Issue 5, 2021

A high-voltage quasi-solid-state flexible supercapacitor with a wide operational temperature range based on a low-cost “water-in-salt” hydrogel electrolyte

Abstract

Recently, “water-in-salt” electrolytes have provided a huge boost to the realization of high energy density for water-based supercapacitors by broadening the electrochemical stability window. However, the high cost and low conductivity of high concentration LiTFSI greatly restrict the possibility of practical application. Herein, we adopt a new strategy to develop a low-cost and quasi-solid-state polyelectrolyte hydrogel accommodating a superhigh concentration of CH3COOK through in situ polymerization, avoiding the problem that many conventional polymers cannot accommodate ultra-high ion concentration. The polyelectrolyte hydrogel with 24 M CH3COOK exhibits a conductivity of up to 35.8 mS cm−1 and a stretchability of 950%. With advanced N-doped graphene hydrogel electrodes, the assembled supercapacitor yields a voltage window of 2.1 V with an energy density of 33.0 W h kg−1 and superior cyclability with 88.2% capacitance retention at 4 A g−1 after 6000 cycles comparable to those supercapacitors using high-cost LiTFSI salts. Besides, the supercapacitor with excellent temperature stability in the range of −20 to 70 °C can light an LED for more than one minute. The assembled flexible device with the PAAK/CMC-24 M gel film sandwiched in between demonstrates excellent bendability from 0° to 180° and shows great potential for flexible/wearable electronic devices. Our feasible approach provides a new route for assembling quasi-solid-state flexible high-energy storage devices with “water-in-salt” electrolytes.

Graphical abstract: A high-voltage quasi-solid-state flexible supercapacitor with a wide operational temperature range based on a low-cost “water-in-salt” hydrogel electrolyte

Supplementary files

Article information

Article type
Paper
Submitted
27 noy 2020
Accepted
06 yan 2021
First published
07 yan 2021

Nanoscale, 2021,13, 3010-3018

A high-voltage quasi-solid-state flexible supercapacitor with a wide operational temperature range based on a low-cost “water-in-salt” hydrogel electrolyte

Y. Deng, H. Wang, K. Zhang, J. Shao, J. Qiu, J. Wu, Y. Wu and L. Yan, Nanoscale, 2021, 13, 3010 DOI: 10.1039/D0NR08437A

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements