Passivated silicon-carbon composite materials

Patent metadata

Field	Value
Publication number	US-12046744-B2
Application number	US-202318128921-A
Country	US
Kind code	B2
Filing date	Mar 30, 2023
Priority date	Sep 30, 2020
Publication date	Jul 23, 2024
Grant date	Jul 23, 2024

Abstract

Passivated silicon-carbon composite materials and related processes are disclosed that overcome the challenges for providing amorphous nano-sized silicon entrained within porous carbon. Compared to other, inferior materials and processes described in the prior art, the materials and processes disclosed herein find superior utility in various applications, including energy storage devices such as lithium ion batteries.

First claim

The invention claimed is:

1. A passivated silicon-carbon composite, comprising:
a) a porous carbon scaffold comprising a pore volume, wherein the pore volume comprises greater than 70% microporosity;
b) silicon domains that are impregnated into the pore volume of the porous carbon scaffold;
c) a carbonaceous layer at least partially covering the silicon domains; and
d) a plurality of layers of passive silicon located below a terminally passivated silicon surface, wherein the plurality of layers of the passive silicon are formed by alternating a process gas comprising silicon and a passivation gas to thereby react the passivation gas with a surface functional group of the silicon, such that oxygen content is layered with the passive silicon that is impregnated into the pore volume of the porous carbon scaffold,
and wherein a Z of less than 10, wherein Z=1.875×[(M1100−M)/M1100]×100, wherein M1100 is a mass of the passivated silicon-carbon composite at 1100° C. and M is a minimum mass of the passivated silicon-carbon composite between 800° C. and 1100° C. when the passivated silicon-carbon composite is heated under air from about 25° C. to about 1100° C., as determined by thermogravimetric analysis.

2. The composite of claim 1 , wherein the passivated silicon-carbon composite comprises a silicon content of 30% to 60% by weight.

3. The composite of claim 1 , wherein the passivated silicon-carbon composite comprises a Dv50 between 5 nm and 20 microns.

4. The composite of claim 1 , wherein the passivated silicon-carbon composite comprises a φ of greater than or equal to 0.1, wherein φ=(Max peak height dQ/dV in Regime I)/(Max peak height dQ/dV in Regime III), wherein dQ/dV is measured in a half-cell coin cell, and Regime I is 0.8V−0.4V and Regime III is 0.15V−0V 1.

5. The composite of claim 1 , wherein the passivated silicon-carbon composite comprises a surface area less than 30 m 2 /g.

6. The composite of claim 1 , wherein the passivated silicon-carbon composite comprises a surface area less than 10 m 2 /g.

7. The passivated silicon-carbon composite of claim 1 , wherein a mole ratio of oxygen to silicon is less than 0.5 mol/mol.

8. The passivated silicon-carbon composite of claim 7 , wherein the mole ratio of oxygen to silicon increases less than 0.01 mol/mol/day when exposed to 25° C. in the presence of air.

9. The passivated silicon-carbon composite of claim 7 , wherein the passivated silicon-carbon composite gasses less than 0.005 mol/mol silicon/h in an aqueous suspension at 45° C.

Assignees

• Group14 Technologies Inc

Inventors

• Costantino Henry R
• Sakshaug Avery J
• Dhanabalan Abirami
• Timmons Christopher
• Feaver Aaron M

Classifications

• H01M2004/021

  Physical characteristics, e.g. porosity, surface area · CPC title

• H01M4/362

  Composites · CPC title

• H01M4/0428

  Chemical vapour deposition · CPC title

• C23C16/45523

  Pulsed gas flow or change of composition over time · CPC title

• C23C16/4417

  Methods specially adapted for coating powder · CPC title