Constructing a Multifunctional SEI Layer Enhancing Kinetics and Stabilizing Zinc Metal Anode

Abstract

Zn dendrite growth and parasitic reactions at the interface of zinc anode/electrolyte in aqueous zinc batteries severely hinder its lifespan in application. Herein, the zinc anode is effectively stabilized by introducing trace amounts of 4‐aminobutane‐1‐phosphate (ABPA) into the ZnSO4 electrolyte. The ABPA adsorbs onto the surface of zinc anode and then further decomposes to a high conductive organic/inorganic composite in situ SEI layer including amino, partial carbon chain, and zinc phosphate. In the SEI layer, the residual undecomposed carbon chain promotes the desolvation of Zn2+, the amino induces uniform Zn2+ plating and zinc phosphate facilitates the migration of Zn2+. Thus, this in situ SEI layer not only suppresses water‐related side reactions but also enhances the Zn2+ transport kinetics. As a result, Zn||Zn symmetric cell delivers an ultralong cycle life of over 13 000 cycles at 50 mA cm−2 and 1 mAh cm−2. A high average Coulombic efficiency of 99.72% is achieved in over 1000 cycles in Zn||Cu half‐cell. The Zn||I2 full cell delivers a high‐capacity retention of 91.42% after 40,000 cycles. Moreover, a 49 mAh Zn||I2 pouch cell maintains 80.28% capacity retention over 300 cycles and 61.22% after 1000 cycles.