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

Abstract

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‐CuSO4‐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−2 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.