近年來,三元NCM鋰離子電池因其高的能量密度,而成為新能源汽車動力電源的首選。但是它的熱安全性和熱穩(wěn)定性也受到了廣泛的關注,由于電池內(nèi)部電化學反應和熱特性不能通過實驗直接測量研究。因此,有必要使用數(shù)字仿真模擬技術來解決這些挑戰(zhàn)。由于溫度在放電過程中不斷地發(fā)生變化,會直接影響電化學模型中的某些特定參數(shù)的變化,因而僅憑電化學模型難以獲得準確可靠的結(jié)果。因此,建立電化學模型和熱模型之間的耦合至關重要�；诖�,本論文將電化學模型與熱模型耦合,建立了3D有限元平均電化學熱耦合模型來研究電池的電化學和熱特性。此外,通過多參數(shù)的優(yōu)化技術來改善電池熱性能。主要研究內(nèi)容如下:首先,以30 Ah NCM三元鋰離子電池為研究對象,對其進行了性能測試,包括放電測試和直流內(nèi)阻(DCR)測試等,以確保其電化學性能和熱性能滿足研究要求。從這些測試中獲得的參考數(shù)據(jù),即放電過程中的電壓變化和溫升變化,用于驗證所開發(fā)模型的準確性和有效性。其次,在COMSOL Multiphysics~?5.4上建立了30 Ah電池的3D有限元平均電化學熱耦合模型,并通過實驗數(shù)據(jù)驗證了其準確性和有效性。在電壓和溫升方面該模型實驗與仿真曲線...

【文章頁數(shù)】：96 頁

【學位級別】：碩士

【文章目錄】：
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



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