Lithium-ion Battery Electrochemical-Thermal Coupling Simulation

Lithium-ion batteries are the key to the realization of new energy industry and are widely used in daily life.In the automotive industry,it is a general trend to use new energy lithium-ion batteries as power instead of fuel automotive engines.In lithium-ion batteries,cathode materials are related to temperature,capacity,power,life,internal resistance,cycle characteristics and so on.At present,researchers have carried out research from many aspects,but based on the battery appearance,it is impossible to explore the internal electrochemical reactions and temperature of batteries in depth.Therefore,in order to systematically explore the effect of cathode materials on the internal electrochemistry and temperature of batteries,this paper carries out research from the perspective of numerical simulation.In this paper,the electrothermal simulation of the cathode materials of 18650cylindrical battery is studied.On the basis of the research,the analysis of the cathode materials is carried out in many aspects.Finally,the battery pack and the layout are simulated and analyzed.Mainly from the following several explanations:?1?From the point of view of single battery,a lithium-ion battery model was established by using multi-physical field simulation software and Newman model based on electrochemical-thermal coupling.The thermal stability and thermal safety of LiCoO₂?LiFePO₄?LiMn₂O₄?LiNi_0.8Co_0.15Al_0.05O₂?NCA??LiNi_1/3Co_1/3Mn_1/3O₂?NCM?cathode materials for lithium batteries were studied.?2?Based on the electrochemical model of COMSOL software,the rela tionship between the electrochemical parameters and the cathode materials was studied by analyzing the cathode materials NCA and LFP from the viewpoint of electrochemical parameters,such as capacity,thickness,power and internal resistance.?3?After determining the appropriate cathode material NCA,based on numerical simulation,the lithium-ion battery module is simulated and explored.The multi-field coupling of electrochemical-thermal-fluid field under air-cooled conditions is explored,and the relationship between the temperature of the battery pack and the air velocity,the distance between the batteries and the arrangement of the batteries is explored.?4?The cross-arrangement is designed for air-cooling,the direction of air inlet and outlet is analyzed,and the cooling effect of cross-arrangement is compared with that of linear arrangement,so that a better arrangement can be obtained under the same working conditions of four batteries.In summary,the model of lithium-ion batteries is established by using multi-physical field simulation software and Newman model based on electrochemical-thermal coupling.Based on COMSOL electrochemical simulation method,the internal temperature,electrochemical parameters and battery modules are simulated and explored.The better thermal stability material was determined,the relationship between cathode material and electrochemical parameters was revealed,and the better cooling mode of battery module was obtained,which has certain guiding significance for the research direction and method of lithium battery.