Electroactive material

• US 9,947,920 B2
• Filed: 01/18/2017
• Issued: 04/17/2018
• Est. Priority Date: 09/03/2010
• Status: Active Grant

• Current Assignee: Nexeon Limited
• Original Assignee: Nexeon Limited
• Inventors: Green, Mino
• Primary Examiner(s): Usyatinsky, Alexander
• Application Number:
  US15/409,168
• Publication Number:
  US 20170133669A1
• Time in Patent Office: 454 Days
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: C01B 33/02 Silicon forming single crystals or homogeneous polycrystalline material with defined structure C30B
• 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 10/054 Accumulators with insertion or intercalation of metals other than lithium, e.g. with magnesium or aluminium
• CPC Class Codes: H01M 10/0568 characterised by the solutes
• CPC Class Codes: H01M 2004/021 Physical characteristics, e.g. porosity, surface area
• CPC Class Codes: H01M 2004/027 Negative electrodes
• CPC Class Codes: H01M 4/0402 Methods of deposition of the material
• CPC Class Codes: H01M 4/0404 by coating on electrode collectors
• CPC Class Codes: H01M 4/134 Electrodes based on metals, Si or alloys
• CPC Class Codes: H01M 4/1395 of electrodes based on metals, Si or alloys
• 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 4/483 for non-aqueous cells H01M4/485 takes precedence
• CPC Class Codes: H01M 4/505 of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
• CPC Class Codes: H01M 4/525 of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
• 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 4/5815 : Sulfides
• CPC Class Codes: H01M 4/587 : for inserting or intercalating light metals
• CPC Class Codes: H01M 4/621 : Binders
• CPC Class Codes: H01M 4/623 : fluorinated polymers
• CPC Class Codes: H01M 4/625 : Carbon or graphite
• CPC Class Codes: H01M 4/64 : Carriers or collectors
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries
• CPC Class Codes: Y02P 70/50 : Manufacturing or production processes characterised by the final manufactured product

Abstract

A composition for use in a lithium ion battery includes a plurality of elongate elements and a plurality of particles. The elongate elements and particles each include a metal or semi-metal selected from one or more of the group including silicon, tin, germanium, aluminum or mixtures thereof. The composition may include additional ingredients such as a binder, a conductive material and a further electro-active material, such as graphite. The compositions can be used for the fabrication of electrodes, preferably anodes in the manufacture of lithium ion batteries and optionally batteries based on magnesium ions or sodium ions. The composition is able to intercalate and release lithium during the charging and discharging cycles respectively of a battery into which it has been incorporated. Methods of fabricating the composition and electrodes including the composition are included as well as electrodes thus prepared and devices including such electrodes.

Claims

1. An electrode composition comprising an electroactive material comprising a plurality of electroactive elongate elements and a plurality of electroactive particles, the elongate elements and particles each comprising a metal or semi-metal selected from one or more of the group consisting of silicon, tin and germanium or mixtures thereof, characterised in that

a. the plurality of electroactive elongate elements are selected from one or more of the group consisting of fibres, tubes, ribbons and flakes;

and

b. the plurality of electroactive particles are selected from one or more of the group consisting of pillared particles, porous particles, porous particle fragments and particles, the plurality of electroactive particles having an average diameter of 80 nm to 15 μ

m; and

c. the average diameter of the plurality of electroactive particles is more than three times larger than the average diameter of the plurality of electroactive elongate elements; and

d. the average length of the plurality of electroactive elongate elements is less than half the average diameter of the plurality of electroactive particles.

2. The composition according to claim 1, wherein the porous particles are selected from one or more of porous particles comprising a random or ordered network of linear, branched or layered elongate elements having one or more discrete or interconnected void spaces or channels defined there between or fragments thereof.

3. The composition according to claim 2, wherein the fragments comprise one or more of:

(i) peaks or troughs extending over the fragment surface;

(ii) a layered elongate element in which the elongate elements are fused together;

(iii) a branched elongate element having a diameter in the range 50 to 100 nm and branches every 100 to 400 nm; and

(iv) a substantially irregular shape and surface morphology including indentations or irregularities arising from the pores or channels or network of pores or channels originally bounded by the silicon structure.

4. The composition according to claim 1, wherein the pillared particles have an overall diameter in the range 5 to 35 μ

m.

5. A composition according to claim 1, wherein the pillared particles have a pillar length of up to 10 μ

m.

6. The composition according to claim 1, wherein the elongate elements have a diameter of at least 50 nm.

7. The composition according to claim 1, wherein the elongate elements are selected from one or more of:

a. fibres having a diameter in the range 100 to 500 nm;

b. ribbons having a thickness in the range 0.08 μ

m to 1 μ

m, a width in the range 240 nm to 300 nm, a length in the range 0.8 μ

m to 20 μ

m and an aspect ratio in the range 10;

1 to 200;

1;

c. flakes having a thickness in the range 80 nm to 100 nm, a width in the range 0.8 μ

m to 10 μ

m, a length in the range 0.8 μ

m to 20 μ

m and an aspect ratio in the range 10;

1 to 200;

1; and

d. tubes having a wall thickness in the range 0.08 μ

m to 2 μ

m, an outer wall diameter of between 2.5 and 100 times larger than the wall thickness and a length of between 10 and 500 times as large as the wall thickness.

8. The composition according to claim 1, wherein a weight ratio of the electroactive elongate elements to electroactive particles is in the range 9:

1 to 1;

9.

9. The composition according to claim 1, wherein the metal or semi-metal is a silicon comprising material selected from silicon, silicon alloy, silicon oxide, silicon nitride, silicon boride or mixtures thereof wherein optionally at least some of the elongate elements or particles comprise silicon with a purity in the range 90% to 99.95%.

10. The composition according to claim 1, which comprises 50 to 90% by weight of the electroactive material.

11. The composition according to claim 1, wherein the electroactive material comprises 40 to 100% by weight silicon comprising elongate elements, silicon comprising particles and further silicon comprising components.

12. An electrode comprising a current collector and the composition according to claim 1.

13. An electrode according to claim 12, wherein the composition further comprises one or more components selected from a binder, and a conductive material.

14. A battery comprising a cathode, an anode comprising the electrode according to claim 12 and an electrolyte.

15. A device employing a battery according to claim 14.

16. The composition of claim 1, further comprising an electroactive material other than silicon, tin and germanium or mixtures thereof.

17. The composition according to claim 1 wherein the electrode composition has a density in the range 0.3 g/cm³ to 0.9 g/cm³.

18. A method for making a composition according to claim 1, the method comprising:

providing a plurality of electroactive elongate elements selected from one or more of the group consisting of fibres, tubes, ribbons and flakes; and

providing, separately from the plurality of electroactive elongate elements, a plurality of electroactive particles selected from one or more of the group consisting of pillared particles, porous particles, porous particle fragments and particles, the plurality of electroactive particles having an average diameter of 80 nm to 15 μ

m;

mixing the plurality of electroactive elongate elements with the plurality of electroactive particles.

19. The method according to claim 18, wherein the plurality of electroactive elongate elements and the plurality of electroactive particles are mixed with one or more of a binder and a conductive material.