Micropore-Confined Organic Solid for a High-Rate and Durable Electrode

Kaiya Nakasone; Showa Kitajima; Hitoshi Kasai; Kouki Oka; Daisuke Takimoto

doi:10.1021/acsami.5c11604

Micropore-Confined Organic Solid for a High-Rate and Durable Electrode

ACS Appl Mater Interfaces. 2025 Aug 6;17(31):44631-44638. doi: 10.1021/acsami.5c11604. Epub 2025 Jul 27.

Authors

Kaiya Nakasone¹, Showa Kitajima², Hitoshi Kasai², Kouki Oka^{2

3

4}, Daisuke Takimoto⁵

Affiliations

¹ Graduate School of Science and Engineering, University of the Ryukyus, Nishihara, Okinawa 903-0213, Japan.
² Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan.
³ Carbon Recycling Energy Research Center, Ibaraki University, 4-12-1, Nakanarusawacho, Hitachi, Ibaraki 316-8511, Japan.
⁴ Deuterium Science Research Unit, Center for the Promotion of Interdisciplinary Education and Research, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan.
⁵ Faculty of Science, University of the Ryukyus, Nishihara, Okinawa 903-0213, Japan.

Abstract

The redox reactions of solid-state anthraquinone (AQ) confined within the micropores of activated carbon (AC) were investigated. A thin layer of AQ solid was adsorbed into the micropores of AC without inhibiting the formation of the electrical double layer. The AQ solid exhibited pseudocapacitive behavior and achieved 100% of its theoretical charge capacity (926 C g_-AQ^-1). Electrochemical impedance spectroscopy revealed that the capacitor response time of the AQ solid was shorter than those of the molecules dissolved in the electrolyte. This indicates that a direct charge transfer occurred from the carbon surface to the AQ solid. Regarding rechargeable aqueous air battery performance, the AQ solid demonstrated a discharge capacity of 257 mAh g_-AQ^-1 (99% of theoretical capacity) and a Coulombic efficiency of 99%. Both the cycling stability and rate performance of the AQ solid were superior compared with previously reported anode materials for rechargeable aqueous air batteries.

Keywords: anthraquinone; electrochemical impedance spectroscopy; high-rate and durable electrode; micropore-confined organic solid; rechargeable organic-based aqueous air battery.