一种多功能隔膜实现对多硫离子和锂离子的双重调控

Polysulfide shuttle and lithium dendrite growth severely limit the practical application of lithium−sulfur batteries (LSBs); however, a rational design of a separator can achieve the effect of two birds with one stone. Herein, nitrogen-doped carbon nanotubes with dispersed TiN/CoO particles (TCCNT) were designed and applied as a separator modification layer for LSBs. The porous structure of TCCNT can confine the diffusion of soluble polysulfides by physical adsorption first, and then the TiN/CoO particles carried on its surface/inside can not only further anchor the polysulfides via chemisorption but also act as a catalyst to facilitate their conversion. Meanwhile, the good lithophilicity of TiN was beneficial to homogenizing the Li+ fluxes, guiding a uniform deposition of lithium and realizing a stable cycle of the lithium symmetric battery for up to 2000 h at 5 mA cm−2. Ascribed to the rational layout of the TCCNT layer that allows maximization of the synergistic effect between various material components, an LSB equipped with a modified separator displayed satisfactory electrochemical performance in both cases of conventional and high sulfur loadings, demonstrating its practical application potential.