【摘要】 采用改进的固相法一步反应成功制备了掺杂Cr的系列正极材料L i[Mn1/3-x/3N i1/3-x/3Co1/3-x/3Crx]O2(x=0,0.015,0.025,0.050,0.100),用XRD,SEM和充放电测试等考察了它们的物理性质和电化学性能。结果表明,所合成的正极材料具有O2层状结构,规则的形貌和均匀的粒径尺寸分布,其嵌锂脱锂均为一步机理。加入适量的Cr可提高该系列正极材料的电化学性能和循环稳定性。x=0.015时的正极材料电化学性能最佳,室温下其首次放电比容量为138.60 mAh.g-1,并且循环性能最好。更多还原

【Abstract】 The layered Li[Mn_1/3-x/3Ni_1/3-x/3Co_1/3-x/3Cr_x]O₂（x=0,0.015,0.025,0.050,0.100） materials were prepared by means of an improved solid-state reaction,and their physical and electrochemical properties were investigated by XRD,SEM and electrochemical testing techniques.When（x=）0 and 0.015,the mean size of samples is about 800 nm and the samples have uniform morphology and normal grain-size distribution.The materials showed only one plateau between 2.5 V～4.5 V.A significant structure transformation to the spinel-type phase was not found in the charge-discharge cycling.The layered structure was stabilized and the discharge capacity was also increased by doping appropriate amount of Cr³⁺.The 1.5 mol% chromium-doped active materials exhibited the best cycle performance.It delivered an initial discharge capacity of 138.60 mAh· g^-1 in a cut-off range between 2.5 V and 4.5 V at room temperature,but the capacity and retention were found to decrease when the concentration of Cr³⁺ was over 1.5 mol%.更多还原