Jin Shikai, Allam Omar, Lee Kyungbin, Lim Jeonghoon, Lee Michael J, Loh Sze Hou, Jang Seung Soon, Lee Seung Woo
George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
Small. 2022 Sep;18(35):e2202898. doi: 10.1002/smll.202202898. Epub 2022 Aug 4.
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 at 50 mA g ), rate capability (111 mAh g at 1 A g ), 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.
具有氧化还原活性氧官能团的有机材料作为碱金属离子存储的电极材料备受关注,这是由于其丰富的元素组成、结构可调节性以及增强的能量存储性能。在此,通过一锅法溶剂热还原法制备了一种由还原氧化石墨烯和氧官能化碳量子点(CQD)组成的混合碳框架,并进行了系统研究以考察其对Li⁺、Na⁺和K⁺离子的氧化还原机制及电化学性能。由于引入了CQD,该混合阴极在碱金属离子的电荷存储性能方面实现了持续改善,并且具有令人印象深刻的可逆容量(50 mA g⁻¹时为257 mAh g⁻¹)、倍率性能(1 A g⁻¹时为111 mAh g⁻¹)以及Li⁺离子的循环稳定性(10000次循环后保持79%)。此外,密度泛函理论计算揭示了不同碱金属离子的CQD结构 - 电化学反应趋势。这些结果为采用CQD物种实现最佳碱金属离子存储提供了重要见解。