Process for preparing silicon-containing composite particles

Patent metadata

Field	Value
Publication number	US-12476237-B2
Application number	US-202118031894-A
Country	US
Kind code	B2
Filing date	Oct 22, 2021
Priority date	Oct 23, 2020
Publication date	Nov 18, 2025
Grant date	Nov 18, 2025

Abstract

Silicon-containing composite particles, the process comprising the steps of:
(a) providing a plurality of porous particles comprising micropores and/or mesopores, wherein the D 50 particle diameter of the porous particles from 0.5 to 200 μm; the total pore volume of micropores and mesopores is from 0.4 to 2.2 cm 3 /g; and the PD 50 pore diameter is no more than 30 nm; c (b) combining a charge of the porous particles with a charge of a silicon-containing precursor in a batch pressure reactor, wherein the charge of porous particles has a volume of at least 20 cm 3 per litre of reactor volume (cm 3 /L RV ), and wherein the charge of the silicon-containing precursor comprises at least 2 g of silicon per litre of reactor volume (g/L RV ); and (c) heating the reactor to a temperature effective to cause deposition of silicon in the pores of the porous particles, thereby providing the silicon-containing composite particles.

First claim

The invention claimed is:

1 . A process for preparing silicon-containing composite particles, comprising the steps of:
(a) providing a plurality of porous particles having pores comprising micropores and/or mesopores, wherein:
(i) a D50 particle diameter of the porous particles is in the range from 0.5 to 200 μm;
(ii) a total pore volume of micropores and mesopores as measured by gas adsorption is in the range from 0.4 to 2.2 cm 3 /g;
(iii) a PD50 pore diameter of the porous particles as measured by gas adsorption is no more than 30 nm;
(b) combining a charge of the porous particles with a charge of a silicon-containing precursor in a batch pressure reactor, wherein the charge of the porous particles has a volume of at least 20 cm 3 per litre of reactor volume (cm 3 /L RV ), and wherein the charge of the silicon-containing precursor comprises at least 2 g of silicon per litre of reactor volume (g/L RV ); and (c) heating the reactor to a temperature effective to cause deposition of silicon in the pores of the porous particles, thereby providing the silicon-containing composite particles.

2 . The process of claim 1 , wherein one or more porous particles are porous conductive particles.

3 . The process of claim 1 , wherein the porous particles are porous carbon particles.

4 . The process of claim 1 , wherein the porous particles have a D50 particle diameter in the range from 0.5 to 150 μm.

5 . The process of claim 1 , wherein the porous particles have a total volume of micropores and mesopores in the range from 0.45 to 2.2 cm 3 /g.

6 . The process of claim 1 , wherein the PD 50 pore diameter of the porous particles is no more than 25 nm.

7 . The process of claim 1 , wherein a volumetric ratio of micropores to mesopores is from 90:10 to 55:45.

8 . The process of claim 1 , wherein the porous particles have a BET surface area in the range from 750 m 2 /g to 4,000 m 2 /g.

9 . The process of claim 1 , wherein the silicon-containing precursor is a silicon-containing liquid or gas at 100 kPa and 20° C.

10 . The process of claim 9 , wherein the silicon-containing precursor comprises one or more of silane (SiH 4 ), disilane (Si 2 H 6 ), trisilane (Si 3 H 8 ) methylsilane, dimethylsilane and chlorosilanes.

11 . The process of claim 1 , wherein the charge of porous particles used in step (b) has a volume of at least 200 cm 3 /L RV .

12 . The process of claim 1 , wherein the charge of silicon-containing precursor used in step (b) comprises at least 5 g/L RV of silicon.

13 . The process of claim 1 , wherein the batch pressure reactor contains no oxygen gas.

14 . The process of claim 1 , wherein step (b) further comprises adding an inert padding gas to the batch pressure reactor.

15 . The process of claim 1 , wherein the batch pressure reactor of step (b) contains charges consisting of the porous particles, the silicon-containing precursor and optionally an inert padding gas or hydrogen.

16 . The process of claim 1 , wherein the mass ratio of the porous particles to the silicon-containing precursor (silicon equivalent basis) in step (b) is from 95:5 to 40:60.

