Single-Atom Zinc and Anionic Framework as Janus Separator Coatings for Efficient Inhibition of Lithium Dendrites and Shuttle Effect

Abstract

The two key problems for the industrialization of Li−S batteries are the dendrite growth of lithium anode and the shuttle effect of lithium polysulfides (LiPSs). Herein, we report the Janus separator prepared by coating anionic Bio-MOF-100 and its derived single-atom zinc catalyst on each side of the Celgard separator. The anionic metal−organic framework (MOF) coating induces the uniform and rapid deposition of lithium ions, while its derived single-atom zinc catalyzes the rapid transformation of LiPSs, thus inhibiting the lithium dendrite and shuttle effect simultaneously. Consequently, compared with other reported Li−S batteries assembled with single-atomic catalysts as separator coatings, our SAZ-AF Janus separator showed stable cyclic performance (0.05% capacity decay rate at 2 C with 1000 cycles), outstanding performance in protecting lithium anode (steady cycle 2800 h at 10 mAh cm −2 ), and equally excellent cycling performance in Li−SeS 2 or Li−Se batteries. Our work provides an effective separator coating design to inhibit shuttle effect and lithium dendrite.

The LiTFSI/COFs Fiber as Separator Coating with Bifunction of Inhibition of Lithium Dendrite and Shuttle Effect for Li-SeS2 Battery

“…The comparison of the performance of the ATFG-COF/PP with the reported materials in Li-SeS 2 batteries was added to Table S1 in the revised supporting information. Compared to previous reports, the fiber ATFG-COF coating is a multi-functional coating that can inhibit both lithium dendrites and shuttle effects, thus showing better performance than the SAZ-AF Janus separator [31]. Furthermore, cells with ATFG-COF also showed good performance in the reported Li-SeS 2 batteries [31][32][33].…”

“…Compared to previous reports, the fiber ATFG-COF coating is a multi-functional coating that can inhibit both lithium dendrites and shuttle effects, thus showing better performance than the SAZ-AF Janus separator [31]. Furthermore, cells with ATFG-COF also showed good performance in the reported Li-SeS 2 batteries [31][32][33].…”

“…On the one hand, carbonyl groups can effectively transfer lithium ions; amino groups can form hydrogen bonds with TFSI − to fix TFSI − in the channel, thus further promoting the transport of lithium ions. Compared with the separator with functional coating, the ATFG-COF/PP also showed a high level of lithium-ion transport [31].…”

“…(1) to effectively induce the uniform deposition and stripping of lithium ions on the lithium anode and inhibit the generation of lithium dendrite; (2) to improve the number of lithium ions transferred; (3) to effectively inhibit the shuttle effect so as to obtain high-performance lithium-selenium disulfide batteries. Compared to previous reports, the fiber ATFG-COF coating is a multi-functional coating that can inhibit both lithium dendrites and shuttle effects, thus improving the performance of batteries [31][32][33].…”

“…Therefore, the design of a separator coating that can simultaneously inhibit the growth of lithium dendrite and the shuttle effect of polysulfides/polyselenides will be a major boost for high-performance Li-SeS 2 batteries. So far, however, there have been few reports of such functional coatings for Li-SeS 2 batteries [31][32][33].…”