Ultrastable sodium metal plating/striping by engineering heterogeneous nucleation on TiO2 nanotube arrays

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2022-03, Vol.431, p.134272, Article 134272
• Main Authors: Wang, Jinshan, Lian, Ruqian, Zhao, Si, Zheng, Lituo, Huang, Yiyin, Wei, Mingdeng, Mathur, Sanjay, Hong, Zhensheng
• Format: Article
• Language: English
• Subjects: Electrochemical deposition; Heterogeneous nucleation; Sodium metal anode; TiO2 nanotube arrays
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2021.134272

[Display omitted] •3D spaced TiO2 nanotube arrays (STNTs) were coated with ultra-fine metal nanocrystals.•We propose an absorption-diffusion regulation strategy to regulate Na deposition.•AIMD simulations demonstrate a mixed Na-Ag layer at the interface.•STNTs-Ag||Na displays a high Coulombic efficiency ∼99.5% even after 500 cycles.•STNTs-Ag-Na exhibits an ultralow overpotential of 4 mV and long cycling life over 1400 h. Sodium metal is considered as an excellent anode material for sodium-based energy storage devices with both high energy density and low cost, but the uncontrollable growth of sodium metal seriously limits its application. Herein, we firstly propose 3D spaced TiO2 nanotube arrays (STNTs) uniformly coated with ultra-fine metal (Ag, Cu) nanocrystals as a substrate with absorption-diffusion regulation strategy to control the sodium metal deposition behavior. TiO2 has a higher sodiophilic activity with larger Na absorption energy than the traditional copper substrate. Moreover, it is found by ab initio molecular dynamics (AIMD) simulations that it is much easier for Na to spread upon the surface of silver compared to copper, and thus forming a mixed Na-Ag layer at the interface. As a result, sodium metal is inclined to deposit inside or along the nanotube in STNTs-Ag in nanoscale. Finally, STNTs-Ag||Na half-cell displays a high Coulombic efficiency ∼99.5% even after 500 cycles with 1 mAh cm−2. Symmetric cell of STNTs-Ag-Na exhibits an ultralow overpotential of 4 mV and a long-term cycling life over 1400 h. Moreover, STNTs-Ag-Na anode coupling with Na3V2(PO4)3 cathode exhibits a significantly reduced polarization voltage with 22 mV and improved rate performance with 110 mAhg−1 at 10 C.