Evaluating the suitability of tungsten, titanium and stainless steel wires as current collectors in microbial fuel cells

Abstract

Abstract An appropriate current collector (CC) is crucial for harvesting substantial power in a microbial fuel cell (MFC). In the present study, stainless steel (SS) and titanium wires were used as the CCs for both the anode and cathode of MFC-1 and MFC-2, respectively. Tungsten wire (TW) was used as the anode CC in MFC-3, with SS wire as the cathode CC. In MFC-4, TW was used as the cathode CC with SS wire as the anode CC, and in MFC-5 both electrode CCs were TW. The power density, current density, oxidation current and bio-capacitance were compared to select the best and most cost effective CC material to enhance the power output of MFCs. Maximum power densities (mW/m2) of 32.28, 93.10, 225.38, 210.74, and 234.88 were obtained in MFC-1, MFC-2, MFC-3, MFC-4, and MFC-5, respectively. The highest current density (639.86 mA/m2) and coulombic efficiency (23.12 ± 1.5%) achieved in MFC-5 showed TW to be the best CC for both electrodes. The maximum oxidation current of 7.4 mA and 7 mA and bio-capacitance of 10.3 mF/cm2 and 9.7 mF/cm2 were achieved in MFC-3 and MFC-5, respectively, suggesting TW is the best as the anode CC and SS wire as the cathode CC to reduce MFC fabrication costs.