Thermoelectric supercapacitors: materials, challenges and future outlook

Self-powered devices are the most interesting research subject in recent times, focusing on the advancement of the flexible and wearable electronics market. A variety of self-powered systems have been designed using different energy harvesting (solar cells, mechanical as well as thermal energy harvester) and storage devices such as supercapacitors. Environmental degradation, the inadequacy in the supply of existing fossil fuels, as well as fast-rising energy demand have all raised alarm bells for our planet's long-term viability. To address these challenges, researchers must pursue steadfast studies on urgent needs by using 'green' energies such as wind, solar, tidal, mechanical, as well as geothermal sources. Because these green energy resources are intermittent, new energy harvesting as well as storage devices must be designed to keep and distribute the captured energy gradually, efficiently and meticulously. The low-grade thermal energy generally squandered without usage can be particularly beneficial for consistently powering electronic equipment, including sensors and wearable electronics. This review deals with a detailed discussion of the mechanism and fabrication of thermoelectric supercapacitors. The challenges, possible solutions, and the prospects of thermoelectric supercapacitors have also been highlighted.