Critical challenges in the system development of direct alcohol fuel cells as portable power supplies: An overview

Direct alcohol fuel cells (DAFCs) are considered a reasonable alternative power source because alcohol has a much higher energy density than hydrogen. Most DAFC development has focused on small portable application by using passive systems. DAFCs with active feed systems have appeared as potential portable power sources for larger applications, as they are easily handled, simple systems with smaller volumes than polymer electrolyte membrane fuel cells (PEMFCs). A general active DAFC system consists of a fuel and oxidant supplying system, product management and fuel concentration control. However, system development and commercialization are constrained by various critical challenges. This paper highlights the critical challenges of the fuel cell system rather than fundamental problems in the membrane electrode assembly (MEA), including fuel feed fluctuation, contaminant poisoning, two-phase flow, low power density, and heat and water management. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.