In the context of the energy crisis and thermal pollution, there is an urgent need to switch to sustainable and clean energy sources, especially green energy generation. Thermoelectric generators (TEGs) can directly convert low-quality thermal energy into electricity when there is a temperature difference between the two sides. However, poor thermal management can lead to the accumulation of waste heat on the cold side of the TEG, reducing the efficiency of power generation, so an effective cooling mechanism must be applied to the TEG. However, most traditional cooling methods cannot achieve high efficiency, lightweight components, and low energy consumption at the same time, and it is still challenging to improve the performance of TEG in the long term.
Recently, a field team from the School of Medicine and Bioinformatics Engineering at Northeastern University proposed a strategy to improve thermal management and increase the sum energy of TEG by using sustainable evaporative cooling of highly hygroscopic and adhesive ionic gels (PIGs). Appropriate swelling levels and poly-[2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (PDMAPS) chains with group interactions prevent lithium chloride (LiCl) and 1-ethyl-3-methylimidazole acetate ([EMIM][Ac]) leakage, while carbon nanotubes (CNTs) and MIL-101 (Cr) optimize evaporative cooling of PIG. PIGs have a high adsorption rate (252.72% at 25 °C, 90% RH for 12 hours) and stable adsorption-desorption kinetics. At the same time, PIG exhibited high adhesion (130.89 Nm−1) on the TEG. The evaporative cooling of the PIG enhances the temperature difference between the upper and lower surfaces of the TEG. At a heat source temperature of 50–80 °C, the potential of the PIG-TEG tripled, and the output power density stabilized at ∼706.25 mW m−2 after heating at 50 °C for 1 hour. In addition, the PIG-TEG can maintain stable output enhancement for a long time (more than 24 hours). In addition, we integrated the PIG-TEG for a long-lasting power supply to the equipment and designed a mobile trolley model that uses waste heat for self-power. PIG enables thermoelectric output enhancement for TEGs and provides ideas for clean energy conversion, wearables, and mobile power supplies.
Figure 1. Preparation and characterization of PIG
Figure 2. Determine the optimal concentration of LiCl solution
Figure 3. Adsorption and desorption properties of PIG
Figure 4. Adhesion properties of PIG
Figure 5. Schematic diagram of the principle of PIG to improve the thermoelectric performance of TEG
Figure 6. PIG is used to improve the thermoelectric performance of TEG
Figure 7. Application of PIG-TEG device output enhancement
该研究工作以“Hygroscopic ionogel for enhanced thermoelectric generation performance”为题发表在国际学术期刊《Materials Today Sustainability》（影响因子7.1，文章DOI：10.1016/j.mtsust.2024.100976）。 东北大学医工学院硕士研究生韩艺轩为论文第一作者，东北大学医工学院田野副教授为论文通讯作者。
Original link: https://doi.org/10.1016/j.mtsust.2024.100976 Source: Frontiers of Polymer Science