Lithium metal batteries are strongly considered as one of the most promising candidates for next-generation high-performance battery systems. However, the uncontrollable growth of lithium dendrites and the highly reactive lithium metal result in the severe safety risks and the short lifespan for high-energy-density rechargeable batteries. Here, we demonstrate a hydrophobic and ionically conductive ethylene-vinyl acetate (EVA) copolymer layer can not only endow lithium metal anodes with an air-stable and anti-water surface, but also efficiently suppress the lithium-dendrites growth during the electrochemical cycling process. Therefore, the introduction of the EVA copolymer as a bifunctional protection layer simultaneously improves the anti-water/air performance and electrochemical cycling stability of lithium metal anode.

锂金属电池被强烈认为是下一代高性能电池系统最有希望的候选者之一。然而，锂树枝状晶体的不可控制的生长和高反应性的锂金属导致高能量密度可充电电池的严重安全风险和短寿命。在这里，我们证明了疏水性和离子导电性的乙烯-乙酸乙烯酯（EVA）共聚物层不仅可以赋予锂金属阳极以空气稳定性和防水性，而且还可以有效地抑制电化学循环过程中锂树枝状晶体的生长。因此，引入EVA共聚物作为双功能保护层同时改善了锂金属阳极的抗水/空气性能和电化学循环稳定性。