半固態鋰離子電池的穿刺分析

Abstract

由於近年來智慧型手機與電動車迅速發展，使得提供與儲存電能的鋰離子電池變得極為重要。在市場趨勢上，為了滿足產品需求，所以電池電容量在近幾年逐漸提升，而電池在充放電產生的大電流，會使其溫度會有顯著的變化，因此電池的熱穩定性成為非常重要的安全性課題之一。 對於液態鋰離子電池來說，內部的電解液為易燃性材料，所以其熱穩定性較差；而固態鋰離子電池則在電容量受到限制，於是為了減少電池內部電解液與維持電池電容量，使用固態電解質與液態電解液組合而成的半固態鋰離子電池就此誕生。半固態鋰離子電池作為新型電池，我們可以為其建立一維電化學模型，並可將其用在模擬電池的充放電行為與電池溫度變化。此外，模擬可以減少實驗電池的使用，僅需藉由部分電池參數，即可得到電池電性的資料。 穿刺電池試驗為電池安全性檢測的其中一個項目，而其藉由電池溫度來判定試驗結果，所以電池穿刺後的溫度極為重要，若能藉由部分實驗參數，模擬電池穿刺後的溫度變化，對電池研究會有很大的幫助。在部分鋰離子電池穿刺實驗的文獻中，有對電池穿刺後的溫度進行模擬，而在各文獻所使用的模型架構有許多不同處，本論文會對各模型間差異進行比較，並藉由一開始所建立的半固態鋰離子電池之一維電化學模型與三維熱傳模型的組合，模擬其電池穿刺後的溫度變化情形，並與工研院所做的實驗結果比對，用來驗證模型架構的準確性。

Due to the rapid development of mobile devices and electric vehicles in recent years, lithium-ion batteries which supply and store electrical energy have become extremely important. In order to meet the demand of the market, battery capacity has gradually increased over the past few years, which often leads to significant temperature rise during charging and discharging by large current flow. Therefore, thermal stability of the battery becomes one of the most important and urgent issues when it comes to battery safety. For traditional lithium-ion batteries, the internal electrolyte is a flammable material which means it has poor thermal stability; while the relatively new all-solid-state lithium battery has better thermal stability, it has limited in capacity. To keep the best of both batteries, semi-solid-state lithium battery using the combination of both solid and liquid electrolyte was born. In this work, an one-dimensional electrochemical model for this new breed of battery is proposed. This model can not only be used to simulate the charge-discharge behavior and the temperature change of the battery, but also obtaining charge-discharge curve data with merely a few battery parameters. This results in reduction of numbers of batteries needed for experiment, which is great save of time and cost. Battery penetration test is one of the items of battery safety test, and the battery temperature is used as an indicator to judge the results. Therefore, the temperature of the penetrated battery is extremely important. The battery penetration model will be a great help in the battery research, if we can only use some experiment parameters to simulate the battery temperature after penetration. In some literature of battery penetration experiments, they set up different simulated model to predict the battery temperature change. In this thesis, we will compare each model and sort out the best set up to simulate the battery temperature change. The model has one-dimensional electrochemical of semi-solid-state lithium-ion battery and three-dimensional heat transfer. In the end, the experimental results of the ITRI were compared to verify the accuracy of the simulated model.