Three‐Dimensional Porous CoFe2O4/Graphene Composite for Highly Stable Sodium‐Ion Batteries

• Published in: ChemElectroChem Vol. 6; no. 5; pp. 1552 - 1557
• Main Authors: Zhou, Dan, Xue, Li‐Ping, Wang, Ning
• Format: Journal Article
• Language: English
• Published: Weinheim John Wiley & Sons, Inc 01.03.2019
• Subjects: anode materials; Anodes; Cobalt ferrites; CoFe2O4; Dimensional stability; Electrode materials; Electron transport; Energy storage; Graphene; graphene networks; Interface reactions; Interface stability; Lithium-ion batteries; sodium storage; Sodium-ion batteries; Structural stability
• ISSN: 2196-0216; 2196-0216
• DOI: 10.1002/celc.201801519

Sodium‐ion batteries (SIBs) are promising alternatives to lithium‐ion batteries (LIBs), because of the low cost and great potential in large‐scale energy storage. Herein, we present a simple two‐step hydrothermal route to construct a novel CoFe2O4/graphene composite. The composite is composed of nanoporous CoFe2O4 hollow spheres that are well‐anchored onto nitrogen‐doped graphene sheets (CoFe2O4@3D‐NG) with a unique 3D network structure, which can not only offer short pathways for Na+ diffusion and conductive networks for electron transport, but also render sufficient active sites for Na+ interfacial reaction and rigid structural stability for volume expansion. When used as an anode material for SIBs, the CoFe2O4@3D‐NG electrode delivers an impressively high performance of Na storage, which includes a large initial discharge capacity of 596 mAh g−1 at 50 mA g−1, a high rate capability of 79 mAh g−1 at 1000 mA g−1, and a long cyclability of 118 mAh g−1 after 1200 cycles at 500 mA g−1. This work indicates a promising way to design and fabricate advanced CoFe2O4‐based anode materials for high‐performance Na‐storage. Battery network: A CoFe2O4@3D‐NG composite with nanoporous CoFe2O4 hollow spheres that are well‐anchored onto 3D nitrogen‐doped graphene networks is prepared through a two‐step hydrothermal method. The resultant CoFe2O4@3D‐NG anode delivers large specific capacity, long cycling stability, and improved rate capability, which provide a promising potential toward advanced transition metal oxide anode materials for sodium‐ion batteries.