dc.description.abstract | Benzimidazole Graphene functionalized Polysulfone(PSU) High temperature proton exchange membrane prepared under electric field poling Proton exchange membrane fuel cells (PEMFC) operating at high temperatures can have a
good tolerance for carbon monoxide poisoning catalysts, and operating at high temperatures can improve the overall operating efficiency of the battery, and it does not require a good management system for water…etc.
However, the key element that can demonstrate the high-temperature fuel cell is the proton exchange membrane. The membrane must have good proton transfer ability, and also need to have good thermal and chemical stability and mechanical strength to extend the fuel.
The thin film material used in the commercial high-temperature PEMFC is PBI (polybenzimidazole). This polymer material is selected because it has good adsorption
capacity for phosphoric acid and can have good proton transfer capacity at high temperature, but high adsorption capacity However, the mechanical strength is decreased. In addition, the high price of this material is not conducive to widespread use. Therefore, the development of
a proton exchange membrane with high proton transfer ability, high chemical stability and certain mechanical strength has been studied by related materials scholars for many years.
The polymer material used in this study is a sulfonated polymer with high stability. This polymer has good adsorption capacity for phosphoric acid and has a high proton transfer capacity when the operating temperature is less than 160°C. When the operating temperature
is greater than 160°C, the retention capacity of phosphoric acid decreases and the proton transfer capacity also decrease.
In order to improve the performance of the film at high temperatures (greater than 160°C), graphene oxide was also added in this experiment. This inorganic material has good thermal and chemical stability, and its structure has a lot of The oxygen-containing functional group
(such as: hydroxyl, carboxyl, ether), so it has good adsorption capacity for phosphoric acid.
However, graphene oxide is not easy to disperse in solution. In this study, graphene oxide was
additionally functionalized, and benzimidazole functional groups were added to the structure.
On the one hand, graphene oxide was added to the solution. In addition, it can increase the adsorption capacity of phosphoric acid to increase proton transfer.
In PEMFC’s thesis research, the method of adding inorganic substances to improve the characteristics of the film, the addition of inorganic substances is less than 2%, the main reason is that the addition of too much inorganic substances will lead to the mechanical
strength of the film is too strong, and the film is too rigid and easy to break. In addition, the dispersibility of inorganic substances in the film will also lead to the performance of the film.
Too much inorganic substances will cause agglomeration in the film and reduce the performance of the film.
In order to increase the content of inorganic substances in the film without losing the properties of the film, this study uses grafting to bond the inorganic substances in the polymer structure. This method can improve the mechanical strength of the film without causing The
film is too rigid and brittle; in addition, it also avoids the stacking of inorganic substances in the film. In the proton transfer test, it can be found that when the inorganic substance is added to 8%, the conductivity can always rise, indicating that this method can make the film
accommodate More inorganic substances will not reduce the performance of the film due to excessive inorganic substances.
In addition, in order to further improve the overall physical properties of the film, this study applied an electric field during the production process of the film based on the research methods of the previous laboratory, so that the inorganic substances and polymers can be
aligned in the film in order to enable the proton transfer path in the film. Shorter and straighter, thereby improving transmission efficiency.
The fuel cell test is the previous test result. It is tested with reference to the composite film added with 8wt% functionalized graphene oxide. It can be heated immediately and rises as the temperature rises, which is the highest at 180°C. The open circuit voltage is 0.913V, and the power density reaches 246.4 mW/cm2. | en_US |