Pseudocapacitive energy storage in supercapacitor electrodes differs significantly from the electrical double-layer mechanism of porous carbon materials, which requires a change from conventional thinking when choosing appropriate electrolytes. Here we show how simply changing the solvent of an electrolyte system can drastically influence the pseudocapacitive charge storage of the two-dimensional titanium carbide, Ti3C2 (a representative member of the MXene family). Measurements of the charge stored by Ti3C2 in lithium-containing electrolytes with nitrile-, carbonate- and sulfoxide-based solvents show that the use of a carbonate solvent doubles the charge stored by Ti3C2 when compared with the other solvent systems. We find that the chemical nature of the electrolyte solvent has a profound effect on the arrangement of molecules/ions in Ti3C2, which correlates directly to the total charge being stored. Having nearly completely desolvated lithium ions in Ti3C2 for the carbonate-based electrolyte leads to high volumetric capacitance at high charge–discharge rates, demonstrating the importance of considering all aspects of an electrochemical system during development.

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The research was sponsored by the Fluid Interface Reactions, Structures, and Transport (FIRST) Center, an Energy Frontier Research Center (EFRC) funded by the US Department of Energy, Office of Science, and Office of Basic Energy Sciences. Access to the HFBS was provided by the Center for High Resolution Neutron Scattering, a partnership between the NIST and the NSF under agreement no. DMR-1508249. Certain commercial equipment, instruments or materials are identified in this paper in order to specify the experimental procedure adequately. Such identification is not intended to imply recommendation or endorsement by the National Institute of Standards and Technology, nor is it intended to imply that the materials or equipment identified are necessarily the best available for the purpose. J. Li and H. Wang from Drexel University are acknowledged for helping with material characterization. Y. Honda and Y. Soda from Murata Manufacturing Co. are acknowledged for helpful discussions and help with the characterization.

Author information


  1. A. J. Drexel Nanomaterials Institute and Department of Materials Science and Engineering, Drexel University, Philadelphia, PA, USA

    • Xuehang Wang
    • , Tyler S. Mathis
    • , Ke Li
    • , Christine Hatter
    • , Patrick Urbankowski
    • , Asia Sarycheva
    •  & Yury Gogotsi
  2. Materials Science Department—CIRIMAT, Université Paul Sabatier, Toulouse, France

    • Zifeng Lin
    •  & Patrice Simon
  3. Department of Materials Science and Engineering, Sichuan University, Chengdu, China

    • Zifeng Lin
  4. Materials Science and Technology Division, Materials Theory Group, Oak Ridge National Laboratory, Oak Ridge, TN, USA

    • Lukas Vlcek
  5. Joint Institute for Computational Sciences, University of Tennessee, Knoxville, Oak Ridge, TN, USA

    • Lukas Vlcek
  6. Murata Manufacturing Co., Ltd, Nagaokakyo-shi, Kyoto, Japan

    • Takeshi Torita
  7. Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA

    • Naresh C. Osti
    •  & Eugene Mamontov
  8. NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD, USA

    • Madhusudan Tyagi
  9. Department of Materials Science and Engineering, University of Maryland, College Park, MD, USA

    • Madhusudan Tyagi
  10. Réseau sur le Stockage Electrochimique de l’Energie (RS2E), CNRS FR3459, Amiens, France

    • Patrice Simon


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X.W. and Y.G. planned the study. X.W., T.S.M, Z.L. and T.T. conducted electrochemical testing. K.L. synthesized all MXenes, Z.L. performed the in situ XRD measurement and L.V. performed the MD simulation. C.H., P.U. and A.S. performed TEM, XPS and Raman investigations, respectively. N.C.O., M.T. and E.M. performed the neutron scattering. All authors contributed to writing the manuscript under supervision from P.S. and Y.G.

Competing interests

The authors declare no competing interests.

Corresponding author

Correspondence to Yury Gogotsi.

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  1. Supplementary Information

    Supplementary Discussions 1–3, Supplementary Tables 1–3, Supplementary Figures 1–15, Supplementary references.

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