Abstract
Kinetics of electrochemical reactions are several orders of magnitude slower in solids than in liquids as a result of the much lower ion diffusivity. Yet, the solid state maximizes the density of redox species, which is at least two orders of magnitude lower in liquids because of solubility limitations. With regard to electrochemical energy storage devices, this leads to high-energy batteries with limited power and high-power supercapacitors with a well-known energy deficiency. For such devices the ideal system should endow the liquid state with a density of redox species close to the solid state. Here we report an approach based on biredox ionic liquids to achieve bulk-like redox density at liquid-like fast kinetics. The cation and anion of these biredox ionic liquids bear moieties that undergo very fast reversible redox reactions. As a first demonstration of their potential for high-capacity/high-rate charge storage, we used them in redox supercapacitors. These ionic liquids are able to decouple charge storage from an ion-accessible electrode surface, by storing significant charge in the pores of the electrodes, to minimize self-discharge and leakage current as a result of retaining the redox species in the pores, and to raise working voltage due to their wide electrochemical window.
This is a preview of subscription content, access via your institution
Relevant articles
Open Access articles citing this article.
-
Interior and Exterior Decoration of Transition Metal Oxide Through Cu0/Cu+ Co-Doping Strategy for High-Performance Supercapacitor
Nano-Micro Letters Open Access 25 January 2021
Access options
Subscribe to this journal
Receive 12 print issues and online access
$259.00 per year
only $21.58 per issue
Rent or buy this article
Prices vary by article type
from$1.95
to$39.95
Prices may be subject to local taxes which are calculated during checkout






References
Rolison, D. R. & Nazar, L. F. Electrochemical energy storage to power the 21st century. MRS Bull. 36, 486–493 (2011).
Augustyn, V. et al. High-rate electrochemical energy storage through Li+ intercalation pseudocapacitance. Nat. Mater. 12, 518–522 (2013).
Wagemaker, M., van Eck, E. R. H., Kentgens, A. P. M. & Mulder, F. M. Li-ion diffusion in the equilibrium nanomorphology of spinel Li4+xTi5O12 . J. Phys. Chem. B 113, 224–230 (2009).
Merlet, C. et al. On the molecular origin of supercapacitance in nanoporous carbon electrodes. Nat. Mater. 11, 306–310 (2012).
Merlet, C. et al. Highly confined ions store charge more efficiently in supercapacitors. Nat. Commun. 4, 2701 (2013).
Duduta, M. et al. Semi-solid lithium rechargeable flow battery. Adv. Energy Mater. 1, 511–516 (2011).
Dunn, B., Kamath, H. & Tarascon, J.-M. Electrical energy storage for the grid: a battery of choices. Science 334, 928–935 (2011).
Bruce, P. G., Scrosati, B. & Tarascon, J.-M. Nanomaterials for rechargeable lithium batteries. Angew. Chem. Int. Ed. 47, 2930–2946 (2008).
Choi, N.-S. et al. Challenges facing lithium batteries and electrical double-layer capacitors. Angew. Chem. Int. Ed. 51, 9994–10024 (2012).
Weissmann, M., Crosnier, O., Brousse, T. & BÃclanger, D. Electrochemical study of anthraquinone groups, grafted by the diazonium chemistry, in different aqueous media-relevance for the development of aqueous hybrid electrochemical capacitor. Electrochim. Acta 82, 250–256 (2012).
Yang, Z. et al. Electrochemical energy storage for green grid. Chem. Rev. 111, 3577–3613 (2011).
Chmiola, J. et al. Anomalous increase in carbon capacitance at pore sizes less than 1 nanometer. Science 313, 1760–1763 (2006).
Simon, P. & Gogotsi, Y. Materials for electrochemical capacitors. Nat. Mater. 7, 845–854 (2008).
Merlet, C., Rotenberg, B., Madden, P. A. & Salanne, M. Computer simulations of ionic liquids at electrochemical interfaces. Phys. Chem. Chem. Phys. 15, 15781–15792 (2013).
Huang, J., Sumpter, B. G. & Meunier, V. Theoretical model for nanoporous carbon supercapacitors. Angew. Chem. Int. Ed. 47, 520–524 (2008).
Feng, G. et al. The importance of ion size and electrode curvature on electrical double layers in ionic liquids. Phys. Chem. Chem. Phys. 13, 1152–1161 (2011).
