An Efficient and Stable Lithium-Oxygen Battery Based on Metal-Organic Framework Separator Operating at 160 ^°C

A lithium oxygen battery (LOB) with molten salt electrolyte operating at elevated temperature has aroused great interest because it enables fast reaction kinetics. However, there is still a lack of open literature on the separator (membrane) of this kind of LOB. Metal-organic framework (MOF) materials are widely used as components of separators in many kinds of energy storage devices, due to their regular crystalline and well-defined pore structures. In this work, a MOF material, zirconium (II) 1,4-benzenedicarboxylate after lithiation (UiO-66-SO₃Li) with a narrow pore size (6 Å), is used as a key component of the separator for LOB operating at elevated temperature. A “rolling dough” method is adopted to prepare the separator, which achieves 100% material utilization. The LOB with this membrane operates at 160 °C and delivers a specific capacity of 5.1 mAh cm⁻² with an overpotential as low as 40 mV at 0.1 mA cm⁻² and a prolonged cycle life, 180 cycles with a high coulombic efficiency of 99.9% at 0.5 mA cm⁻². This MOF-based membrane provides efficient Li⁺ transfer and restricts discharge product migration during battery operation, which is promising for the development of LOB in large-scale practical applications.