Controllable magnetic field aligned sepiolite nanowires for high ionic conductivity and high safety PEO solid polymer electrolytes

Poly (ethylene oxide) (PEO) polymer electrolyte , attracts great attention owing to its excellent flexibility, good processability and high safety compared with liquid electrolytes . However, its low ionic conductivity and weak ability to suppress the lithium dendrite severely restrict the further progress of PEO . Herein, we prepare a high ionic conductivity solid polymer electrolyte for all-solid-state lithium batteries by mixing PEO and magnetically aligned functionalized sepiolite (KFSEP) nanowires. The ionic conductivity of PEO/LiTFSI/10%⊥KFSEP solid polymer electrolyte is 2.0 × 10 −5 S cm −1 at 20 °C (The ionic conductivity of PEO/LiTFSI solid polymer electrolyte is 4.0 × 10 −7 S cm −1 at 20 °C). The experiments and simulation analysis indicate that the aligned nanowires provide a fast-moving channel for lithium ions . The capacity of Li/PEO/LiTFSI/10%⊥KFSEP/LFP cell is 130 mAh g −1 at 1.0 C under 60 °C after 450cycles. Furthermore, Li/PEO/LiTFSI/10%⊥KFSEP/LFP cell shows 150 mAh g −1 at 0.2 C under 25 °C. The Li/PEO/LiTFSI/10%⊥KFSEP/Li cell can work normally more than 600 h, indicating the high stability and lithium dendrite suppressing function of PEO/LiTFSI/10%⊥KFSEP. Overall, a high performance solid polymer electrolyte with higher safety is constructed by incorporating magnetically aligned sepiolite nanowires into PEO.