J. Mater. Sci. Technol. ›› 2022, Vol. 108: 133-141.DOI: 10.1016/j.jmst.2021.09.015

• Research Article • Previous Articles     Next Articles

Rational construction of phosphate layer to optimize Cu-regulated Fe3O4 as anode material with promoted energy storage performance for rechargeable Ni-Fe batteries

Shuhua Hao, Yupeng Xing, Peiyu Hou, Gang Zhao(), Jinzhao Huang, Shipeng Qiu, Xijin Xu()   

  1. Laboratory of Functional Micro and Nano Materials and Devices, School of Physics and Technology, University of Jinan, Jinan 250024, China
  • Received:2021-06-25 Revised:2021-09-12 Accepted:2021-09-22 Published:2021-10-27 Online:2021-10-27
  • Contact: Gang Zhao,Xijin Xu
  • About author:sps_xuxj@ujn.edu.cn (X. Xu).
    * E-mail addresses: sps_zhaog@ujn.edu.cn (G. Zhao),

Abstract:

Flexible aqueous energy storage devices with high security and flexibility are crucial for the progress of wearable energy storage. Particularly, aqueous rechargeable Ni-Fe batteries owning a large theoretical capacity, low cost and outstanding safety characteristics have emerged as a promising candidate for flexible aqueous energy storage devices. Herein, Cu-doped Fe3O4 (CFO) with 3D coral structure was prepared by doping Cu2+ based on Fe3O4 nanosheets (FO). Furthermore, the Fe-based anode material (CFPO) grown on carbon fibers was obtained by reconstructing the surface of CFO to form a low-crystallization shell which can enhance the ion transport. Excitingly, the newly developed CFPO electrode as an innovative anode material further exhibited a high capacity of 117.5 mAh g-1 (or 423 F g-1) at 1 A g-1. Then, the assembled aqueous Ni-Fe batteries with a high cell-voltage output of 1.6 V deliver a high capacity of 49.02 mAh g-1 at 1 A g-1 and retention ratio of 96.8% for capacitance after 10 000 continuous cycles. What's more, the aqueous quasi-solid-state batteries present a remarkable maximal energy density of 45.6 Wh kg-1 and a power density of 12 kW kg-1. This work provides an innovative and feasible way and optimization idea for the design of high-performance Fe-based anodes, and may promote the development of a new generation of flexible aqueous Ni-Fe batteries.

Key words: Ni-Fe batteries, High voltage window regulation, High energy and power density, Anode materials, Amorphous phosphate layer