Thermal Modeling of Lithium-Ion Battery Under High-Frequency Current Excitation and Comparative Study of Self-Heating Scheme

Abstract

High-frequency ripple current excitation reduces the lithium precipitation risk of batteries during self-heating at low temperatures. To study the heat generation behavior of batteries under high-frequency ripple current excitation, this paper establishes a thermal model of LIBs, and different types of LIBs with low-temperature self-heating schemes are studied based on the established thermal model. Under the consideration of contact impedance, this paper tests the heat production of the battery under high-frequency ripple current and establishes an accurate thermal model of a lithium-ion battery under the excitation of high-frequency ripple current, and the absolute value of the maximum relative error between the measurement results and the thermal model is reduced from 181.4% to less than 20.6%, which makes the battery thermal model under high-frequency ripple current excitation more accurate. Then, based on the established thermal model, the calculation method of the minimum heating power required for different batteries under the same low-temperature self-heating conditions is proposed for batteries of different sizes, thermal properties, and internal resistances, and the preferred low-temperature self-heating scheme for different types of batteries is proposed by comparing the current multiplicity required for different high-frequency ripple current self-heating schemes.

Keywords

• lithium-ion battery
• self-heating
• high-frequency current ripple
• thermal model