Kondrat, S. & Kornyshev, A. Superionic state in double-layer capacitors with nanoporous electrodes. J. Phys. Condens. Matter 23, 022201 (2011).
Armand, M., Endres, F., MacFarlane, D. R., Ohno, H. & Scrosati, B. Ionic-liquid materials for the electrochemical challenges of the future. Nat. Mater. 8, 621–629 (2009).
Frackowiak, E., Lota, G. & Pernak, J. Room-temperature phosphonium ionic liquids for supercapacitor application. Appl. Phys. Lett. 86, 164104 (2005).
Varzi, A., Balducci, A. & Passerini, S. Natural cellulose: a green alternative binder for high voltage electrochemical double layer capacitors containing ionic liquid-based electrolytes. J. Electrochem. Soc. 161, A368–A375 (2014).
Brandt, A. & Balducci, A. Theoretical and practical energy limitations of organic and ionic liquid-based electrolytes for high voltage electrochemical double layer capacitors. J. Power Sources 250, 343–351 (2014).
Shim, Y. & Kim, H. J. Nanoporous carbon supercapacitors in an ionic liquid: a computer simulation study. ACS Nano 4, 2345–2355 (2010).
Brousse, T., Bélanger, D. & Long, J. W. To be or not to be pseudocapacitive? J. Electrochem. Soc. 162, A5185–A5189 (2015).
Simon, P., Gogotsi, Y. & Dunn, B. Where do batteries end and supercapacitors begin? Science 343, 1210–1211 (2014).
Conway, B. E. Transition from “supercapacitor’ to “battery” behavior in electrochemical energy storage. J. Electrochem. Soc. 138, 1539–1548 (1991).
Lota, G. & Frackowiak, E. Striking capacitance of carbon/iodide interface. Electrochem. Commun. 11, 87–90 (2009).
Lota, G., Fic, K. & Frackowiak, E. Alkali metal iodide/carbon interface as a source of pseudocapacitance. Electrochem. Commun. 13, 38–41 (2011).
Senthilkumar, S. T., Selvan, R. K., Lee, Y. S. & Melo, J. S. Electric double layer capacitor and its improved specific capacitance using redox additive electrolyte. J. Mat. Chem. A 1, 1086–1095 (2013).
Senthilkumar, S. T., Selvan, R. K. & Melo, J. S. Redox additive/active electrolytes: a novel approach to enhance the performance of supercapacitors. J. Mat. Chem. A 1, 12386–12394 (2013).
Yu, H. et al. A novel redox-mediated gel polymer electrolyte for high-performance supercapacitor. J. Power Sources 198, 402–407 (2012).
Wang, Y., Cardona, C. M. & Kaifer, A. E. Molecular orientation effects on the rates of heterogeneous electron transfer of unsymmetric dendrimers. J. Am. Chem. Soc. 121, 9756–9757 (1999).
Sathyamoorthi, S., Suryanarayanan, V. & Velayutham, D. Organo-redox shuttle promoted protic ionic liquid electrolyte for supercapacitor. J. Power Sources 274, 1135–1139 (2015).
Ghilane, J., Fontaine, O., Martin, P., Lacroix, J. C. & Randriamahazaka, H. Formation of negative oxidation states of platinum and gold in redox ionic liquid: electrochemical evidence. Electrochem. Commun. 10, 1205–1209 (2008).
Fontaine, O. et al. Mass transport and heterogeneous electron transfer of a ferrocene derivative in a room-temperature ionic liquid. J. Electroanalyt. Chem. 632, 88–96 (2009).
Chen, X. et al. Imidazolium functionalized TEMPO/iodide hybrid redox couple for highly efficient dye-sensitized solar cells. J. Mat. Chem. A 1, 8759–8765 (2013).
Yu, H. et al. Redox-active alkaline electrolyte for carbon-based supercapacitor with pseudocapacitive performance and excellent cyclability. RSC Adv. 2, 6736–6740 (2012).
Xie, H. J., Gélinas, B. & Rochefort, D. Redox-active electrolyte supercapacitors using electroactive ionic liquids. Electrochem. Commun. 66, 42–45 (2016).
Rosanske, T. W. & Evans, D. H. Rate constants for the electrode reactions of some quinones in aprotic media at platinum, gold and mercury electrodes. J. Electroanal. Chem. Interfacial Electrochem. 72, 277–285 (1976).
