Electrodes for metal-ion batteries

Patent metadata

Field	Value
Publication number	US-10476072-B2
Application number	US-201515533633-A
Country	US
Kind code	B2
Filing date	Dec 14, 2015
Priority date	Dec 12, 2014
Publication date	Nov 12, 2019
Grant date	Nov 12, 2019

Abstract

An electrode for a metal-ion battery is provided wherein the active layer of the electrode comprises a plurality of porous particles comprising an electroactive material selected from silicon, germanium, tin, aluminium and mixtures thereof and a plurality of carbon particles selected from one or more of graphite, soft carbon and hard carbon. The ratio of the D50 particles size of the carbon particles to the D50 particle diameter of the porous particles is in the range of from 1.5 to 30. Also provided are rechargeable metal-ion batteries comprising said electrode and compositions of porous particles and carbon particles which may be used to prepare the active layer of said electrode.

First claim

The invention claimed is:

1. An electrode for a metal-ion battery, the electrode comprising an active layer in electrical contact with a current collector, wherein the active layer comprises:
(i) a plurality of porous particles comprising at least 60 wt % of an electroactive material selected from the group consisting of silicon, germanium, tin, aluminium and mixtures thereof, wherein the plurality of porous particles has a D 50 particle diameter in a range of from 0.5 to 18 μm, and an intra-particle porosity in a range of from 30 to 90%; and
(ii) a plurality of carbon particles selected from the group consisting of graphite, soft carbon, hard carbon and mixtures thereof, wherein the plurality of carbon particles has a D 50 particle diameter in a range of from 1 to 50 μm,

wherein the plurality of carbon particles (ii) makes up at least 50% by weight of the active layer, and wherein a ratio of the D 50 particle diameter of the plurality of carbon particles (ii) to the D 50 particle diameter of the plurality of porous particles (i) is in a range of from 1.5 to 30.

2. An electrode according to claim 1 , wherein the plurality of porous particles (i) comprises at least 60 wt % silicon or tin.

3. An electrode according to claim 1 , wherein the plurality of porous particles (i) comprises at least 0.01 wt % of at least one of aluminium and germanium.

4. An electrode according to claim 1 , wherein the plurality of porous particles (i) comprises a minor amount of one or more additional elements selected from the group consisting of antimony, copper, magnesium, zinc, manganese, chromium, cobalt, molybdenum, nickel, beryllium, zirconium, iron, sodium, strontium, phosphorus, tin, ruthenium, gold, silver, and oxides thereof.

5. An electrode according to claim 1 , wherein the plurality of porous particles (i) has a particle size distribution span of 5 or less.

6. An electrode according to claim 1 , wherein an average aspect ratio of the plurality of porous particles (i) is less than 3:1.

7. An electrode according to claim 1 , wherein the plurality of porous particles (i) are spheroidal particles having an average sphericity (S av ) of at least 0.70.

8. An electrode according to claim 1 , wherein the intra-particle porosity of the plurality of porous particles (i) is in a range of from 35 to 90%.

9. An electrode according to claim 8 , wherein the intra-particle porosity of the plurality of porous particles (i) is in a range of from 40 to 90%.

10. An electrode according to claim 1 , wherein the plurality of porous particles (i) has a pore diameter distribution having at least one peak at a pore size of less than 350 nm, as determined by mercury porosimetry.

11. An electrode according to claim 1 , wherein the plurality of porous particles (i) has a pore diameter distribution having at least one peak at a pore size of more than 50 nm, as determined by mercury porosimetry.

12. An electrode according to claim 1 , wherein the plurality of porous particles (i) has a BET surface area of less than 300 m 2 /g.

13. An electrode according to claim 1 , wherein the plurality of carbon particles (ii) is a plurality of graphite particles.

14. An electrode according to claim 1 , wherein the D 50 particle diameter of the plurality of carbon particles (ii) is at least 2 μm and no more than 45 μm.

