将氢氧化物共沉淀法制备的(Ni1/3Co1/3Mn1/3)(OH)2在500℃热处理5h得到具有尖晶石结构、纳米尺寸的氧化物M3O4(M=Ni1/3Co1/3Mn1/3).将其与LiOH及不同量的纳米MgO混合均匀,并在850℃热处理24 h制备了Li(Ni1/3Co1/3Mn1/3)1-xMgxO2(x=0,0.01,0.02,0.03,0.04,0.05)正极材料.随着Mg掺杂量的增大,正极材料的晶胞参数增大;少量的Mg掺杂增大了锂离子的扩散系数,而过度掺杂却使锂离子扩散系数有所降低,其中Li(Ni1/3CO1/3Mn1/3)098Mg002O2的锂离子扩散系数最大,其脱出和嵌入扩散系数分别为DLi-dem=29.20x 10-11 cm2·S-1和DLi-in=4.760×10-11 cm2·s-1;其以3C倍率充放电的平均放电比容量为139.3 mAh·g-1,比未掺杂的原粉约高9.5 mAh·g-1;另外其循环性能也得到了大幅度改善.%Abstract: Nano-sized M3O4 (M=Ni,/3Coi,3Mnw) powder with a spinel structure was prepared by sintering co-precipitated M(OH>2 at 500 °C for 5 h. The so-obtained M3O4 was then mixed with LiOH and different amounts of nano-MgO. The mixture was sintered at 850 °C for 24 h to synthesize Li(Nii?C0i/3Mn,?)I-,MgxO2 (x=0, 0.01, 0.02, 0.03, 0.04,0.05) cathode materials. The lattice parameters increased while the diffusion coefficients of Li' ion showed an increasing and then decreasing trend with an increase in the amount of Mg substitution. Li(Nii/3Coi/3Mnm)o9eMgoo202 had the highest Li* ion diffusion coefficients, which were 29.20* 10~11 cm^s"1 for Li* de-intercalation and 4.760 *10~11 cnf-s"1 for Li* intercalation. Its discharge capacity at 3C rate was 139.3 mAh-g1, which is 9.5 mAh-g"1 higher than that of the pristine material. Furthermore, its cycle performance was also improved significantly compared with the un-doped counterpart.
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