Ni-Coated Carbon Fiber as an Alternative Cathode Electrode Material to Improve Cost Efficiency of Microbial Fuel Cells

By Luo, Shuai; He, Zhen
Published in Electrochimica Acta NULL 2016

Abstract

Abstract Electrode material is a key component in microbial fuel cells (MFCs), and exploring cost-effective electrode materials will greatly help with {MFC} development, especially the scaling up. In this study, a commercially available material - nickel-coated carbon fiber (Ni-CF) has been investigated as an alternative cathode electrode material to carbon cloth (CC). Both three-electrode cell and {MFC} tests are carried to examine electrochemical performance and actual electricity generation of the prepared cathode electrodes. It is found that Ni-CF exhibited higher current generation in linear sweep voltammetry (LSV) and lower resistance in electrochemical impedance spectroscopy (EIS) tests than those of {CC} and CF. When being coated with AC, Ni-CF has the highest actual loading amount among the tested materials. As a result, AC/Ni-CF leads to lower charge transfer resistance (95.1 ?) and higher current density (8.07 mA m?2) than AC/CC (115.3 ? and 3.40 mA m?2). In the {MFC} test, the cathode using AC/Ni-CF results in the maximum power density of 6.50 W m?3, higher than AC/CC at 4.29 W m?3. This high power output gives cost efficiency of AC/Ni-CF at 299.0 mW $?1, nearly twice that of AC/CC (151.7 mW $?1). The initial {AC} coating amount of 4 g is found to be the optimal amount to achieve optimally actual {AC} loading amount on the cathode electrode with balanced catalytic ability and (possible) oxygen transfer. Those results encourage further investigation of Ni-CF for {MFC} applications towards improved performance and cost efficiency.

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