Ethanol is a sustainable,carbon-neutral transportation fuel.It is an ideal fuel source for direct oxidation
fuel cells for portable and mobile applications,as it offers multiple advantages over hydrogen and
methanol, including ease of transportation,storage and handling as well as higher energy density.
Tremendous efforts have been made to improve direct ethanol fuelcells (DEFC) that use proton exchange
membranes. This type of acid DEFC still exhibit slow performance (the state-of-the-art peak power
density is 96 mWcm2 at 90 1C), despite employing expensive platinum-based catalysts. However,it
has been recently demonstrated that the use of anion exchange membranes and non-platinum catalysts
in DEFCs enables a dramatic boost in performance (the state-of-the-art peak power density can be as
high as 185 mWcm2 at 60 1C). This article provides an overview of both acid and alkaline DEFC
technologies by describing their working principles, cell performance, system efficiency, products of the
ethanol oxidation reaction, and cost.Recent innovations and future perspectives of alkaline DEFCs are
particularly emphasized.