Progress and challenges: Review for direct liquid fuel cell

Summary Direct liquid fuel cell (DLFC) is one of the leading fuel cell types due to their great features of superior energy density, modest configuration, small size in fuel container, immediate boosting, and effortless storage and carriage. Commercially used liquid fuel types are prepared using alcohols, such as methanol or ethanol, glycol, and acids. DLFCs face great challenges although they are potentially far‐reaching depending on the expensive catalysts and the use of high‐loading catalyst. More questions that should be addressed to ensure excellent DLFC performance include cathode flooding, fuel crossover, numerous side yield production, fuel security, and unverified elongated‐duration robustness. Further studies need to be carried out to ensure the continuous improvement of the quality of DLFCs' performance and their penetration in the commercial market. To date, direct liquid fuel cells made of methanol and ethanol have been successfully produced in commercial scale, but other types of DLFCs are still under study. In this review, introduction to DLFC will be discussed by covering work and commercialization as well as recent progress and challenges encountered.