A method of producing nanoparticles comprises effecting conversion of a nanoparticle precursor composition to the material of the nanoparticles. The precursor composition comprises a first precursor species containing a first ion to be incorporated into the growing nanoparticles and a separate second precursor species containing a second ion to be incorporated into the growing nanoparticles. The conversion is effected in the presence of a molecular cluster compound under conditions permitting seeding and growth of the nanoparticles.

Described herein are electrochemically active-material structures comprising silicon and one or more inert elements, chemically and/or atomically dispersed in these electrochemically active-material structures. Also described are negative battery electrodes and lithium-ion electrochemical cells comprising such electrochemically active-material structures as well as methods of fabricating such structures, electrodes, and lithium-ion electrochemical cells. Some examples of atomically-dispersed inert elements include, but are not limited to, hydrogen (H), carbon (C), nitrogen (N), and chlorine (Cl). Unlike silicon, inert elements do not interact with lithium at an operating voltage of the negative battery electrode and therefore do not contribute to the overall cell capacity. At the same time, these inert elements help to mitigate silicon swelling by operating as a mechanical buffer, support structure, and/or additional conductive pathways. Such electrochemically active-material structures can be formed by reacting (chemically or electrochemically) one or more precursors that include silicon and corresponding inert elements.

A process for gasification of solid feed material to produce a syngas includes: providing a plasma heated carbonaceous bed in a bottom section of a reactor vessel; forming a bed of deposited feed material on top of the carbonaceous bed; reacting the feed material with hot gases rising from the bottom section; forming, in a middle section of the reactor vessel, a syngas mixture containing a varying quantity of unreacted particles of the feed material; allowing the syngas mixture to rise into a top section of the reactor vessel; and at least partially quenching, by injecting a quench fluid including water, steam, or a mixture thereof, in a second, upper part of the top section, at least some of the unreacted particles sufficiently to reduce the number of unreacted particles exiting the reactor vessel that are likely to be deposited on walls of external ductwork.