Ionic Thermoelectric Effect Inducing Cation‐Enriched Surface of Hydrogel to Enhance Output Performance of Triboelectric Nanogenerator

Abstract

The most robust consensus related to ionic‐hydrogel‐based triboelectric nanogenerator (TENG) is that the charge density at the solid interface plays a pivotal role in its output performance. However, there has been no reliable evidence of the mechanism regarding the influence of ion enrichment on TENG. Higher surface charge density at the solid interface could result in higher output performance. Herein, the ionic hydrogel is prepared through polymerization reaction of the organic monomers with LiCl as the ionic conductor. The ion migration on the hydrogel surface is regulated via tuning the temperature difference between the top and bottom sides. Upon contacting with the upper electrode, more induction charges are induced on the cation‐enriched surface of hydrogel, leading to a larger output of the TENG. At the temperature difference of 25 °C, the open‐circuit voltage and maximum output power density is increased by 77% and 166% compared with the TENG without temperature field, respectively. When the temperature of the hydrogel surface is higher than 50 °C, the output performance of TENG would decrease due to the water loss of hydrogel. This research will advance further understanding of the mechanism of thermoelectric ionic conductors in TENGs, self‐powered sensors, and wearable devices.

Power Generation by Thermal Evaporation Based on a Button Supercapacitor

“…It is worth noting that since the device itself possessed the function of energy storage, its electrical conductivity is lower than that of reported analogous devices to avoid short-circuit discharge. Figure d further compares the thermopower in this work with that of the reported ion–thermoelectric materials, especially due to the Soret effect. − It is worth noting to emphasize that the output performance of this button-type thermal evaporation power generation device exceeded that of most previously reported analogous devices, as shown in Table S3.…”

Textile electronics for wearable applications

“…This is the highest output voltage for wearable energy harvesting systems for mechanical energy [252]. Furthermore, hybrid generator, which can incorporate two or more energy harvesting effects, have also been examined as highly efficient mechanical energy harvester [253,254].…”

Ultrafast and Cost-Effective Fabrication of High-Performance Carbon-Based Flexible Thermoelectric Hybrid Films and Their Devices

“…9,10 Additionally, the power factor S 2 σ is widely used to evaluate the thermoelectric performance of film-based thermoelectric materials since their κ is difficult to be correctly measured due to the limitation of current techniques. 11 To date, many thermoelectric materials, such as inorganic semiconductors and ceramics, 12,13 conducting polymers, 14,15 carbon and related composites, 16,17 and ionogels, 18,19 have been developed to exhibit promising thermoelectric properties. 20 Historically, some newly developed carbon materials such as graphene and carbon nanotubes (CNTs) have been studied to explore their thermoelectric potential.…”

“…Their thermoelectric potential is evaluated by the dimensionless figure-of-merit ZT = S 2 σ T /κ, where T is the absolute temperature, σ is the electrical conductivity, S is the Seebeck coefficient, and κ is the thermal conductivity. , Additionally, the power factor S 2 σ is widely used to evaluate the thermoelectric performance of film-based thermoelectric materials since their κ is difficult to be correctly measured due to the limitation of current techniques . To date, many thermoelectric materials, such as inorganic semiconductors and ceramics, , conducting polymers, , carbon and related composites, , and ionogels, , have been developed to exhibit promising thermoelectric properties . Historically, some newly developed carbon materials such as graphene and carbon nanotubes (CNTs) have been studied to explore their thermoelectric potential. − However, these materials are relatively expensive; therefore, conventional carbon materials that can realize an industrial scale are valuable for practical thermoelectric applications and future commercialization.…”