Abstract:

Guiding the uniform distribution of Li⁺ flux can effectively inhibit the formation and growth of lithium dendrites， promoting the industrial application of lithium metal batteries. In this study， MoS₂ nanosheets with single or few layers， completed structure were prepared by chemical intercalation method， then two-dimensional MoS₂ nanosheets were sprayed onto electrospun polyacrylonitrile（PAN） fiborus membrane to obtain MoS₂@PAN composite separator. The introduction of MoS₂ coating not only improved ion conductivity（1.02 mS/cm）， Li⁺ transfer number （0.59）， and electrolyte affinity， but also reduced the pore size of the composite membrane， resulting in a uniform pore size distribution. Synergistic effect of these characteristics regulated the Li⁺ flow through MoS₂@PAN separator and promoted the uniform Li^{deposition on the surface of lithium metal， inhibiting the formation and growth of lithium dendrites. Therefore， the Li/Li symmetric cell with MoS₂@PAN separator achieved a stable cycle with a low overpotential of 14 mV for 500 h at 1 mA/cm2， and there was no obvious lithium dendrite growth on the Li anode surface after cycling. Moreover， the LiFePO₄/Li battery assembled with MoS₂@PAN separator maintained an initial capacity of 92% after 550 cycles at 2C， demonstrating more stable cycling performance. This study redistributes the Li+ flux through a separator to achieve uniform Li deposition， providing a feasible strategy for suppressing the formation and growth of lithium dendrites.}

Key words: Two-dimensional material, MoS₂ nanosheet, Lithium metal battery separator, Regulating Li⁺ flux, Suppressing the formation and growth of lithium dendrites