摘要
以LiNO3、AI（NO3）3·9H2O和球形Ni（OH）2为原料，采用熔盐包裹法在空气中合成了球形LiNi0．95AI0．05O2。研究了合成产物的形貌、结构和电化学性能，考察了合成温度、合成时间和锂过量对合成产物结构和电化学性能的影响。实验结果表明，在空气中合成的LiNi0．95AI0．05O2具有α-NaFeO2型层状有序结构、良好的球状形貌和相当高的电化学性能。在空气中合成LiNi0．95AI0．05O2的最佳工艺条件为煅烧温度750℃，煅烧时间16h，锂过量摩尔分数10％。在室温下以30mA／g的电流密度在2．5～4．35V电压之间充放电，样品首次放电比容量达176．0mA·h／g，经30次循环，放电比容量仍保持在167．1mA·h／g，容量保持率为94．9％。
A spherical cathode material LiNi0.95AI0.05O2 was synthesized by meh-sah coating method in air using LiNO3, AI（ NO3 ）3 · 9H2O and spherical Ni（OH） 2 as starting materials. The morphology, structure and performence of the resulted product were characterized. The effects of synthesizing temperature, time and excess Lithium on the structure and electrochemical property of the resulted products were systemically investigated. The experimental results show that the synthesized material LiNi1-x Alx O2 has the α-NaFeO2 type ordered layered structure, spherical morphology and good electrochemical performance. The optimized conditions to synthesize LiNi0.95AI0.05O2 are to calcine at 750℃ for 16 h with 10% excess lithium in the starting materials. The sample prepared under such conditions has the highest initial discharge capacity of 176 mA · h/g, the smallest irreversible capacity loss of 22.5% and the discharge capacity of LiNi0.95AI0.05O2 still retains at 167.1 mA · h/g and the capacity retention ratio is 94. 9% after 30 cycles at a constant current density of 30 mA/g between 2.5 and 4.35 V versus Li at room temperature.
出处
《应用化学》
CAS
CSCD
北大核心
2008年第12期1430-1434,共5页
Chinese Journal of Applied Chemistry
基金
广西自然科学基金资助项目(0575100)
广西教育厅科研项目(0420022)
