Hyperbranched polyamidoamine protective layer with phosphate and carboxyl groups for dendrite-free Zn metal anodes

Zinc metal is regarded as one of the most promising anodes for Zn-based batteries in next-generation energy storage systems. However, the dendrite growth and interfacial corrosion lead to poor reversibility and cycle life of Zn anodes. Herein, we synthesize a 2-phosphate-1,2,4-butane tricarboxylic acid modified hyperbranched polyamidoamine containing rich terminal groups of phosphate and carboxyl (HPC) as modified layer for the Zn anodes. Importantly, the in situ acid-etching promotes the exposure of (002)Zn plane and the generated salt-polymer complexes could be adhered to the Zn anodes tightly. This greatly favors the uniform deposition of Zn and inhibits interfacial corrosion. Consequently, stable HPC@Zn anode plating/stripping for over 1200 h at a high areal capacity of 4 mAh cm−2 and a current density of 4 mA/cm2 is obtained. This study provides a new avenue of hyperbranched polymer in interfacial design for highly reversible and stable Zn metal anodes.