Potassium single cation ionic liquid electrolyte for potassium-ion batteries

• 山本, 大樹

  AIST-Kyoto University Chemical Energy Materials Open Innovation Laboratory (ChEM-OIL)･Institute of Advanced Industrial Science and Technology (AIST)･Graduate School of Energy Science, Kyoto University

• 松本, 一彦

  AIST-Kyoto University Chemical Energy Materials Open Innovation Laboratory (ChEM-OIL)･Institute of Advanced Industrial Science and Technology (AIST)

• 萩原, 理加

  AIST-Kyoto University Chemical Energy Materials Open Innovation Laboratory (ChEM-OIL)･Institute of Advanced Industrial Science and Technology (AIST)･Graduate School of Energy Science, Kyoto University

• Matsumoto, Kazuhiko

  AIST-Kyoto University Chemical Energy Materials Open Innovation Laboratory (ChEM-OIL)･Institute of Advanced Industrial Science and Technology (AIST)･Graduate School of Energy Science, Kyoto University

• Hagiwara, Rika

  AIST-Kyoto University Chemical Energy Materials Open Innovation Laboratory (ChEM-OIL)･National Institute of Advanced Industrial Science and Technology (AIST)･Graduate School of Energy Science, Kyoto University

抄録

Potassium-ion batteries (PIBs) are a promising post-lithium-ion battery (LIB), as their resources are abundant and low-cost and may have a higher voltage than LIBs. However, the high operating voltage and extremely high reactivity of potassium metal require a chemically safe electrolyte with oxidative and reductive stabilities. In this study, a potassium single cation ionic liquid (K-SCIL), which contains only K⁺ as the cationic species and has a high electrochemical stability, low flammability, and low vapor pressure, is developed as an electrolyte for PIBs. The mixture of potassium bis(fluorosulfonyl)amide and potassium (fluorosulfonyl)(trifluoromethylsulfonyl)amide at a molar ratio of 55:45 had the lowest melting point of 67 °C. The K⁺ concentration in this K-SCIL is high (8.5 mol dm⁻³ at 90 °C) due to the absence of solvents and bulky organic cations. In addition, the electrochemical window is as wide as 5.6 V, which enables the construction of PIBs with a high energy density. A high current density can be achieved with this K-SCIL, owing to the absence of a K⁺ concentration gradient. The electrolyte was successfully used with a graphite negative electrode, enabling the reversible intercalation/deintercalation of K⁺, as confirmed by X-ray diffraction.

収録刊行物

• The Journal of Physical Chemistry B

  The Journal of Physical Chemistry B 124 (29), 6341-6347, 2020-07-23

  American Chemical Society (ACS)

キーワード

• Materials Chemistry
• Surfaces, Coatings and Films
• Physical and Theoretical Chemistry

詳細情報

• CRID: 1050569159935483648
• NII論文ID: 120006942804
• ISSN: 15206106
• ISSN: 15205207
• DOI: 10.1021/acs.jpcb.0c03272
• HANDLE: 2433/260566
• Web Site: https://pubs.acs.org/doi/pdf/10.1021/acs.jpcb.0c03272
• 本文言語コード: en
• 資料種別: journal article
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