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High‐Voltage and Low‐Temperature Aqueous Supercapacitor Enabled by “Water‐in‐Imidazolium Chloride” Electrolytes
Author(s) -
Tatlisu Ammar,
Huang Zhifeng,
Chen Ruiyong
Publication year - 2018
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.201802046
Subject(s) - supercapacitor , aqueous solution , electrolyte , ionic liquid , chloride , graphene , chemistry , electrochemistry , inorganic chemistry , chemical engineering , electrode , materials science , catalysis , nanotechnology , organic chemistry , engineering
Symmetric aqueous high voltage supercapacitors up to 3 V have been demonstrated using concentrated aqueous 1‐butyl‐3‐methylimidazolium chloride ([BMIm]Cl), namely, “water‐in‐imidazolium chloride”, as working electrolytes, and graphene nanoplatelets‐coated carbon paper as electrodes. Performance enhancement was further achieved either through adding redox species such as 4‐hydroxy‐2,2,6,6‐tetramethylpiperidin‐1‐oxyl (4hT) into the electrolytes (110 Wh kg −1 for a 20 m [BMIm]Cl/H 2 O with 0.1 m 4hT) or by pre‐inserting ClO 4 − anions into the graphene platelets. Moreover, the newly studied aqueous electrolytes allow low‐temperature operation at −20 °C and even at −32 °C, retaining competitive energy storage capability (maximum energy densities of 36 and 21 Wh kg −1 , respectively).