Stabilizing Zn Anodes by Molecular Interface Engineering with Amphiphilic Triblock Copolymer
Xiujuan Chen, Peiyuan Gao, Wei Li, Nhat Anh Thieu, Zane Grady, Novruz G. Akhmedov, Konstantinos A. Sierros, V. Murugesan, Valery V. Khramtsov, David Reed, Xiaolin Li, Xingbo Liu
Abstract
High Resolution Image Download MS PowerPoint Slide Aqueous Zn-based electrochemical technologies hold promise for large-scale energy storage applications, yet challenges persist in the unsatisfied Zn reversibility arising from an unstable Zn/electrolyte interface. Here, we employ molecular interface engineering using amphiphilic Pluronic triblock copolymers as electrolyte additives to stabilize the Zn anodes. With a balanced hydrophilic–hydrophobic nature, Pluronic F127 adsorbed on the Zn surface constructs a hydrodynamic interphase, where the hydrophobic PPO center shields the Zn surface from water-induced side reactions, while PEO side blocks guide the homogeneous Zn 2+ redistribution. Additionally, F127 contributes to the Zn 2+ solvation structure to weaken the water activity at the interfacial region. As a result, F127 additive enables cycling durability over 9300 and 3100 h at 1 and 5 mA cm –2, respectively, and considerable cyclability with high-capacity retention across a wide current density range in Zn||VO 2 full cells. This study highlights the potential of amphiphilic block copolymers in stabilizing metallic anode interfaces in aqueous electrolytes.