Review of Thermoelectric Generators at Low Operating Temperatures: Working Principles and Materials

Abstract

Thermoelectric generators (TEGs) are a form of energy harvester and eco-friendly power generation system that directly transform thermal energy into electrical energy. The thermoelectric (TE) method of energy harvesting takes advantage of the Seebeck effect, which offers a simple solution for fulfilling the power-supply demand in almost every electronics system. A high-temperature condition is commonly essential in the working mechanism of the TE device, which unfortunately limits the potential implementation of the device. This paper presents an in-depth analysis of TEGs at low operating temperature. The review starts with an extensive description of their fundamental working principles, structure, physical properties, and the figure of merit (ZT). An overview of the associated key challenges in optimising ZT value according to the physical properties is discussed, including the state of the art of the advanced approaches in ZT optimisation. Finally, this manuscript summarises the research status of Bi2Te3-based semiconductors and other compound materials as potential materials for TE generators working at low operating temperatures. The improved TE materials suggest that TE power-generation technology is essential for sustainable power generation at near-room temperature to satisfy the requirement for reliable energy supplies in low-power electrical/electronics systems.

A 7.5-mV Input and 88%-Efficiency Single-Inductor Boost Converter with Self-Startup and MPPT for Thermoelectric Energy Harvesting

“…Energy harvesting technology can be used in passing sensing devices in internet of things (IoTs) [ 1 , 2 , 3 ] due to the self-power [ 4 , 5 ], which can provide the supply voltage instead of the battery. Recently, there is a lot of research concentrating on harvesting piezoelectric energy [ 6 ], radio frequency (RF) energy [ 7 ], photovoltaic energy [ 8 ] and thermoelectric energy [ 9 , 10 , 11 ].…”

Pyroelectric Nanogenerator Based on an SbSI–TiO2 Nanocomposite

“…Low-temperature waste heat is especially difficult to recover successfully using currently available technologies [ 2 ]. Thermal energy can be converted into electric energy by applying electrochemical systems [ 3 ], thermogalvanic cells [ 4 , 5 ], thermoelectric [ 6 , 7 , 8 ], thermomagnetic [ 9 , 10 ], and pyroelectric generators [ 11 , 12 , 13 ]. However, all mentioned technologies suffer from low efficiency and limited reliability.…”

Environment-Monitoring IoT Devices Powered by a TEG Which Converts Thermal Flux between Air and Near-Surface Soil into Electrical Energy

“…This contribution investigates thermal energy that can be converted into electrical energy by a thermoelectric generator (TEG) using spatial variations in temperature [12]. Thermoelectric transducers and generators are based on the Seebeck effect [13] and are composed of several pairs of p-type and n-type semiconductor blocks ordered in parallel and connected electrically in series [12].…”

“…This contribution investigates thermal energy that can be converted into electrical energy by a thermoelectric generator (TEG) using spatial variations in temperature [12]. Thermoelectric transducers and generators are based on the Seebeck effect [13] and are composed of several pairs of p-type and n-type semiconductor blocks ordered in parallel and connected electrically in series [12]. The open circuit voltage of a thermoelectric element depends on the temperature difference (∆T) between a hot and a cold surface and also on material properties called Seebeck coefficients [14,15].…”