Phosphosilicate Gel-Sulfonated Poly(ether ether ketone) Nanocomposite Membrane for Polymer Electrolyte Membrane Fuel Cell

Abstract

Polymer electrolyte membrane fuel cells (PEMFC) are important in the field of renewable energy resources. Phosphoric acid doped proton conducting polymers are mainly used as polymer electrolytes. But the main problems of such electrolyte are leaching out of the phosphoric acid, flooding, low mechanical stability and fuel cell crossover. Phosphosilicate gel is one of the most attractive solid state highly proton conductive material. It has immense potential in the field of electrochemical devices such as fuel cell, metal hydrate batteries and supercapacitors. Nanocomposition of phosphosilicate gel with proton conducting polymer can serve as a potential electrolyte for the PEMFC. For low temperature range PEMFC it is composited with sulfonated poly(ether ether ketone) (SPEEK). Membranes were characterized by SEM, FTIR, NMR and by measuring water uptake, ion exchange and proton conductivity. Fuel cell performance of the membranes was taken at different operating temperatures. Best performance obtained for SPEEK at temperature 70°C. Performance enhances with phosphosilicate gel loading. Around 1.83 times enhancement in the peak power is achieved on going from 50°C to 70°C operating temperature for SPEEK with phosphoslicate gel of less than 10 nm particle size.