Insights on the Behavior of Imidazolium Ionic Liquids as Electrolytes in Carbon-Based Supercapacitors: An Applied Electrochemical Approach
| Autor: | Paulo F.R. Ortega, Ricardo Santamaría, Clara Blanco, Garbas A. dos Santos, João Paulo C. Trigueiro, Rodrigo L. Lavall, Glaura G. Silva, Noemí Quintanal |
|---|---|
| Přispěvatelé: | Ministerio de Economía y Competitividad (España), Principado de Asturias |
| Rok vydání: | 2020 |
| Předmět: |
Supercapacitor
Materials science chemistry.chemical_element Ionic bonding 02 engineering and technology Electrolyte 010402 general chemistry 021001 nanoscience & nanotechnology Electrochemistry 01 natural sciences 0104 chemical sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials law.invention Capacitor chemistry.chemical_compound General Energy chemistry Chemical engineering law Electrode Ionic liquid Physical and Theoretical Chemistry 0210 nano-technology Carbon |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
| ISSN: | 1932-7455 1932-7447 |
| DOI: | 10.1021/acs.jpcc.0c04217 |
| Popis: | This study aims to increase the knowledge on the interactions that occur at the electrode/electrolyte interface in carbon-based electric double-layer capacitors (EDLCs) when solvent-free ionic liquids are used as electrolytes. Many previous studies found in the literature are conducted using theoretical approaches, and they are unable to model all the variables and the complexity of an actual device with a complex carbon surface and an ionic liquid (IL). Here, the compatibility between imidazolium ionic liquids and different carbon materials-an activated carbon (AC), a mesoporous carbon (MES), multiwalled carbon nanotubes (MWCNTs), and reduced graphene oxide (RGO)-is empirically investigated applying synchronous chronopotentiometric tests to various symmetrical EDLCs. The study of the simultaneous evolution of the cell and electrode potentials of the various carbon/ILs cells, monitoring the evolution of specific capacitances and electrical resistances for each independent electrode, allows inferring about the ion-electrode compatibility, the limiting factors for charge accumulation, and its impacts on the performance of the global cell. The results indicate that the sp2 structures of MWCNTs and RGO favor interactions with the EMI+ cation on the negative electrode. In the positive electrodes, MES and AC favor interactions with the BF4- and TFSI- anions, respectively, yielding a higher specific capacitance and lower resistance. The authors thank the Conselho Nacional de Desenvolvimento Cienti ico e Tecnoló gico (CNPq)−Brazil for the financial support (PVE 2014, process number 400714/2014- 0), the Spanish Government and European Union (AEI/ FEDER, EU; project MAT2016-77114-R), N.Q.’s predoctoral contract (BES2017-082038), and Principado de Asturias (FEDER: IDI/2018/000121). The work was partially supported by the Brazilian Institute of Science and Technology (INCT) in Carbon Nanomaterials. P.F.R.O. acknowledges the Fundaca̧ o de Amparo a ̃ ̀Pesquisa do Estado de Minas Gerais (FAPEMIG)−Brazil (DOF no. 2720262/2018). P.F.R.O. and G. A.d.S. also acknowledge the scholarships received from CNPq. R.L.L. is a recipient of a fellowship from CNPq (grant number 313304/2017-3). P.F.R.O, G.G.S., and R.L.L. are members of the Rede Mineira de Quimica (RQ-MG) ́ −Brazil. |
| Databáze: | OpenAIRE |
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