Functionalized Agarose Self‐Healing Ionogels Suitable for Supercapacitors

• DOI: 10.1002/cssc.201500648
• Publication Date: 2015-08-17T21:47:53Z
• Authors: Tushar J. Trivedi; Dhrubajyoti Bhatt...; Jong‐Sung Yu; Arvind Kumar
• Keywords: Activated Carbon; FACILE SYNTHESIS; carbohydrates; Ionic Liquids; Functionalizations; 01 natural sciences; ionic liquids; Imidazole Derivative; Electrolytes; DISSOLUTION; Electrochemistry; Liquid Electrolyte Systems; Gel; Charge-Discharge Cycle; Hydrogen Bonding Network; Sepharose; Imidazoles; Acetylation; Chemistry; functionalization; Electrolytic Capacitors; Mechanical Processes; 570; CHemICAL-MODIFICATION; Capacitors; Mechanics; Electric Capacitance; CARBON NANOTUBES; Ionic Liquid; REGENERATION; TECHNOLOGY; Cellulose; Mechanical Phenomena; Rheological Measurements; Specific Capacitance; Methanol; Liquids; 1-Butyl-3-Methylimidazolium; Hydrogen Bonds; gels; Solid Electrolytes; 540; Carbon; 1-Butyl-3-Methylimidazolium Chloride; 0104 chemical sciences; electrochemistry; Sols; Self-Healing Properties; Gels

AbstractAgarose has been functionalized (acetylated/carbanilated) in an ionic liquid (IL) medium of 1‐butyl‐3‐methylimidazolium acetate at ambient conditions. The acetylated agarose showed a highly hydrophobic nature, whereas the carbanilated agarose could be dissolved in water as well as in the IL medium. Thermoreversible ionogels were obtained by cooling the IL sols of carbanilated agarose at room temperature. The ionogel prepared from a protic–aprotic mixed‐IL system (1‐butyl‐3‐methylimidazolium chloride and N‐(2‐hydroxyethyl)ammonium formate) demonstrated a superior self‐healing property, as confirmed from rheological measurements. The superior self‐healing property of such an ionogel has been attributed to the unique inter–intra hydrogen‐bonding network of functional groups inserted in the agarose. The ionogel was tested as a flexible solid electrolyte for an activated‐carbon‐based supercapacitor cell. The measured specific capacitance was found to be comparable with that of a liquid electrolyte system at room temperature and was maintained for up to 1000 charge–discharge cycles. Such novel functionalized‐biopolymer self‐healing ionogels with flexibility and good conductivity are desirable for energy‐storage devices and electronic skins with superior lifespans and robustness.