Cells current-voltage characteristic

Sasaki K, Watanabe K, Teraoka Y (2004) Direct-alcohol solid oxide fuel cells current-voltage characteristics and fuel gas compositions. J Electrochem Soc 151(7) A965-A970... 

The equivalent circuit diagram used to model solar cell current-voltage characteristics is shown at the top of Figure 1.1. The schematic energy level diagram of a DSSC at the bottom of Figure 1.1 shows the various charge transfer processes that occur in photoelectrochemical cells and relates these processes to current pathways via components of the model circuit. An illumination current density /l is induced upon photoexcitation of the... 

Figure 1.1 Simple equivalent circuit (top) for modeling solar cell current-voltage characteristics and energy level diagram (bottom) mapping the various charge transfer processes in a DSSC to the current pathways of the model circuit. The dominant mechanisms are described by a current density Jl induced upon photoexcitation and electron injection into the conduction band of the metal oxide semiconductor surface MO, linear (Jsh) and nonlinear (/jj) reverse current densities in parallel with photocurrent source and a series resistance to account for electrode and ionic resistances. In Section 1.2.2 M0 = Ti02, Sn02, X = Br, I.

An important experimentally available feature is the current-voltage characteristic, from which the terminal voltage ([/v ) supplied by the electrochemical cell at the corresponding discharge current may be determined. The product of current / and the accompanying terminal voltage is the electric power P delivered by the battery system at a given time. 

FIG. 60. Current-voltage characteristics of a solar cell made at 65 MHz and 42 mW/cm-, The dashed line indicates the maximum-power point. 

In Figure 4 we compare the current-voltage characteristics of the investigated Mg-air cell with different Mg-anodes. 

Figure 4. Current-voltage characteristics of Mg-air cells with different Mg- anodes.

Figure 7. Current-voltage characteristics of one and the same Mg-air cell initial and after 12th mechanical recharge.

Figure 14.10 gives a schematic presentation of the current-voltage characteristics of hydrogen and oxygen on platinum. The theoretical open circuit cell voltage at 25 °C and standard conditions is 1.229 V, for both the fuel cell and electrolyzer. 

Fig. 14.10 Current-voltage characteristics of hydrogen oxidation and oxygen reduction in a fuel cell, and hydrogen and oxygen evolution in an electrolyzer.

Fig. 2. Schematic current/voltage characteristic of a fuel cell...

The impregnation of porous nickel discs with CoPc was difficult because of the limited solubility of the chelate in the usual solvents. CoPc cathodes with carbon as substrate were therefore prepared for use in H2/O2 fuel cells. A mixture of 72 mg CoPc and 48 mg acetylene black, with PTFE as binder, was pressed into a nickel mesh of area 5 cm2. Electrodes of this type were tested in an H2/O2 fuel cell with 35% KOH electrolyte in an asbestos matrix at 80° C. Figure 5 compares the current/voltage characteristics of CoPc cathodes (14 mg/cm2) with those of other catalysts, including platinum (9 mg/cm2), silver (40 mg/cm2), and pure acetylene black (20 mg/cm2). An hydrogen electrode (9 mg Pt/cm2) was used as the anode in all tests. To facilitate comparison of the activity of different cathodes, the pure ohmic internal resistance of the cells (of the order of 0.02 ohm) was eliminated. 

It is further important to note that all the current/voltage characteristics depicted in Fig. 6 are unchanged by the presence of liquid fuels such as methanol, formaldehyde, formic acid, or hydrazine. The phthalocyanine electrode remains completely inert toward such substances. For this reason, no mixed potential can be formed at a phthalocyanine electrode, as for example can occur at a platinum electrode, when it is used as cathode in a methanol cell containing sulfuric acid. This is shown by a comparison (see Fig. 7) of the stationary characteristics of the platinum alloy we found to be the most active in the presence of methanol, namely a Raney ruthenium—rhodium electrode, with an iron phthalocyanine electrode, both measured in 4.5 N H2SO4+2M CH3OH. 

Current-Voltage Characteristics of Platinoid and Graphite Electrodes in Air. The SPE sensor cells have been optimized for detection of certain oxidizable or reducible species in air. To achieve this, the sensing electrode is maintained at a voltage when there is minimal interference by the O2 in the air. The two electrodes studied in detail have been platinoid and graphite sensing electrodes. 

To compare quantitatively the current-voltage characteristic of an illuminated electrode, given by formula (31), with experimental data, Butler (1977) and Wilson (1977) measured the photocurrent, which arises in a cell with an n-type semiconductor photoanode ( 2, W03) when irradiated with monochromatic light at a frequency satisfying the condition ha>> Eg. In this case a light-stimulated electrochemical reaction of water oxidation with oxygen evolution... 

Figure 11 Current-voltage characteristics for N3-dye-sensitized Ti02 solar cells under illumination and dark using the electrolyte with and without TBP.

Figure 8. Current-voltage characteristic of photoanode D fsee also Figures 6 and 7) under 92.5 mW/cm2 insolation in the n-WSes/2M KI-0.05M lt/C cell...

Figure 6. Effect of chemisorption of Ru3 on the grain boundaries of a chemically vapor-deposited, thin-film n-GaAs photoanode. The grains are of 3-5 pm in size. The current-voltage characteristics shown are for the n-GaAs/0.8M KnSe-0.1 M KsSet-lM KOH/C cell. ((-------------) freshly etched (---) Ru3 chemisorbed)...

Reichman, J. "The Current-Voltage Characteristics of Semiconnductor-Electrolyte Junction Photovoltaic Cells " Appl Phys Ltr, 36, p 574, 1980. 

Figure 2. Current-voltage characteristics of the cell cond. glass/Pblg + RbAgJs/ RbAgsls/Ag + RbAgJg/cond. glass under chopped illumination (200 mW/cm2) at 25°C (voltage scan rate 25 mV/s)...

Fig. 4 Current voltage characteristic of an ideal Zr02 cell...

Experimental current-voltage characteristic of a pumping cell having the structure shown in Fig. 3b for two different O2 concentrations in N2. The temperature of the device was 750 C. 

Fig. 39. Current-voltage characteristics of the state-of-the-art single cell SOFC. From ref. [99].

Subcell Approach Stumper et al.135 presented the subcell approach to measure localized currents and localized electrochemical activity in a fuel cell. In this method a number of subcells were situated in different locations along the cell s active area and each subcell was electrically isolated from each other and from the main cell. Separate load banks controlled each subcell. Figure 8 shows the subcells in both the cathode and anode flow field plates (the MEA also had such subcells). The current-voltage characteristics for the... 

Under illumination with a light source, a typical solar cell exhibits the current-voltage characteristics shown in Figure 3. The current drawn by the cell when the terminals are connected to each other is the short circuit current (7SC, in mA/cm2). In the presence of an external load with infinite resistance (open circuit condition), the voltage developed is the open-circuit voltage (Voc, in V). 

FIGURE 3. A typical current-voltage characteristic for a photovoltaic cell. 

Fig. 10.16. Schematic illustration of the layout of a unit cell in an active matrix display circuit (left frame). It consists of a transistor connected to row and column electrodes and a pixel electrode pad. This circuit drives an overlying layer of electronic ink. The frame on the right shows the current-voltage characteristics of a typical transistor in a large...

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