Humidity-Tolerant Moisture-Driven Energy Generator with MXene Aerogel–Organohydrogel Bilayer

Humidity-Tolerant Moisture-Driven Energy Generator with MXene Aerogel–Organohydrogel Bilayer

ACS Nano

10.1021/acsnano.2c10747

https://doi.org/10.1021/acsnano.2c10747

Kaiying Zhao, Jae Won Lee, Zhi Gen Yu, Wei Jiang, Jin Woo Oh, Gwanho Kim, Hyowon Han, Yeonji Kim, Kyuho Lee, Seokyeong Lee, HoYeon Kim, Taebin Kim, Chang Eun Lee, Hyeokjung Lee, Jihye Jang, Jong Woong Park, Yong-Wei Zhang, Cheolmin Park

General Materials Science

13 February 2023

Zhao, K., Lee, J. W., Yu, Z. G., Jiang, W., Oh, J. W., Kim, G., Han, H., Kim, Y., Lee, K., Lee, S., Kim, H., Kim, T., Lee, C. E., Lee, H., Jang, J., Park, J. W., Zhang, Y.-W., & Park, C. (2023). Humidity-Tolerant Moisture-Driven Energy Generator with MXene Aerogel–Organohydrogel Bilayer. ACS Nano, 17(6), 5472–5485. https://doi.org/10.1021/acsnano.2c10747

High-performance, moisture-driven energy generators (MEG) harness the preferential interaction of ionized moisture with hydrophilic active materials. Free-standing and film-type MEGs are particularly interesting owing to their wearability and portability without needing a water container. However, most MEGs work in limited humidity conditions where moisture is rapidly evaporated from the devices with a high moisture gradient. Herein, we present a high-performance MEG with excellent humidity tolerance and sustainable power-production capability. The demonstrated bilayer-based device comprises a negatively surface-charged, hydrophilic MXene (Ti3C2Tx) aerogel and polyacrylamide (PAM) hydrogel containing ionic salts sandwiched between the top and bottom electrodes. The preferential adsorption on the surface of the highly porous MXene aerogel of positive charges supplied from the salts, and water in the hydrogel, results in high open circuit voltage output when the relative humidity ranges from 20% to 95%. Our MXene aerogel MEG with an active area of 1cm2 produces a maximum open circuit??? voltage, current density, and power density of approximately 570 mV, 1160 μA/cm2, and 24.8 μW/cm2, respectively. y replacing the hydrogel with an organohydrogel of PAM that has excellent water retention and structural stability, a device with long-term electricity generation is realized, which has an output voltage of approximately 320 mV lasting for more than 15 days in a broad temperature range (from –20 to 80 °C). The first principle simulation reveals that the mechanism of MEG originated from the excellent surface charging effect of the cation since the cation has a much lower diffusion energy barrier than the anion, resulting in the separated distribution of cations and anions on the top and bottom of the Mxene surface. Our MXene aerogel MEGs connected in series supply sufficient power for commercial electronic components in various outdoor environments. Moreover, a mechanically flexible, free-standing MXene aerogel MEG can be mounted on the skin for sensitively recognizing finger bending and facial expression changes through the variation of its output current.

Publisher Copyright

There was no specific funding for the research done

This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Nano, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see 10.1021/acsnano.2c10747.

https://oar.a-star.edu.sg/communities-collections/articles/22551

1936-0851
1936-086X

Institute of High Performance Computing