Industrial membrane of proton exchange membrane

Industrial membrane of proton exchange membrane – Cheersonic

Proton exchange membrane fuel cell (PEMFC) has the advantages of light weight, high efficiency, high specific power, high energy conversion rate, low starting temperature and environmental friendliness. It is an ideal power source for new energy vehicles and portable electronic products.

Membrane electrode (MEA) is the core component of proton exchange membrane fuel cell, mainly composed of gas diffusion layer (GDL), catalytic layer (CL) and proton exchange membrane (PEM).

Proton exchange membrane (PEM) is one of the core components of PEMFC, which can transfer protons but insulate electrons, which directly affects the performance and service life of fuel cells. A PEM with good performance must meet the following conditions: 1) Strong proton conductivity; 2) Good mechanical properties and not easy to deform; 3) High thermal and electrochemical stability.

At present, the membrane materials used in industrial applications are mainly perfluorosulfonic acid membranes, non-perfluorosulfonic acid membranes, and non-fluorinated proton exchange membranes.
Perfluorosulfonic acid membrane

The perfluorosulfonic acid membrane, represented by the Nafion® series membranes of DuPont, USA, is composed of a carbon main chain and ether branched chains with sulfonic acid groups. The main chain has a polytetrafluoroethylene structure, which makes the molecules have extremely high Chemical stability, thermal stability and high mechanical properties ensure the long service life of the polymer membrane; the sulfonic acid group on the branch is hydrophilic, can adsorb water molecules, and has excellent ion conductivity.

However, under high temperature conditions, the conductivity of the membrane becomes poor, and the cost is high and expensive, and methanol permeation is prone to occur.
Non-perfluorosulfonic acid membrane

In order to overcome the disadvantages of expensive perfluorosulfonic acid membranes and low working temperature, researchers have carried out a large number of new types of non-perfluorosulfonic acid membranes, such as polytrifluorostyrene sulfonic acid membranes, Ballard’s BAM3G membranes, and PTFE Ethylene-hexafluoropropylene film, etc.

The non-perfluorosulfonic acid membrane is generally embodied as the main chain perfluorinated, which is beneficial to ensure the proton exchange membrane has a corresponding service life under the harsh oxidizing environment of the fuel cell. The proton exchange group is generally a sulfonic acid group. According to the method of introduction, the partially fluorinated sulfonic acid type proton exchange membrane: the perfluorinated main chain is polymerized, and the monomer with sulfonic acid group is grafted to the main chain; After the main chain is polymerized, the side chain of the monomer is branched and finally sulfonated; the sulfonated monomer is directly polymerized. Non-perfluorosulfonic acid membranes significantly reduce the cost of the membrane, but the electrochemical performance is not as good as Nafion® membranes.
Non-fluorinated proton exchange membrane

The non-fluorinated proton exchange membrane is essentially a hydrocarbon polymer membrane, which is the development trend of the proton exchange membrane. Its main feature is that the cost is lower than the former two, and it is environmentally safe. Among them are mainly sulfonated polyetherketone (SPEK), sulfonated polybenzimidazole (SPBI), sulfonated polyarylethersulfone (SPAES), sulfonated polyimide (SPI) and sulfonated polyphenyl (SPP), etc.

The emergence and development of fuel cell technology is of great strategic significance for alleviating environmental pollution and energy crisis. Proton exchange membrane is the core component of MEA. How to prepare a proton exchange membrane with high conductivity, high stability, low price, safety, reliability, and environmental friendliness is an urgent problem to be solved.

At present, ultrasonic coating systems can produce highly durable and uniform carbon-based catalyst ink coatings on the electrolysis process of fuel cells and proton exchange membrane (PEM) electrolyzers (such as Nafion) without the membrane being deformed. The uniform catalyst coating is deposited on PEM fuel cells, GDL, electrodes, various electrolyte membranes and solid oxide fuel cells. The sprayed suspension contains carbon black ink, PTFE binder, ceramic slurry, platinum and other precious metals. Ultrasonic spraying of other metal alloys, including platinum, nickel, iridium, and ruthenium-based fuel cell catalyst coatings of metal oxide suspensions, can also be used to manufacture PEM fuel cells, polymer electrolyte membrane (PEM) electrolyzers, DMFC (direct methanol) Fuel cells) and SOFC (solid oxide fuel cells) can generate large loads and high battery efficiency.