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Electrical Double‐Layer Capacitors Based on a Ternary Ionic Liquid Electrolyte Operating at Low Temperature with Realistic Gravimetric and Volumetric Energy Outputs
Author(s) -
Yambou Emmanuel Pameté,
Gorska Barbara,
Béguin François
Publication year - 2021
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.202002809
Subject(s) - electrolyte , ionic liquid , ternary operation , gravimetric analysis , materials science , electrode , chemical engineering , supercapacitor , viscosity , ionic conductivity , quasi solid , capacitance , chemistry , composite material , organic chemistry , dye sensitized solar cell , catalysis , computer science , engineering , programming language
We report on electrical double‐layer capacitors (EDLCs) performing effectively at low temperature (down to −40 °C), owing to the tuned characteristics of both the ionic liquid (IL) electrolyte and carbonaceous electrodes. The transport properties of the electrolyte have been enhanced by adding a low‐viscosity IL with the tetracyanoborate anion, [EMIm][TCB], to a mixture of [EMIm][FSI] with [EMIm][BF 4 ], which was already successfully applied for this application. The formulated ternary electrolyte, [EMIm][FSI] 0.6 [BF 4 ] 0.1 [TCB] 0.3 , remained in the liquid state until it reached the glass transition at −99 °C and displayed a relatively low viscosity and high conductivity ( η =23.6 mP s and σ =14.2 mS cm −1 at 20 °C, respectively). The electrodes were made of a hierarchical SiO 2 ‐templated carbon with well‐defined and uniform mesopores of ∼9 nm facilitating ion transport to the interconnected micropores accounted for the charge storage, whereas the high density of the electrodes promoted high volumetric energy outputs of the cells.