Proton Conductivity of an Agar/PEO-based Solid Electrolyte containing Silica Aerogel Particles

초록

A fuel cell is an energy conversion device which converts the chemical energy from a fuel into electricity, directly, and has many advantages such as high energy conversion efficiency, high power density, no greenhouse gas emission, and so on. It is expected as a potential future power generation source. Among various fuel cell types, a proton exchange membrane fuel cell (PEMFC) uses a water-based polymer membrane responsible for internal proton transport from the anode to the cathode. The polymer membrane acts as pathway for internal proton transport from the anode to the cathode in the operation of PEMFCs. The agar-PEO can be used as a proton exchange membrane. The agar is natural polymer and has a proton conductivity. PEO (Poly ethylene oxide) gives flexibility to membrane and compensate the low thermal and mechanical stability of agar. But, PEO has a crystallinity on the high temperature, which affects ionic conductivity of the natural polymer. It was reported that the ceramic fillers could lower crystallinity of the polymer and the ionic conductivity increased in case of the smaller size of ceramic particles. In this study, the agar-PEO based film with dispersed silica aerogel was prepared for the electrolyte. The silica aerogel is advanced materials with extremely high porosity. The proton conductivity values of membrane were analyzed according to the silica aerogel concentration using E.I.S (electrochemical spectroscopic and microscopic analysis) method. The surface morphology of the membrane was obtained by FE-SEM. The structure was examined by X-ray diffraction.