A fast charging/discharging all-solid-state lithium ion battery based on PEO-MIL-53(Al)-LiTFSI thin film electrolyte

Abstract

Metal–organic framework aluminum 1,4-benzenedicarboxylate (MIL-53(Al)) is used as a filler for a polyethylene oxide (PEO) based thin film electrolyte. With the participation of MIL-53(Al), the ionic conductivity of this electrolyte is increased from 9.66 × 10⁻⁴ S cm⁻¹ to 3.39 × 10⁻³ S cm⁻¹ at 120 °C and the oxidation potential is raised from 4.99 V to 5.10 V. In addition, an all-solid-state LiFePO₄/Li button battery based on the electrolyte is fabricated. At 5 C and 120 °C, the battery delivers the discharge capacity of 136.4 mA h g⁻¹ in the initial cycle, 129.2 mA h g⁻¹ in the 300^th cycle, and 83.5 mA h g⁻¹ in the 1400^th cycle. At 10 C and 120 °C, its discharge capacity is 116.2 mA h g⁻¹ in the initial cycle and 103.5 mA h g⁻¹ in the 110^th cycle. The results indicate that this metal–organic framework (MIL-53(Al)) is a novel structural modifier for solid polymer electrolytes in fast charging/discharging lithium ion batteries.