One-dimensional architectures in polymer solid electrolytes: design principles, ion-transport mechanisms and practical implementation

Polymer solid electrolytes (PSEs) are promising for practical solid-state batteries due to their interfacial adaptability, film-forming ability, and processability. However, they still suffer from low ionic conductivity, low Li⁺ transference number, and insufficient mechanical support, which originate from disordered Li⁺ pathways, inadequate suppression of anion migration, and weak load-bearing frameworks. One-dimensional (1D) architectures offer a structural design paradigm to address these interconnected limitations by engineering oriented Li⁺ transport pathways, long-range functional interfaces, and percolated supporting networks. This review systematically examines 1D architectures in PSEs, first summarizing their classification, critical design variables, and fabrication methods. Mechanistically, it focuses on how oriented structures reduce Li⁺ transport tortuosity, continuous interfaces promote interfacial Li⁺ transport and amplify interfacial regulation, and interconnected supporting skeletons enhance stress transfer and mechanical integrity. This review further discusses the remaining challenges in this field, including standardization of structural descriptors, mechanistic decoupling, high-voltage stability evaluation, scalable fabrication, and validation under realistic battery conditions. Overall, 1D architectures are not only structural units in PSEs, but also a design paradigm for the coordinated optimization of Li⁺ transport pathways, interfacial functions, and mechanical stability, providing new insights into the construction of high-performance solid-state electrolytes.