超细氧化钇材料的制备及其在包覆LiCoO_(2)材料中的应用

Preparation of Ultrafine Y_(2)O_(3) and Its Application in Coated LiCoO_(2)

本文以自制亚微米氧化钇为包覆物,采用高速固相包覆机包覆LiCoO_(2)(LCO),并采用X射线衍射仪(XRD)、扫描电镜(SEM)及电化学测试等手段对LCO包覆前后的物相结构、表面形貌及电化学性能进行研究。结果表明:氧化钇包覆并未影响LCO的晶体结构,氧化钇以颗粒状均匀分布在正极材料表面;与未包覆LCO相比,氧化钇包覆后的材料极化明显减小,倍率性能和循环稳定性显著提升,其最佳包覆量为0.5%(w)。

Submicron Yttrium oxide coated LiCoO_(2)(LCO)was successfully prepared by high-speed solid-phase mixing machine using yttrium oxide as coating material.The crystal structure,morphology and electrochemical properties of uncoated and yttrium oxide coated LCO were investigated by X-ray diffraction(XRD),scanning electron microscopy(SEM)and electrochemical measurements.The results indicate that the crystal structure is not affected by yttrium oxide coating.Comparing with the uncoated LCO,the polarization decreased after yttrium oxide coating,the rate capability and the cycle performance improved significantly,the optimum coating amount is 0.5%(w).