TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Composition: The nanoscale silicon comprises crystalline nanoparticles having average particle size of 250 nm or less. The silicon comprises highly-porous nanostructured silicon. The silicon-silicon oxide-carbon composite composition contains 45-80 wt.% nanosilicon, and further contains inert metal coating. The anode material contains 40-85 wt.% elemental silicon, and further contains silicon-oxide-carbon composite formed by pyrolysis of organic silicon oxide precursor. The active material comprises 0.5-15 wt.% inert metal coating. The particulate metal comprises magnesium. Alternately, silicon-silicon oxide-carbon composite material comprises nanoscale silicon embedded within silicon oxide-carbon matrix material having discharge specific capacity of 1000 mAh/g or more at rate of C/20 and 50-cycle discharge specific capacity of 90% or more of 5-cycle discharge capacity when discharged at rate of C/3 from 1.5-0.005 V against lithium. The nanoscale silicon comprises silicon nanoparticles. Preferred Process: The metal coating is formed by adding reducing agent to dispersion of composite material and dissolved metal salt. During formation of nanostructured elemental silicon, silicon precursor material is precipitated from solution comprising metal powder mixed with dissolved silicon precursor material to form crosslinked silicon composition, and reduction product is etched with acid to dissolve and remove magnesium oxide. Preferred Properties: The silicon-silicon oxide-carbon composite composition has BET surface area of 30 m2/g ok more, specific capacity of 850 mAh/g or more at discharge rate of C/3 when discharged at room temperature from 1.5-0.005 V against lithium metal, and specific capacity of 750 mAh/g or more at discharge rate of C/3 at 50 cycle when discharged at room temperature from 1.5-0.005V against lithium metal.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Composition: The tetraalkoxysilane is tetraethoxysilane. The alkylalkoxysilane is dimethyldiethoxysilane, diphenyldimethoxysilane and/or trimethylmethoxysilane.    TECHNOLOGY FOCUS - POLYMERS - Preferred Process: The silicon oxide-carbon matrix is formed from pyrolysis of sol-gel precursor or precursor material comprising crosslinked polysiloxane polymer. The silicon oxide-carbon matrix material is synthesized from pyrolysis of highly-crosslinked polysiloxane polymer. Preferred Composition: The matrix of crosslinked silicon comprises polysiloxane polymer, or silicate.