A Gaussian-Polynomial Approximation Model for the Discharge Behavior of a Lithium-Ion Battery

鋰電池放電行為的高斯－多項式近似模型

翁志祁(Che-Chi Weng)

《華岡工程學報》 19期 (2005/06) Pp. 65-71

https://doi.org/10.29987/CCUHKJE.200506.0006

摘要

本研究結合一個一次元的多項式函數與一個一次元高斯函數來描述鋰電池的放電行為。一次元的多項式在描述電池放電中段的行為，而一次元高斯函數則在模擬電池放電的最末端的行為。在電池剩餘容量百分比與電池電壓的函數圖中可以看到，實際的量測值與本模型的誤差大多發生在電池放電的初期，然而在電池放電的中段及末端，本模型則有非常優異的表現，其電壓誤差都在零點一個伏特之內，若以剩餘電池容量的百分比計量，其誤差則在兩個百分點以內。對於使用者而言，重要的是，現在還剩多少電池容量可供使用，而非目前已使用了多少電量。所以，對於電池放電末段行為的瞭解，遠比放電前段的描述更為重要。我們的模型對於任一放電曲線的描述僅需五個參數，因此，本模型提供了既精確又簡單的數學模式來描述鋰電池的放電行為。

關鍵字

鋰電池 ； 可充電電池 ； 電池剩餘容量 ； 放電曲線 ； 高斯函數 ； 多項式函數 ； 電

並列摘要

In this research, a first order polynomial and a first order Gaussian function are combined to describe the discharge behavior of a Lithium-ion cell battery. The first order polynomial is used to describe the middle part of the discharge curve, and the first order Gaussian is to fit the final part of the curve. As a result, in the curve of percentage of remain capacity versus voltage, the major difference between the observed discharge curve and the curve generated from our model happens only in the beginning of the discharge. In the middle and the later part of the discharging, our model fits very well to the observed discharge curve. The differences are well within 0.1 volts. As to the percentage of remaining capacity, the differences are within 2 percents. To the users, the important concern is how much the capacity remains to be used, rather than how much capacity they have used. Thus, the understanding of the later part of the discharge curve is much more important than that of the earlier part. In our model, it takes only 5 parameters to describe the behavior of discharge in each case. Therefore, we believe that we have developed a simple, yet accurate model to describe the discharge behavior of a lithium-ion battery.

並列關鍵字

Lithium-ion battery ； rechargeable battery ； polynomial ； Gaussian ； Gaussian-Polynomial Approximation Model ； battery discharge behavior