Developing high-capacity anodes is a must to improve the energy density of lithium batteries for electric vehicle applications. Alloy anodes are one promising option, but without pre-stored lithium, the overall energy density is limited by the low-capacity lithium metal oxide cathodes. Recently, lithium metal has been revived as a high-capacity anode, but faces several challenges owing to its high reactivity and uncontrolled dendrite growth. Here, we show a series of Li-containing foils inheriting the desirable properties of alloy anodes and pure metal anodes. They consist of densely packed Li_xM (M = Si, Sn, or Al) nanoparticles encapsulated by large graphene sheets. With the protection of graphene sheets, the large and freestanding Li_xM/graphene foils are stable in different air conditions. With fully expanded Li_xSi confined in the highly conductive and chemically stable graphene matrix, this Li_xSi/graphene foil maintains a stable structure and cyclability in half cells (400 cycles with 98% capacity retention). This foil is also paired with high-capacity Li-free V₂O₅ and sulfur cathodes to achieve stable full-cell cycling.

开发高容量阳极是提高电动汽车锂电池能量密度的必要条件。合金阳极是一种有前途的选择，但由于没有预先存储锂，因此总能量密度受到低容量锂金属氧化物阴极的限制。近来，锂金属已经恢复为高容量阳极，但是由于其高反应性和不受控制的枝晶生长，因此面临若干挑战。在这里，我们展示了一系列含锂的箔，这些箔继承了合金阳极和纯金属阳极的理想性能。它们由密集填充的Li _x M（M = Si，Sn或Al）纳米颗粒组成，这些纳米颗粒被大石墨烯片包裹。在石墨烯片的保护下，大而独立的Li _xM /石墨烯箔在不同的空气条件下稳定。Li _x Si /石墨烯箔具有完全膨胀的Li _x Si限制在高导电性和化学稳定的石墨烯基体中，可在半电池中保持稳定的结构和可循环性（400个循环，容量保持率达98％）。该箔还与高容量的无锂V ₂ O ₅和硫阴极配对，以实现稳定的全电池循环。