Aligned Hollow Silicon Nanorods Containing Ionic Liquid Enhanced Solid Polymer Electrolytes with Superior Cycling and Rate Performance.

The low lithium-ion conductivity of polyethylene oxide (PEO)-based polymer electrolytes limits their application in solid-state lithium batteries and related fields. Here, ionic liquids (ILs) are injected into hollow silicon nanorods (HSNRs) to prepare a composite solid polymer electrolyte (CSPE) with aligned HSNRs containing ILs (F-ILs@HSNRs). Applying a magnetic field promoted uniform dispersion and orientation of F-ILs@HSNRs in CSPE. The addition of F-ILs@HSNRs reduced PEO crystallinity and formed Li transport pathways at the F-ILs@HSNRs/PEO interface. Calculations and multi-physics simulations reveal that ILs within F-ILs@HSNRs contribute most to lithium-ion conduction, followed by the F-ILs@HSNRs/PEO interface. When F-ILs@HSNRs are arranged perpendicular to the electrodes, the CSPE exhibits the shortest Li migration pathways, resulting in stable and efficient lithium-ion conduction. The conductivity (2.14 × 10 S cm) and lithium-ion migration number t (0.307) are the highest, being 125 times and 184% higher, respectively, than those of PEO-LiTFSI, when compared to CSPEs with randomly arranged or parallel-aligned F-ILs@HSNRs. Furthermore, Li|CSPE|Li batteries and LiFePO|CSPE|Li batteries display stable cycling for over 2000 h, with coulombic efficiency approaching 100%. Excellent electrochemical reversibility is also confirmed in the rate performance test.