Gupta, N. & Linschitz, H. Hydrogen-bonding and protonation effects in electrochemistry of quinones in aprotic solvents. J. Am. Chem. Soc. 119, 6384–6391 (1997).
Chuang, C.-M., Huang, C.-W., Teng, H. & Ting, J.-M. Hydrothermally synthesized RuO2/Carbon nanofibers composites for use in high-rate supercapacitor electrodes. Compos. Sci. Technol. 72, 1524–1529 (2012).
Conway, B. E., Birss, V. & Wojtowicz, J. The role and utilization of pseudocapacitance for energy storage by supercapacitors. J. Power Sources 66, 1–14 (1997).
He, S. & Chen, W. High performance supercapacitors based on three-dimensional ultralight flexible manganese oxide nanosheets/carbon foam composites. J. Power Sources 262, 391–400 (2014).
Hubig, S. M., Rathore, R. & Kochi, J. K. Steric control of electron transfer. Changeover from outer-sphere to inner-sphere mechanisms in arene/quinone redox pairs. J. Am. Chem. Soc. 121, 617–626 (1999).
Bard, A. J. Inner-sphere heterogeneous electrode reactions. Electrocatalysis and photocatalysis: the challenge. J. Am. Chem. Soc. 132, 7559–7567 (2010).
Chen, L., Bai, H., Huang, Z. & Li, L. Mechanism investigation and suppression of self-discharge in active electrolyte enhanced supercapacitors. Energy Environ. Sci. 7, 1750–1759 (2014).
Randriamahazaka, H. & Asaka, K. Electromechanical analysis by means of complex capacitance of bucky-gel actuators based on single-walled carbon nanotubes and an ionic liquid. J. Phys. Chem. C 114, 17982–17988 (2010).
Roldán, S., Blanco, C., Granda, M., Menéndez, R. & Santamaría, R. Towards a further generation of high-energy carbon-based capacitors by using redox-active electrolytes. Angew. Chem. Int. Ed. 50, 1699–1701 (2011).
Forster, R. J. & O’Kelly, J. P. Protonation reactions of anthraquinone-2,7-disulphonic acid in solution and within monolayers. J. Electroanal. Chem. 498, 127–135 (2001).
Zhang, J. & Zhao, X. S. Conducting polymers directly coated on reduced graphene oxide sheets as high-performance supercapacitor electrodes. J. Phys. Chem. C 116, 5420–5426 (2012).
Acknowledgements
S.A.F. is indebted to la Chaire Total de la foundation Balard for the position of an invited professor at the Institute Charles Gerhardt, Montpellier, France, as well as the Austrian Federal Ministry of Economy, Family and Youth and the Austrian National Foundation for Research, Technology and Development and funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No 636069).
Author information
Authors and Affiliations
Contributions
E.M. and L.C. contributed equally to this work and carried out the experiments. O.F., F.F. and S.A.F. conceived and designed the experiments, directed the project and analysed the results. F.F., S.A.F. and O.F. co-wrote the manuscript. A.V. and A.M. helped with synthesis of anionic species. All authors contributed to the discussion and interpretation of the results.
Corresponding author
Ethics declarations
Competing interests
The authors declare no competing financial interests.
Supplementary information
Supplementary Information
Supplementary Information (PDF 3680 kb)
Rights and permissions
About this article
Cite this article
Mourad, E., Coustan, L., Lannelongue, P. et al. Biredox ionic liquids with solid-like redox density in the liquid state for high-energy supercapacitors. Nature Mater 16, 446–453 (2017). https://doi.org/10.1038/nmat4808
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/nmat4808
This article is cited by
-
Anion chemistry in energy storage devices
Nature Reviews Chemistry (2023)
-
Anti-self-discharge ultrathin all-inorganic electrochromic asymmetric supercapacitors enabling intelligent and effective energy storage
Rare Metals (2023)
-
Review of the role of ionic liquids in two-dimensional materials
Frontiers of Physics (2023)
-
Enhanced electrochemical performance of olive stones-derived activated carbon by silica coating for supercapacitor applications
Journal of Applied Electrochemistry (2022)
-
Experimental and Computational Study of Lithium Salt-/Plastic Crystal-Assisted Ionogels
Arabian Journal for Science and Engineering (2022)