Optimizing BESS performance: Anisotropic thermal properties and innovative parallel-flow cooling solutions

Abstract

As the demand for efficient energy storage solutions intensifies, container-type battery energy storage systems (BESS) have gained prominence. BESS usually utilizes large-format laminated lithium-ion battery (LIB) modules, which inherently possess unique anisotropic thermal properties. Specifically, the surface regions with elevated temperatures exhibit high thermal conductivity, while the cooler zones at both ends manifest reduced conductivity. Such disparities emphasize the challenge of developing an effective battery thermal management system (BTMS) for these modules. To address this, our study introduces an innovative BTMS configuration wherein the batteries are aligned in series, while cooling air flows parallel to them. This parallel-flow cooling approach capitalizes on the anisotropic properties, intensifying airflow over the surfaces and recirculating cooling air to optimize heat dissipation from hotspots. Consequently, our system reduces the peak temperature from 42.3 °C to 37.5 °C, as well as the temperature difference (ΔT) from 14.3 °C to 10.2 °C across the entire BESS, respectively representing 11.3 % and 28.7 % changes. This leads to a substantial 75.9 % enhancement in the performance index, significantly augmenting both the safety and commercial viability of the BESS.