Laminated Zinc-Copper Electrodes as Reversible and Dendrite-Free Anodes for Aqueous Rechargeable Zinc-Ion Batteries

Abstract

Aqueous rechargeable zinc-ion batteries (AR-ZIBs) have become a research hotspot in the field of rechargeable batteries in recent years due to their advantages of high safety, high energy density, environmentally friendly, and low cost. However, the uneven Zn2+ plating/stripping on the surface of the bare Zn anodes leads to uncontrolled Zn dendrite growth and seriously limits the lifespan of the AR-ZIBs. The uneven electric field distribution is widely considered the main driving force for the Zn dendrite growth, and how to eliminate or degrade the uneven electric field distribution became a great challenge to overcome the durability issues of the anode of the AR-ZIBs. Herein, a laminated Zn-Cu composite anode with alternating Zn and Cu lamellae was first prepared via a facile strategy. Benefiting from the unique laminated Zn-Cu composite structure, the homogeneity of the surface electric field has been improved tremendously due to the inherent excellent electrical conductivity of the two-dimensional copper skeleton in the composite anode. Furthermore, the Zn-Cu intermediate phase throughout the Zn-Cu composite anode can significantly enhance the Zn2+ adsorption, which synergistically induces uniform Zn nucleation, resulting in a highly reversible Zn2+ plating/stripping chemistry. Consequently, the symmetric battery based on those anodes could operate steadily to 1000 h in the neutral electrolyte and exhibits excellent cycling durability. Furthermore, the laminated Zn-Cu composite anode and Na2V6O16·3H2O cathode were assembled into a full battery in the neutral electrolyte, which demonstrates outstanding cycling stability within 1000 cycles. And the alkaline full battery can provide ultra-long cyclic stability of 4000 cycles, significantly better than the cell based on the bare Zn anode.