Structured silicon particles

• US 10,103,379 B2
• Filed: 02/28/2013
• Issued: 10/16/2018
• Est. Priority Date: 02/28/2012
• Status: Active Grant

• Current Assignee: Nexeon Limited
• Original Assignee: Nexeon Limited
• Inventors: Macklin, William James, Scott, Fiona, Friend, Christopher Michael
• Primary Examiner(s): Slifka, Sarah A.
• Assistant Examiner(s): Ohara, Brian R
• Application Number:
  US14/371,822
• Publication Number:
  US 20140349183A1
• Time in Patent Office: 2,056 Days
• CPC Class Codes: A61K 47/02 Inorganic compounds
• CPC Class Codes: A61K 9/14 Particulate form, e.g. powders, Processes for size reducing of pure drugs or the resulting products, Pure drug nanoparticles microspheres A61K9/16; microcapsules A61K9/50; nanocapsules, nanoparticles of the matrix type A61K9/51
• CPC Class Codes: C01P 2002/84 by UV- or VIS- data
• CPC Class Codes: C01P 2006/40 Electric properties
• CPC Class Codes: C09C 1/28 Compounds of silicon C09C1/0009, C09C1/0015, C09C1/0078 take precedence
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 4/0404 by coating on electrode collectors
• CPC Class Codes: H01M 4/0471 involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis
• CPC Class Codes: H01M 4/13 Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
• CPC Class Codes: H01M 4/131 Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• CPC Class Codes: H01M 4/134 Electrodes based on metals, Si or alloys
• CPC Class Codes: H01M 4/136 Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
• CPC Class Codes: H01M 4/362 Composites
• CPC Class Codes: H01M 4/364 as mixtures
• CPC Class Codes: H01M 4/38 of elements or alloys
• CPC Class Codes: H01M 4/386 Silicon or alloys based on silicon
• CPC Class Codes: H01M 4/387 Tin or alloys based on tin
• CPC Class Codes: H01M 4/48 of inorganic oxides or hydroxides
• CPC Class Codes: H01M 4/58 of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
• CPC Class Codes: H01M 4/5805 Phosphides
• CPC Class Codes: H01M 4/581 : Chalcogenides or intercalation compounds thereof
• CPC Class Codes: H01M 4/5815 : Sulfides
• CPC Class Codes: H01M 4/582 : Halogenides
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries

Abstract

A composite particle is provided. The particle comprises a first particle component and a second particle component in which: (a) the first particle component comprises a body portion and a surface portion, the surface portion comprising one or more structural features and one or more voids, whereby the surface portion and body portion define together a structured particle; and (b) the second component comprises a removable filler; characterized in that (i) one or both of the body portion and the surface portion comprise an active material; and (ii) the filler is contained within one or more voids comprised within the surface portion of the first component. The use of the particle in applications such as electrochemical cells, metal-ion batteries such as secondary battery applications, lithium air batteries, flow cell batteries, fuel cells, solar cells, filters, sensors, electrical and thermal capacitors, micro-fluidic devices, gas or vapor sensors, thermal or dielectric insulating devices, devices for controlling or modifying the transmission, absorption or reflectance of light or other forms of electromagnetic radiation, chromatography or wound dressings is disclosed.

Claims

1. A composite particle comprising a first particle component and a second particle component in which:

(a) the first particle component comprises a body portion and a surface portion, the surface portion comprising one or more structural features and one or more voids, wherein the one or more structural features and the one or more voids extend between the body portion and a particle boundary of the composite particle, whereby the surface portion and body portion define together a structured porous or pillared particle; and

(b) the second particle component consists of a removable filler that is removable from the composite particle during processing;

characterised in that (i) the one or more structural features of the surface portion comprise an electroactive material comprising a member selected from the group consisting of silicon, tin, germanium, gallium, lead, zinc and aluminium;

(ii) the filler is contained around the one or more structural features and within the one or more voids comprised within the surface portion of the first particle component; and

(iii) the filler has a sublimation or disintegration temperature of at least 50°

C. and/or is soluble in an ionic liquid or an electrolyte solution.

2. The composite particle according to claim 1, wherein the filler is soluble in an electrolyte solution having a salt concentration of at least 0.7 M.

3. The composite particle according to claim 1, wherein the filler is soluble in a solution comprising a member selected from the group consisting of N-methylpyrrolidone, propylene carbonate, ethylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, gamma butyro lactone, 1,2-dimethoxy ethane, 2-methyl tetrahydrofuran, dimethyl sulphoxide, 1,3-dioxolane, formamide, dimethylformamide, acetonitrile, nitromethane, methylformate, methyl acetate, phosphoric acid trimester, trimethoxy methane, sulpholane, methyl sulpholane and 1,3-dimethyl-2-imidazolidione.

4. The composite particle according to claim 1, wherein the filler sublimes or degrades at a temperature in the range 70 to 200°

C.

