【摘要】 用共沉淀法于 85 0℃在空气中煅烧 2 4h合成出层状LiNi0 .5Mn0 .5O2 正极材料 ,并用XRD ,SEM ,粒度分析和电性能测试考察了所得材料组成、结构、形貌及电化学性能 .本层状LiNi0 .5Mn0 .5O2 正极材料具有α NaFeO2 结构 ,六方晶系 ,R3m空间群 ,其晶胞参数为a =0 2 897nm ,c =1 43 1nm .当材料分别在在 2 8～ 4 2 ,2 8～ 4 4,2 8～ 4 7V间进行充放电时 ,其首次放电容量分别为 14 5 ,15 3 ,195mAh·g-1,且随着充放电电压升高 ,材料的首次放电不可逆容量增大 ,循环稳定性减弱 .该材料显示出层状LiNiO2 正极材料的充放电特性 ,在 2 0次充放电循环后 ,材料仍保持原层状结构更多还原

【Abstract】 The layered LiNi 0.5Mn 0.5O 2 cathode material for lithium ion batteries was synthesized in atmosphere at 850 ℃ for 24 h. XRD analysis, SEM and electrochemical tests were used to characterize the composition, structure, appearance and electrochemical performances of the aimed material. The lattice parameters of the hexagonal layered LiNi 0.5Mn 0.5O 2 (space group R3m) with an α-NaFeO 2 structure are a=0 2897 nm, c=1 431 nm. The composition studies show that the predominant oxidation states of Ni and Mn in the compound are 2+ and 4+ respectively with small content of Ni 3+ and Mn 3+ ions. The material shows the electrochemical properties like LiCo xNi 1-xO 2 cathode material. Initial discharge capacities of 145, 153, 195 mAh·g -1 were respectively obtained in the range of 2 8～4 2, 2 8～4 4, 2 8～4 7 V, and its electrochemical stability descended with the increase of the charge-discharge voltage. The material also retains the primary layered structure after 20 charge-discharge cycles.更多还原