Aminosilane Molecular Layer Enables Successive Capture-Diffusion-Deposition of Ions toward Reversible Zinc Electrochemistry

The aqueous zinc (Zn) battery is a safe and eco-friendly energy-storage system. However, the use of Zn metal anodes is impeded by uncontrolled Zn deposition behavior. Herein, we regulate the Zn-ion deposition process for dendrite-free Zn metal anodes using an aminosilane molecular layer with high zincophilic sites and narrow molecule channels. The aminosilane molecular layer causes Zn ions to undergo consecutive processes including being captured by the amine functional groups of aminosilane and diffusing through narrow intermolecular channels before electroplating, which induces partial dehydration of hydrated Zn ions and uniform Zn ion flux, promoting reversible Zn stripping/plating. Through this molecule-induced capture-diffusion-deposition procedure of Zn ions, smooth and compact Zn electrodeposited layers are obtained. Hence, the aminosilane-modified Zn anode has high Coulombic efficiency (similar to 99.5%), long lifespan (similar to 3000 h), and high capacity retention in full cells (88.4% for 600 cycles). This strategy not only has great potential for achieving dendrite-free Zn anodes in practical Zn batteries but also suggests an interface-modification principle at the molecular level for other alternative metallic anodes.

Automated summary

The deposition behavior of Zn metal anodes in aqueous Zn batteries can be regulated using an aminosilane molecular layer, resulting in dendrite-free Zn metal anodes. This is achieved through a capture-diffusion-deposition process of Zn ions, induced by the aminosilane molecular layer, which promotes reversible Zn stripping/plating and leads to smooth and compact Zn electrodeposited layers. The aminosilane-modified Zn anode exhibits high Coulombic efficiency, long lifespan, and high capacity retention in full cells, making it a promising solution for practical Zn batteries and providing insights into interface modification for other metallic anodes at the molecular level.