Electrical Resistance of Graphitic and Graphitized Cathode Materials at Elevated Temperatures

摘要

Cathode electrical resistance is of great importance for energy savings in reduction cells. Resistivity of the cathodes tested is found in the order of HC > HC100 > SMH, as their graphitization increases from 35% graphitic-CH35, 100% graphitic-HC100 to fully graphitized-SMH, and the graphitization is the strongest factor affecting resistivity. After electrolysis, the graphic CC35 and HC100 get higher resistivity than before at the temperatures <750°C; and both come up to almost same resistivity values but lower than that before electrolysis at temperatures of 750°C - 965°C; and the fully graphitized SMH has the lowest and the most stable resistivity at temperatures of 25°C - 965°C. SEM-EDS shows that sodium and fluorides have penetrated into the cathodes, which may contribute partly to the lowered resistivity at high temperatures after electrolysis. The results may help developing a strategy to utilize these factors to save electrical energy.