鋰離子電池之電容量衰退模型

Modeling for Capacity Fade in Lithium-ion Battery

楊孟昇(Meng-Sheng Yang)

指導教授 ： 林巍聳

國立臺灣大學/電機資訊學院/電機工程學研究所/碩士(2015年)

https://doi.org/10.6342/NTU.2015.01459

摘要

鋰離子電池已經廣泛的應用於智慧型手機、筆記本電腦、電動工具以及電動車等工業產品，相對於鉛蓄電池，鋰離子電池有下列優點：高功率密度、高能量密度、無記憶效應、操作電壓高以及工作溫度範圍寬。做為電動車的電源，鋰離子電池必須承受變動性的負載電流和再生電流，變動性的電流需求很容易引起電極板、電解液、分隔膜的性能劣化而造成電容量衰退甚至縮短電池的循環壽命。本論文針對鋰離子電池在多種放電流的循環使用環境，建立電容量衰退與循環次數的關係，放電流循環考慮電動車負載常見的變動電流峰值和再生電流充電現象，經由分析歸納出各類型放電流循環的放電流特徵，然後利用複迴歸分析推導出放電流特徵與壽命損害因子之間的關係式，並將壽命損害因子代入鋰離子電池的電容量半經驗模型而得到電容量衰退模型，電容量衰退模型可以預測鋰離子電池的剩餘循環壽命，本論文藉由鋰離子電池的充放電循環實驗，取得電容量與循環次數的關係數據來驗證電容量衰退模型。

關鍵字

鋰離子電池 ； 電容量衰退模型 ； 電池循環壽命

並列摘要

Lithium-ion batteries have been widely used in smart phones, lab top computers, electric tools, and electric vehicles. In comparison with lead-acid batteries, Lithium -ion batteries have the merits of high power density, high energy density, no memory effect, high working voltage, and wide temperature range in operation. While supplying an electric vehicle, Lithium-ion batteries are frequently challenged by fluctuating discharge/charge currents resulted from changes in load demand and regenerative braking. Under the vehicle environment, the cell plate, electrolyte, and separators of the battery may suffer from damage that eventually causes capacity fade to the battery. This thesis focuses on modeling the capacity fade of the Li-ion battery under the vehicle environment. A good capacity fade model can be used to predict the rest cycle life of the battery. The capacity fade model is basically a semi-empirical model whose adjustable parameters, called the damage factors, are induced from experimental data. The experimental data are obtained by testing the battery on discharge/charge cycles with features commonly found in supplying an electric vehicle. The relation between the damage factors and the features is found by the multiple regression analysis. When the damage factors are determined, the capacity fade model can give estimate to the rest cycle life of the battery. The effectiveness of the capacity fade model has been validated by the experimental data.

並列關鍵字

Li-ion battery ； capacity fade model ； estimation of cycle life

參考文獻

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Göteborg, Sweden: Division of Electric Power Engineering