Experimental Study on Temperature Sensitivity of the State of Charge of Aluminum Battery Storage System

Abstract

The operating temperature of a battery energy storage system (BESS) has a significant impact on battery performance, such as safety, state of charge (SOC), and cycle life. For weather-resistant aluminum batteries (AlBs), the precision of the SOC is sensitive to temperature variation, and errors in the SOC of AlBs may occur. In this study, a combination of the experimental charge/discharge data and a 3D anisotropic homogeneous (Ani-hom) transient heat transfer simulation is performed to understand the thermal effect of a novel battery system, say an aluminum-ion battery. The study conducts a turbulence fluid dynamics method to solve the temperature distribution of the battery rack, and the entropy generation method analyzes the heat generation of AlB during the charging/discharging process. The AlB is modeled by a second-order Thevenin equivalent circuit to estimate the status of the battery. An extended Kalman filter is applied to obtain the accurate SOC for monitoring the battery cell. The current study conducts the Galvanostatic Intermittent Titration Technique (GITT) on aluminum-ion batteries under different operation temperatures: 25 °C, 40 °C, 60 °C, and 80 °C. According to the sensitivity analysis of the SOC, the temperature sensitivity tends to or greater than one, ST≥1, while the operation temperature is above 40 °C, and the SOC modification of EKFtmep estimator improves the battery state of charge in the error range below 1%.