Galvanostatic discharge

Table 3. Capacitance values (F g1) of the KOH activated carbons (A-C A-CS A-PM A-PS A-AC) estimated by galvanostatic discharge, cyclic voltammetry and impedance spectroscopy. ecific ca acitancejiF m alculated erjurfdceareao carbon.

Sample Galvanostatic discharge C/Fg1 Cyclic voltammetry C/Fg1 Impedance spectroscopy C/Fg1 Specific capacitance uF cm 2... 

Figure 1. Galvanostatic discharge curve (three-electrode cell), at 2 mA, for a PPy/CNTspellet electrode m= 9.6 mg.

Figure 3. Galvanostatic discharge curves (three-electrode cell) at 2 mA ofaPPy/CNTs pellet electrode (m=6.7 mg) before (2) and after (1) galvanostatic cycling in a symmetric capacitor (two electrode cell) at U=0.8 V. After the discharge (1), the electrode was charged up to 0.2 V (curve 3) and then discharged (curve 4).

Figure 2. Galvanostatic discharge of a PAN1 electrode with current density at 20 mA/g (1) and 200 mA/g (2) in oxygen-saturated 1MHCI.

Figure 2 shows that in the case of galvanostatic discharge of a PANI electrode with relatively low currents, a region of stable potential value (E 0.1 V) appears (curve 1 in Figure 2). This region actually corresponds to the electroreduction of oxygen at the PANI electrode.

Figure 6. The galvanostatic discharge curves and self-charge curve for Zn-Air coin battery with PANI/TEG gas-diffusion electrode.

Polyaniline (PANI) was investigated as electrocatalyst for the oxygen reduction reaction in the acidic and neutral solutions. Galvanostatic discharge tests and cyclic voltammetry of catalytic electrodes based on polyaniline in oxygen-saturated electrolytes indicate that polyaniline catalyzes two-electron reduction of molecular oxygen to H2O2 and HO2". 

Fig. 11.3 Electrochemical performance of CNFs CNTs. (a) Galvanostatic discharge/charge (Li inser-tion/extraction, voltage decrease/increase) curves of CNFs CNTs at a cycling rate of C/5 in 1M LiPF6 in 1 1 (v/v) ethylene carbonate (EC)/dimethyl carbonate (DMC) (b) comparison of the electrochemical performance of pristine CNTs and CNFs CNTs in 1M LiPF6 in EC/DMC solution (reprinted with permission from [25]).

Galvanostatic discharge of a fuel cell (MRED method) provided information related to liquid water in a fuel cell in a minimally invasive manner.157 Stumper et al.158 showed that through a combination of this MRED method with a current mapping (segmented fuel cell similar to the one discussed in Stumper et al.135), it was possible to obtain the local membrane water content distribution across the cell area. The test cell was operated with a current collection plate segmented on the cathode along the reactant flow direction. In addition to the pure ohmic resistance, this experimental setup allowed the determination of the free gas volume of the unit cell (between the inlet and outlet valves). Furthermore, the total amount of liquid water presented in the anode or cathode compartment was obtained. 

Fluorination of natural graphite powder (x4 pm) by a gas mixture of F2, HF and IF5 yielded high fluorine content samples, CF0.8, CF0 9 and CF] 0 [34]. The structural parameters obtained by X-ray diffraction were 7C = 0.59 nm and oq = 0.246 nm. XPS data indicated the existence of two Cls peaks at 287.0 eV and 289.4 eV, and one F]S peak at 688.0 eV, which are intermediate values between those for semi-ionic and covalent C—F bonds. Galvanostatic discharge of these CFV samples was done... 

Fig. 6. Galvanostatic discharge curves of button-type cells Li/1 M L1CIO4 + EC PC DME/LT—CFV, HT—CF, at 40 mAg 1. LT—CFV fluorine-graphite intercalation compound prepared at a low temperature, HT—CFV graphite fluoride prepared at a high temperature (reproduced with permission from J. Power Sources, 68 (1994) 708 [34]).

Fig. 22. Galvanostatic discharge curves of Li/Li+-MEP-7/C6oFv and C7UF, cells at 10 fiA/cm2 (reproduced by permission of the Electrochemical Society from J. Electrochem. Soc., 143 (1996) 2270 [70]).

Figure 18. Galvanostatic discharge curves at room temperature and at 0.1 mA cm for layered cobalt and nickel oxides, and spinel manganese oxide in ethylene carbonate-diethyl carbonate-LiN(CF3S02)2 [134] (by permission of Elsevier Seience S.A. S. Megahed, B. Scrosati, J. Power...

Sample Galvanostatic discharge C/Fg- Cyclic voltammetry C/Fg- Impedance spectroscopy C/Fg- Specific capacitance irF cm ... 

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