Highly stable and ultrafast electrode reaction of graphite for sodium ion batteries
2015; Elsevier BV; Volume: 293; Linguagem: Inglês
10.1016/j.jpowsour.2015.05.116
ISSN1873-2755
AutoresZhiqiang Zhu, Fangyi Cheng, Zhe Hu, Zhiqiang Niu, Jun Chen,
Tópico(s)Supercapacitor Materials and Fabrication
ResumoSodium ion battery is a potential sustainable energy storage system due to its abundance and low cost. To date, some Na-storage anode materials have achieved long life span, but the rate performance still remains insufficient. Herein, we show that in some linear ether-based electrolytes, graphite can not only render unprecedented cyclability (∼6000 cycles), but also exhibit ultrahigh rate capability (up to 10 A g−1), along with a reversible capacity of ∼110 mAh g−1. By combining electrochemical measurements and structural analysis (e.g. in situ Raman and ex situ XRD measurements), we reveal that graphite undergoes a stage-evolution mechanism induced by the insertion of solvated sodium ions. Furthermore, kinetic studies have shown that this process accompanies with an intercalation pseudocapacitive behavior, which should be responsible for the obtained superior electrode properties.
Referência(s)