Monodispersed MOF-Modified Nanofibers as Versatile Building Blocks for the Ion Regulations in Safe Lithium-Sulfur Batteries

Lithium-sulfur battery is the most promising candidateforthe next generation of rechargeable batteries because of the highenergy density. However, the severe shuttle effect of lithium polysulfides(LiPSs) and degradation of the lithium anode during cycling are significantissues that hinder the practical application of lithium-sulfurbatteries. Herein, monodispersed metal-organic framework (MOF)-modifiednanofibers are prepared as building blocks to construct both a separatorand a composite polymer electrolyte in lithium-sulfur systems.This building block possesses the intrinsic advantages of good mechanicalproperties, thermal stability, and good electrolyte affinity. MOFs,grown continuously on the monodispersed nanofibers, can effectivelyadsorb LiPSs and play a key role in regulating the nucleation andstripping/plating process of the lithium anode. When assembled intothe separator, the symmetric battery remains stable for 2500 h ata current density of 1 mA cm(-2), and the lithium-sulfurfull cell shows improved electrochemical performance. In order toimprove the safety property, the composite polymer electrolyte isprepared with the MOF-modified nanofiber as the filler. The quasi-solid-statesymmetric battery remains stable for 3000 h at a current density of0.1 mA cm(-2), and the corresponding lithium-sulfurcell can cycle 800 times at 1 C with a capacity decay rate of only0.038% per cycle.

Automated summary

Monodispersed metal-organic framework (MOF)-modified nanofibers are used to construct the separator and composite polymer electrolyte in lithium-sulfur systems, effectively addressing the shuttle effect and degradation issues, and improving the electrochemical performance of lithium-sulfur batteries.