Novel Quasi Solid-State Succinonitrile-based Electrolyte with Low-flammability for Lithium-ion Battery

Quasi solid-state succinonitrile (SN)-based polymer electrolytes have emerged for lithium-metal batteries due to their excellent ion-conductivity at room temperature, wide electrochemical stability window (ESW, usually >5 V). However, the practical application of these solid SN-based polymer electrolytes is hampered by the flammability and the inherent instability of SN to Li-metal anode. In this work, solid SN-based polymer electrolytes were prepared with succinonitrile, ethoxylated trimethylolpropane triacrylate (ETPTA), triethyl phosphate (TEP) and fluoroethylene carbonate for Li-metal battery via in situ polymerization method. The SN-based polymer electrolytes with 5 wt% triethyl phosphate and FEC showed good nonflammability, superior ion-conductivity as high as 1.01×10 −3 S/cm, and wide ESW of 5.41 V. This SN-based polymer electrolyte also exhibited excellent interfacial compatibility to lithium metal anode. And it also delivered a high specific capacity of 156 mAh/g at 0.2 C at ambient temperature, and presented stable cycling at 1.0 C with a specific capacity retention of 98.4% after 1000 cycles. This work provides an alternative and simple strategy to realize the practical application of the solid-state SN-based polymer electrolyte.