Electrolyte protection film and preparation method thereof, electrolyte and metal lithium secondary battery

The invention relates to the technical field of lithium metal battery preparation, in particular to an electrolyte protection film and a preparation method thereof, an electrolyte and a metal lithium secondary battery. The protective film comprises the following components: an organic polymer and a binder; wherein the organic polymer is a heteroatom doped polyacrylonitrile organic polymer. The electrolyte protective film prevents the metal lithium from reacting with the electrolyte to generate dead lithium, and reduces the consumption of lithium, so that the cycle performance of the metal lithium is improved, the capacity retention ratio is improved, and the battery has excellent cycle performance. 本申请涉及锂金属电池制备技术领域，尤其涉及一种电解质保护膜及其制备方法、电解质以及金属锂二次电池。所述保护膜的组分包括有机聚合物和粘结剂；其中，所述有机聚合物为杂原子掺杂的聚丙烯腈类有机聚合物。该电解质保护膜，阻止了金属锂与电解质发生反应产生死锂，减少锂的消耗，从而提高金属锂的循环性能，并提高了容量保持率，从而使得电池具有优异的电池循环性能。