Sulfuric acid cell voltage, effects

The unit consumption of electric power is mainly determined by the cell voltage and the current efficiency, and Table 2 shows the control standard of the electrolyte which has a great effect in decreasing the cell voltage. Zinc concentration and sulfuric acid concentration were reviewed and their control standards were changed from 60 g/liter to 55 g/liter and 160 g/liter to 185 g/liter, respectively, to reduce the solution resistance. Further, impurities in the circulated electrolyte were also reviewed, and the control standard for the Mg concentration was changed from 10 g/liter to 5 g/liter and that of the Mn concentration from 4 g/liter to 2 g/liter to reduce the solution resistance. 

Another limiting factor to be mentioned is the slow kinetics of oxidation at the Pt-Rn anode. When in inflow of electrolyte in the flow cell system contains only methanol/sulfuric acid (mixed-reactant mode) the effect on Pt cathode in building a mixed-potential is dramatic, in contrast to RuxSCy, see Fig. 16. This again is in agreement with the results generated by OEMS (cf Fig. 13). The FFC voltage already breaks down to 0.33 V. This result confirms that RuxSCy performs better when methanol concentration exceeds 2 M due to its tolerance. 

Electrolyte Sulfuric Concentration Effect on THE Cell Voltage of a Lead-Acid Battery... 

Equation 5.12 indicates that sulfuric acid has a strong effect on the cell voltage of the lead-acid battery. Table 5.10 lists the calculated and measured open cell voltages (or electromotive force) as a function of sulfuric acid concentration [11]. It can be seen that the cell voltage increases with an increasing sulfuric acid concentration, which is exactly the tendency predicted by Equation 5.12. 

---