title: A miniaturized microbial fuel cell with three-dimensional graphene macroporous scaffold anode demonstrating a record power density of over 10,000 W m(-3) .
abstract: A microbial fuel cell (MFC) is a bio-inspired renewable energy converter which directly converts biomass into electricity. This is accomplished via the unique extracellular electron transfer (EET) of a specific species of microbe called the exoelectrogen. Many studies have attempted to improve the power density of MFCs, yet the reported power density is still nearly two orders of magnitude lower than other power sources/converters. Such a low performance can primarily be attributed to two bottlenecks: (i) ineffective electron transfer from microbes located far from the anode and (ii) an insufficient buffer supply to the biofilm. This work takes a novel approach to mitigate these two bottlenecks by integrating a three-dimensional (3D) macroporous graphene scaffold anode in a miniaturized MFC. This implementation has delivered the highest power density reported to date in all MFCs of over 10,000 W m(-3). The miniaturized configuration offers a high surface area to volume ratio and improved mass transfer of biomass and buffers. The 3D graphene macroporous scaffold warrants investigation due to its high specific surface area, high porosity, and excellent conductivity and biocompatibility which facilitates EET and alleviates acidification in the biofilm. Consequently, the 3D scaffold houses an extremely thick and dense biofilm from the Geobacter-enriched culture, delivering an areal/volumetric current density of 15.51 A m(-2)/31,040 A m(-3) and a power density of 5.61 W m(-2)/11,220 W m(-3), a 3.3 fold increase when compared to its planar two-dimensional (2D) control counterparts.
authors.affiliation: School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, AZ 85287, USA. hren12@asu.edu.
authors.forename: Hao
authors.initials: H
authors.lastname: Ren
authors.affiliation: Institute of Microelectronics & Tsinghua National Laboratory for Information Science and Technology (TNList), Tsinghua University, Beijing, 10084, P. R. China. RenTL@tsinghua.edu.cn.
authors.forename: He
authors.initials: H
authors.lastname: Tian
authors.affiliation: School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ 85287, USA.
authors.forename: Cameron L
authors.initials: CL
authors.lastname: Gardner
authors.affiliation: Institute of Microelectronics & Tsinghua National Laboratory for Information Science and Technology (TNList), Tsinghua University, Beijing, 10084, P. R. China. RenTL@tsinghua.edu.cn.
authors.forename: Tian-Ling
authors.initials: TL
authors.lastname: Ren
authors.affiliation: School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, AZ 85287, USA. hren12@asu.edu.
authors.forename: Junseok
authors.initials: J
authors.lastname: Chae
mesh_terms: D001674:Bioelectric Energy Sources; D004560:Electricity; D004566:Electrodes; D006108:Graphite; D016062:Porosity
chemical_list: D006108:Graphite