Nanohole-structured, iron oxide-decorated and gelatin-functionalized graphene for high rate and high capacity Li-Ion anode

Abstract

Graphene hybrid nanostructures have emerged as potential candidates as efficient anode materials for lithium-ion batteries. However, two-dimensional plate-like structures protect rapid transport of lithium ions through the thickness direction, resulting in a long pathway of lithium ions and low rate performances. Here, we report a nanohole-structured, iron oxide-decorated and gelatin-functionalized graphene (D-N-GG) for high rate and high capacity lithium-ion anode. Initially, to produce effective path way of lithium ions, physical nanoholes on the graphene layers were generated by microwave-irradiated iron nanoparticles. And then, the gelatin was used to form nitrogen-doped graphene having more active sites for lithium ion storage. Finally, D-N-GG was synthesized by two-step microwave irradiations shows a three-dimensional interconnected mesoporous structure with a uniform decoration of iron oxide nanoparticles on the nanohole-structured graphene, resulting in highly conductive networks and short diffusion lengths for effective lithium ion transport. As a result, the obtained D-N-GG nanostructure delivered a reversible capacity of 924 mAh g(-1) even over 40 cycles along with a coulombic efficiency in excess of 99%. Especially, even after 65 cycles with variable current density of 100-800 mA g(-1), the discharge capacity returned to 1096 mAh g(-1), which indicated a very stable and high-rate cyclic performance. (C) 2017 Elsevier Ltd. All rights reserved.