 Fe0.2 Mn0.4 O2 had a typical layered rhombohedral structure and a large portion of the material had a characteristic of single crystal.The electrochemical properties of the NaNi0.4 Fe0.2 Mn0.4 O2 material were studied by galvanostatic charge-discharge test.The charge and discharge capacity of the first cycle is 141.9 mAh/g and 140.0 mAh/g at a rate of 0.1 C with an initial coulombic efficiency of 98.7%.In addition,the NaNi0.4 Fe0.2 Mn0.4 O2 could deliver discharge capacities of 129.5 mAh/g,112.6 mAh/g,97.8 mAh/g,82.9 mAh/g and 72.8 mAh/g at 0.2 C,0.5 C,1 C,2 C and 3 C rate,respectively.The capacity retention was about 70.0%after 100 cycles at 0.5 C,showing a good rate capability and a limited cyclability.
NaNi0.4 Fe0.2 Mn0.4 O2sodium ion batteriesco-precipitationcathode materialtransition metal oxide
NETL
NSTL
万方数据
