Elektrospun, ion-conducting polymer membranes as solid electrolytes

在本研究计画中，我们拟以不同离子配位聚合物与导电盐添加剂合成电纺固体电解质。在确定和优化的电化学性能，我们打算确定通过膜的离子传输的基本传导机制。四种不同的聚合物，选择的锂，钠和镁导电盐和添加剂将用于通过静电纺丝制备纤维膜。将测试这些膜的热性能、机械性能和电化学性能，以确定性能最佳的离子传导系统。四种不同的聚合物，聚环氧乙烷（PEO），聚丙烯腈（PAN），聚甲基丙烯酸甲酯（PMMA），聚偏二氟乙烯（PVdF），和选定的溶解的导电盐将静电纺丝成纤维膜，将通过热分析，X射线衍射和温度依赖的阻抗谱根据其结晶度和离子电导率进行检查。将通过固态NMR光谱检查选定的离子传导系统，以确定其局部离子动力学。 静电纺丝Li和Na基导电盐@聚合物系统显示出比具有更高导电盐浓度的可比溶液封装或热压样品提高一到两个数量级的离子电导率。两种体系的电化学稳定性保持相当。甚至PVdF也显示出作为静电纺丝LiBF4@PVdF膜的显著增强的离子电导率。在静电纺丝固体电解质膜的成功合成和表征之后，我们将通过润滑剂和纳米惰性材料来增强和优化其机械和电化学性能。基于光谱结果，我们将推导出不同膜系统的基本传导机制。由于纤维膜的固有各向异性，该机制将显著不同于现有技术的热压样品的溶液浇铸。我们打算实现室温下电导率> 10 - 3 S cm-1、热稳定性> 80°C以及足够的机械和电化学稳定性的电纺固态电解质系统。 目的是了解与常规合成的溶液浇铸或热压系统相比，电纺膜的离子迁移率和电导率的增加，并优化此类系统以用于固态电池和超级电容器应用中的潜在用途。

In the proposed project we intend to synthesize electrospun solid electrolytes composed by different ion-coordinating polymers and conductive salt additives. After determination and optimization of the electrochemical properties we intend to identify the underlying conduction mechanism for the ion transport through the membranes. Four different polymers, selected Li, Na and Mg conductive salts and additives will be used to prepare fiber membranes via electrospinning. Such membranes will be tested concerning their thermal, mechanical and electrochemical properties in order to identify the best performing ion conductive systems. Four different polymers, polyethylene oxide (PEO), polyacrylonitrile (PAN), polymethyl¬ methacrylate (PMMA), polyvinylidene fluoride (PVdF), and selected dissolved conductive salts will be electrospun to fiber membranes which will be examined by thermal analysis, X-ray diffraction and temperature-dependent impedance spectroscopy according their crystallinity and ion conductivity afterwards. Selected ion conducting systems will be checked by solid state NMR spectroscopy to determine their local ion dynamics. Electrospun Li and Na-based conductive salt@polymer systems showed one to two orders of magnitude enhanced ion conductivity than comparable solution cased or hot-pressed samples with higher conductive salt concentration. The electrochemical stability of the two systems kept comparable. Even PVdF showed a significant enhanced ion conductivity as an electrospun LiBF4@PVdF membrane. After the successful synthesis and characterization of electrospun solid electrolyte membranes we will enhance and optimize the mechanical and electrochemical properties by lubricants and nano-scaled inert materials. Based on the spectroscopic results we will derive the underlying conduction mechanisms of the different membrane systems. Due to the intrinsic anisotropy of the fiber membranes this mechanism will be significantly different than for the state-of-the-art solution-casted of hot-pressed samples. We intend to achieve electrospun solid state electrolyte systems with conductivities > 10−3 S cm−1 at room temperature, thermal stability > 80°C and a sufficient mechanical and electrochemical stability. The aim is to understand the increase of the ion mobility and conductivity of the electrospun membranes compared with conventionally synthesized solution-casted or hot-pressed systems, and to optimize such systems for a potential usage in sild state battery and super capacitor applications.