New Technology Dramatically Reduces Cost and Process Expenses of Hydrogen Fuel Cells

Korea Institute of Energy Research Develops Method to Reduce Platinum Catalyst Usage to One-Fifth

[Asia Economy Reporter Kim Bong-su] Domestic researchers have developed a core technology to manufacture transportation and building fuel cells, which are emerging as next-generation energy sources, at a low cost.

The Korea Institute of Energy Research announced on the 5th that Dr. Jeong Chi-young's research team at the Fuel Cell Demonstration Research Center, in collaboration with Professor Lee Sung-chul of Hanyang University's Department of Chemical Engineering, developed a core technology for manufacturing MEA (Membrane Electrode Assembly) with reduced platinum usage through ionomer nano-control technology within fuel cell electrodes based on a wet electro-spray method. MEA is a key component where the fuel cell electrode and electrolyte membrane are bonded; it is the part where the actual electrochemical reaction occurs to generate electricity when hydrogen and oxygen react, and it is made of expensive platinum, accounting for about 40% of the cost of a fuel cell stack.

The research team secured core technology to reduce costs and simplified the process, opening the way for large-area and mass production of the high value-added MEA product. They drastically reduced platinum usage to the level of 0.1 mg/cm². This technology meets the technical target set by the U.S. Department of Energy (US DOE 2025 Target), which is the quantitative performance goal for vehicle fuel cells (0.1 mg/cm² platinum usage by 2025).

Fuel cells are attracting attention as a new alternative energy source as countries worldwide declare carbon neutrality and transition to a hydrogen economy to prevent global warming. Their applications are expanding in various fields such as transportation and power generation. The global market size is expected to grow at an average annual rate of 30%, reaching approximately 50 trillion KRW by 2030.

In particular, polymer fuel cells are gaining attention as next-generation energy conversion devices for transportation and building power generation. Polymer fuel cells use a polymer membrane as the electrolyte, operate at low temperatures, and offer high energy density and efficiency, making them advantageous for a wide range of uses such as vehicle propulsion and on-site power generation.

The problem is that current technology is costly. The electrodes of polymer fuel cells are manufactured by a slurry process mixing expensive platinum catalysts and Nafion (a fluorine-based proton-conductive polymer electrolyte) ionomer (which delivers protons inside the catalyst layer and acts as an adhesive binding the catalyst particles). However, during the dispersion, coating, and drying processes of the catalyst slurry, ionomer aggregation occurs, reducing the accessibility of Nafion ionomer to the platinum catalyst surface, increasing oxygen transport resistance, and decreasing catalyst activity.

The research team developed a higher-level electrode design and core manufacturing technology that minimizes oxygen transport resistance while reducing platinum catalyst usage from the current 0.5 mg/cm² level to below 0.1 mg/cm². They designed a new vertical-structured electrode by precisely controlling the ionomer on the electrode surface to about 2 nanometers through a wet electro-spray process, forming a thin and uniform Nafion ionomer layer. The vertical structure arranges platinum catalyst, Nafion ionomer, and pores vertically, optimizing the transport distances of ions, electrons, and oxygen necessary for the reaction, thereby maximizing fuel cell performance.

The wet electro-spray process applies a high voltage to the slurry, enabling continuous maintenance of high dispersion of catalyst and ionomer through electrical repulsion during electrode manufacturing. This process allows for ionomer thinning and high dispersion, and the formed ionomer layer reduces catalyst poisoning rates and lowers oxygen transport distance to about 20-30% of the conventional level, maximizing platinum catalyst utilization by more than three times compared to existing methods.

Conventional thin-film electrodes have the disadvantage that lowering ionomer content increases catalyst content on the electrode surface, raising hydrophilicity and making it difficult to remove water generated during fuel cell operation. In contrast, the developed technology controls the shape of the ionomer coated on the electrode in an inverse micelle form, creating a water-repellent electrode that easily removes water generated during operation, improving fuel cell operational performance and durability. The electrode direct coating method simplifies the process and has excellent scalability for continuous mass production lines, reducing mass production equipment installation costs to about half compared to existing processes and potentially doubling production speed.

The research results were published online on the 10th of last month in the international environmental engineering journal ‘Applied Catalysis B - Environmental’ (IF 19.503, ranked 1st in JCR Environmental Engineering field, top 0.73%).

This content was produced with the assistance of AI translation services.