Leveraging nano sol properties for enhanced zinc anode performance in aqueous zinc-ion batteries

Aqueous zinc-ion batteries (AZIBs) are gaining attention as safer and cost-effective alternatives to lithium-ion batteries (LIBs) for large-scale energy storage. Despite their potential, challenges such as zinc dendrite formation and spontaneous corrosion hinder long-term performance. To address these issues, surface coatings on zinc anodes have been explored to address these issues, but conventional organic and metallic coatings often increase charge transfer resistance due to their dense structure. In this study, we propose titanium dioxide nano sols (NS-TiO2) as a novel solution to improve zinc anode performance. Synthesized via a cost-effective sol-gel method, NS-TiO2 forms a thin, porous coating that enhances ion transport and reduces charge transfer resistance, while effectively mitigating dendrite formation. The amorphous structure of NS-TiO2 provides superior ion and electron mobility by creating additional diffusion channels, facilitating homogeneous Zn2+ deposition. In a symmetric cell, NS-TiO2@Zn electrodes demonstrated exceptional cycling stability, maintaining performance for over 2400 h at 5 mA cm-2. Additionally, in an asymmetric Cu ||NS-TiO2@Zn cell, Coulombic efficiency exceeded 99.69 % for 440 cycles. These findings highlight the potential of NS-TiO2 coatings to significantly enhance the cycling stability and efficiency of AZIBs, offering a promising pathway for improving large-scale energy storage technologies.