关键词: 准固态电解质, 锂金属电池, 紫外光固化技术, 电化学性能

Abstract:

Lithium-ion batteries (LIBs) are widely used in portable electronic devices, electric vehicles, and large-scale energy storage systems due to their high energy density, long cycle life, and environmental friendliness. However, conventional liquid electrolytes can promote lithium dendrite growth during cycling, leading to internal short circuits, accompanied by side reactions and interfacial instability-severely compromising both safety and longevity of LIBs. Polymer-based composite solid-state electrolytes have emerged as promising candidates for constructing high-safety lithium metal batteries. However, their conventional fabrication methods often require high-temperature or extended thermal curing processes, limiting their scalability and practical deployment. In this study, we present a novel UV-curing-based fabrication route for the rapid construction of a composite solid-state electrolyte membrane, denoted as OICSE-Al₂O₃-1, composed of ethoxylated trimethylolpropane triacrylate doped with aluminum oxide (Al₂O₃) nanoparticles. The experimental results reveal that the addition of Al₂O₃ effectively suppresses the formation of crystalline domains within the polymer matrix, thereby enhancing the ionic conductivity. Specifically, OICSE-Al₂O₃-1 achieves an ionic conductivity of 5 × 10^-4 S/cm at 30 ℃, while also modulating the polymer chain alignment and optimizing the distribution of ion-conducting channels, which facilitates efficient lithium-ion transport (with a lithium-ion transference number t_{\mathrm{L}{\mathrm{i}}^{+}} of 0.66). Furthermore, the addition of Al₂O₃ broadened the electrochemical stability window to 5 V and significantly improved the cycling stability of the electrolyte. At a discharge rate of 0.5 C, OICSE-Al₂O₃-1 retained 89.3% of its initial capacity after 200 cycles. It also demonstrates stable lithium plating/stripping behavior over 1300 h at a current density of 200 μA/cm². Moreover, this study presents an efficient, room-temperature fabrication strategy for quasi-solid-state electrolytes, extending their potential applications in advanced energy storage technologies.

Key words: quasi-solid-state electrolyte, lithium metal battery, UV-curing technology, electrochemical performance