Multilayer stacked thermoelectric generator with temperature-window-matched materials for waste heat recovery in series-hybrid electric vehicles

To enhance exhaust waste-heat recovery in series-hybrid electric vehicles (SHEVs), a multilayer stacked thermoelectric generator (TEG) is proposed. L-shaped copper plates redistribute exhaust heat across the module layers. The inner-layer thermoelectric modules (TEMs) use skutterudite and half-Heusler for their p- and n-type legs, respectively. Bi 2 Te 3 -based TEMs are employed in the middle and outer layers to create a temperature-zone-matched material arrangement. A computational-fluid-dynamics (CFD) and thermal-electric hybrid numerical model is established to quantify the effects of electrical interconnection topology, fin thickness ( t ), fin spacing ( d ), and coolant velocity ( V w ). Relative to an all-Bi 2 Te 3 configuration, the temperature-window-matched design increased the maximum output power ( P out ) from 342.11 to 392.05 W. Among four candidate topologies, a hybrid configuration yielded the highest P out . In this configuration, the outer- and middle-layer TEMs form a parallel branch that is connected in series with the inner-layer TEMs. The hybrid configuration achieved a peak P out of 417.16 W, 6.41% higher than that of the fully series configuration. Increasing V w enhanced heat rejection but also substantially increased pumping losses, yielding an optimal operating range of 0.5–1.25 m/s. By balancing heat-transfer enhancement against back-pressure losses, the TEG achieved a maximum net output power of 330.38 W at t = 0.2 mm and d = 2 mm. This numerical assessment demonstrates the performance potential of the multilayer TEG and provides design guidance for exhaust waste-heat recovery in SHEVs. Prototype fabrication and experimental validation will be pursued in future work.