PyroGenesis filed a new patent application regarding nano Silicon:
 
NANO-SILICON PARTICLES/WIRE PRODUCTION BY ARC FURNACE FOR RECHARGEABLE BATTERIES
 
https://patentscope.wipo.int/search/fr/detail.jsf?docId=WO2021068054&_cid=P10-KNIVER-47877-1&fbclid=IwAR0Zs0Ko9sxWM6zWmIQN_IIBdJaju1_AAS_xJ9CGPoLGAR2BpE949Td_CY4
 
A process and an apparatus using pure silicon as raw material with no other pre- processed material for producing nano-Silicon and/or nano-Silicon-carbon coated composite material in the form of particles, nanowires or a combination of both, for use in a high capacity and high energy efficiency manufacturing of anodes for Lithium-ion batteries. The apparatus comprises a reactor including at least one electrode and adapted to provide at least one arc, e.g. a DC transferred arc, for melting and vaporizing silicon provided in the reactor. A quenching system is provided for delivering a gas for quenching, in the reactor, the so-produced silicon vapour so as to form nano particles and/or nano wires. The reactor is under vacuum. The gas can be injected by a vortex and/or via the electrode that is hollow. The electrode is consumable and vertically movable to control an arc voltage and to compensate for electrode erosion.

DESCRIPTION OF VARIOUS EMBODIMENTS [00081] The present subject matter relates to a process that uses pure silicon as raw material with no other pre-processed material. The arc process is proven to be scalable, knowing that the calculated specific vaporization energy of silicon is about 5 kWhr/kg which lies within the energy requirement of many different arc processes (for instance silicon smelting requires 11-13 kWhr/kg of silicon [18] compared to Siemens process 100 kWh/kg [Reference 19]).