Microbial electrolysis cells (MEC) invented on the basis of microbial fuel cells (MFC) provide a novel method for biohydrogen production. This paper reviews the research progress of MEC ever since its invention in 2005. The principle of MEC and the evaluating parameters of the system are briefly introduced. Hydrogen production performance of MEC in different system architectures and electrode materials are compared. The existing problems and limiting factors of MEC for its practical utilization are discussed and the future research trends, as well as research approaches of MEC are proposed. Finally, the prospective applications of MEC in hydrogen production from biomass and energy recovery from organic wastewater are also stated.Microbial electrolysis cells (MEC) invented on the basis of microbial fuel cells (MFC) provide a novel method for biohydrogen production. This paper reviews the research progress of MEC ever since its invention in 2005. The principle of MEC and the evaluating parameters of the system are briefly introduced. Hydrogen production performance of MEC in different system architectures and electrode materials are compared. The existing problems and limiting factors of MEC for its practical utilization are discussed and the future research trends, as well as research approaches of MEC are proposed. Finally, the prospective applications of MEC in hydrogen production from biomass and energy recovery from organic wastewater are also stated
