Flexible SnS2/CNTs/porous Cu tube textile anode for enhanced sodium-ion batteries

Abstract

Achieving fast charging and stability of metal sulfide anode materials is essential but challenging for advanced sodium-ion batteries (SIBs) because of their sluggish sodiation kinetics and poor intrinsic conductivity. Herein, the tin sulfide (SnS2) nanoparticles with tunable sizes were successfully synthesized on the carbon nanotubes via hydrothermal method, which grown on porous copper tube textiles via chemical vapor deposition to form free-standing electrodes. Obviously, the uniform carbon nanotubes supported on textiles could construct integrated conductive network and improve the electronic conductivity. The smaller SnS2 particles enable to expose more abundant grain boundaries and surface atoms, generating enhanced surface capacitive behaviors and effective solid phase diffusions of sodium ions. Therefore, the optimum SnS2/CNTs/textile electrode delivers a high reversible capacity of 565.5 mAh g−1 at the current density of 200 mA g−1 after 100 cycles and superior rate performance of 383.5 mAh g−1 at 1000 mA g−1 after 500 cycles. Based on above analysis, the flexible integrated electrode design is expected to provide useful instructions for advanced sodium ion batteries.