Direct methanol fuel cell system and time-delayed shut-down method thereof

摘要

A direct methanol fuel cell system (100) includes a fuel-supplying unit (130) feeding a mixing tank (120) with high concentration fuel; the mixing tank mixing and storing the fuel fed from the fuel-supplying unit and an outlet stream discharged from the fuel cell main body; a fuel feeder (140) supplying mixed fuel stored in the mixing tank (120) to the fuel cell (110) main body; and a controller (160) controlling the fuel-supplying unit (130) to stop operating in response to a stop request signal, and controlling the fuel feeder (140) to operate to circulate the mixed fuel via the anode of the fuel cell main body until a fuel concentration of the mixed fuel is less than or equal to a reference concentration. The decrease of the methanol concentration during shut-down of the DMFC system prevents the electrolyte membrane and the catalysts from being deteriorated. The time delayed shut-down can be controlled by a methanol sensor or by use of a timer.