Porous separators are key components for lithium-ion batteries (LIBs) and they have drawn considerable attention because of their vital role in governing battery cost and performance (e.g., power density, safety, and longevity). Here, zirconia-coated separators were fabricated via a facile biomineralization process with the aim to improve the performance of commercialized polypropylene separators. The as-prepared organic-inorganic composite separators show excellent thermal stability, even at the melting temperature (160 °C) of polypropylene. This is due to the well-distributed zirconia coatings on the separator surfaces. Furthermore, the interfacial impedance of the composite separators is only 343.8 Ω, which is four times lower than the pristine polypropylene ones. The results demonstrate an attractive method to prepare organic-inorganic composite separators with outstanding properties, which makes them promising candidates for high-performance LIBs.
Keywords: lithium-ion battery; polydopamine; polyolefin separators; thermal stability; zirconia coating.