Effect of reactant gas flow orientation on the current and temperature distribution in self-heating polymer electrolyte fuel cells

Fuel cell polarisation performance is typically reported under controlled/constant temperature conditions, as a sign of robust metrology. However, in practice, fuel cells self-heat as they generate current; which varies the temperature across the polarisation curve and affects performance. More detail regarding the internal cell operation can be gleaned by current and temperature distribution mapping. For the case of an unheated cell, ‘self-heating’ increases the cell temperature and improves performance, resulting in a ‘voltage recovery’ and a more homogeneous current and water distribution. For actively heated cells, a reduced current is observed in regions of high temperature and low humidity.