12-Stack and bipolar plates design for direct methanol fuel cells

The focus of this chapter is the design of a direct methanol fuel cell (FC) (DMFC) stack. In particular, the design of bipolar plates will be addressed and the reader will be able to build his own FC stack and design bipolar plates based on the desired performance. The discussion will be intentionally inspired by simplicity and intends to provide immediately usable tools and solutions, which are based on the direct experience of the authors [110]. The trip into the word of DMFC stack design starts from some recalls of thermodynamics and electrochemical, which are fundamental for choosing the operation point of the FC stack and the calculation of the flow rate of the reactants. Once the flow rates are known, the architecture of the FC stack can be defined, on the basis on the application, and the rest of FC stack components can be designed. This chapter covers the DMFC stack design principles, including stack architecture, reactants distribution, heat management, and stack clamping. The chapter aims to provide some useful guidelines to optimize the DMFC stack design and performance, a topic less covered in FC literature. In the following discussion, if not explicitly indicated, the sign of all numerical values is to be considered positive.