Tunable MXene-Derived 1D/2D Hybrid Nanoarchitectures as a Stable Matrix for Dendrite-Free and Ultrahigh Capacity Sodium Metal Anode

Abstract

Although sodium (Na) is one of the most promising alternatives to lithium as an anode material for next-generation batteries, uncontrollable Na dendrite growth still remains the main challenge for Na metal batteries. Herein, a novel 1D/2D Na₃Ti₅O₁₂-MXene hybrid nanoarchitecture consisting of Na₃Ti₅O₁₂ nanowires grown between the MXene nanosheets is synthesized by a facile approach using cetyltrimethylammonium bromide (CTAB)-pretreated Ti₃C₂ MXene. Used as a matrix for the Na metal anode, the Na₃Ti₅O₁₂ nanowires, formed benefiting from the CTAB stabilization, have chemical interaction with Na and thus provide abundant Na nucleation sites. These 1D nanostructures, together with the unique confinement effect from the 2D nanosheets, effectively guide and control the Na deposition within the interconnected nanochannels, preventing the "hot spot" formation for dendrite growth. A stable cycling performance can be achieved at a high current density up to 10 mA cm^-2 along with an ultrahigh capacity up to 20 mAh cm^-2.