Composite membranes for fuel cells

Abstract

The current ecological situation attracts particular attention to alternative energy sources with no detrimental impact on the ecosystem. In comparison with conventional energy sources, fuel cells exhibit the following advantages: small and compact size, light weight, lack of noise when working, and cost-effectiveness in terms of fuel consumption. Most importantly, fuel cells are environmentally friendly, since no harmful substances are released into the atmosphere during their operation. Their goal is to convert chemical energy from various sources into environmentally friendly electric power. At present, chemical sources of energy are used everywhere, including batteries for mobile phones, laptops, as well as cars and uninterruptible power supplies, to name a few. The main components of solid polymer fuel cells are proton-exchange membranes, the main function of which is to ensure the transfer of protons from the anode to the cathode. The proton conductivity of such materials is determined by the presence of hydrophilic channels that transport mobile protons. The proton-exchange membrane must meet the following requirements: electrochemical and chemical stability in aggressive chemical environments, mechanical and thermal strength, low permeability to reagent gases (fuel and oxidizer), high ion exchange capacity and electrical conductivity, as well as a relatively low cost. This paper considers perfluorinated sulfonic acid membranes, organic–inorganic and acid–base composite membranes, as well as hybrid membranes obtained by sol-gel process, which can contribute to the development of technologies related to fuel cells in the future.