Synergistic Anisotropic Network and Hierarchical Electrodes Endow Cost-Effective N-Type Quasi-Solid State Thermocell with Boosted Electricity Production.

Quasi-solid state thermocells hold immense potential for harnessing untapped low-grade heat and converting it into electricity via the thermogalvanic effect. However, integrated N-type thermocells face limitations in thermoelectric performance due to the rare N-type systems and the poor electroactivity of the electrode interfaces. Herein, a low-cost, high-power N-type quasi-solid state thermocell employing PVA-CuSO-Cu is presented, which is enhanced by synergistic engineering of an anisotropic network and hierarchical electrodes. The anisotropic polymer network, combined with the salting-out effect, yields impressive mechanical properties that exceed those of most N-type quasi-solid state thermocells. Furthermore, through the synergistic construction of aligned ion transport pathways in the anisotropic thermocell and optimization of the electroactive interface between electrodes and thermocell, a remarkable enhancement of 1500% in output power density (compared to pristine thermocell), reaching 0.51 mW m at ∆T = 5 °C. It is believed that this cost-effective N-type thermocell, enhanced by the synergistic anisotropic network and hierarchical electrodes, paves the way for effective energy harvesting from diverse heat sources and promises to reshape sustainable energy utilization.