Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7991572 | Journal of Alloys and Compounds | 2018 | 7 Pages |
Abstract
Na2+2xFe2-x(SO4)3 (NFS) is recently reported as a promising cathode material for Na-ion batteries with high voltage generation and high energy density, making it competitive to sodium battery cathodes. Nevertheless, owing to its insulating nature, a formidable challenge remains as to realize high rate capability. Herein, Na2+2xFe2-x(SO4)3/reduced graphene oxide (rGO) has been designed and realized by a facile one-stepped synthesis. Its structural, morphological and electrochemical properties have been characterized and compared with those of the bare NFS material. As a result, NFS/rGO cathode demonstrates enhanced electrochemical performance, as reflected by the initial specific capacity of 90â¯mAh gâ1 and a high specific capacity of 80â¯mAh gâ1 over 100 cycles at a current density of 0.1â¯C (1â¯Câ¯=â¯120â¯mAâ¯gâ1), an excellent rate capability with specific capacity of 60â¯mAh gâ1 at high current density of 20â¯C (2.4â¯Aâ¯gâ1) and long-term cycle life with capacity retention of 84% over 500 cycles at 20â¯C rate (2.4â¯Aâ¯gâ1). This improvement may be attributed to the high electronic conductivity of rGO, which facilitates the charge transfer reactions between the active materials and electrolyte interface, and promotes the sodium ion diffusion in the electrode. Therefore, Na2+2xFe2-x(SO4)3/rGO is favorable to realizing superior electrochemical performance for the sulfate, which presents a significant step forward in the development of low-cost large-scale batteries.
Related Topics
Physical Sciences and Engineering
Materials Science
Metals and Alloys
Authors
Min Zhang, Hui Qi, Hailong Qiu, Tong Zhang, Xiaosen Zhao, Huijuan Yue, Gang Chen, Chunzhong Wang, Yingjin Wei, Dong Zhang,