Electrical Conductivity Enhancement of Carbon-Based Slurry. Electrodes for Application in Hydrogen Energy and Power Systems.

A novel idea of using carbon foam (CF) is introduced to enhance the electrochemical performance of a slurry electrode system in a proton flow reactor system. Steam-activated and acid-washed Norit from peat is used as active charge carrier particles to prepare 15 wt.% carbon slurry to be used in this study. The experimental electrochemical system provides variable slurry flow rates between 0 to 200 ml.min-1, while using two channel widths of 1.6 cm to 2 cm. Two sets of CFs with 10 pores per inch (PPI) and 5 PPI are used to understand the effect of introducing CFs with different pore sizes on the performance of slurry electrode. Slurry is charged slurry up to 100 C under constant application of 10 mA and 30 mA. After adding CF, the results show a significant drop in charging potential to generate both levels of current of 25% after using 5 PPI and 41% with 10 PPI. Furthermore, using the narrow channel flow of 1.6 cm and increasing the slurry flow rate from 50 ml.min-1 to 150 ml.min-1 lower the charging potential considerably by 19% and 21% (compared to base slurry) for 5 PPI and 10 PPI CF, respectively. Application of CF further enables the system to attain higher discharging time during the discharge cycle, and a maximum of 336% and 115% discharging capacity improvement is observed with 10 PPI and 5 PPI CF, respectively.