Investigation Of The Effects Of Current Collector Structure On Methanol Fuel Cell

The Direct Methanol Fuel Cell (DMFC) is a kind of fuel cell using methanol aqueous solution as the fuel, oxygen in the air as the oxidants. With the rapid development of microelectronics technology, all kinds of portable electronic products are emerged in an endless stream. The contradiction between the increasingly diversified product functions and the shortage of electrical power working time is becoming more conspicuous. DMFC has the peculiarities of high energy density, environmentally-friendly and convenience of fuel supplement, so it has become a research focus throughout the world. However, there are still many bottlenecks which should be solved before DMFC is put into use. The current collector of different structure has an important influence on the output performance of the fuel cell , which is one of the key basic research in DMFC. This paper focuses on the study of the current collector structure, which is the key issues.First of all, this paper designed and fabricated circular current collector and parallel current collector which have the same open ratio and different structure. Then the current collector plated on TiN protective layer. In this paper, the effects of various operating parameters (TiN protective layer, packing pressure, methanol concentration) on the performance of DMFC are studied. The results show that the performance of DMFC is assembled by the fuel cell than the uncoated TiN current collector is about 4 times higher,because it has good electrical conductivity and corrosion resistance. Package pressure affects diffusion layer mass transfer and contact resistance. In the case of 0.5 MPa, the DMFC gets the best performance. The best concentration of methanol aqueous solution is 1mol/L, and the maximum power density of the fuel cell can reach 13.69 mW/cm2 at 50 ℃.Then, this paper studied the effects of the same open ratio and different current collector structure of anode and cathode on the performance of DMFC, respectively. The main content of the study is the analysis from the perspectives of material transfer and ohmic resistance in the diffusion layer. The results show that the optimal feature size of circular current collector is 2.5 mm, parallel current collector optimal feature size is 2 mm without metal mesh current collector. The optimal feature size of circular current collector is 2-3mm,parallel current collector optimal feature size is 2mm with metal mesh current collector.Finally, the experiment based on the above analysis and research, carried out at the same time, changing the cathode and the anode current collector experiment. Experiments show that both ends of the current collector changed at the same time, the optimal feature size is circular current collector as 1.5 mm and parallel as current collector 2 mm wide. Cross interleaved parallel current collector arrangement is better than rib to rib and rib to channel arrangement of DMFC. The design of rib and channel of unequal width is conducive to improving the mass transfer in diffusion layer.