Research on PTC Auxiliary Heating Starting Strategy Based on One-dimensional Multiphase Cold Start Stack Model (Supporting Information)

The study investigates the optimization of auxiliary heating strategies during the cold start of fuel cells, analyzing the effects of factors such as bipolar plate materials, coolant types, positive temperature coefficient (PTC) heating power, initial current density, and coolant flow rate on cold start performance. The findings indicate that metal bipolar plates, due to their lower thermal mass, heat up faster than graphite bipolar plates, facilitating a quicker cold start. While coolant circulation enhances temperature distribution uniformity, it also increases the system’s thermal mass. Increasing PTC heating power can accelerate the heating process, but it offers limited improvements in cold start performance and increases energy consumption. Under conditions of −20 °C, by optimizing parameters such as current density and coolant flow rate, the fuel cell stack can achieve a cold start in approximately 55 s, significantly improving cold start performance and reducing energy consumption. This research provides optimized strategies for the application of fuel cells in cold environments.