Polymer Template Synthesis of Soft, Light, and Robust Oxide Ceramic Films

Oxide ceramic materials underpin a wide variety of technologies. However, the inherent fragility of these materials limits their use in emerging fields like wearable electronics and soft energy storage devices. Here, we develop a sol-gel electrospinning technique followed by calcination to create a range of oxide ceramic nanofiber films that exhibit significant softness without fragility after various deformations. This approach causes the ceramic crystals to fuse together at a low temperature during their growth within the polymer nanofiber templates. All the synthesized ceramic films, from SiO₂ to BaTiO₃, Li_0.33La_0.56TiO₃, and Li₇La₃Zr₂O₁₂, have silk-like softness of <31 mN, low density of <0.36 g/cm³ and robust fire resistance to 1,000°C. Fabricated separators based on these films display large electrolyte uptakes of >900% and high thermal insulation performance, enhancing the rate capability and safety of lithium batteries. The reported method allows scalable synthesis of soft oxide ceramic films with properties appealing for applications.