The long-standing issue of Li-dendrite formation and growth during repeated plating or stripping processes prevents the practical application of Li-metal anodes for high-specific-energy batteries. Here we develop an approach to control dendrite growth by coating the separator with functionalized nanocarbon (FNC) with immobilized Li ions. During cycling, the Li dendrites grow toward each other simultaneously from both the FNC layer on the separator and the Li-metal anode; when the dendrites meet, the growth changes direction: rather than penetrating the separator, a dense Li layer is formed between the separator and the Li anode. This controlled growth alleviates the solid electrolyte interphase formation, reduces the decomposition of the electrolyte, and improves the cyclability of the Li-metal cell. In a Li/LiFePO₄ coin cell with three different electrolytes, we show that this approach enables a long stable cycle life (>800 cycles with 80% retention of the initial capacity) and improved efficiency (>97%). Our method offers promise for application in practical Li-metal batteries, and it may also be useful for tackling dendrite issues for other metals.

重复电镀或剥离过程中锂枝晶形成和生长的长期存在的问题阻止了锂锂金属阳极在高比能电池中的实际应用。在这里，我们开发了一种通过用功能化的纳米碳（FNC）用固定化的Li离子涂覆隔膜来控制枝晶生长的方法。在循环过程中，Li树枝状晶体同时从隔板上的FNC层和锂金属阳极向彼此生长。当树枝状晶体相遇时，生长方向发生变化：在隔膜和锂阳极之间形成了致密的锂层，而不是穿透隔膜。这种受控的生长减轻了固体电解质相间的形成，减少了电解质的分解，并改善了锂金属电池的循环性。在Li / LiFePO _4中纽扣电池具有三种不同的电解质，我们证明这种方法可实现较长的稳定循环寿命（> 800个循环，初始容量保留80％）和提高的效率（> 97％）。我们的方法为在实际的锂金属电池中应用提供了希望，对于解决其他金属的枝晶问题也可能有用。