17 . The process of claim 1 , wherein the temperature in step (c) is in the range from 300 to 800° C.

18 . The process of claim 1 , wherein the batch pressure reactor in step (c) has a pressure at least 200 kPa.

19 . The process of claim 1 , wherein the batch pressure reactor in step (c) has a pressure at least 700 kPa.

20 . The process of claim 1 , wherein step (c) is carried out above the silicon-containing precursor's critical pressure.

21 . The process of claim 1 , wherein step (c) is carried out below the silicon-containing precursor's critical pressure.

22 . The process of claim 1 , wherein the porous particles are agitated during step (c).

23 . The of claim 1 , wherein in step c) the reactor is heated to a temperature effective to cause deposition of silicon in pores of the porous particles and on the surface of the porous particles.

24 . The process of claim 1 , further comprising the steps of:
(d) evacuating by-product gases which are formed in step c) from the batch pressure reactor; (e) adding additional silicon-containing precursor to the batch pressure reactor, wherein the additional silicon-containing precursor gas comprises at least 2 g of silicon per litre of reactor volume (g/LRV); and (f) heating the reactor to a temperature effective to cause further deposition of silicon in the pores of the porous particles.

25 . The process of claim 24 , wherein steps (d) to (f) are repeated one or more times.

26 . The process of claim 1 , further comprising the step of:
(g) contacting the composite particles from step (c) with a passivating agent, wherein the composite particles are not exposed to oxygen prior to contact with the passivating agent.

27 . The process of claim 24 , further comprising the step of:
(h) contacting the composite particles from step (f) with a passivating agent, wherein the composite particles are not exposed to oxygen prior to contact with the passivating agent.

28 . The process of claim 1 , further comprising the steps of:
(i) combining the composite particles from step (c) with a pyrolytic carbon precursor; and (j) heating the pyrolytic carbon precursor to a temperature effective to cause the deposition of a pyrolytic conductive carbon material into the pores and/or onto an outer surface of the composite particles.

29 . The process of claim 24 , further comprising the steps of:
(k) combining the composite particles from step (f) with a pyrolytic carbon precursor; and (l) heating the pyrolytic carbon precursor to a temperature effective to cause the deposition of a pyrolytic conductive carbon material into the pores and/or onto an outer surface of the composite particles.

30 . The process of claim 26 , further comprising the steps of:
(m) combining the composite particles from step (g) with a pyrolytic carbon precursor; and (n) heating the pyrolytic carbon precursor to a temperature effective to cause the deposition of a pyrolytic conductive carbon material into the pores and/or onto an outer surface of the composite particles.

31 . The process of claim 1 , wherein the steps a)-c) are divided into process Phases 1 to 7:
Phase 1: filling the batch pressure reactor with one or more porous particles, Phase 2: charging the batch pressure reactor with one or more silicon-containing precursors, Phase 3: heating the batch pressure reactor to a target temperature, at which the silicon-containing precursor begins to decompose in the batch pressure reactor, Phase 4:decomposing the silicon-containing precursors, with deposition of silicon in pores and optionally on a surface of the porous particles, thereby providing the silicon-containing composite particles, Phase 5: cooling the batch pressure reactor, Phase 6: removing gaseous reaction products, formed in the course of the deposition, from the batch pressure reactor, Phase 7: withdrawing silicon-containing composite particles from the batch pressure reactor, wherein during Phase 4, a pressure in the batch pressure reactor increases to at least 7 bar.

32 . The process of claim 31 , wherein during Phase 4, the pressure in the batch pressure reactor changes, and

Assignees

• Wacker Chemie Ag
• Nexeon Ltd

Inventors

• Tillmann Jan
• Dräger Christoph
• Kalyakina Alena
• Kneissl Sebastian
• Renner Thomas
• Anderson Markus
• Mason Charles A
• Medrano-Catalan José
• Taylor Richard Gregory
• Whittam Joshua

Classifications

• H01M4/625

  Carbon or graphite · CPC title

• H01M4/362

  Composites · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M2004/027

  Negative electrodes · CPC title

• H01M2004/021

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