Thermoelectric-based battery thermal management with cooling and energy recovery

This work proposes the hybrid battery thermal management system (BTMS) integrating thermoelectric modules (TEM), phase change materials (PCM), and liquid cooling (LC) to achieve dual functionalities of TEM: power generation and cooling. A multi-physics numerical model is established to analyze the system’s performance under varying discharge rates, along with proposing a phase transition temperature-triggered operational strategy. Results demonstrate that under 1 C to 4 C discharge conditions, the passive cooling system maintains the Tmax of batteries below 323.15 K with a ΔT under 5 K, while TEM acts as the thermoelectric generator (TEG) to recover waste heat, exhibiting significant increases in output voltage and power with rising discharge rates. At 5C discharge, thermoelectric cooling (TEC) and LC reduce the Tmax of batteries from 323.74 K to 321.51 K, while LC lowers the TEC hot-side temperature, thereby decreasing system energy consumption. The proposed 340 s delayed activation strategy for active cooling extends TEG power generation time by 340 s and reduces active cooling operation time by 47.2%. In 1C, 2C, 3C, and 4C discharge rates, the peak net energies of 22.15 J, 52.24 J, 53.60 J, and 41.93 J occur at liquid cooling mass flow rates of 0.3 g/s, 0.5 g/s, 0.7 g/s, and 0.7 g/s, respectively. This work provides an innovative solution for the BTMS that balances thermal control efficiency and energy recovery.