Two-Dimensionally Aligned Vermiculite Nanoflakes with Built-In Diatomite Filler for Reversible Lithium-Ion Storage Performance

Vermiculite, a naturally occurring phyllosilicate clay mineral, has a crystalline topology characterized by two layers of cations interspersed, enabling it to maintain electrical neutrality. Expanded vermiculites have unique properties that distinguish them from other clay minerals, i.e, outstanding thermal stability and thermal insulation effectiveness. Exfoliation of vermiculite through a specific physical and chemical method, resulting in the synthesis of nanolayers with a thickness of ~1.4 nm. These nanolayers can serve as fundamental units for the creation of diverse functional materials. Ion exchange can regulate the spacing between layers and the kind or quantity of cations present in vermiculite. Additionally, the chemical processes of surface coating, grafting, or intercalation with diatomite can modify the hydrophobic/hydrophilic properties and surface groups of vermiculite nanoflakes, which significantly enhance the use of vermiculite in various domains, including energy storage, catalysis, adsorption separation, biomedicine and polymer composites. In this work, we explore a novel technique for the fabrication of 2D VCT nanosheets by incorporating diatomite into the structure using ball-milling process. This method allows for the formation of 2D DVCT with a well-maintained structural integrity, achieved by the chemical interaction between the two components. The 2D DVCT nanocomposite anode exhibited superior lithium storage capability, maintaining a capacity of around 178 mAh g-1 for 700 cycles at 100 mA g-1 and 98 mAh g-1 at 200 mA g-1. This study offers structural engineering for high capacity 2D DVCT as anode materials for LIBs with excellent rate and cycling stability.