Fe-decorated-NiCo layered double hydroxide nanoflakes via corrosion engineering for high-energy rechargeable Zn-based batteries

Abstract

The major obstacles of alkaline rechargeable Zn-based batteries are their low energy density and unsatisfactory durability, which are primarily caused by the low capacity and undesirable reversibility of Ni/Co-based cathodes. Meanwhile, the costly and tedious synthetic procedures also hinder their large-scale utilization. Herein, a reliable and cost-effective corrosion engineering approach is proposed to prepare highly active Fe-decorated-NiCo layered double hydroxide (FeNiCo LDH) nanoflakes on a Ni–Co foam (NCF) substrate for alkaline Zn-based batteries. As the Fe decoration can increase the number of active sites and enhance the surface adsorption of hydroxyl ions (OH⁻), the FeNiCo LDH nanoflakes display a large areal capacity of 0.356 mA h cm⁻² at 4 mA cm⁻² and good reversibility, surpassing the electrochemical properties of the pristine NiCo LDH sample. When employed as a cathode, the as-fabricated alkaline Zn-based battery presents a considerable energy density of 2.84 mW h cm⁻³ and can be stably cycled over 5000 cycles. This work offers a low-cost and valid strategy to prepare high-capacity and reversible cathodes for alkaline Zn-based batteries.