標題: Improved lithium storage capacity and high rate capability of nitrogen-doped graphite-like electrode materials prepared from thermal pyrolysis of graphene quantum dots
作者: Gu, Siyong
Christensen, Tommiejean
Hsieh, Chien-Te
Mallick, Bikash Chandra
Gandomi, Yasser Ashraf
Li, Jianlin
Chang, Jeng-Kuei
材料科學與工程學系
Department of Materials Science and Engineering
關鍵字: Nitrogen doping;Graphite-like anodes;Lithium ion battery;Graphene quantum dots;Rate capability
公開日期: 10-九月-2020
摘要: Adopting a solid-phase microwave-assisted technique followed by thermal pyrolysis of N-functionalized graphene quantum dots, novel nitrogen-doped graphite-like (NGL) electrode materials were synthesized and served as the anode for Li-ion batteries. The NGL anode demonstrated reversible capacity of 530 mAh g(-1) at 0.1C, superior rate capability at high C rate operation (420 mAh g(-1) at 5C), remarkable initial coulombic efficiency (>95.7%), and excellent cyclic stability along with high efficiency (>99.1%) during entire cycling. The NGL anode nanostructure enables improved lithium ion mobility and reversible Li+ storage during cycling. The analysis of the Ragone plots revealed that the specific energy of NGL anode reaches to ca. 840 Wh kg(-1) at the power density of 4200 W kg(-1). The diffusion coefficient of Li ions was measured as 1.69 x 10(-9) cm(2) s(-1) for the NGL anode material, substantially improving over commonly used graphite electrodes (15-26 times higher Li+ diffusivity). The high-rate cyclability as well as the cyclic stability of the NGL anodes were also confirmed via long-term cycling of full pouch cells assembled with ternary cathode and NGL anode. The robust design of the NGL anode materials introduced in this work, paves the way for designing next-generation lithium-ion batteries operating at ultrahigh C rates. (C) 2020 Elsevier Ltd. All rights reserved.
URI: http://dx.doi.org/10.1016/j.electacta.2020.136642
http://hdl.handle.net/11536/155386
ISSN: 0013-4686
DOI: 10.1016/j.electacta.2020.136642
期刊: ELECTROCHIMICA ACTA
Volume: 354
起始頁: 0
結束頁: 0
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