Overview on the developments of vapor-feed direct methanol fuel cells

• This paper reviews the development of vapor-feed DMFCs.
• This review summarizes system design and operation of vapor-feed DMFCs.
• This review discusses challenging issues and optimization strategies.
• This review also provides suggestions on technical issues.

Direct methanol fuel cells have attracted extensive attentions from the fuel cell community because it is regarded as a promising candidate to replace the traditional power sources for portable applications. This technical review specially summarizes the development of the vapor-feed direct methanol fuel cell (VF-DMFC) which exhibits diverse characteristics from the liquid-feed system. This work is to provide a technical reference for engineering practice in the field of the VF-DMFC. Details concerning the system design and operation of active, semi-passive and fully-passive VF-DMFCs are provided. As a special subclass, the situation of high-temperature VF-DMFC is also introduced in this work. For the VF-DMFCs, several primary issues such as methanol, water and product managements and electrode optimization are respectively analyzed. Along with this, the mechanisms and strategies for optimization of each issue are remarked. Considering the significance and contribution of modeling works, such information is individually reviewed. Based on an overall evaluation, the emphases of the future work are also discussed.