Study Of The Effects Of Graphite Anode On Cell Voltage Of The Lithium Electrolysis Cell

In this paper, In order to lower the cell voltage and energy consumption, the effects of graphite anode materials, the surface treatment and stirring electrolyte on the chlorine evolution and overpotentials have been examined.The Ag/AgCl reference electrodes were prepared and its electrochemical properties have been characterized. The results shows that the Ag/AgCl reference electrode have shown a good reversibility and consistency in LiCl-KCl metls with the time less than60h. The distance between the working electrode and the reference electrode has effects on the chlorine evolution potential. At the current density of50mA/cm2, the chlorine evolution potential at the distance of zero between them through extrapolation method is0.153V. electrochemical method is employed to measure the chlorine evolution potentials and cell voltage as used anodes for six graphite anode materials. The results show that the high-power graphite is regarded as the most suitable anode maerial for the lithium electrolysis due to its lowest overpotential and cell voltage.Surface treatment will influence chlorine evolution potential. Compared to the graphite anode ground by the2000mesh sand paper, the graphite anode ground by the400mesh sand paper has shown a coarser surface which results in a bigger and fluctuated cell voltage. Addition of LaO to the graphite surface will lower the chlorine evolution potential. The groves with1mm depth and1mm space at the graphite anode surface will make the voltage smaller.Stirring the electrolyte in the cell has almost no effects on the chlorine evolution potential, but it will lower the overpotential and cell voltage. When the stirring rate is in the range of0-20r/min, stirring can significantly reduce the overpotential. As the speed increases, the overpotential decline is not so obvious as before. And overpotential reaches its lowest value at40r/min.Besides, a2000A lithium electrolysis cell is designed, by a pilot experiments the high power graphite with surface treatment has shown a cell voltage of5.9V.