Microstructural engineering of hydrated vanadium pentoxide for boosted zinc ion thermoelectrochemical cells

Abstract

Zinc ion thermoelectrochemical cells (ZTECs) have emerged as one of the attractive candidates for low-grade heat harvesting and energy storage but are greatly limited by the lack of promising cathode materials with superior rate capability and good durability. Here, we propose a facile strategy for the microstructural engineering of hydrate vanadium oxide by a surfactant to overcome such barriers. Impressively, a large Seebeck coefficient of 6.4 mV K⁻¹, remarkable thermal-induced power density of 1.8 W m⁻², and high durability were achieved by optimizing the cathode together with superior energy storage behaviors. Besides, one solid-state ZTEC could achieve a high output voltage of ∼0.83 V and power density of 0.2 W m⁻² with an ultralow temperature difference of 5 K. All the findings demonstrate the promising potential of microstructural engineering for electrode materials in the construction of high-performance thermoelectrochemical devices.