A novel design for conversion and storage of solar thermal energy into electrical energy using a solar thermoelectric device-coupled supercapacitor

Abstract

The conversion of solar-thermal (ST) power into electrical power along with its efficient storage represents a crucial and effective approach to address the energy crisis. The thermoelectric (TE) generator can absorb ST power and transform it into electrical energy, making it a highly viable technology to achieve photo-thermal conversion (PTC). However, the practical application of the pristine TE generator devices on a larger scale is still facing several challenges. On the one hand, the pristine TE generator device has low inherent PTC efficiency, thereby leading to low power conversion. On the other hand, such solar-thermoelectric (STE) conversion does not provide the functionality of electric energy storage. Herein, an effective strategy has been proposed that employs a CoAl₂O₄ PTC coating to decorate the pristine TE generator for developing the STE generator device with the remarkable STE performance and then coupling this device with a supercapacitor (SC) for effective storage power. In comparison to the pristine TE generator, the developed STE device exhibited considerable enhancement in both the open-circuit voltage (V_oc) and its maximum power density, displaying more than a 4- and 15-fold improvement, respectively. In addition, the feasibility of coupling this solar-driven STE generator device in series with a SC for ST conversion and storage was verified, and the working mechanism has been elucidated. This work presents a promising approach to effectively convert and store clean solar power into electrical energy, enabling practical applications of STE generator devices in conjunction with other electrochemical energy storage devices.