Unveiling Zinc Stripping and Molecular Engineering for High-Performance Zinc Anode

Abstract

The unstable zinc anode is a key challenge limiting the cycle life of rechargeable zinc ion batteries. And current research primarily focuses on the zinc plating process, with strategies to induce uniform zinc deposition for stable zinc anode. Here, we demonstrate that the zinc stripping process has a more significant impact on the subsequent zinc deposition, which exacerbates the formation of by-products, dendrites, and “dead zinc”. Therefore, we propose using aspartyl-phenylalanine methyl ester (APM) molecules to regulate the zinc stripping, achieving uniform stripping of the zinc anode by increasing the stripping overpotential across high-energy barriers. Simultaneously, its localized hydrophobic functional groups effectively inhibit the byproducts triggered by solvated water molecules. The experimental results show that the Zn-APM symmetric cell exhibits excellent cycling stability, with stable cycling over 6500 h (>9 months) at 1 mA cm-2 for 1 mAh cm-2 and 700 h at 70% zinc utilization with 10 µm zinc. In addition, the Zn-APM||Zn0.58V2O5‧H2O full cell exhibits 80% capacity retention after 500 cycles at a loading of 8.1 mg cm-2.