Induction of Planar Sodium Growth on MXene (TiCT)-Modified Carbon Cloth Hosts for Flexible Sodium Metal Anodes.

Sodium (Na) metal batteries have attracted increasing attention and gained rapid development. However, the processing, storing, and application of Na metal anodes are restricted by its inherent stickiness and poor mechanical properties. Herein, an MXene (TiCT)-coated carbon cloth (TiCT-CC) host is designed and synthesized, which shows a highly metallic conductive and sodiophilic surface. After a thermal infusion treatment, a Na-TiCT-CC composite with rigidity and bendability is obtained and employed as a metal anode for Na ion batteries. The Na-TiCT-CC electrodes present stable cycling performance and high stripping/plating capacity in both an ether-based (up to 5 mA·h·cm) and a carbonate-based (up to 8 mA·h·cm) electrolyte. The fundamental protection mechanism of MXene TiCT is investigated. TiCT efficiently induces Na's initial nucleation and laterally oriented deposition, which effectively avoids the generation of mossy/dendritic Na. The arrangement of Na atoms deposited on the MXene surface inherits the MXene atomic architecture, leading to a smooth "sheet-like" Na surface. Meanwhile, a flexible Na-based Na-TiCT-CC∥NaV(PO) device is assembled and exhibits capable electrochemical performance.