溶剂对PEO基固态电解质制备与性能的影响

Influence of solvent on preparation and performance of PEO solid electrolyte

采用溶液浇铸法制备了PEO基聚合物固态电解质,并通过X射线衍射(XRD)、扫描电镜、交流阻抗法等方法对不同溶剂制备固态电解质的结构、形貌、电导率以及锂离子迁移数等进行分析表征。结果表明,溶剂对固态电解质的微观结构存在着较大的影响,以丙酮、乙腈为溶剂制备的固态电解质(S_A)表面致密,具有最低的结晶度,而以NMP、乙腈为溶剂制备的固态电解质(S_N)结晶度最高。固态电解质的微观结构直接决定了其机械性能和电化学性能,SA的抗拉强度为2.219 MPa,在80℃下的离子电导率可达到8.3×10^(–4)S/cm。所制备固态电解质可应用于锂离子固态电池的制备与研究中。

In this paper,PEO based polymer solid electrolyte films were prepared using a solution casting method.X-ray diffraction(XRD), SEM and the electrochemical impedance spectra(EIS) were used to study the micro-structure, morphology, ion conductivity and lithium-ion transference number of solid polymer electrolyte(SPE)prepared by different organic solutions. The results show that the solution has a large impact on the micro-structure of SPE. SPE prepared by acetone and acetonitrile(SA) shows a dense surface with the lowest crystallinity, while SPE prepared by NMP and acetonitrile(SN) shows the highest crystallinity. The micro-structure of SPEs directly determine their mechanical and electrical properties. The extension strength of S A film is approximately 2.219 MPa, and its ion conductivity at 80 ℃ reaches 8.3×10-4 S/cm. The as-prepared SPE can be a preferable candidate for Li-ion solid battery use.