Considering the safety problem that is caused by liquid electrolytes and Li dendrites for lithium batteries, a new quasi-solid-state polymer electrolyte technology is presented in this work. A layer of 1,4-phenylene bridged polysilsesquioxane (PSiO) is synthesized by a sol-gel way and coated on the electrospun polyacrylonitrile (PAN) nanofiber to prepare a PAN@PSiO nanofiber composite membrane, which is then used as a quasi-solid-state electrolyte scaffold as well as separator for lithium batteries (LBs). This composite membrane, consisting of the three-dimensional network architecture of the PAN nanofiber matrix and a mesoporous PSiO coating layer, exhibited a high electrolyte intake level (297 wt%) and excellent mechanical properties. The electrochemical analysis results indicate that the ionic conductivity of the PAN@PSiO-based quasi-solid-state electrolyte membrane is 1.58 × 10−3 S cm−1 at room temperature and the electrochemical stability window reaches 4.8 V. The optimization of the electrode and the composite membrane interface leads the LiFePO4|PAN@PSiO|Li full cell to show superior cycling (capacity of 137.6 mAh g−1 at 0.2 C after 160 cycles) and excellent rate performances.

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.

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