Brush electrode

Power Carbon brushes, electrodes, battery cells... 

High-frequency leak detector with brush electrode and ratio shielding... 

Figure 4.530. Impedance behavior of the de Levie brush electrode in the complex plane as a function of frequency for three electrolyte (KCl) concentrations (from de Levie [1963, 1964]).

Figure 4.5.31. Cyclic voltammogram for a gold-wire brush electrode at 20mVs" in comparison with that for a single gold wire electrode on a normalized identical current-response scale (from Pell and Conway [2001]).

Impedance and Voltammetry Behavior of Brush Electrode Models of Porous Electrodes... 

Voltammetry at a de Levie Brush Electrode as a Model for Electrochemical Supercapacitor Behavior, J. Electroanal. Chem. 500, 121-133. 

Figure 4.4 Internal resistance obtained from Nyquist plots using impedance spectra of two MFCs with either a carbon cloth or graphite brush electrode. Rm is obtained as the value of the x-intercept. [Reprinted from Logan et al. (2007), with permission from the American Chemical Society.]...

An example of a Nyquist plot obtained under these conditions is shown in Fig. 4,4 for a range of 10 to 0.005 Hz with sinusoidal perturbation of 10 mV amplitude Logan et al. 2007) The ohmic resistance of the brush electrode was Rn= 8 Q, but it was Rn = 31 Q for a carbon cloth electrode (cube MFCs with 4 cm spacing in 200 mM PBS). Additional details of this method can be found in Bard and Faulkner (2001). 

Testing of the smaller brush electrode in a cube-type MFC produced the highest power density yet achieved for an air cathode MFC of 2400 mW/m at a current density of 0.82 mA/cm (R xi = 50 Q) Logan et al. 2007). The power was 73 W/m based on normalizing power to the reactor liquid volume. Ce ranged from 40% to 60% depending on current density. 

Hasvold et al. (1997) reported that stainless steel brush electrodes were used as cathodes in an undersea vehicle power source, but that carbon brush electrodes performed better. However, they did not test these cathodes in any MFC applications. 

The lower volumetric power density than that produced with the flat anode reflects the larger volume of reactor used to accommodate the brush electrode. 

Configuring the electrodes in the MFC. The MFC electrodes currently thought to be the most suitable for scale up consist of high specific surface area graphite brush electrodes and tubular cathodes. These electrodes could be placed in sequence (/.e., anodes then cathodes) or randomly in the same tank (Fig 9.4). Groups of anodes and cathodes would form a single anode-cathode module, with many electrodes placed in a single tank or module. The brushes and tubes within the module would need to be in close proximity to each other to minimize the distance for proton transfer and thus... 

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