Interfacial construction between reduced graphene oxide and iron oxide induced high electrochemical performance for flexible battery
Yongqiang Guo, Chao Chen, Yi Li, Yutao Chen, Shenghu Li, Taotao Gao, Hai Liu, Wenlong Liu, Dan Xiao, Xiaoqin Li
Abstract
Fiber-shaped Ni/Fe batteries with high safety, cheap cost, and environmental friendliness have a wide range of applications in wearable and portable devices. However, their development is limited by the sluggish kinetics of the Fe-based anode. Herein, a well-designed fibrous Fe-based anode containing reduced graphene oxide (rGO) and Fe 2 O 3 was constructed by a one-step co-electrodeposition strategy. Theoretical investigations reveal the improved carrier density as a result of the effective electrostatic interaction between rGO and Fe 2 O 3 . This interconnected heterostructure builds a bridge for electron transfer and ion diffusion, significantly accelerating the electrochemical reaction kinetics. The as-prepared rGO/Fe 2 O 3 anode delivers an extraordinary volumetric capacity of 40.1 mAh cm −3 along with excellent rate capacity and cyclic stability. After coupling with the NiCoO cathode, the fabricated fibrous quasi-solid-state Ni/Fe battery shows the maximum volumetric energy density and power density of 19.9 mWh cm −3 and 961.6 mW cm −3 . Moreover, this fibrous Ni/Fe battery confirms good capacity retention of 82.3% after 10,000 cycles and noteworthy mechanical flexibility. These results suggest a new prospect to design and construct highly efficient Fe-based anodic materials for energy storage.