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 ca-pacity,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 assem-bled 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 kg1.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.
基金项目
This work was supported by the National Natural Science Foundation of China(51802177)
Independent Culti-vation Program of Innovation Team of Ji'nan City(Grant 2019GXRC011)