Abstract
A simple and scalable method to fabricate a novel high-energy asymmetric supercapacitor using tomato-leaf-derived hierarchical porous activated carbon (TAC) and electrochemically deposited polyaniline (PANI) for a battery-free heart-pulse-rate monitor is reported. In this study, TAC is prepared by simple pyrolysis, exhibiting nanosheet-type morphology and a high specific surface area of ≈1440 m2 g−1, and PANI is electrochemically deposited onto carbon cloth. The TAC- and PANI- based asymmetric supercapacitor demonstrates an electrochemical performance superior to that of symmetric supercapacitors, delivering a high specific capacitance of 248 mF cm−2 at a current density of 1.0 mA cm−2. The developed asymmetric supercapacitor shows a high energy density of 270 µWh cm−2 at a power density of 1400 µW cm−2, as well as an excellent cyclic stability of ≈95% capacitance retention after 10 000 charging–discharging cycles while maintaining ≈98% Coulombic efficiency. Impressively, the series-connected asymmetric supercapacitors can operate a battery-free heart-pulse-rate monitor extremely efficiently upon solar-panel charging under regular laboratory illumination.
Original language | English |
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Article number | 2300258 |
Journal | Small |
Volume | 19 |
Issue number | 33 |
DOIs | |
State | Published - 16 Aug 2023 |
Bibliographical note
Publisher Copyright:© 2023 Wiley-VCH GmbH.
Keywords
- activated carbon
- asymmetric supercapacitors
- ionic liquid electrolytes
- large potential windows
- polyaniline
ASJC Scopus subject areas
- Engineering (miscellaneous)
- General Chemistry
- General Materials Science
- Biotechnology
- Biomaterials