Sulfonyl Molecules Induced Oriented Lithium Deposition for Long-Term Lithium Metal Batteries

Abstract

Dendrites growth and unstable interfacial Li⁺ transport hinder the practical application of lithium metal batteries (LMBs). Herein, we report an active layer of 2,4,6-trihydroxy benzene sulfonyl fluorine on copper substrate that induces oriented Li⁺ deposition and generates highly crystalline solid-electrolyte interphase (SEI) to achieve high-performance LMBs. The lithiophilic -SO₂ ^- groups of highly crystalline SEI accept the rapidly transported Li⁺ ions and form a dense inner layer of LiF and Li₃ N, which regulate Li⁺ plating morphology along the (110) crystal surface toward dendrite-free Li anode. Thus, Li||Cu cells with lithiophilic SEI achieve an average deposition efficiency of 99.8 % after 700 cycles, and Li||Li cells operate well for 1100 h. Besides, Li||LiNi_0.8 Co_0.1 Mn_0.1 O₂ cells with modified SEI exhibit a capacity retention that is 14 times than that of conventional SEI. Even at -60 °C, Li||Cu cells reach stable deposition efficiency of 83.2 % after 100 cycles.

Keywords: Li anodes; Li metal batteries; highly crystalline solid electrolyte interphase; lithiophilic groups; oriented Li deposition.