镍系复合氧化物Li_aNi_(0.78)Co_(0.2)Cd_(0.02)O_2的合成及电化学性能

以LiOH·H2O,含镉球状Ni(OH)2和Co2O3为原料,采用改进固相反应法合成镍系复合氧化物LiaNi0.78Co0.2Cd0.02O2锂离子电池正极材料,并通过ICP＿AES,XRD,SEM,TEM及电化学性能测试对该材料进行表征.实验表明,由Co和Cd部分取代Ni元素的复合正极材料LiaNi0.78Co0.2Cd0.02O2仍具有较完好的层状结构,表面分布均匀,颗粒粒径分布窄,且电化学性能稳定.常温下具有较高的可逆容量和优异的循环稳定性,其可逆容量最高达157.8mAh/g,循环50次后容量仍保持138.3mAh/g左右.

Synthesis and Electrochemical Characteristics of Nickel-based Complex Oxide LiaNi0.78Co0.2Cd0.02O2

The nickel_based complex oxide LiaNi0.78Co0.02O2 cathode materials for lithium_ion rechargeable batteries was synthesized by the improved solid_state reaction method with LiOH·H2O, ball_like Cd_doped Ni(OH)2 and Co2O3 as raw materials. The analysis ICP_AES proved that the as_prepared compounds were near the stoichiometric form. The XRD, SEM and electrochemical characteristics testing were also carried out. The results showed that the complex cathode material LiaNi0.78Co0.2Cd0.02O2 has layered structure, homogeneous surface distributions,uniform particles with good crystal morphology as well as stable electrochemical performances. At ambient temperature the resulted materials have a high reversible capacity and good cycling stability.Its highest initial reversible capacity is more than 157.8 mAh/g and still kept at 138.3 mAh/g after 50 continuous cycles.