In this study, an innovative planar stack design employing graphite plate with bipolar structure on the same side to replace current stainless steel is investigated. The design, fabrication, and performance evaluation of a 25cm2, air-breathing, room-temperature, direct methanol fuel cell are described. The cell is completely passive with external pumps for controlling the methanol flow rate. This planar design consists of an open cathode side which allows a completely passive, self-breathing operation of the stack. Single cells with active area of 25cm2 showed a maximum power density of 25-40mW. A three-cell stack was constructed in an innovative planar configuration and it produced a power output of 110mW at 3M of methanol concentration at room temperature. In addition, the performance gives rise to 280mW at 3M under air-forced mode. The more concentrated methanol solution attains higher power due to instant take away of the methanol crossover through the membrane while the oxygen within the air is ready to react with the proton from the membrane with an appropriate rate and current output.
