https://pvbuzz.com/silicon-battery-technology/

Note this gem.....found in the article....

These current manufacturing methods for silicon metal nanopowders are expensive, not very scalable and not commercially feasible.

A recently proven Carbothermic process (patent pending) called the PUREVAP™ Quartz Reduction Reactor (QRR) Project has successfully produced transformed and purified quartz into high purity silicon metal (4N+ Si) in one step.

Engineering plans have been finalized that will upgrade HPQ Silicon’s PUREVAP™ QRR into a PUREVAP™ reactor. The reactor would enable the low-cost transformation of melted silicon metal into spherical nanopowders and nanowires.