Topology optimization-devised tri-material liquid cooling plate for energy storage battery thermal management

• A tri-material topology optimization is built for battery thermal management. • Multi-physics model unveils dynamic and uneven battery thermal behaviors. • Optimized cooling plate outperforms in cooling efficiency and flow resistance. • Comparative analysis evaluates the bottom versus side cooling designs. Traditional designs of liquid cooling plates using single thermally conductive material are either constrained by predefined topologies or fail to adequately mitigate hotspot issues, which remain insufficient for design freedom and performance trade-offs. To overcome these limitations, we propose a density-based topology optimization model that simultaneously optimizes the layout of flow channels and spatial distribution of two thermally conductive solids—enabling functional structures tailored to poorly ventilated areas. The tri-material liquid cooling plate integrates conjugate heat transfer modeling with a multi-physics battery model to accurately capture the electrochemical-thermal-hydrodynamic interaction in 46.59 kWh battery module. The optimized design yields bifurcated flow patterns that reduce fluid energy dissipation by up to 19.5 and 12.6 %, respectively, compared to straight-channel and single-solid designs at Reynolds number of 900, while improving thermal diffusion performance by over 10 % in terms of performance evaluation criterion. The comparative analysis further reveals that side-mounted composite cold plate outperforms the bottom-mounted counterpart under high discharge rates of 0.5–1C, achieving comprehensive evaluation improvements of 0.09–0.12 due to shorter heat transfer paths and increased thermal contact areas. These results demonstrate that tri-material topology optimization enables co-design of structure and material distribution, offering a scalable solution for high-efficiency and cost-effective liquid cooling design in energy storage systems.