High-Performance Copolymerized Polycarbonate-Based Solid Electrolytes for Lithium Metal Batteries

Abstract

Polycarbonate-based solid electrolytes exhibit a high dielectric constant and remarkable oxidation resistance; nervertheless, their development is constrained by low room-temperature ionic conductivity and poor electrode compatibility. To overcome these challenges, a solid polymer electrolyte (PVT) was designed containing carbonate and fluorinated side chain structures through an in situ copolymerization strategy. This structure not only enhances lithium salt dissociation and ion migration but also forms a stable LiF interface on the lithium metal anode. The PVT electrolyte demonstratesa high ionic conductivity of 1.71 × 10^–4 S cm^–1 at 30 °C, surpassing that of PVE electrolyte (without F-containing chain segments, 1.23 × 10^–4 S cm^–1). The Li|PVT|Li cell can cycle for more than 1200 h at 0.1 mA cm^–2-0.1 mAh cm^–2, while the Li|PVE|Li cell operates for only 1000 h. Moreover, the capacity retention rate of Li|PVT|LFP cells remains above 80% after 200 cycles at 25 °C and 0.1C.