A Self-Powered Temperature Sensor Based on Silver Telluride Nanowires

Abstract

Thermoelectric devices are effective in harvesting energy from waste heat with a temperature difference relative to the environment, which can be applied in vehicles, aircrafts, and power plants. In our research, we developed a thin, light-weight, and flexible thermoelectric nanogenerator based on the nanocomposite of silver telluride (Ag 2 Te) nanowires and poly (3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). The Seebeck coefficient of the nanocomposite was determined to be 100 μV/K. A linear relationship between the output voltage and the temperature difference across the thermoelectric nanogenerator was observed. Not only for the purpose of energy harvesting, the thermoelectric nanogenerator can also function as a self-powered sensor for water temperature measurement. Increasing research efforts have been devoted to renewable energy owing to the large energy consumption in recent years. Comparing to fossil fuel, renewable energy with the advantages of reduced carbon emission and secure long-term energy supply is more mandatory for the sustainable development of the world. Nanogenerators, which are emerging new energy technologies that can harvest renewable energy from the environment, have attracted global attention.1-4 Thermoelectric nanogenerator, which works based on thermoelectric effect, 5-7 is capable of converting waste heat into electricity with a temperature difference relative to environmental temperature. Many studies [8][9][10][11] have demonstrated that nanomaterials can enhance their ZT values by suppressing the thermal conductivity compare to their bulk counterparts. The reduction of thermal conductivity in nanomaterials is because phonon scattering and energy-dependent scattering of electrical carriers occur in the presence of nanoscale interfaces.12 These properties result in nanomaterials are good candidates to fabricate thermoelectric nanogenerator to harvest tiny-scale thermal energy 13,14 and show the potential to be applied in the collection of heat energy from vehicles, aircrafts, and power plants. In addition, thermoelectric nanogenerator can be used as alternative to photovoltaic cells to convert solar energy into electrical power. [15][16][17][18] In this paper, we developed a thin, light-weight, and flexible thermoelectric nanogenerator (Figure 1a) based on the nanocomposite Ag 2 Te nanowires and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). The Ag 2 Te nanowires were synthesized at ambient temperature, which means that the energy-saving concept can be completely utilized, starting from the nanomaterial preparation. The as-prepared thermoelectric nanogenerator showed a Seebeck coefficient of 100 μV/K and a linear relationship between the output voltage and the temperature difference across the device. Under a temperature difference of 25• C, the thermoelectric nanogenerator provided an output voltage of 2.6 mV. And we have demonstrated that the thermoelectric nanogenerator can be applied as a self-powered sensor for water temperature measureme...

Design, Performance, and Application of Thermoelectric Nanogenerators

“…d 1 –d 3 ) Schematic diagram, photograph, and corresponding output voltage of the flexible TEG. Reproduced with permission . Copyright 2015, ECS.…”

“…Furthermore, the performances of two TEGs in serial and parallel connections are also investigated; the total voltage of two serial TEGs is 38 mV and the current density in parallel is about 32 nA mm −2 under the same temperature difference of 55 K. As a self‐powered temperature sensor, the detection sensitivity, recovery time, and response time are 0.15 K, 9 s, and 17 s, respectively. Figure d 1 ,d 2 illustrates structural schematics and photographs of a flexible TEG based on Ag 2 Te nanowires . Figure d 3 exhibits TE performances of the flexible TEG with an output voltage of 2.6 mV and a Seebeck coefficient of about 100 µV K −1 under a temperature difference of 25 K. Owing to the characteristics of small size, light weight, and good flexibility of the TEG, it can be attached to a cup filled with hot water as a self‐powered temperature sensor to detect the temperature of water.…”

“…After decades of research and development, the structures and performance of TEGs are gradually optimized and improved, and there are a large number of potential applications for TEGs in different fields. Various kinds of TEGs can achieve power generation and heating/refrigeration, showing many merits such as high sensitivity to temperature change and emission‐free operation. These advantages enable TEGs to be utilized in different fields, including self‐powered sensor systems, automotive and control devices, water condensation, and implantable/wearable electronics …”

“…d) Photograph of the smart mug attached with the as‐prepared TEGs. Reproduced with permission . Copyright 2015, ECS.…”

“…A change in temperature will result in a change in the temperature difference and TE current. Therefore, it can be used for the detection of atmospheric temperature and water temperature in a cup . Figure e displays a stretchable TEG that can act as a self‐powered strain sensor; the temperature difference between two sides of the TEG remains constant, and the TE current is constant without any strain.…”