用作锂离子电池正极材料的不同晶型五氧化二铌的制备及其电化学性能

Synthesis and electrochemical properties of Nb_2O_5 with different crystal type as cathode material for lithium ion batteries

以水合草酸铌(C_(10)H_5NbO_(20))为原料,采用一种简单的一步煅烧法,制备出不同晶型的五氧化二铌.利用X射线衍射分析(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)对其物相和形貌进行表征,并对其电化学性能进行测试.结果表明:煅烧温度对Nb_2O_5的晶型和形貌有很大影响,与800℃的Nb_2O_5混合相和1 000℃的H-Nb_2O_5相比,600℃煅烧的TNb_2O_5晶粒尺寸较小;用作锂离子电池正极材料时,其表现出比容量高、循环稳定性强以及优越的倍率性能(在1 000mA g^(-1)的电流密度下维持160mAh g^(-1))等优点,展示了良好的电化学性能.

Nb2O5 with different crystal type was successfully fabricated by a facile calcination method using C10H5NbO20as raw material.Phase compositions and microstructures of the as-prepared Nb2O5 were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM)and Transmission electron microscopy(TEM).The electrochemical properties of Nb2O5 were also investigated.Results show that calcination temperature has a great influence on the crystal phase composition and the crystal morphology.The size of the Nb2O5 with which calcined at 600°C is much smaller than that of 800°C and 1 000°C with respectively.As a cathode for Li-ion batteries,the T-Nb2O5 delivers high specific capacity,good cycling stability and rate capability of 160 mAh g^-1 at 1 000 mA g^-1,exhibiting good electrochemical properties.