A flexible symmetric thread‐like supercapacitor (TSC) with high operating voltage window and good electrochemical performance is manufactured, that fulfills the requirements of wearable electronics. First, iron oxide (Fe2O3) nanosheets are directly grown in situ on the surface of stainless steel yarn (SSY) by an acid corrosion and self‐oxidation process, and then a polypyrrole (PPy) coating is covered on the surface of Fe2O3 nanosheets via chemical oxide method to obtain the thread‐like PPy@Fe2O3@SSY composite electrode. The electrode achieves a wide potential range of −1.0–0.8 V (versus Ag/AgCl) and a high areal specific capacitance of 667.8 mF cm−2 with outstanding galvanostatic charge/discharge cycling stability of 87.5% capacitance retention after 10 000 cycles in 1 m lithium sulfate (Li2SO4) aqueous solution. The symmetric TSC based on the PPy@Fe2O3@SSY electrode and carboxymethyl cellulose sodium salt/Li2SO4 gel electrolyte exhibits a wide operating voltage window of 1.8 V, and its maximum energy density can reach 39.3 μWh cm−2. Additionally, the TSC demonstrates excellent electrochemical performance under various bending states and a bending cycling test. The preparation method and raw materials are low‐cost and scalable, and the overall performance of the TSC is excellent, which makes this device a promising energy storage device for wearable electronics.
Herein, a simple and convenient one‐step method to prepare ternary graphene/polypyrrole/silver (GE/PPy/Ag) nanocomposites with UV irradiation is demonstrated. The prepared GE/PPy/Ag nanocomposites show the desired design, in which Ag nanoparticles wrapped by a PPy layer are deposited on the surface of GE. Such a structure can combine the advantages of the three components, including the large surface area of GE, high pseudocapacitance of PPy, and superior conductivity of Ag, and overcome the shortcomings of the three components, including restacking of GE, poor cycling stability of PPy, and reunion of Ag nanoparticles. In addition, the Ag nanoparticles can store/release charges via reversible Ag/Ag+ redox to further improve the electrochemical performance of GE/PPy/Ag nanocomposites as supercapacitor electrodes. The GE/PPy/Ag nanocomposite prepared with 90 min UV irradiation exhibits the highest areal capacitance (294.2 mF cm−2), and the symmetric quasi‐solid‐state supercapacitor retains 80.1% capacitance retention after 5000 cycles. The GE/PPy/Ag nanocomposite can also be formulated as screen‐printing ink to fabricate planar micro‐supercapacitors by the screen‐printing technique, for applications in flexible energy storage devices.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.