【作者】 杨柳；

【导师】 顾大明；

【作者基本信息】 哈尔滨工业大学 ， 无机化学， 2008， 硕士

【摘要】 采用溶液浇铸法,首次选用LiNi_0.8Co_0.2O₂为无机添加剂制备了聚环氧乙烷（poly ethylene oxide, PEO）基全固态复合聚合物电解质（Solid Polymer Electrolyte,SPE）膜,并与皂石、改性蒙托土（MMT）为无机添加剂制备的SPE膜等进行了比较,考察了无机添加剂的种类、含量、环境温度、锂盐含量、水分含量、体系成膜热处理时间、搅拌温度、搅拌时间等因素对体系化学及物理性能的影响,优化了制备工艺,计算了体系的活化能。利用XRD、SEM、FTIR、DSC、机械拉伸、线性扫描伏安法、计时电流法等手段对电解质膜的晶体结构、微观形貌、结构组成、机械性能、离子迁移数,电化学稳定窗口等进行了表征。XRD测试结果表明,LiNi_0.8Co_0.2O₂等无机添加剂的加入降低了PEO的结晶度,有利于SPE膜离子电导率的提高;SEM测试表明,各无机添加剂使SPE膜更加致密和平整;FTIR测试表明,各无机添加剂的加入没有改变PEO主链的拓扑结构;DSC测试表明,LiNi_0.8Co_0.2O₂降低了PEO的结晶相的百分含量,这与XRD的测试结果是相吻合的;机械拉伸实验表明,无机添加剂的加入提高了SPE膜的机械强度,改善了膜材料的可加工性能,同时保持了良好的塑性特征;线性扫描伏安测试表明,所制备的SPE膜电化学稳定窗口在3.5V左右,需要进一步提高;计时电流测试表明,无机添加剂提高了SPE膜的离子迁移数,其中PEO-LiClO₄-LiNi_0.8Co_0.2O₂膜材料的离子迁移数达到0.83,其离子电导率达到5×10^-4S/cm（25℃）。更多还原

【Abstract】 A new kind of PEO-based solid composite polymer electrolyte （SPE） film was prepared using a solution casting method when LiNi_0.8Co_0.2O₂ was first time used as inorganic additive, and it was compared with other kind of SPE films using saponite and MMT as inorganic additive respectively. Factors of the kind and the content of inorganic additive, temperature, concentration of lithium salts, concentration of water, time for heat treatment on a film, temperature and time for the insert of the polymer and so on were checked to confirm their effect on the conductivity of SPE to obtain optimal techniques and calculate the activation energy and the concentration of crystalline phase of this system. The SPE films were also characterized by X-ray diffraction （XRD）, scanning electronic microscopy （SEM）, Fourier transform infrared spectrometer （FTIR）, differential scanning calorimetry （DSC）, mechanical tension, linear scanning voltammetry to obtain their structure of crystalline phase, microcosmic pattern, composition, mechanical behaviour, Li-ion transport number and the electrochemical stability window.The XRD results showed that the inorganic additives such as LiNi_0.8Co_0.2O₂ depress the crystallinity of PEO and increase the ionic conductivity of the SCPE films; The SEM results showed that the inorganic additives make the SCPE films more compact and smooth; The FTIR results showed that the inorganic additives did not change the topology structure of the PEO chain segment; The DSC results showed that LiNi_0.8Co_0.2O₂ depress the concentration of crystalline phase, which matched up to the results of the XRD; The mechanical tension results showed that the inorganic additives increase the mechanical strength of the SCPE films, and improve the processing properties of it; The linear voltammetry results showed that the electrochemical stability window of SPE film is about 3.5V;The inorganic additives especially LiNi_0.8Co_0.2O₂ improved the transmission of Li⁺ markedly; Moreover, the ionic conductivity of the SPE film reached 5×10^-4S/cm（25℃）。更多还原