A high ionic conductivity composite polymer solid electrolyte based on UiO-66 modified with -NH2

Solid electrolytes offer the advantages of a wide temperature operating range, high safety, and excellent cycling stability. However, their commercialization is hindered by challenges such as low ionic conductivity, high interface impedance, and poor mechanical properties. In this study, a metal-organic framework material UiO-66 was synthesized and subsequently modified with -NH 2 and -NO 2 functional groups. The modified material was blended with poly(ethylene oxide) (PEO) to produce a composite polymer solid electrolyte, which was used to assemble a Li||Li symmetric battery. The experimental findings revealed that UiO-66-NH 2 /PEO exhibited high ionic conductivity of 6.79 × 10⁻⁴ S/cm at 60°C, a high Li + transference number of 0.49, and a wide electrochemical window of 5.1 V. Notably, its lithium-ion transference number was higher than that of UiO-66/PEO (0.27) and UiO-66-NO 2 /PEO (0.36). Moreover, UiO-66-NH 2 /PEO demonstrated improved interface compatibility and lower interface impedance, presenting a promising material option for advancing the field of all-solid-state lithium-ion batter.