Hollow Co-Fe LDH as an effective adsorption/catalytic bifunctional sulfur host for high-performance Lithium–Sulfur batteries

Lithium–sulfur batteries (LSBs) have been regarded as one of the most promising candidates for energy storage devices because of their high energy density, high theoretical capacity, and low cost. However, severe shuttle effect and sluggish redox reaction kinetics of lithium polysulfides (LiPSs), resulting in unsatisfactory rate performance and cycling stability, greatly hinder the further development of LSBs. Herein, we successfully synthesized a hollow structured Co-Fe layered double hydroxide (Co-Fe LDH). This Co-Fe LDH could inhibit the diffusion and accelerate the redox reaction kinetics of LiPSs, indicating that Co-Fe LDH is an effective adsorption/catalytic bifunctional sulfur host. When served as a cathode material for LSBs, the sulfur-loaded Co-Fe LDH (Co-Fe LDH@S) delivers a high specific capacity and outstanding cyclic stability with a low average capacity decay rate at 1 C. This composite cathode also displays excellent rate performance with a high capacity of 530.7 mAh g–1at 2 C. The results demonstrate that the Co-Fe LDH@S composites are a promising cathode for high-performance LSBs. [Display omitted] •Hollow structured Co-Fe layered double hydroxides were successfully synthesized.•Co-Fe LDH have abundant polar metal active sites and hydroxyl groups.•Co-Fe LDH can effectively suppress shuttle effect and boost the reduction of LiPSs.•Co-Fe LDH@S composites show a high specific capacity and excellent cycling stability.