Simulation And Experimental Study On Coupling Thermal Pressure Of Lithium Ion Batteries

With the rapid economic growth and the need for modernization,the consumption of fossil fuel resources such as oil,coal,natural gas and other resources has intensified,and the problems of energy shortage and environmental pollution have become more and more serious.New energy vehicles have become the current main development direction of automotive industry with their clean and environmentally friendly characteristics.And the power battery as its core energy storage component has received wide attention from all over the world.The current power battery,due to its short cruising range and poor performance consistency of the battery pack,seriously restricts the rapid development of new energy vehicles;and the thickness uniformity of lithium.ion battery pole pieces is one of the most critical factor affecting the consistency of battery performance.Therefore,this paper studies the roll process of the battery pole piece through the thermal coupling simulation and experiment of the lithium ion battery pole piece to improve the manufacturing precision and thickness direction thickness consistency of the lithium ion battery pole piece.Aiming at the problem of poor consistency of thickness and narrow rolling width during the actual rolling process of the pole piece,this paper combines the research method of finite element thermodynamic coupling simulation and experiment to analyze the rolling process of the existing lithium ion battery pole piece.Firstly,the basic theory and manufacturing process of lithium ion battery and the theory of battery plate rolling pressure are analyzed.Secondly,based on the elastoplastic finite element method,the rolling model of ?100×150 two.roller roller press was established,and Influence the law of the changes of the rolling process parameters such as rolling speed,rolling temperature and coating thickness were studied.Finally,through the pole piece rolling test,The influence of the parameters in lithium ion batteries of the positive electrode sheet rolling process such as slurry ratio,rolling speed,rolling temperature and coating thickness on the thickness uniformity,microscopic morphology and electrochemical performance of ternary NCA batteries were studied.The research results show that: for this type of pole piece roller press studied in this paper,during the rolling process of the pole piece,when the other process parameters are certain,reducing the rolling speed can improve the thickness uniformity of the pole piece to some extent.During the rolling process of the pole piece,when the other process parameters are certain,reducing the coating thickness can improve the thickness uniformity of the pole piece to some extent.When other process parameters are certain,the rolling temperature is increased,and the thickness uniformity of the pole piece can also be improved.This is because reducing the areal density,appropriately increasing the compaction density,and increasing the thickness uniformity of the pole piece and the uniformity of the surface morphology of the pole piece reduce the internal resistance of the battery,especially the charge at the junction of the electrolyte and the positive electrode sheet.Transfer impedance,thereby improving the electrochemical performance of the battery,and vice versa,may reduce the electrochemical performance of the battery.The above research results can provide certain technical support and theoretical guidance for subsequent research and on.site production.