On September 4, 2018, the Cabinet Office of Japan, the Japan Science and Technology Agency (JST), and Asahi Glass Co., Ltd. issued a joint announcement that they have developed an electrolyte film with mechanical durability (dry and wet cycle durability) five times that of traditional products.
The thickness of the new product is 5 μm, which is one-fifth of the thickness of the conventional product. It is expected that the size of the fuel cell stack will be reduced by 30%, and the power output of the fuel cell will be improved.
Japan develops fuel cell electrolyte membrane with five times higher durability
The findings are part of the Fuel Cell Electrolyte Membrane Thinning Project by the Cabinet Office's Innovation Research and Development Promotion Program (ImPACT), which combines AGC's fluorocarbon polymer technology with the university's expertise in membrane structure analysis and simulation.
In Japan's current development stage of fuel cells, simplifying the system and increasing output power are currently the main issues. Both can be achieved by thinning the electrolyte membrane, but at the same time the durability of the membrane will be significantly reduced.
Therefore, the research team began to conduct basic research on the "deterioration behavior" of electrolyte membranes, clarified the mechanism of degradation, grasped the macroscopic film characteristics to control degradation, and understood the film characteristics at a microscopic level. Eventually, a "dry cycle index" that can represent the durability of the dry cycle life was found, and the durability could be predicted based on the physical properties of the electrolyte membrane.
Based on the results of this research, a new concept of electrolyte polymer was designed, and an electrolyte film with the best physical properties was successfully developed to improve the wet / dry cycle durability.
In the future, it is planned to carry out process development and system verification within a few years in order to put research and development products into practice.