乙醇洗涤对LiNi0.8Co0.15Al0.05O2正极材料性能的影响

摘要

采用乙醇溶剂对不同LiNi0.8Co0.15Al0.05O2正极材料进行洗涤.采用电感耦合等离子体原子发射光谱(ICP-AES)、傅里叶变换红外光谱(FTIR)、X射线衍射(XRD)、扫描电子显微术(SEM)、充放电测试和电化学阻抗谱(EIS)对样品的元素含量、结构、形貌和电化学性能进行表征.结果表明,乙醇洗涤能够有效去除新制备的LiNi0.8Co0.15Al0.05O2表面残留的LiOH/Li2O杂质,不会破坏材料的本体结构、表面形貌和电化学性能,使得材料具有更好的耐H2O和CO2腐蚀性.并且,使用乙醇立即对新制备的材料进行洗涤,再置于相对湿度80％的空气中储存3个月后,其放电比容量和循环性能相对于未洗涤样品得到大幅提升.%Different LiNi0.8Co0.15Al0.05O2 cathode materials were washed by ethanol solvent. Inductively coupled plasma atomic emission spectroscopy (ICP-AES), Fourier transformed infrared (FTIR) spectrum, X-ray diffraction (XRD), scanning electron microscopy (SEM), charge?discharge test and electrochemical impedance spectroscopy (EIS) were used to evaluate the elemental contents, structures, morphologies and electrochemical properties of samples. The results show that ethanol washing can remove effectively the synthetic residues LiOH/Li2O on the freshly-prepared LiNi0.8Co0.15Al0.05O2 and make the sample much more resistant to H2O and CO2, without destroying its bulk structure, surface morphology and electrochemical performances. Moreover, the discharge specific capacity and cycle performance of LiNi0.8Co0.15Al0.05O2 after storage in air with a relative humidity of 80％ for three months are improved by immediate ethanol washing.