A sensor of liquid methanol for direct methanol fuel cells.

The methanol sensors are of significance to maintain the efficient and stable operation of direct methanol fuel cells (DMFCs). The issues, including stability, the relationship between temperature, current density and concentration need, however, urgent attention. A novel electrochemical methanol sensor which is based on current output limited by methanol diffusion is developed. The stability of sensors was lifted steeply through introducing a reference electrode, narrowing the methanol flow channel, and adding a water container. The relationship between the temperature, response current and methanol concentration was determined with the help of theoretical derivation and the validity was verified by the fitting result. Other sensors can avail of this relationship to correct the temperature effect. Application test indicated that the sensor may be of great potential for the accurate monitoring of methanol concentration at the levels of DMFCs application.