Solid polymer electrolytes (SPEs) are promising for the next-generation all-solid-state lithium metal battery (LMB) applications. The effect of semicrystalline structure on ion transport is two-fold: the crystalline domains provide a tortuous diffusion pathway (structural effect) while the tethered chains can cause sluggish ion diffusion (dynamic effect). These two effects are intertwining in a bulk semicrystalline SPE system. In this work, we fabricate a series of polymer single crystal (PSC)-based SPEs by infiltrating lithium bis(trifluoromethylsulfonyl) imide (LiTFSI) into poly(ethylene oxide) (PEO) PSC films. The obtained SPE films show anisotropic conducting behavior with the in-plane conductivity being one to three orders of magnitudes greater than the through-plane conductivity, which can be attributed to the PSC-guided ion transport. The room temperature in-plane conductivity of the PSC SPE can be comparable to its amorphous counterpart, indicating that the tortuosity effect plays a major role in the reduced ionic conductivity of semicrystalline SPEs. PSC-LiTFSI superstructure is observed in the PSC SPEs due to selective perforation of the crystalline PEO lamellae by LiTFSI salts. This work demonstrates the importance of the crystalline morphology on the ion transport in semicrystalline SPEs.

固态聚合物电解质（SPE）有望用于下一代全固态锂金属电池（LMB）应用。半结晶结构对离子迁移的影响是双重的：结晶域提供曲折的扩散途径（结构效应），而束缚链会导致缓慢的离子扩散（动态效应）。这两种效应在本体半结晶SPE系统中交织在一起。在这项工作中，我们通过将双（三氟甲基磺酰基）酰亚胺锂（LiTFSI）渗透到聚（环氧乙烷）（PEO）PSC膜中来制造一系列基于聚合物单晶（PSC）的SPE。所获得的SPE膜表现出各向异性的导电行为，其中面内电导率比贯穿面电导率大一到三个数量级，这可以归因于PSC引导的离子传输。PSC SPE的室温面内电导率可与它的无定形对应物相媲美，这表明曲折效应在半结晶SPE降低的离子电导率中起主要作用。在PSC SPEs中观察到PSC-LiTFSI的超结构，这是由于LiTFSI盐对结晶PEO薄片的选择性穿孔。这项工作证明了结晶形态对半结晶SPE中离子迁移的重要性。