An ether-functionalised cyclic sulfonium based ionic liquid as an electrolyte for electrochemical double layer capacitors

JOURNAL OF POWER SOURCES

卷:326

Article

Neale, Alex R.¹  Murphy, Sinead¹  Goodrich, Peter¹  Schuetter, Christoph²  Hardacre, Christopher¹  Passerini, Stefano²  Balducci, Andrea²  Jacquemin, Johan¹ 

[1] Queens Univ Belfast, Sch Chem & Chem Engn, David Keir Bldg, Belfast BT9 5AG, Antrim, North Ireland

[2] Karlsruhe Inst Technol, Helmholtz Inst Ulm, Helmholtzstr 11, D-89081 Ulm, Germany

关键词: Electrolyte;    Ionic liquid;    Sulfonium;    Supercapacitor;   

DOI  :  10.1016/j.jpowsour.2016.06.085

来源: Elsevier

【 摘 要 】

A novel cyclic sulfonium cation-based ionic liquid (IL) with an ether-group appendage and the bis {(trifluoromethyl)sulfonyl}imide anion was synthesised and developed for electrochemical double layer capacitor (EDLC) testing. The synthesis and chemical-physical characterisation of the ether-group containing IL is reported in parallel with a similarly sized alkyl-functionalised sulfonium IL. Results of the chemical-physical measurements demonstrate how important transport properties, i.e. viscosity and conductivity, can be promoted through the introduction of the ether-functionality without impeding thermal, chemical or electrochemical stability of the IL. Although the apparent transport properties are improved relative to the alkyl-functionalised analogue, the ether-functionalised sulfonium cation-based IL exhibits moderately high viscosity, and poorer conductivity, when compared to traditional EDLC electrolytes based on organic solvents (propylene carbonate and acetonitrile). Electrochemical testing of the ether-functionalised sulfonium IL was conducted using activated carbon composite electrodes to inspect the performance of the IL as a solvent-free electrolyte for EDLC application. Good cycling stability was achieved over the studied range and the performance was comparable to other solvent-free, IL-based EDLC systems. Nevertheless, limitations of the attainable performance are primarily the result of sluggish transport properties and a restricted operative voltage of the IL, thus highlighting key aspects of this field which require further attention. (C) 2016 The Authors. Published by Elsevier B.V.

【 授权许可】

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