Analysing and optimizing the electrolysis efficiency of a lithium cell based on the electrochemical and multiphase model

Abstract

Based on an electrochemical multiphysical simulation, a method for analysing electrolysis efficiency has been presented that considers the energy consumption required to produce a single kilogram of lithium and for the production of lithium, rather than the voltage in various parts. By adopting them as the criteria for analysing electrolysis efficiency in the lithium cell, several structural parameters have been optimized, such as the anode radius and anode–cathode distance. These parameters strongly affect the cell voltage and the velocity field distribution, which has a significant impact on the concentration distribution. By integrating the concentration distribution, the lithium production and energy consumption per kilogram, lithium is computed. By appointing the minimum of the chlorine and lithium concentration as the secondary reaction intensity, it is clear where the secondary reaction intensity is strong in the cell. The structure of a lithium electrolysis cell has been optimized by applying an orthogonal design approach, with the energy consumption notably decreasing from 35.0 to 28.3 kWh (kg Li) −1 and the lithium production successfully increasing by 0.17 mol.

Comparing the effects of Cu-Ti/RuO2-IrO2 electrode configuration on the electro-reduction of nitrate

“…It is seen that a higher efficiency of nitrate electro-reduction (Figure 8(a)) as well as a higher energy consumption (Figure 8(b)) was obtained using the shorter copper cathode (12.8 cm) at input power ranging from 8 to 49 W. A longer cathode facilitates the development of turbulent conditions, in the gas and liquid phases, which improves mass transfer. Consequently, more side reactions occur; hence, the nitrate removal becomes less effective (Zhao et al 2020). It should be noted that gas bubbles accumulate at the upper part of the electrodes with a higher void fraction between the electrodes forming in longer electrodes, resulting in lower reaction efficiency (Nagai et al 2003).…”

“…It should be noted that gas bubbles accumulate at the upper part of the electrodes with a higher void fraction between the electrodes forming in longer electrodes, resulting in lower reaction efficiency (Nagai et al 2003). The reduction in energy consumption with increased cathode length is due to a faster reduction in the current density and the electric potential as the cathode surface area increases, i.e., with a longer electrode (Zhao et al 2020).…”

Reduction of Energy Consumption in Lithium Electrolytic Cell by Improving Design and Operating Conditions

“…8), was used to represent the fluid dynamics of the liquid lithium drops as shown in the next equations: denote the volume fractions of the continuous and dispersed phases. 27 The continuity equation (Eq. 14) also assumes that the electrolyte was saturated in lithium and so, the mass transfer from the lithium drops to the electrolyte solution was neglected.…”

Embedding reservoirs in industrial models to exploit their flexibility

“…The model is shown in Figure 5. Existing models tend to use electrochemical multiphysics techniques (Hofer, 2011;Zhao et al, 2020), which are not wellsuited for light applications like flexibility estimation.…”