Effect of serpentine flow-field design on the water management of polymer electrolyte fuel cells: An in-operando neutron radiography study

Three different regimes of operation can be defined based on the current density: gradually increasing hydration (<400 mA cm−2), flooding (400 mA cm−2 ≤ j ≤ 600 mA cm−2) and drying out (>600 mA cm−2). The reduced overall quantity of water in the channels with an increase in current density can be attributed to faster gas velocity and higher cell temperature.