电动汽车三元锂离子电池的电化学-热特性分析与优化设计研究

发布时间：2024-05-15 01:59

　　近年来,三元NCM锂离子电池因其高的能量密度,而成为新能源汽车动力电源的首选。但是它的热安全性和热稳定性也受到了广泛的关注,由于电池内部电化学反应和热特性不能通过实验直接测量研究。因此,有必要使用数字仿真模拟技术来解决这些挑战。由于温度在放电过程中不断地发生变化,会直接影响电化学模型中的某些特定参数的变化,因而仅凭电化学模型难以获得准确可靠的结果。因此,建立电化学模型和热模型之间的耦合至关重要。基于此,本论文将电化学模型与热模型耦合,建立了3D有限元平均电化学热耦合模型来研究电池的电化学和热特性。此外,通过多参数的优化技术来改善电池热性能。主要研究内容如下:首先,以30 Ah NCM三元锂离子电池为研究对象,对其进行了性能测试,包括放电测试和直流内阻(DCR)测试等,以确保其电化学性能和热性能满足研究要求。从这些测试中获得的参考数据,即放电过程中的电压变化和温升变化,用于验证所开发模型的准确性和有效性。其次,在COMSOL Multiphysics~?5.4上建立了30 Ah电池的3D有限元平均电化学热耦合模型,并通过实验数据验证了其准确性和有效性。在电压和温升方面该模型实验与仿真曲线...

【文章页数】：96 页

【学位级别】：硕士

【文章目录】：
Abstract
摘要
Chapter 1:Introduction
    1.1 Research background and significance
    1.2 Research basis
        1.2.1 Construction and working principle of LIB
        1.2.2 Classification of battery modeling methods
    1.3 Research progress
        1.3.1 Current research status on battery modeling theory
        1.3.2 Research status of electrochemical-thermal coupled models
        1.3.3 Research status of parametric studies
    1.4 Main research contents
Chapter 2:LIB experimental and performance study
    2.1 Sample battery technical parameters and test equipment
    2.2 Battery performance test
        2.2.1 Battery actual capacity calibration
        2.2.2 Direct current resistance test
        2.2.3 Battery entropy heat coefficient test
        2.2.4 Constant current discharge test
    2.3 Analysis of experimental data
        2.3.1 Analysis of DCR
        2.3.2 Analysis of battery entropy heat coefficient
        2.3.3 Analysis of constant current discharge voltage-capacity curve
        2.3.4 Analysis of constant current discharge temperature rise curve
    2.4 Summary
Chapter 3:Development and verification of the average3D electrochemical-thermal coupled model
    3.1 Basic principle involved in the electrochemical-thermal coupled model
        3.1.1 Electrochemical model
            3.1.1.1 Electrochemical kinetics
            3.1.1.2 Conservation of charge in solid phase
            3.1.1.3 Conservation of charge in liquid phase
            3.1.1.4 Conservation of mass in solid phase
            3.1.1.5 Conservation of mass in liquid phase
        3.1.2 Thermal model
        3.1.3 Development of the electrochemical-thermal coupled model
            3.1.3.1 Development of geometric models
            3.1.3.2 Model input parameters
            3.1.3.3 Mesh generation
    3.2 Verification of an average3D electrochemical-thermal coupled model
        3.2.1 Constant current discharge voltage-capacity curve verification
        3.2.2 Discharge temperature curve verification
    3.3 Summary
Chapter 4:Analysis of electrochemical and thermal characteristics
    4.1 Parameter selection
    4.2 Parametric study on the electrochemical and thermal characteristics
        4.2.1 The effect of the discharge rate on the battery performance
        4.2.2 The effect of the initial/operating temperature on the battery performance
        4.2.3 The effect of the aspect ratio on the battery performance
        4.2.4 The effect of positive electrode active material particle size on the battery performance
        4.2.5 The effect of positive electrode thickness on the battery performance
        4.2.6 The effect of positive electrode solid-phase volume fraction on the battery performance
        4.2.7 The effect of heat transfer coefficient on the battery performance
    4.3 Summary
Chapter 5:A multi-parameter optimization to improve thermal performance
    5.1 Parameter analysis and optimization design
        5.1.1 Experimental design
        5.1.2 Response surface analysis and optimization method
    5.2 Discussion on the optimization results
        5.2.1 Multiple linear regression
        5.2.2 Analysis of variance(ANOVA)
        5.2.3 Response surface analysis
        5.2.4 Optimization results
    5.3 Summary
Chapter 6:Summary and prospect
    6.1 Summary
    6.2 Prospect
References
Acknowledgement
Scientific research projects and achievements during master's degree study
    Participated in scientific research projects
    Academic and scientific research achievements
    Conferences



本文编号：3973733