MXene-derivative pompon-like Na2Ti3O7@C anode material for advanced sodium ion batteries

Abstract

Sodium-ion batteries are considered as the next generation of attractive promising batteries on account of their ample raw materials and low-cost. Two-dimensional MXene materials have been deemed to be potential anode material for sodium ion batteries. Nevertheless, multilayer Ti3C2Tx material suffers from low specific capacity, limiting its commercial applications. Here, a pompon-like MXene-derivative sodium titanate with carbon-encapsulated has been fabricated. The Na2Ti3O7@C possesses crosslinked nanoribbon structure with suitable interlayer spacing and open porosity, which are beneficial to ions diffusion and electrolyte infiltration. More importantly, the thin carbon layer outside can significantly improve the electron transmission efficiency and maintain structural stability. When applied to anode material of sodium ion batteries, the Na2Ti3O7@C delivers a high reversible capacity of 173 mA h g−1 at 200 mA g−1 and exceptional stable cycling life up to 200 cycles with only 0.026% attenuation per cycle at 2 A g−1.