A high-performance 75 W direct ammonia fuel cell stack

The low-temperature direct ammonia fuel cell (DAFC) is an attractive option for zero-emission transportation. However, the demonstration of high-performance and durable DAFCs and the identification of their suitable market are not yet reported. Here, we show a high-performance DAFC enabled by a hydrophobic spinel cathode, which achieves peak power density of 410 mW cm−2 and continuous operation for 80 h at 300 mA cm−2. We assemble five 50 cm2 cells into a 75 W DAFC stack, showing a comparable area-specific performance to that of the single cell. The best combination of performance and durability for the single cell and, particularly, the demonstration of, to the best of our knowledge, the world's first DAFC bipolar stack constitute a significant development of DAFC technology. We also perform an in-depth techno-economic analysis of a 2 kW, 10 kWh DAFC system serving for drones. DAFC systems with the performance obtained herein could be a competitive power source alongside hydrogen fuel cells and Li-ion batteries.