Experimental Evidence on the Effect of Temperature on the Performance of a Lithium-Ion Battery

The current energy transition highlights the importance not only of energy production, but also of its efficient storage, for which lithium-ion batteries are currently the leading technology. In many applications, these devices operate outdoors at temperatures below 0 °C, and consequently, their performance is reduced due to the lower mobility of the ions. With the aim of evaluating this decrease in performance, measurements were carried out on a commercial LiFePO4 module in the temperature range −20 ÷ +55 °C. The results show that the battery capacity decreases by 15% compared to the value measured at room temperature when the operating temperature drops to approximately −10 °C, and by 35% at approximately -20 °C. The paper also introduces a modified version of the Arrhenius kinetic model that allows for the analytical evaluation of the change in battery capacity as a function of temperature. The modified model proposes a quadratic dependence of the activation energy on the temperature through a temperature coefficient that for the two tested modules is equal to 8.0·10⁻⁵ eV/K² and 6.7·10⁻⁵ eV/K², respectively.