Simultaneous realization of high sulfur utilization and lithium dendrite-free via dual-effect kinetic regulation strategy toward lithium-sulfur batteries

Abstract

With the high theoretical specific capacity and energy density, lithium-sulfur batteries (LSBs) have been intensively studied as promising candidates for energy storage devices. However, LSBs are largely hindered by inferior sulfur utilization and uncontrollable dendritic growth. Herein, a hierarchical functionalization strategy of stepwise catalytic-adsorption-conversion for sulfur species via the synergetic of the efficiently catalytic host cathode and light multifunctional interlayer has been proposed to concurrently address the issues arising on the dual sides of the LSBs. The multi-layer SnS2 micro-flowers embedded into the natural three-dimensional (3D) interconnected carbonized bacterial cellulose (CBC) nanofibers are fabricated as the sulfur host that provides numerous catalytic sites for the rapid catalytic conversion of sulfur species. Moreover, the distinctive CBC-based SnO2–SnS2 heterostructure network accompanied high conductive carbon nanofibers as the multifunctional interlayer promotes the rapid anchoring-diffusion-conversion of lithium polysulfides, Li+ flux redistribution, and uniform Li deposition. LSBs equipped with our strategy exhibit a high reversible capacity of 1361.5 mA h g−1 at 0.2 C and superior cycling stability with an ultra-low capacity fading of 0.031% per cycle in 1000 cycles at 1.5 C and 0.046% at 3 C. A favorable specific capacity of 859.5 mA h g−1 at 0.3 C is achieved with a high sulfur mass loading of 5.2 mg cm−2, highlighting the potential of practical application. The rational design in this work can provide a feasible solution for high-performance LSBs and promote the development of advanced energy storage devices.