【摘要】 本文通过固相法制备出NaNi_1/3Fe_1/3Mn_1/3O_2-xF_x（x=0,0.005,0.01,0.02）正极材料.该材料的电化学性能表明F元素的掺杂有利于提高其循环性和稳定性.其中当F元素的掺杂量为0.01时,材料的电化学性能最为优异,在150 mA g^-1的电流密度下,循环70圈容量仍保持在110 mA hg^-1.通过XPS、Raman等表征方法研究了F元素掺杂提高材料电化学性能的机理.本工作对于F元素掺杂钠电层状正极材料研究具有一定的参考意义.更多还原

【Abstract】 The F-doped O3-type NaNi_1/3Fe_1/3Mn_1/3O_2-xF_x（x = 0, 0.005, 0.01, 002 and noted as NFM-F0, NFM-F0.005,NFM-F0.01, NFM-F0.02, respectively, united as NFM-Fs）cathode materials were investigated systematically. The rate performance and capacity retention of the O3-type cathode materials are significantly improved as a function of specific F-doping levels. Optimum performance is achieved in the NFM-F0.01 material having a capacity of ¹10 mA h g^-1 at a current density of 150 mA g^-1 after 70 cycles. The results indicate that the binding energy of oxygen changes as a result of F-doping, and in addition, F-doping results in changes to the stoichiometry of Mn³⁺/Mn⁴⁺, which stabilizes the O3-type layered structure, thus allowing cycling performance to be improved. However, NFM-F0.02, having a higher F-doping level, retains a high capacity retention, although a slight loss is observed. The results suggest there is an optimum F-doping level for the NFM-F system to deliver enhanced cycling performance.更多还原