Simple fabrication of Nb2O5 /PANI nanocomposite for high performance lithium sulfur batteries

Abstract Lithium-sulfur batteries have attracted significant attention due to their high theoretical capacity density (1675 mA h g⁻ ¹) and low production cost. However, under practical conditions, the low conductivity of sulfur, volume expansion, and shuttle effect of lithium polysulfide (LiPSs) still hinder the broad application of lithium-sulfur batteries. A self-assembled flexible electrode material (Nb₂O₅/PANI-cc@S) is designed and fabricated here. The core of Nb₂O₅ nanowire arrays is coated with a shell of PANI and assembled with carbon cloth (cc) as a new sulfur fluid collector. The composite exposes more active sites between sulfur and the catalytic medium to capture LiPSs. In addition, the extra free space between Nb₂O₅ nanowire arrays is conducive to the penetration of liquid electrolytes. Moreover, the shell structure of PANI on the electrode surface enhances the structural stability of the composite electrode material. It effectively inhibits the outward diffusion of polysulfide and the volume expansion during the cycle. Thanks to these synergies, the self-supporting Nb₂O₅/PANI-cc@S has a high specific capacity of 1265.7 mA h g⁻ ¹ at 0.1 C and retains an impressive 1112.2 mA h g⁻ ¹ capacity even after 100 cycles at 0.1 C. It shows great potential to promote the practical application of flexible lithium-sulfur batteries.