15. An electrode according to claim 1 , wherein the plurality of porous particles (i) makes up from 1 to 30 wt % of the active layer.

16. An electrode according to claim 1 , wherein the active layer has an inter-particle porosity of at least 2% and no more than 30%.

17. An electrode according to claim 1 , wherein the active layer has a density in a range of from 1 to 2 g/cm 3 .

18. An electrode according to claim 1 , wherein a percent average cross-sectional area of the active layer occupied by the plurality of porous particles (i) is in a range of from 1% to 25%.

19. An electrode according to claim 1 , wherein a percent average cross-sectional area of the active layer occupied by inter-particle pores of the active layer is in a range of from 2% to 30%.

20. An electrode according to claim 1 , wherein the active layer comprises at least one of a binder and one or more conductive additives.

21. An electrode according to claim 1 , wherein the active layer has a thickness in a range of from 15 μm to 2 mm.

22. An electrode composition comprising:
(i) a plurality of porous particles comprising at least 60 wt % of an electroactive material selected from the group consisting of silicon, germanium, tin, aluminium and mixtures thereof, wherein the plurality of porous particles has a D 50 particle diameter in a range of 0.5 to 18 μm, and an intra-particle porosity in a range of from 30 to 90%; and
(ii) a plurality of carbon particles selected from the group consisting of graphite, soft carbon, hard carbon and mixtures thereof, wherein the plurality of carbon particles has a D 50 particle diameter in a range of from 1 to 50 μm,
wherein the plurality of carbon particles makes up at least 50% by weight of the electrode composition, based on solids content of the electrode composition, and wherein a ratio of the D 50 particle diameter of the plurality of carbon particles (ii) to the D 50 particle diameter of the plurality of porous particles (i) is in a range of from 1.5 to 30.

23. An electrode composition according to claim 22 , wherein the plurality of porous particles (i) makes up at least 1 wt % and no more than 30 wt % of the electrode composition, based on the solids content of the electrode composition.

24. An electrode composition according to claim 22 , comprising at least one of a binder and one or more conductive additives.

25. An electrode composition according to claim 22 , in the form of a slurry, wherein the electrode composition further comprises a solvent.

26. A rechargeable metal-ion battery comprising:
(i) an anode, wherein the anode comprises an electrode, wherein the electrode comprises an active layer in electrical contact with a current collector, wherein the active layer comprises:
(a) a plurality of porous particles comprising at least 60 wt % of an electroactive material selected from the group consisting of silicon, germanium, tin, aluminium and mixtures thereof, wherein the plurality of porous particles has a D 50 particle diameter in a range of from 0.5 to 18 μm, and an intra-particle porosity in a range of from 30 to 90%; and
(b) a plurality of carbon particles selected from the group consisting of graphite, soft carbon, hard carbon and mixtures thereof, wherein the plurality of carbon particles has a D 50 particle diameter in a range of from 1 to 50 μm,
wherein the plurality of carbon particles (ii) makes up at least 50% by weigh of the active layer, and wherein a ratio of the D 50 particle diameter of the plurality of carbon particles (ii) to the D 50 particle diameter of the plurality of porous particles (i) is in a range of from 1.5 to 30;

(ii) a cathode comprising a cathode active material capable of releasing and reabsorbing metal ions; and
(iii) an electrolyte between the anode and the cathode.

27. An electrode according to claim 1 , wherein the electroactive material is silicon.

28. An electrode composition according to claim 22 , wherein the electroactive material is silicon.

Assignees

• Nexeon Ltd

Inventors

• Friend Christopher
• Hatazawa Tsuyonobu

Classifications

• H01M4/587

  for inserting or intercalating light metals · CPC title

• H01M4/583

  Carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title

• H01M10/0525

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

• H01M4/1395

  of electrodes based on metals, Si or alloys · CPC title

• H01M4/386

  Silicon or alloys based on silicon · CPC title