Fabrication of Composite Gel Electrolyte and F-Doping Carbon/Silica Anode from Electro-Spun P(VDF-HFP)/Silica Composite Nanofiber Film for Advanced Lithium-Ion Batteries.

Abstract

The aim of this work is to effectively combine the advantages of polymer and ceramic nanoparticles and improve the comprehensive performance of lithium-ion batteries (LIBs) diaphragm. A flexible film composed of electro-spun P(VDF-HFP) nanofibers covered by a layer of mesoporous silica (P(VDF-HFP)@SiO2) was synthesized via a sol-gel transcription method, then used as a scaffold to absorb organic electrolyte to make gel a electrolyte membrane (P(VDF-HFP)@SiO2-GE) for LIBs. The P(VDF-HFP)@SiO2-GE presents high electrolyte uptake (~1000 wt%), thermal stability (up to ~350 °C), ionic conductivity (~2.6 mS cm-1 at room temperature), and excellent compatibility with an active Li metal anode. Meanwhile, F-doping carbon/silica composite nanofibers (F-C@SiO2) were also produced by carbonizing the P(VDF-HFP)@SiO2 film under Ar and used to make an electrode. The assembled F-C@SiO2|P(VDF-HFP)@SiO2-GE|Li half-cell showed long-cycle stability and a higher discharge specific capacity (340 mAh g-1) than F-C@SiO2|Celgard 2325|Li half-cell (175 mAh g-1) at a current density of 0.2 A g-1 after 300 cycles, indicating a new way for designing and fabricating safer high-performance LIBs.