A novel hierarchical porous activated carbon-organic composite cathode material for high performance aqueous zinc-ion hybrid supercapacitors
Abstract
Zinc-ion hybrid supercapacitors (ZIHSCs) are among the most promising electrochemical energy storage technologies because of their high energy density, environmental sustainability, low price, and inherent security. Hence, we have developed a novel energy storage system that uses a hierarchical porous activated carbon with redox-active organic materials as an active hybrid cathode material for ZIHSCs. The large surface area of chitosan-derived activated carbon (Ch-C), the fast electron transfer mechanism of bis-glycinyl naphthalene diimide (H2BNDI), and zinc's bivalent nature all together contribute to the high energy density of redox-active zinc-ion hybrid supercapacitors (RAZIHSCs). The fabricated device exhibited an outstanding energy output of 250 Wh kg-1 @ 0.1 A g-1 and a power output of 9.5 kW kg-1 @ 10 A g-1 due to the additional pseudocapacitive behaviour arising out of the redox-active H2BNDI material. Additionally, 100% coulombic efficiency and 80% capacitance retention are still attained after 10000 cycles at a high current density of 5 A g-1. As a result of the complex chemical reactions between Zn2+-ions and H2BNDI moiety in the composite cathode, the proposed RAZIHSCs demonstrated a lower self-discharge rate (23% in 25 h) with extremely low leakage current density (15 mA g-1).
- Publication:
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Journal of Power Sources
- Pub Date:
- February 2023
- DOI:
- 10.1016/j.jpowsour.2022.232551
- Bibcode:
- 2023JPS...55732551P
- Keywords:
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- Activated carbon;
- Redox-active organic material;
- Composite cathode material;
- Zinc-ion hybrid supercapacitor;
- High energy density;
- Less leakage current