煅烧温度对溶胶-凝胶法合成LiNi_(0.8)Co_(0.15)Al_(0.05)O_2正极材料物相结构的影响

Influence of calcination temperature on phase structure of LiNi_(0.8)Co_(0.15)Al_(0.05)O_2 anode material by sol-gel

以硝酸锂、硝酸镍、硝酸钴、硝酸铝和柠檬酸为原料,采用溶胶-凝胶法合成了镍钴铝三元(LiNi_(0.8)Co_(0.15)Al_(0.05)O_2)正极材料前驱体,经热处理后得到LiNi_(0.8)Co_(0.15)Al_(0.05)O_2正极材料。采用扫描电子显微镜和X射线衍射仪对正极材料进行了表征与分析。结果表明:随着温度的升高,正极材料的颗粒更为均匀,分散性良好,晶体杂相减少。当煅烧温度升高至700℃及以上时得到了α-NaFeO_2型层状结构的LiNi_(0.8)Co_(0.15)Al_(0.05)O_2正极材料。随着煅烧温度的升高,LiNi_(0.8)Co_(0.15)Al_(0.05)O_2正极材料中的杂质相逐渐减少,纯度不断提高,层状结构性能不断改善,结晶度逐渐提高,锂离子嵌入与脱出通道畅通,材料的晶粒尺寸不断增大。当煅烧温度为800℃时,正极材料的层状结构性能最佳。

LiNi0.8Co0.15Al0.05O2 anode materials were synthesized by sol-gel method with lithium nitrate,nickel nitrate,cobalt nitrate,aluminum nitrate and citric acid as raw materials.The materials were characterized and analyzed by SEM and XRD.The results showed that the particles of LiNi0.8Co0.15Al0.05O2 were more uniform,more dispersible and less impurities with increasing the temperature.The anode materials withα-NaFeO2 layered crystal structure can been obtained when the calcination temperature raised at 700℃ and over.With increasing the temperature,the impurity decreased,the purity increased,the layered crystal structure and crystallinity were improved,as well as the channels of lithium ion intercalation and deintercalation were optimized.When the calcination temperature raised at 800℃,the layered crystal structure of LiNi0.8Co0.15Al0.05O2 was the best.