Get access
Advertisement

Capacitance Effects Superimposed on Redox Processes in Molecular-Cluster Batteries: A Synergic Route to High-Capacity Energy Storage

Authors

  • Dr. Heng Wang,

    1. Department of Chemistry and Research Center of Materials Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan)
    Search for more papers by this author
  • Zhaoyang Zeng,

    1. Institut für Physikalische Chemie, WWU Münster, Corrensstrasse 30, 48149 Münster (Germany)
    Search for more papers by this author
  • Naoya Kawasaki,

    1. Department of Chemistry and Research Center of Materials Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan)
    Search for more papers by this author
  • Prof. Hellmut Eckert,

    Corresponding author
    1. Institut für Physikalische Chemie, WWU Münster, Corrensstrasse 30, 48149 Münster (Germany)
    • Hellmut Eckert, Institut für Physikalische Chemie, WWU Münster, Corrensstrasse 30, 48149 Münster (Germany)

      Hirofumi Yoshikawa, Department of Chemistry and Research Center of Materials Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan)

      Kunio Awaga, Department of Chemistry and Research Center of Materials Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan)

    Search for more papers by this author
  • Dr. Hirofumi Yoshikawa,

    Corresponding author
    1. Department of Chemistry and Research Center of Materials Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan)
    • Hellmut Eckert, Institut für Physikalische Chemie, WWU Münster, Corrensstrasse 30, 48149 Münster (Germany)

      Hirofumi Yoshikawa, Department of Chemistry and Research Center of Materials Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan)

      Kunio Awaga, Department of Chemistry and Research Center of Materials Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan)

    Search for more papers by this author
  • Prof. Kunio Awaga

    Corresponding author
    1. Department of Chemistry and Research Center of Materials Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan)
    2. JST, CREST, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan)
    • Hellmut Eckert, Institut für Physikalische Chemie, WWU Münster, Corrensstrasse 30, 48149 Münster (Germany)

      Hirofumi Yoshikawa, Department of Chemistry and Research Center of Materials Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan)

      Kunio Awaga, Department of Chemistry and Research Center of Materials Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan)

    Search for more papers by this author

Abstract

Rechargeable molecular-cluster batteries (MCBs) based on the manganese cluster complex [Mn12O12(CH3CH2C(CH3)2COO)16(H2O)4] ([Mn12]) that exhibited a capacity of approximately 200 A h kg−1 in the battery voltage range of 4.0 to 2.0 V were developed. In these batteries, the capacity of approximately 100 A h kg−1 in the range of 4.0–3.0 V is caused by a chemical reduction from [Mn12]0 to [Mn12]8−, whereas the other half in the range of 3.0–2.0 V cannot be explained by a redox change of the Mn ions. We performed the cyclic voltammetry (CV) and 7Li solid-state NMR measurements on the Mn12-MCBs to investigate the origin of the capacity below 3.0 V. Pseudo-rectangular-shaped CV curves in the range of 3.0–2.0 V demonstrate the presence of an electrical double-layer (EDL) capacitance in Mn12-MCBs, which corresponds to approximately 100 A h kg−1. 7Li NMR studies suggest that Li ions form an EDL with electrons in carbon black electrodes in the capacitance voltage range. The capacitance effects are not formed by the single-carbon electrodes alone, but appear only in the mixture of Mn12 and the carbon black electrodes. This type of coexistence of capacitance effects and redox reaction in one electrochemical cell is quite unusual and can serve as a new working principle for high-performance energy-storage devices.

Get access to the full text of this article

Ancillary