In-situ growth of hydrophobic zinc succinate interphase with high ionic conductivity toward stable zinc anodes

Aqueous zinc-ion batteries (ZIBs) are a promising solution for energy storage due to their affordability, high performance, environmental friendliness, and excellent safety features. However, zinc metal anodes are prone to capacity degradation and short circuits due to side reactions and dendrite growth during cycling. To address this issue, a dual-function artificial solid electrolyte interphase (SEI) made of zinc succinate complex (ZnSA) is in-situ constructed on zinc anodes by a simple and cost-effective soaking approach. This interphase is hydrophobic and highly ionic conductive (4.5 mS cm−1). It has a low electronic conductivity (1.6 mS cm−1) and a large Zn2+ transfer number (0.63). The hydrophobic SEI progressively represses water-induced side reactions, lowers zinc nucleation overpotential, accelerates zinc ion diffusion, and regulates homogeneous zinc deposition. As a result, the ZnSA@Zn symmetric cell achieves an impressive lifespan of 4450 h at 1 mA cm−2 for 0.5 mAh cm−2, which is significantly better than the bare zinc cell and superior to many recently reported zinc anodes. Furthermore, the V2O5//ZnSA@Zn batteries exhibit outstanding rate performance and remarkable long-term operation stability for 2000 cycles at 1 A/g. This innovative and cost-effective strategy opens up new possibilities for developing high-performance aqueous zinc-ion batteries.