Polymeric acid additive strategy for long-lifetime aqueous zinc-ion batteries

Abstract

The electrochemical performance of aqueous zinc-ion batteries (ZIBs) is constrained by technical challenges, including uncontrolled parasitic reactions leading to uneven zinc deposition and dendritic growth. To solve these challenges, we propose a multifunctional electrolyte containing hydrolytic polymaleic anhydride (HPMA). Rich in functional carboxyl groups, HPMA provides a strongly acidic environment that maintains a low pH, effectively eliminating OH^--related passivation on the zinc anode surface. Furthermore, HPMA dynamically adsorbs onto the zinc surface, forming a polymeric SEI layer that enhances interfacial stability and induces preferential Zn (002) orientation, enabling dendrite-free zinc deposition. Consequently, HPMA significantly extends the lifetime of zinc anodes, achieving up to 3000 h at a current density of 5 mA cm^-². Moreover, Zn//MnO₂ full batteries and Zn//AC hybrid supercapacitors with HPMA additives demonstrate excellent stability and enhanced capacity retention. This work underscores the potential of polymeric acid additives in optimizing zinc anode interfaces with electrolytes.