TAILIEUCHUNG - Modeling
The ‘ideal’ rechargeable battery is obviously the one that has high power and energy density, high discharge rate, ﬂat discharge curves, good low-temperature performance, and long service and shelf life as well as safety. However, the mentioned preferable characteristics of rechargeable batteries conﬂict with one another and require trade-offs. The objective of advanced battery research and development should be to obtain a compromise among the battery requirements. | Modeling Chee Burm Shin Ajou University Suwon Republic of Korea 2009 Elsevier . All rights reserved. Introduction The ideal rechargeable battery is obviously the one that has high power and energy density high discharge rate flat discharge curves good low-temperature performance and long service and shelf life as well as safety. However the mentioned preferable characteristics of rechargeable batteries conflict with one another and require trade-offs. The objective of advanced battery research and development should be to obtain a compromise among the battery requirements. Mathematical modeling of batteries plays an important role in battery development as nearly limitless design iterations can be performed using computer simulations. There are a wide variety of battery models with varying degrees of complexity. They may be classified into analytical models electrical models and electrochemical models. Analytical models have been developed where analytical expressions are formulated to calculate actual battery capacity and lifetime. One of the earliest analytical models is Peukert s equation which expresses the nonlinear relationship between the battery capacity and the discharge rate. More sophisticated analytical models have been proposed where the capacity and lifetime are expressed in terms of discharge current temperature and additional operating parameters. Analytical battery models can include both constant load and variable load. All these models capture rate-capacity effects and some capture thermal effects but none addresses the effects of phenomena such as storage and aging. These models are flexible and can be easily configured for specific batteries. They are computationally efficient because they require only simple evaluation of analytical expressions. Electrical models are based on constructing equivalent electrical circuits comprised of voltage sources resistors and capacitors. The charge stored in the battery is modeled by using a capacitor .
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