The dissolution of high surface area silica with tetralkylammonium hydroxides at concentrations greater than 0.2 M, produces polyanionic cage structures, [R₄N⁺][⁻OSiO_1.5]_x or Q_x, where x = 6, 8 or 10. The value x depends on the type of alkyl or alkanol group. If R = Me or Me₃NCH₂CH₂OH⁺ group (choline) x = 8 is favored. These silicate anions can be functionalized by reaction with chlorosilanes or siloxanes to produce [RSiMe₂OSiO_1.5]_x. The octafunctional molecules are 1.2–1.4 nm in diameter, each functional group occupies a different octant in Cartesian space and as such all functional groups are either orthogonal to or opposite each other. This highly symmetrical structure offers the opportunity to construct multiple kinds of materials one nanometer at a time in one, two or three dimensions. In this review, we discuss methods of synthesizing the polyanionic silicates, their transformation into octafunctional building blocks, “cubes,” and their use in formulating polyfunctional compounds and nanocomposites therefrom. Examples of tailoring global properties by tailoring the chemistries used to link cubes are given.

Ceramic electrolytes are proposed as key components in resolving challenges extant in developing next generation, high energy density Li batteries by replacing liquid electrolytes to improve safety and performance. Among numerous candidates, c-LLZO offers multiple desirable properties: high ionic conductivities (0.1–1 mS cm⁻¹), Li stability, a wide electrochemical operating window (∼6 V) and pH stability (7–11.5). However, incorporation into prototype cells has yet to be demonstrated as c-LLZO membranes at thicknesses <50 μm have not been achieved. Processing dense, thin films matching bulk counterpart properties remains a very difficult target arising from energy and/or equipment intensive sintering, Li volatilization, and contamination from substrates. We show that using metalloorganic derived flame made nanoparticles can overcome these processing challenges resulting in a significantly reduced energy input required for densification, 10–40 fold shorter dwell times at sintering temperatures, compared to common solid state reaction derived c-LLZO. Furthermore, surface/volume ratios of the films are determined to be a critical factor affecting final microstructures and phase compositions of the sintered films. Through careful control of the processing variables, 10–15 grains thick, dense (94 ± 1%) c-LLZO thin (<30 μm), flexible films with high ambient ionic conductivities (0.2 ± 0.03 mS cm⁻¹) are achieved using conventional casting–sintering of flame made nanoparticles. These c-LLZO membranes greatly increase the selection of complementary cell components and simplify battery configurations broadening opportunities for cell designs.