【摘要】：鋰離子電池因為其優(yōu)良的特性使其在便攜式電子產(chǎn)品、電動車、航空航天領(lǐng)域中都有大量應(yīng)用。因此對不同溫度環(huán)境下的鋰電池外特性和管理策略研究至關(guān)重要。本課題基于熱耦合模型實現(xiàn)了對具體型號鋰電池常溫與低溫環(huán)境下溫度與端電壓的準確仿真,并且實現(xiàn)了低溫下電池健康預(yù)熱策略的研究以及常溫下電池健康充電策略的研究與驗證,具體工作如下:首先,考慮到溫度對鋰離子電池性能的影響,針對鋰離子電池熱耦合模型的參數(shù)進行修正。鋰離子電池熱耦合模型中的參數(shù)是由P2D模型參數(shù)約減而來,根據(jù)參數(shù)約減關(guān)系建立了熱耦合模型中溫度敏感參數(shù)與溫度之間的函數(shù)關(guān)系,提高模型在不同溫度環(huán)境下對鋰電池外特性的仿真精度。并且根據(jù)電池內(nèi)部不同的電化學反應(yīng)機理和激勵響應(yīng)分析方法,設(shè)計了鋰電池電流激勵工況解耦出不同的主要反應(yīng),進而由最小二乘方法對鋰電池熱耦合模型描述的不同反應(yīng)過程的參數(shù)分別進行準確辨識。其次,構(gòu)建-15℃低溫環(huán)境下鋰電池預(yù)熱系統(tǒng),基于改進的熱耦合模型,研究了采用高頻充放電電流的預(yù)熱策略。在鋰電池預(yù)熱過程中,根據(jù)電池不同溫度與荷電狀態(tài)控制電流大小使得電池內(nèi)部負極反應(yīng)極化過電勢的值小于平衡電勢,并且能高效預(yù)熱電池。實驗驗證表明該策略能夠?qū)崿F(xiàn)對低溫環(huán)境下的鋰電池能進行健康地預(yù)加熱,抑制鋰沉積等副反應(yīng)。最后,通過熱耦合機理模型分析了鈷酸鋰電池與磷酸鐵鋰電池充電過程中過電勢特點。為控制充電過程較高的電池內(nèi)部溫升對電池壽命的影響,提出了基于模型控制恒流充電過程中電池內(nèi)部溫度的新的充電策略,通過模型仿真與實驗驗證了控制策略的可行性,并且實驗驗證了該充電策略不僅與傳統(tǒng)的恒流恒壓充電策略用時與充電容量相當,而且可以延緩鋰電池容量的衰減。
[Abstract]:Lithium ion batteries have been widely used in portable electronic products, electric vehicles and aerospace due to their excellent characteristics. Therefore, it is very important to study the external characteristics and management strategies of lithium batteries at different temperatures. Based on the thermal coupling model, the simulation of the temperature and terminal voltage of a specific type of lithium battery at room temperature and low temperature is realized. The research of battery health preheating strategy at low temperature and the research and validation of battery health charging strategy at room temperature are realized. The specific work is as follows: firstly, considering the effect of temperature on the performance of lithium ion battery, The parameters of the thermal coupling model of lithium ion battery are modified. The parameters in the thermal coupling model of lithium ion battery are reduced by the parameters of P2D model. The functional relationship between the temperature sensitive parameters and the temperature in the thermal coupling model is established according to the parameter reduction relation. The simulation accuracy of the model for the external characteristics of lithium battery at different temperatures is improved. According to the different electrochemical reaction mechanism and excitation response analysis method inside the battery, different main reactions are designed to decouple the current excitation conditions of lithium battery. Furthermore, the parameters of different reaction processes described by the thermal coupling model of lithium battery are identified accurately by the least square method. Secondly, the preheating system of lithium battery at -15 鈩，

本文編號：2123914