Investigation of the Temperature Dependence of Parameters in the Generalized Peukert Equation Used to Estimate the Residual Capacity of Traction Lithium-Ion Batteries

Abstract

The Peukert equation is widely used in various analytical models of lithium-ion batteries. However, the classical Peukert equation is applicable to lithium-ion batteries only in a limited range of discharge currents. Additionally, it does not take into account the temperature impact on a battery’s released capacity. In this paper, the applicability of the generalized Peukert equation C = Cm/(1 + (i/i0)n) is investigated for the residual capacity determination of lithium-ion batteries based on the Hausmann model. It is proved that all the parameters (Cm, i0, and n) of this equation depend on a battery’s temperature. That is why, for a battery-released capacity calculation, it is necessary to take into account the battery’s temperature. The equations are found to describe the temperature dependence of all the parameters of the generalized Peukert equation. The physical meaning of all the parameters is established and it is shown that the generalized Peukert equation obtained with temperature consideration is applicable to any current and temperature of a battery.

Keywords

• Peukert equation
• lithium-ion battery
• temperature dependence
• current dependence
• capacity