Numerical study on the influence of overvoltage on the electric field in aluminum reduction cells

The anode overvoltage and the cathode overvoltage are more than 10 percent of the working voltage in aluminum reduction cells, which is important for the stability operation and energy saving. The influence of the overvoltage on the electric field was studied and analyzed based on Tafel overvoltage equations. The results indicate that electric field is affected by the overvoltage. The voltage drop(excluding the decomposition voltage of alumina) is 2.018V without overvoltage and 2.495V with overvoltage. The total overvoltage is 0.477V. More uniform current density distribution is gotten with overvoltage. The minimum current density increases and the maximum is reduced. The overvoltage affects the current distribution of bath and metal by different degrees. The conclusion provides the influence of overvoltage on electric field and is helpful to further understand the current distribution and the electric field. It sets the foundation for more accurate simulation of cell multi-physical field.