title: Power generation by packed-bed air-cathode microbial fuel cells.
abstract: Catalysts and catalyst binders are significant portions of the cost of microbial fuel cell (MFC) cathodes. Many materials have been tested as aqueous cathodes, but air-cathodes are needed to avoid energy demands for water aeration. Packed-bed air-cathodes were constructed without expensive binders or diffusion layers using four inexpensive carbon-based materials. Cathodes made from activated carbon produced the largest maximum power density of 676 ± 93 mW/m(2), followed by semi-coke (376 ± 47 mW/m(2)), graphite (122 ± 14 mW/m(2)) and carbon felt (60 ± 43 mW/m(2)). Increasing the mass of activated carbon and semi-coke from 5 to ≥ 15 g significantly reduced power generation because of a reduction in oxygen transfer due to a thicker water layer in the cathode (∼3 or ∼6 cm). These results indicate that a thin packed layer of activated carbon or semi-coke can be used to make inexpensive air-cathodes for MFCs.
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control, THU-VEOLIA Environment Joint Research Center for Advanced Environmental Technology, School of Environment, Tsinghua University, Beijing 100084, PR China.
authors.forename: Xiaoyuan
authors.initials: X
authors.lastname: Zhang
authors.forename: Juan
authors.initials: J
authors.lastname: Shi
authors.forename: Peng
authors.initials: P
authors.lastname: Liang
authors.forename: Jincheng
authors.initials: J
authors.lastname: Wei
authors.forename: Xia
authors.initials: X
authors.lastname: Huang
authors.forename: Chuanyi
authors.initials: C
authors.lastname: Zhang
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Logan
mesh_terms: D001674:Bioelectric Energy Sources; D002384:Catalysis; D011211:Electric Power Supplies; D004566:Electrodes
keywords: Granular activated carbon; Granular semi-coke; Microbial fuel cell; Oxygen transfer; Packed-bed air-cathode