Ion-selective and chemical-protective elastic block copolymer interphase for durable zinc metal anode

Abstract

Aqueous rechargeable batteries based on zinc anodes are among the most promising systems to replace conventional lithium-ion batteries owing to their intrinsic safety, high ionic conductivity, and economic benefits. However, inferior reversibility of zinc anode resulting from zinc dendrites and surface side reactions limits the practical realization of zinc-ion batteries. Herein, we develop a thin but robust polymeric artificial interphase to enhance reversibility of zinc anode. The grafted maleic anhydride groups in the polymer structure restrain the detrimental reactions through selective zinc-ion penetration and homogenize ion distribution, leading to a smooth electrode surface after plating-stripping processes. Consequently, the coated zinc anode shows excellent stability with a long-term symmetric cell lifespan (>3,000 h at 3 mA·cm −2 ) and maintains capacity retention of 80% after 2,500 cycles, paired with a manganese oxide cathode. This study provides a facile fabrication process and accessible analysis methods to rationalize the development of high-performance zinc-ion batteries. • Artificial interphase is presented to improve the stability of the zinc anode • SEBS-MA layer induces uniform zinc deposition and prevents side reactions • Characterization methods reveal the ion behavior inside the interphase layer Lee et al. report a multifunctional polymeric protective layer for zinc anode. The protective layer promotes stable zinc deposition and stabilizes anode interphase with suppressing hydrogen gas evolution and chemical side reactions, leading to a highly durable battery operation.