Lithium metal batteries are regarded as the “Holy Grail” among varieties of energy storage systems. Nevertheless, the development and practical application of lithium metal batteries have been seriously hindered by the safety issues, which are generated from threatening lithium dendrites, flammable separator and electrolytes. In this work, a flame retardant sandwiched separator has been prepared by simply coating ammonium polyphosphate wrapped by SiO₂ (APP@SiO₂) on the surface of commercial polyolefin, thus significantly improving the safety of lithium metal batteries. The APP@SiO₂ separator impregnated with sufficient electrolyte exhibits excellent flame retardant performance, which manifests self-extinguishing performance. In addition, thermal stability, ionic conductivity, and electrochemical performances have been also improved obviously. More importantly, the APP@SiO₂ separator possesses a satisfactory ability to suppress lithium dendrites, owing to the fact that the high ionic conductivity of modified separator can promote uniform deposition of Li⁺ and the dangerous lithium dendrites contacted with separator are consumed by the reaction with SiO₂. Therefore, a facile but effective approach can endow the multifunctional sandwiched separator with a favorable potential application for high performance and safety lithium metal batteries.

锂金属电池被视为各种储能系统中的“圣杯”。然而，锂金属电池的开发和实际应用受到安全问题的严重阻碍，这些安全问题是由危险的锂树枝状晶体，易燃隔膜和电解液产生的。在这项工作中，已经通过简单地在商用聚烯烃表面上涂覆被SiO ₂（APP @ SiO ₂）包裹的聚磷酸铵来制备阻燃夹层隔板，从而显着提高了锂金属电池的安全性。APP @ SiO ₂浸渍有足够电解质的隔膜显示出优异的阻燃性能，表现出自熄性能。此外，热稳定性，离子电导率和电化学性能也得到了明显改善。更重要的是，APP @ SiO ₂隔膜具有令人满意的抑制锂树枝状结晶的能力，这是因为改性隔膜的高离子电导率可以促进Li ^+的均匀沉积，并且与隔膜接触的危险锂树枝状结晶被反应所消耗。与SiO ₂。因此，一种简便而有效的方法可以使多功能夹层隔膜在高性能和安全性锂金属电池中具有良好的潜在应用。