Author(s)

Davis George Moye^1*, Pedro L. Moss², Dhevathi Rajan Rajagopalan Kannan³, Xujie Chen^#, Omonayo Bolufawi³, Wanjun Cao^#, Simon Y. Foo³

¹Moye Consultants, Tallahassee, FL, USA.
²Greencastle Sustainable Electrical Energy Systems, Tallahassee, FL, USA.
³Department of Electrical and Computer Engineering, Florida A&M University and Florida State University, Tallahassee, FL, USA.

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·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.

Lithium-Ion Capacitor, Randles Equivalent Circuit Model, Butler-Volmer Equation

Moye, D. , Moss, P. , Kannan, D. , Chen, X. , Bolufawi, O. , Cao, W. and Foo, S. (2020) Improvements to Temperature, Warburg Impedance, and Voltage Computations for a Design-Based Predictive Model for Lithium-Ion Capacitors. Materials Sciences and Applications, 11, 347-369. doi: 10.4236/msa.2020.116024.