Flexible nonwoven ZrO2 ceramic membrane as an electrochemically stable and flame-resistant separator for high-power rechargeable batteries

New-generation rechargeable batteries should not only have higher energy densities and faster rate capabilities than the exisiting ones, they should also be eco-friendly, low cost and safe. One of the most critical and enduring component of rechargeable batteries, the state-of-the-art polyolefin separators fail to perform sufficiently in several battery applications, notably those requiring high current densities and elevated temperatures. Herein, we report a nonwoven ZrO2 ceramic membrane with a robust nanofiber microstructure via polymeric electrospinning followed by a high-temperature organic burn-off. The as-synthesized ZrO2 membrane shows remarkable mechanical flexibility, ample porosity, excellent electrolyte wettability and infiltration, outstanding heat and flame-resistance, and high electrochemical inertness. When tested in a lithium or sodium battery, the ZrO2 separator can withstand higher current densities and have longer cycling lives than the state-of-the-art separators. Therefore, the ZrO2 membrane shown in the current work can be represented as a promising alternative separator for a new-generation of safe, high-power batteries.