Effect of Nanostructured Inorganic Ceramic Filler on Poly(ethylene oxide)-Based Solid Polymer Electrolytes

Abstract

In view of the ongoing changes in energy science and technology, the possibilities of energy storage are getting increasingly important. In particular, storing electrical energy is more complex than with fossil fuels.Lithium-Ion batteries are the most commonly used media for energy storage, but they also have some safety-related problems: toxic decomposition products can leak out and the devices can catch fire. Research is underway to find alternatives to minimize this potential hazards. Great improvements in safety matters can be achieved by replacing liquid electrolytes with ceramic/polymer hybrid electrolytes. These hybrid electrolytes combine the advantages of polymer electrolytes with the benefits of inorganic ceramic fillers.1 Flexibility, good contact ability and in addition the good processability is provided through the polymer. The inorganic ceramic filler in contrast adds mechanical stability, opens new pathways for the Lithium-Ions and can enhance the stability of the electrolyte.Figure 1: different Lithium-ion pathways in ceramic/polymer hybrid electrolytes dependent on different filler amounts. 2 In this work the impact of the manufacturing method on the conductivity of a series of electrolytes was examined. Therefore, hot pressing, solution casting and electrospinning were tested. Also, different distribution methods for the particles in the material were tested to monitor the influence of agglomeration on the conductivity. The materials were characterized regarding the crystallinity using X-Ray diffraction, the surface and particle distribution was monitored with SEM/EDX, the thermal character was investigated using DSC, the conductivity was determined using impedance spectroscopy and the electrochemical behavior was tested using cyclic voltammetry. Furthermore, the Arrhenius equation was used to interpret the results of impedance spectroscopy regarding their activation energy. The addition of inorganic ceramic fillers leads to an enhancement of the ionic conductivity in PEO based electrolytes and increases processability and stability of the electrolyte. In this work conductivities of 10-5 S/cm were reached at room temperature. The performance of the electrolyte was increased above three orders of magnitude compared to a PEO electrolyte without inorganic ceramic fillers. Walke, P.; Kirchberger, A.; Reiter, F.; Esken, D.; Nilges, T., Effect of nanostructured Al2O3 on poly(ethylene oxide)-based solid polymer electrolytes. Zeitschrift für Naturforschung B 2021, 76 (10-12), 615-624. Chen, L.; Li, Y.; Li, S.-P.; Fan, L.-Z.; Nan, C.-W.; Goodenough, J. B., PEO/garnet composite electrolytes for solid-state lithium batteries: From “ceramic-in-polymer” to “polymer-in-ceramic”. Nano Energy 2018, 46, 176-184. Figure 1