FEM輔助鋰離子二次電池安全閥之開發研究

Abstract

鋰離子二次電池具有高能量密度的特性，一旦鋰離子電池發生異常，釋放出來的能量將可能導致爆炸，因此鋰電池需要一些保護措施來預防危險發生。安全洩壓閥是設計在電池殼體上的一種防爆結構，會在電池發生異常，內壓升高至設計值時釋放壓力，避免電池內壓過高而爆炸。 本研究將使用有限元素法來輔助安全閥的設計開發，並提出一種簡便的安全閥設計概念，要藉由將電池的部份結構弱化，利用弱化後的結構達到安全閥的功效；本研究並嘗試分析影響此類型安全閥破裂壓大小的各項參數，最後整理出設計的操作窗，直接應用於安全閥之設計方案。

The lithium-ion secondary battery has a characteristic of high energy density. In case of hazard situations, the energy released from the battery may result in exploding, which venders the needs for some protective devices as a safe guard. The safety vent is a kind of anti-blast structure designed on the shell of the battery. It will cause a release of the pressure at a designated value while the battery is performed in abnormal situations where its inner pressure is building up. This study used FEM as a tool to assist the design of the safety vent, and a simple and effective design of the safety vent was obtained as a result. This study also attempts to find the parameters that influence the amount of breaking pressure for this type of safety vent. From a systematic approach, an operation window that can be applied directly to the safety vent design was devised from this study.