Redox‐active organic compounds have attracted substantial attention as charge storage materials, owing to their high theoretical capacity. Herein, a two‐dimensional organic electrode material is prepared by using hydrothermally polymerized dopamine molecules on graphene nanosheets. Two‐dimensional polydopamine is employed as a positive electrode for storing alkali metal ions based on the surface redox reaction between oxygen functional groups and alkali ions. The two‐dimensional polydopamine positive electrodes deliver high capacities of 255 mAh g−1in Li cells, 150 mAh g−1in Na cells, and 124 mAh g−1in K cells at 0.1 A g−1, demonstrating a promising organic positive electrode for rechargeable alkali‐ion batteries.
Carbon Quantum Dot Modified Reduced Graphene Oxide Framework for Improved Alkali Metal Ion Storage Performance
Organic materials with redox‐active oxygen functional groups are of great interest as electrode materials for alkali‐ion storage due to their earth‐abundant constituents, structural tunability, and enhanced energy storage properties. Herein, a hybrid carbon framework consisting of reduced graphene oxide and oxygen functionalized carbon quantum dots (CQDs) is developed via the one‐pot solvothermal reduction method, and a systematic study is undertaken to investigate its redox mechanism and electrochemical properties with Li‐, Na‐, and K‐ions. Due to the incorporation of CQDs, the hybrid cathode delivers consistent improvements in charge storage performance for the alkali‐ions and impressive reversible capacity (257 mAh g−1at 50 mA g−1), rate capability (111 mAh g−1at 1 A g−1), and cycling stability (79% retention after 10 000 cycles) with Li‐ion. Furthermore, density functional theory calculations uncover the CQD structure‐electrochemical reactivity trends for different alkali‐ion. The results provide important insights into adopting CQD species for optimal alkali‐ion storage.
more » « less- Award ID(s):
- 1805052
- NSF-PAR ID:
- 10370440
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Small
- Volume:
- 18
- Issue:
- 35
- ISSN:
- 1613-6810
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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