Hybrid Membrane with SnS₂ Nanoplates Decorated Nitrogen-Doped Carbon Nanofibers as Binder-Free Electrodes with Ultrahigh Sulfur Loading for Lithium Sulfur Batteries

Abstract

Lithium sulfur batteries have been regarded as promising energy storage devices due to their superiority in energy density. However, the low sulfur loading, low active material utilization, and poor cycling stability restrict their commercial applications. Herein, we prepared a three-dimensional structure of SnS2 nanoplates decorated on nitrogen-doped carbon nanofibers (3D SnS2@N-CNFs) by an electrospinning process followed by a hydrothermal technique. The 3D free-standing SnS2@N-CNFs were applied as the current collector and polymeric binder containing a Li2S6 catholyte for lithium polysulfide batteries. The obtained SnS2@N-CNFs show the strong physicochemical adsorption of polysulfides and can effectively reduce the electrochemical polarization. The cell with SnS2@N-CNFs exhibits high electrochemical performance. As a result, SnS2@N-CNFs with high sulfur loading of approximately 7.11 mg displayed the first discharge capacity of 1010 mAh g–1 at 0.2 C with 0.08% capacity decay per cycle over 150 cycles. Meanwhile, the electrode with sulfur loading up to 22.65 mg also exhibits an extremely high capacity of 14.67 mAh, much higher than commonly presented blade-cast sulfur electrodes. The fibrous membrane is promising for assembling with high sulfur loading, which exhibits a superior electrochemical performance in lithium sulfur batteries.