A Self‐Standing and Flexible Electrode of Yolk–Shell CoS2 Spheres Encapsulated with Nitrogen‐Doped Graphene for High‐Performance Lithium‐Ion Batteries. Issue 11 (2nd February 2015)

• Record Type: Journal Article
• Authors: Qiu, Wenda; Jiao, Jiqing; Xia, Jian; Zhong, Haimin; Chen, Liuping
• Is Part Of: Chemistry. Volume 21:Issue 11(2015)
• Page Start: 4359
• Page End: 4367
• Publication Date: 2015-02-02
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201405821
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Flexible lithium‐ion batteries (LIBs) have recently attracted increasing attention with the fast development of bendable electronic systems. Herein, a facile and template‐free solvothermal method is presented for the fabrication of hybrid yolk–shell CoS₂ and nitrogen‐doped graphene (NG) sheets. The yolk–shell architecture of CoS₂ encapsulated with NG coating is designed for the dual protection of CoS₂ to address the structural and interfacial stability concerns facing the CoS₂ anode. The as‐prepared composite can be assembled into a film, which can be used as a binder‐free and flexible electrode for LIBs that does not require any carbon black conducting additives or current collectors. When evaluating lithium‐storage properties, such a flexible electrode exhibits a high specific capacity of 992 mAh g⁻¹ in the first reversible discharge capacity at a current rate of 100 mA g⁻¹ and high reversible capacity of 882 mAh g⁻¹ after 150 cycles with excellent capacity retention of 89.91 %. Furthermore, a reversible capacity as high as 655 mAh g⁻¹ is still achieved after 50 cycles even at a high rate of 5 C due to the yolk–shell structure and NG coating, which not only provide short Li‐ion and electron pathways, but also accommodate large volume variation.</p> </abstract>