Nonuniform Compensation of the Current Density Distribution in the Polymer Electrolyte Fuel Cell Using Local Heating

Abstract

It is well known that reasonable current density distribution can improve fuel cells' output performance and prolong their service life. Which can be achieved by elaborately designed structures and compression, and the reaction occurs evenly in the entire activation area. However, duo the coupling relationships between electrical, thermal and water, the effect of operation conditions (such as the local heating) on the current density mapping is still blank. This paper studies the effect of local heating on polymer electrolyte fuel cell performance and analyses the causes of the output voltage differences through the mapping of the current density distribution. Compared with the inlet and central heating, the heating at the outlet area exhibits the best performance. This is due to the concentration of reactants along the flow field decreases continuously, and the accumulation of liquid water leads to the low current density distribution at the outlet. Here, we show that local heating can compensate for the lowest current density and achieve the more homogeneous current distribution; on the contrary, inlet heating will increase the unevenness of the current density distribution. This study provides practical guidance for the optimal design of the thermal management system.The design of the cooling channel should be locally optimised for more uniform distribution of current density, in addition to the overall temperature balance,