US 12,257,632 B2
Method for making low surface area alloy particulate with high silicon content
Mark N. Obrovac, Halifax (CA); Simeng Cao, Halifax (CA); and Mina Salehabadi, Halifax (CA)
Assigned to Novonix Battery Technology Solutions Inc., Dartmouth (CA)
Filed by NOVONIX BATTERY TECHNOLOGY SOLUTIONS INC., Bedford (CA)
Filed on Apr. 13, 2022, as Appl. No. 17/719,955.
Claims priority of provisional application 63/174,757, filed on Apr. 14, 2021.
Prior Publication US 2022/0331863 A1, Oct. 20, 2022
Int. Cl. B22F 9/04 (2006.01); B22F 1/054 (2022.01); B22F 1/08 (2022.01); H01M 4/1395 (2010.01); H01M 4/38 (2006.01); H01M 10/052 (2010.01); H01M 10/44 (2006.01)
CPC B22F 9/04 (2013.01) [B22F 1/054 (2022.01); B22F 1/08 (2022.01); H01M 4/1395 (2013.01); H01M 4/386 (2013.01); H01M 10/052 (2013.01); H01M 10/44 (2013.01); B22F 2009/043 (2013.01); B22F 2201/10 (2013.01); B22F 2301/205 (2013.01); B22F 2302/45 (2013.01); B22F 2304/054 (2013.01)] 24 Claims
OG exemplary drawing
 
1. A method of making low surface area silicon alloy particles, the method comprising:
obtaining an amount of precursor particles comprising silicon;
dry ball milling the precursor particles in a first milling step to produce an amount of first milled particles having a first volumetric surface area and are amorphous silicon oxide having the formula SiOx wherein x<1;
adding an amount of binding metal particles selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, W, Mo, Nb, Y, Zr, La, Ce, and mischmetal to the amount of first milled particles to form a mixture wherein the amount of binding metal particles in the mixture is at least 10 atomic %; and
ball milling the mixture in a second milling step, thereby forming a second milled mixture, until:
the amount of first milled particles and the amount of binding metal particles have alloyed sufficiently such that the x-ray diffraction pattern comprises no crystalline peaks;
all the phases in the second milled mixture have an average grain size less than 50 nm; and
the surface area of the second milled mixture has a second volumetric surface area that is 80% or less than the first volumetric surface area;
thereby producing an amount of the low surface area silicon alloy particles with a second volumetric surface area less than 35 m2/cm3.