5. The composite particle according to claim 1, wherein the removable filler comprises a member selected from the group consisting of o- and p-cresol, 3-nonanol, 1-methyl cyclohexanol, p-toluenenitrile, 2-methoxyphenol, 2-phenol-2-propanol, 2,3-dimethylanisole, phenol, 2,4-diemthylphenol, 3,4,4-trimethylpentanol, butanediol, oxalic acid, a surfactant and a natural wax or a synthetic wax selected from the group comprising 12-hydroxystearic acid, low molecular weight polyethylene, petroleum waxes such as paraffin wax, and microcrystalline waxes.

6. The composite particle according to claim 1, wherein the first particle component is selected from a pillared particle, a porous particle having voids distributed there through, a porous particle fragment or a fractal, or a scaffold structure.

7. The composite particle according to claim 6, wherein the first particle component is the pillared particle and wherein the surface portion comprises one or more pillars distributed over a body portion.

8. The composite particle according to claim 6, wherein the first particle component is the pillared particle and wherein the voids of the surface portion comprise channels extending from the body portion to the particle boundary.

9. The composite particle according to claim 6, wherein the first particle component is the porous particle having voids distributed there through and wherein the porous particle is a fibre, wire, thread, tube, flake, or ribbon with a minor dimension of at least 10 nm.

10. The composite particle according to claim 6, wherein the first particle component is the porous particle having voids distributed there through and further comprising voids distributed at the surface of the particle.

11. The composite particle according to claim 1, wherein the particle has a principal diameter in the range 0.5 to 10 μ

m.

12. The composite particle according to claim 1, wherein the body portion and the surface portion are formed integrally and the active material comprising the body portion is the same as or is similar to the active material of the surface portion.

13. The composite particle according to claim 1, wherein the active material of the body portion is different to the active material of the surface portion.

14. The composite particle according to claim 1, wherein the active material is an electroactive material.

15. The composite particle according to claim 1, wherein the electroactive material is silicon, a silicon alloy or an electroactive silicon compound.

16. A method of forming a composite particle according to claim 1, the method comprising steps of mixing the first particle component with the filler in liquid form.

17. The method according to claim 16, wherein the filler is provided in a solution comprising a solvent and wherein the solvent is removed by evaporation.

20. The composite particle according to claim 1, wherein the filler is soluble in an electrolyte solution having a salt concentration of between about 0.7 and about 2 M.

21. The composite particle according to claim 1, wherein the filler sublimes or degrades at a temperature in a range between about 70 and about 110°

C.

22. The composite particle according to claim 1, wherein the body portion comprises an electroactive material.

23. The composite particle according to claim 1, wherein the electroactive material comprises an electroactive alloy of a member selected from the group consisting of silicon, tin, germanium, gallium, lead, zinc, and aluminium.

24. The composite particle according to claim 1, wherein the electroactive material comprises a compound comprising a member selected from the group consisting of silicon, tin, germanium, gallium, lead, zinc, and aluminium.

18. A composite material comprising:

a composite particle, the composite particle comprising a first particle component and a second particle component in which;

(a) the first particle component comprises a body portion and a surface portion, the surface portion comprising one or more structural features and one or more voids, wherein the one or more structural features and the one or more voids extend between the body portion and a particle boundary of the composite particle, whereby the surface portion and body portion define together a structured particle; and

(b) the second particle component comprises a removable filler;

characterised in that (i) the one or more structural features of the surface portion comprise an electroactive material comprising a member selected from the group consisting of silicon, tin, germanium, gallium, lead, zinc and aluminium;

(ii) the filler is contained around the one or more structural features within one or more voids comprised within the surface portion of the first particle component; and

(iii) the filler has a sublimation or disintegration temperature of at least 50°

C. and/or is soluble in an ionic liquid or an electrolyte solution;

and a binder; and

optionally further comprising one or more components selected from an electroactive carbon, a conductive carbon and an electroactive component.

19. A composition comprising:

a stable suspension of a composite particle, the composite particle comprising a first particle component and a second particle component in which;

(a) the first particle component comprises a body portion and a surface portion, the surface portion comprising one or more structural features and one or more voids, wherein the one or more structural features and the one or more voids extend between the body portion and a particle boundary of the composite particle, whereby the surface portion and body portion define together a structured particle; and

(b) the second particle component comprises a removable filler;

characterised in that (i) the one or more structural features of the surface portion comprise an electroactive material comprising a member selected from the group consisting of silicon, tin, germanium, gallium, lead, zinc, and aluminium;

(ii) the filler is contained around the one or more structural features within one or more voids comprised within the surface portion of the first particle component; and

(iii) the filler has a sublimation or disintegration temperature of at least 50°

C. and/or is soluble in an ionic liquid or an electrolyte solution; and

wherein the stable suspension is in a liquid carrier; and

optionally wherein the removable filler includes a surfactant to maintain the composite particles in a stable suspension.