TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Compositions: Composition comprises tetravalent silicon compound containing greater than or equal to 1 oxyanions and greater than or equal to 1 alkali cations in which compound is charge compensated by greater than or equal to 1 alkali cations and alkali cation is weakly bound and mobile. Tetravalent silicon compound is reaction product of silicon tetrachloride, sulfuric acid, and lithium amide. Composition comprises reaction product of sulfuric acid, silicon tetrachloride, and alkali metal compound, such as alkali amide, that replaces protons of sulfuric acid with alkali metal ions. Alkali amide is lithium amide (LiNH2). Molar ratio sulfuric acid: silicon is 4: greater than or equal to 1, preferably 2: greater than or equal to 1. Molar ratio alkali: silicon is 4: greater than or equal to 1, preferably 2: greater than or equal to 1. Composition comprises 1st inorganic plastic crystal electrolyte containing reaction product of sulfuric acid, silicon tetrachloride, and alkali amide and 2nd inorganic plastic crystal electrolyte containing reaction product of sulfuric acid, silicon tetrachloride, and alkali amide. Molar ratio sulfate: silicon and alkali: silicon in 1st inorganic plastic crystal electrolyte is 2: greater than or equal to 1. Molar ratio sulfate: silicon and alkali: silicon in 2nd inorganic plastic crystal electrolyte is 3: greater than or equal to 1. Preferred Processes: Sulfuric acid protons are removed sequentially as hydrochloric acid (HCl) and ammonia (NH3). The method includes centrifuging liquid mixture to yield centrifugate, combining alkali amide with centrifugate to yield inorganic plastic crystal electrolyte, homogenizing inorganic plastic crystal electrolyte, and mixing inorganic plastic crystal electrolyte with 2nd inorganic plastic crystal electrolyte to yield mixture of inorganic plastic crystal electrolytes. Preferred Forms: Composition is in the form of plastic crystal. Preferred Parameters: Conductivity of composition is greater than or equal to 10-3 Scm-1. Preferred Definitions:    A=C;    B1=Cl;    C1=sulfate;    M=Li;    x=4;    y=1-3; and    M2=Li or Na.