Fig. 4.

Schematic representation of various “top-down” fabrication techniques for large-scale synthesis of electrode materials: a Liquid exfoliation where the sheets are sheared off by sonicating the bulk material in a liquid medium. b Mechanical exfoliation, whereby a tensile force (possibly produced by Scotch tape) can peel off the constituent layers. c Intercalant-assisted exfoliation where a metal ion (usually Li⁺) is used to intercalate into the bulk precursor in a liquid media coupled with ultrasonication, which shears the sheets apart. d Selective etching, in which an etchant (usually strong acids, e.g., HF) is used to remove one or more constituent atoms and result in the formation of sheets