An expanded clay-coated separator with unique microporous structure for enhancing electrochemical performance of rechargeable hybrid aqueous batteries

In this study, a novel composite separator for rechargeable hybrid aqueous batteries is successfully fabricated by coating porous expanded dickite aqueous slurry using polyacrylic latex as the binder on ES (Ethylene-Propylene Side By Side) nonwoven. The porous expanded dickite is prepared by intercalation and violent chemical reaction, forming porous structure with pore size of 0.3–1.2 μm. The porous morphology of the composite separators could be fine-tuned by varying the content of expanded dickite. The air permeability, porosity, electrolyte uptake, and ionic conductivity of the composite separators gradually improve with the increase of the content of expanded dickite. The improved performance of composite separators helps to improve battery performance, especially at high expanded dickite content. The composite separators with 90 wt.% expanded dickite provide superior cell performance owing to well-tailored pore structure, as compared to a commercialized absorbed glass mat (AGM).