A New Highly-Efficient Direct Methanol Fuel Cell

Direct Methanol Fuel Cell (DMFC) is often viewed as an ideal power source for microelectronics and portable devices such as cell phone, laptop computer, and sensor, etc. However, the drawbacks in conventional DMFC (e.g., methanol crossover through the proton exchange membrane and the low concentration of methanol and water mixture) impede the wide commercial applications of DMFC due to the dissatisfactory electrical output. Moreover, the complex system configuration in conventional DMFC increases fuel cell weight, size, and cost and also reduces the system reliability. In this paper, an innovative Local Vapor Fuel Cell (LVFC) was proposed to promote the electro-catalytic reaction and improve the fuel cell power output. The design of LVFC was based on locally vaporizing the mixture of methanol and water without the complex and bulky vaporizer and blower. The capillary-based fuel feeding in LVFC, instead of pumping, substantially reduced system complexity. The proposed design features the LVFC light in weight, compact in size and high fuel conversion efficiency. The thermally stable high temperature membrane materials and MEA for LVFC were also investigated and developed. After the high temperature membrane and MEA were integrated into the LVFC, the characterization of the LVFC was conducted as a function of temperatures. The experimental results demonstrated that LVFC had higher electrical output with the increase of temperature, and higher thermal and electro-chemical reliability and stability.