A carbon cloth with a coating layer containing aluminum fluoride as an interlayer for lithium metal batteries

Problems in safety and cell performance from dendritic growth of lithium and formation of dead lithium on the surface of electrode during charge has impeded commercialization of lithium metal as an electrode of lithium rechargeable batteries. To solve these problems, use of lithiophilic materials on lithium metal electrode has been suggested. Herein, we propose an interlayer for lithium metal battery composed of carbon cloth with a coating layer containing lithiophilic aluminum fluoride (AlF3). The positive effects of AlF3-containing layer on the carbon cloth on the performance of lithium metal anode are investigated through cycling of Li||Li symmetric and LiCoO2||Li half-cells. We demonstrate that the enhanced cycling stability with the interlayer is attributed to the LiF-rich SEI layer in-situ formed from the reaction between AlF3 and lithium-ions in cycling and suppressed formation of dendrites and dead lithium during lithium plating process. The LiF-rich SEI layer on the carbon cloth induces uniform plating of lithium above and inside the interlayer while the bare carbon cloth results in irregular and local plating of lithium. The reduced decomposition of the electrolyte by the AlF3-containing layer is also considered to be the reason for the improved cycling stability of the lithium metal anode.