Pre-doping iodine to restrain formation of low-active graphitic-N in hard carbon for significantly boosting sodium storage performance. (January 2022)

• Record Type: Journal Article
• Authors: Chen, Jie; Hu, Tao; Zou, Zhuo; Zeng, Qingxin; Jiang, Yali; Tang, Chuyue; Tang, Chun; Li, Wei; Fang, Changxiang; Sun, Wei; Zeng, Lingzhi; Li, Chang Ming
• Is Part Of: Carbon. Volume 186(2022)
• Page Start: 193
• Page End: 204
• Publication Date: 2022-01
• Subjects: Hard carbon -- Pre-doping iodine -- Controllably decreasing -- Low-active graphitic-N -- Sodium-ion batteries; Carbon -- Periodicals; Carbone -- Périodiques; Koolstof; Toepassingen; Electronic journals; 546.681
• DOI: 10.1016/j.carbon.2021.09.061
• Languages: English
• ISSNs: 0008-6223

Abstract

Abstract: Nitrogen doping can improve the electrocatalysis performance of hard carbon (HC) as a promising anode material in sodium-ion batteries, but is very challenging to controllably decrease the content of low-active graphitic-N in C–N configurations for raising the HC anode performance. Here an iodine-predoping approach is used to effectively restrain graphitic-N formation and its mechanism is further revealed, in which iodine preferentially occupies the vacancy sites of graphitic-type carbon to directionally induce nitrogenous species bonding with the vacancy sites of pyridinic- and pyrrolic-type. Experimental characterizations and theoretical calculations solidly confirm the mechanism. As expected, the controllably constructed HC anode exhibits the highest reversible capacity of 483.1 mAh g −1 at 30 mA g −1 among all reported HC works, while delivering a long lifespan up to 6000 cycles decaying only 0.0096% per cycle at 1 A g −1 . This work sheds light on viable fundamentals for controllably constructing desired C–N configuration for host materials. Graphical abstract: Image 1 Highlights: The first strategy for controllably decreasing the low-active graphitic C–N configuration is realized by pre-doping iodine. Iodine can occupy graphitic-type carbon vacancies to induce nitrogen bonding with pyridinic- and pyrrolic-type vacancies. A controllably designed graphitic–N-poor hard carbon anode exhibits excellent Na-storage performance. This work offers fundamentals to open a new avenue in modification of carbon materials for controllable C–N configurations.