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⁻¹ at 50 mA g⁻¹), rate capability (111 mAh g⁻¹ at 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.

中文翻译：

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碳量子点改性还原氧化石墨烯框架提高碱金属离子存储性能

具有氧化还原活性氧官能团的有机材料由于其丰富的地球成分、结构可调性和增强的储能特性而作为碱离子存储的电极材料备受关注。在此，通过一锅溶剂热还原法开发了一种由还原氧化石墨烯和氧功能化碳量子点（CQDs）组成的混合碳骨架，并对其氧化还原机理和锂、钠的电化学性能进行了系统研究。 - 和 K 离子。由于加入了 CQD，混合阴极在碱金属离子的电荷存储性能和令人印象深刻的可逆容量（50 mA g -1 时为^{257 mAh g -1}）、倍率容量（111 mAh g ^-1在 1 A g ^-1下）和锂离子的循环稳定性（10 000 次循环后保持 79%）。此外，密度泛函理论计算揭示了不同碱离子的 CQD 结构-电化学反应趋势。这些结果为采用 CQD 物种实现最佳碱离子存储提供了重要的见解。