A flexible and hydrophilic hydrogel film based all-in-one supercapacitor

• Published in: Journal of energy storage 2023-09, Vol.68, p.107877, Article 107877
• Main Authors: Cui, Shuzhen, Lv, Yaya, Jia, Yuxia, Hu, Qinzheng, Hou, Wenbo, Miao, Wenxing, Shi, Xiuting, Sun, Kanjun, Peng, Hui, Ma, Guofu
• Format: Article
• Language: English
• Subjects: Flexible; Hydrophilic hydrogel; Stretchable; Supercapacitor
• ISSN: 2352-152X
• DOI: 10.1016/j.est.2023.107877

In recent years, the integrated supercapacitors have made remarkable progress, but it is still considered a huge challenge to obtain an ultra-flexible and stable all-in-one supercapacitor under diverse deformations. Herein, a novel all-in-one supercapacitor is constructed through preparing soft enough and hydrophilic polyacrylamide (PAM/LiCl) hydrogel film, subsequently, polymerizing and depositing of hydrophobic polypyrrole (PPy) nanocomposites onto the two-sided surfaces of the PAM/LiCl hydrogel. It is found that the all-in-one supercapacitor exhibits excellent flexible stretching up to 650 % of original length, high specific capacitance (229.8 mF cm−2 at 0.8 mA cm−2), and high ionic conductivity (29 mS cm−1). Interestingly, the all-in-one supercapacitor can remain 30 days without obvious deterioration in capacitance. Moreover, the all-in-one supercapacitor presents also eminent cycling performance. The capacitance can remain 80 % of initial capacitance after 5000 cycles. This all-in-one flexible supercapacitor provides great potential prospects in wearable energy devices involving mechanical impacts. [Display omitted] •PAM/LiCl hydrogel with hydrophilic polymer networks swollen with tunable amounts of water and ions;•In-situ integrating PPy in electrolyte successfully fabricated an all-in-one flexible supercapacitor;•The all-in-one supercapacitor exhibits enhanced capacitive performance, excellent flexibility, and high ionic conductivity;•This research provides a new insight to construct stretchable and compressible integrated flexible supercapacitor.