Sodium-ion batteries (SIBs) and potassium-ion batteries (PIBs) are potential cost-effective electrochemical energy storage devices for future grid-scale energy storage. However, the limited capacities of carbonaceous anodes hamper their development. Edge-nitrogen doping has been demonstrated as an effective strategy to enhance the reversible capacities of carbonaceous anodes. In this work, we demonstrate a general strategy to synthesize three-dimensional high edge-nitrogen doped turbostratic carbons (3D-ENTC) through catalytic pyrolysis of graphitic carbon nitride, which is enabled by metal cyanamides. 3D-ENTC exhibits a three-dimensional carbon nanosheet framework with a high edge-nitrogen doping level of 18.9 at% and a total nitrogen doping level of 21.2 at%. 3D-ENTC displays high capacities of 420 and 403 mAh g-1 at a current density of 50 mA g-1, high rate capabilities, and superior cycling stability when used as the anodes of PIBs and SIBs, respectively. The different charge storage mechanisms of 3D-ENTC as the anodes for PIBs and SIBs are elucidated by in situ electrochemical impedance spectroscopy. We find that 3D-ENTC stores Na+ ions mainly by adsorption, while 3D-ENTC stores K+ ions by adsorption and intercalation. This work opens a new avenue for designing high edge-nitrogen doped carbon anodes for SIBs and PIBs.
Bibliographical noteKAUST Repository Item: Exported on 2021-05-26
Acknowledgements: The research reported in this publication was supported by King Abdullah University of Science and Technology (KAUST). The authors acknowledge the financial support from the National Key Research and Development Plan (Grant NO. 2018YFB1501503), the National Natural Science Foundation of China (Grant NO. 22038004), the Research and Development Program in Key Fields of Guangdong Province (2020B1111380002). W.L.Z. acknowledges the start-up funding of Guangdong University of Technology (GDUT).
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Materials Science(all)
- Electrical and Electronic Engineering