Study on passive micro direct methanol fuel cell

In order to overcome the disadvantages of low mass transport efficiency of oxygen to the cathode and poor performance of passive micro direct methanol fuel cells (DMFC), the structures of the cathode current collector for the passive micro DMFC have been studied. The passive micro DMFC employing the cathode current collector with the planar perforated-plate structure has been fabricated. The effect of the anode methanol concentration and the opening area ratio of the cathode on the performance has been investigated. Owing to the influence of contact resistance and oxygen mass transport, the passive micro DMFC exhibits the optimal performance when opening ratio is 50%. Furthermore, the new parallel channels structure of the cathode current collector has been proposed, and the corresponding passive micro DMFC has also been fabricated by utilizing micro precision processing technology. The test results indicate that the mass transfer of oxygen and performance stability have been improved based on the cathode current collector with the parallel channels structure compared to the conventional planar structure. Moreover, a maximum output power density of 9.7 mW/cm² is achieved. The above studies might be helpful for the developing and application of portable micro power systems.