LiPON薄膜结构与电化学性能研究

Study on Structure and Electrochemical Properties of LiPON Thin Film

采用355nm脉冲激光沉积(PLD)法制备了室温离子电导率为1.6×10-6Scm的LiPON电解质薄膜。用X射线衍射(XRD)、扫描电子显微镜(SEM)、傅立叶变换红外光谱(FTIR)、X射线光电子能谱(XPS)等方法对薄膜的结构和形貌进行表征,讨论了LiPON薄膜的电化学性能与其结构之间的关系。结果表明,该薄膜是一种无针孔、无裂缝、厚度均匀的非晶态结构。N元素插入到Li3PO4中,取代POP和PO3结构中的O使N与P成键形成PN=P或PNPP,增加了薄膜中的网状结构,从而提高了离子电导率。另外,随着N含量增大,LiPON薄膜的室温离子电导率增大。

A LiPON electrolyte thin film with 1.6 × 10-6 S&middotcm-1 ionic conductivity at room temperature was prepared by pulsed laser deposition (PLD). The structure and morphology of the film were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The dependences of electrochemical properties of the thin film on its structure were discussed. The results show that the LiPON thin film with uniform thickness, free of pinholes and cracks presents an amorphous structure. P-N=P formed by N inserting Li3PO4 and replacing O in the structure of P-O-P and PO3 constitute a netlike structure which increases thin film ionic conductivity. In addition, it is find that LiPON ionic conductivity at 25°C increases with N content in the thin film.