title: Aloe vera Derived Activated High-Surface-Area Carbon for Flexible and High-Energy Supercapacitors.
abstract: Materials which possess high specific capacitance in device configuration with low cost are essential for viable application in supercapacitors. Herein, a flexible high-energy supercapacitor device was fabricated using porous activated high-surface-area carbon derived from aloe leaf (Aloe vera) as a precursor. The A. vera derived activated carbon showed mesoporous nature with high specific surface area of ∼1890 m2/g. A high specific capacitance of 410 and 306 F/g was achieved in three-electrode and symmetric two-electrode system configurations in aqueous electrolyte, respectively. The fabricated all-solid-state device showed a high specific capacitance of 244 F/g with an energy density of 8.6 Wh/kg. In an ionic liquid electrolyte, the fabricated device showed a high specific capacitance of 126 F/g and a wide potential window up to 3 V, which results in a high energy density of 40 Wh/kg. Furthermore, it was observed that the activation temperature has significant role in the electrochemical performance, as the activated sample at 700 °C showed best activity than the samples activated at 600 and 800 °C. The electron microscopic images (FE-SEM and HR-TEM) confirmed the formation of pores by the chemical activation. A fabricated supercapacitor device in ionic liquid with 3 V could power up a red LED for 30 min upon charging for 20s. Also, it is shown that the operation voltage and capacitance of flexible all-solid-state symmetric supercapacitors fabricated using aloe-derived activated carbon could be easily tuned by series and parallel combinations. The performance of fabricated supercapacitor devices using A. vera derived activated carbon in all-solid-state and ionic liquid indicates their viable applications in flexible devices and energy storage.
authors.affiliation: Functional Materials Division, ‡Academy of Scientific and Innovative Research (AcSIR), and §Centre for Education, CSIR-Central Electrochemical Research Institute , Karaikudi 630003, Tamilnadu India.
authors.forename: M
authors.initials: M
authors.lastname: Karnan
authors.affiliation: Functional Materials Division, ‡Academy of Scientific and Innovative Research (AcSIR), and §Centre for Education, CSIR-Central Electrochemical Research Institute , Karaikudi 630003, Tamilnadu India.
authors.forename: K
authors.identifier: http://orcid.org/0000-0001-6619-052X
authors.initials: K
authors.lastname: Subramani
authors.affiliation: Functional Materials Division, ‡Academy of Scientific and Innovative Research (AcSIR), and §Centre for Education, CSIR-Central Electrochemical Research Institute , Karaikudi 630003, Tamilnadu India.
authors.forename: N
authors.initials: N
authors.lastname: Sudhan
authors.affiliation: Functional Materials Division, ‡Academy of Scientific and Innovative Research (AcSIR), and §Centre for Education, CSIR-Central Electrochemical Research Institute , Karaikudi 630003, Tamilnadu India.
authors.forename: N
authors.initials: N
authors.lastname: Ilayaraja
authors.affiliation: Functional Materials Division, ‡Academy of Scientific and Innovative Research (AcSIR), and §Centre for Education, CSIR-Central Electrochemical Research Institute , Karaikudi 630003, Tamilnadu India.
authors.forename: M
authors.identifier: http://orcid.org/0000-0001-9094-5822
authors.initials: M
authors.lastname: Sathish
keywords: Aloe vera; bioderived carbon; flexible supercapacitors; ionic liquid; porous carbon