Improvements to Temperature, Warburg Impedance, and Voltage Computations for a Design-Based Predictive Model for Lithium-Ion Capacitors

• 作者: Davis George Moye Dhevathi Rajan Rajagopalan Kannan Omonayo Bolufawi Pedro L. Moss Simon Y. Foo Wanjun Cao Xujie Chen
• 来源期刊: 材料科学与应用期刊(英文)
• 学科: 数学
• 关键词: Lithium-Ion Capacitor Randles Equivalent Circuit Model Butler-Volmer Equation
• 年，卷（期）: clkxyyyqkyw_2020,（6）
• 页码范围: 347-369
• 页数: 23页
• 分类号: O17

摘要

An earlier study manipulated the Butler-Volmer equation to effectively model a lithium-ion capacitor’s (LIC) energy storage as a function of its constituent components and charge current. However, this model had several shortcomings: computed temperature values were too low, voltage was inaccurate, and the model required Warburg impedance values that were two orders of magnitude higher than experimental results. This study began by analyzing the model’s temperature and voltage computations in order to justify output values. Ultimately, these justifications failed. Therefore, in situ temperature rise was measured during charge cycles. Experimental results indicated that temperature increases minimally during a charge cycle (<1%). At high current densities (≥150 A<span style="white-space:nowrap;">·</span>kg^-1) temperature increase is negligible. After it was found that LIC temperature change is minimal during a charge cycle, the model accurately computed LIC voltage during the charge cycle and computed Warburg impedance that agreed with values derived from earlier experimental studies, even falling within the measurements’ precision error.