What is the harm of low temperature cold start to the stack?
In the proton exchange membrane fuel cell, the humidified moisture of the anode hydrogen enters the anode flow field plate, the anode diffusion layer and the anode catalytic layer with the hydrogen, and enters the cathode through the membrane, and the water generated by the cathode reaction also enters the cathode catalytic layer, and the cathode diffusion layer reaches the cathode. flow field, and some of the water will be absorbed by the membrane by back-diffusion.
Water and ice have densities of 0.9998 and 0.9168 g/cm3 at 0°C, respectively, so a 9% volume expansion occurs when water freezes.When the battery is turned on, the waste heat generated melts the waste heat into water, and the volume shrinks. The volume change caused by repeated water-ice phase transitions can cause negative or even permanent damage to the battery material structure, and even short-circuit battery performance degradation.