Sparse Au nanoparticle arrays modulate Zn nucleation pathways and ion transport: a mechanistic approach to dendrite-free aqueous battery cycling

Sparse Au nanoparticle arrays define a new interface paradigm, where engineered sparsity simultaneously controls nucleation, electric fields, ion transport, and side reactions, enabling dendrite-free, ultra-long-life Zn cycling with minimal Au use. Zinc-based rechargeable batteries are a promising low-cost alternative for grid-scale energy storage, but their lifetimes are limited by dendritic growth and side reactions at the metal anode. Here, we demonstrate a simple solution-based strategy to stabilize Zn anodes using a periodically sparse array of gold nanoparticles (Au NPs) deposited by reverse micelle templating. Unlike dense coatings or randomly aggregated particles, isolated Au NPs act as uniformly distributed nucleation sites that homogenize local charge fields, enhance ion transport, and suppress dendrite formation while preserving the active Zn surface. The process, achieved by gold-halide-loaded block copolymer micelles followed by plasma etching, provides precise nanoparticle size control and reproducible submonolayer coverage. Electrochemical testing shows reduced nucleation barriers, improved charge transfer kinetics, and markedly enhanced cycling stability, with symmetric cells exceeding 4000 hours of operation and delivering up to 50-fold lifetime improvements compared to bare Zn. Full-cell tests with V 2 O 5 cathodes further confirm the improved efficiency and stability of Au NP-modified anodes. This work highlights nanoparticle decoration as a cost-effective and scalable interface engineering strategy for achieving long-life Zn batteries without compromising active surface area.