Optimum Design Of High Efficiency Lithium Electrolytic Cell

Lithium metallurgy plays an important role in China's nonferrous metal industry.As a basic material,lithium and its alloys have been widely used in many fields,such as aerospace,electric power,transportation,machinery,military industry and so on.In recent years,with the continuous rise of lithium battery industry,lithium electrolysis industry has also been developed rapidly.China is rich in lithium resources,and is the world's main lithium producer.However,there are still some problems in the lithium metallurgy industry,such as excessive energy consumption,low purity of lithium metal obtained by electrolysis,among which the electrolysis process accounts for a large proportion in the process flow of lithium metallurgy industry.Therefore,it is an effective measure to reduce the energy consumption of lithium metallurgy industry by optimizing the cell structure parameters and improving the cell efficiency.The effective way to save energy in lithium electrolysis production is to reduce the electrolysis temperature under the condition of maintaining the heat balance of the electrolyzer.Therefore,four main structural parameters of the cell are selected,and the optimal combination of cell parameters is obtained through simulation optimization.Under this combination,the electrolytic efficiency of the cell is the highest.Among the added materials,lithium chloride accounts for the largest proportion,so it has a significant impact on the electrolyte composition and electrolysis temperature.In this paper,through the analysis of the coupling relationship between the thermal balance characteristics of lithium electrolytic cell and the amount of lithium chloride added,the appropriate control strategy of the amount of lithium chloride added is sought and applied.Under the condition of maintaining the thermal balance stability of lithium electrolytic cell,the purpose of energy saving in lithium electrolytic production process is realized by reducing the electrolytic temperature.The main work and innovation of this paper are as follows:(1)The three-dimensional electric field model of 1k A lithium cell is established.The simulation software COMSOL is used to analyze the three-dimensional electric field of 1k A lithium cell,and the electric field distribution in the cell is obtained.The electric field is mainly distributed in the graphite anode area,the low carbon steel cathode area and the intermediate electrolysis area.The current flows from the anode to the cathode,and the potential lines in the middle electrolysis area are relatively dense.The effects of different anode diameter,anode insertion depth,electrode spacing and cathode insertion depth on the thermal field of 1 k A lithium cell were studied.The optimal parameter combination was obtained with the aim of current density,and the correctness of the simulation results was verified by experiments.(2)On the basis of literature review,combined with the existing technological process of lithium cell in the electrolysis process,from the point of view of the amount of materials added in the lithium cell,the coupling relationship between the amount of lithium chloride added and the electrolysis temperature was studied and an artificial neural network model was established.The experimental results show that by studying the relationship between the amount of lithium chloride added and the voltage,current,cell temperature,lithium output,and controlling the reasonable amount of lithium chloride added,the requirements of improving the electrolysis efficiency and reducing the energy consumption can be achieved under the condition of maintaining the normal electrolysis temperature.Through the simulation of the three-dimensional thermal field model of the lithium cell,the optimal insertion depth of graphite anode and the distance between graphite anode and low carbon steel cathode are obtained.(3)Design the cell type of lithium metal electrolyzer,install the relevant equipment of high efficiency lithium electrolyzer,design the test scheme and deal with the test results.The correctness of the optimized results of the electric and thermal field model of the three-dimensional cell is verified,and the rationality of the lithium chloride addition model is verified.