原位交联杂化型聚合物电解质膜的形成机理、结构模型及其电化学性能

Formation Mechanism,Structure Model and Electrochemical Performance of an In situ Cross Linking Hybrid Polymer Electrolyte Membrane

合成含有Ti(VI)杂化中心的交联(柠檬酸钛络合体-聚乙二醇)聚酯网络作为基体,水解生成的Nano-TiO2粒子为填料,LiI/I2为导电介质,通过原位聚合复合法制备了Nano-TiO2/(柠檬酸钛络合体-聚乙二醇)/LiI/I2交联杂化型聚合物电解质膜.采用局域密度近似(LDA)法、Raman光谱、傅里叶变换红外(FTIR)光谱、透射电子显微镜(TEM)和能量散射X射线分析(EDXA)探讨了交联杂化聚合物基体的形成机理,并建立了其相应的结构模型.在此基础之上,研究了四异丙氧基钛(Ti(iOPr)4)的含量对Nano-TiO2/(柠檬酸钛络合体-聚乙二醇)/LiI/I2电解质膜的结构及电化学性能的影响.研究表明:当Ti(iOPr)4含量高于12%(w)时,Nano-TiO2粒子和Ti(VI)杂化中心的共同作用不仅有效提高了电解质膜的离子电导率(σ),而且显著改善了电解质膜与电极间的界面稳定性;Ti(iOPr)4含量为48%(w)时,电解质膜的室温离子电导率达到最大值9.72×10-5S·cm-1,电解质膜的界面电阻于6d后趋于稳定.

A Nano-TiOJpoly（citric acid titanium complex-polyethylene glycol）/Lil/12 crosslinked hybrid polymer electrolyte membrane has been prepared via in-situ polymerization and compositing. Specifically, the method used the synthesized crosslinked network of poly（citric acid titanium complex-polyethylene glycol） containing the Ti（VI） hybrid center as a substrate, the hydrolyzed Nano-TiO2 as fillers and Lil/12 as conductive ionics. The formation mechanism of the crosslinked hybrid polymer matrix is discussed. A structural model was established with a local density approximation （LDA） method. The influence of l]（iOPr）4 content on the structure and electrochemical performance of the electrolyte membrane were investigated with Raman spectra, Fourier transform infrared spectra （FTIR）, transmission electron microscopy （TEM）, and an energy dispersive X-ray analysis （EDXA） technique. It was found that when the Ti（iOPr）4 contentwas higher than 12% （w）, the combined action of Nano-TiO2 particles and the Ti（VI） hybrid center improved not only the room-temperature ionic conductivity （a）, but also the interfacial stability. At 48% （w） Ti（iOPr）4 content, the value of （7 reached a maximum of 9.72x 10-5 S- cm-1 and the interface resistance became stable after 6 d.