Electrodes for metal-ion batteries

• US 10,476,072 B2
• Filed: 12/14/2015
• Issued: 11/12/2019
• Est. Priority Date: 12/12/2014
• Status: Active Grant

• Current Assignee: Nexeon Limited
• Original Assignee: Nexeon Limited
• Inventors: Friend, Christopher, Hatazawa, Tsuyonobu
• Primary Examiner(s): Walls, Cynthia K
• Application Number:
  US15/533,633
• Publication Number:
  US 20170346079A1
• Time in Patent Office: 1,429 Days
• CPC Class Codes: H01M 2004/027 Negative electrodes
• CPC Class Codes: H01M 4/364 as mixtures
• 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 4/587 for inserting or intercalating light metals
• CPC Class Codes: H01M 4/625 Carbon or graphite
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

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.

Claims

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 D₅₀ particle diameter in a range of from 0.5 to 18 μ

m, 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 D₅₀ particle diameter in a range of from 1 to 50 μ

m,

wherein the plurality of carbon particles (ii) makes up at least 50% by weight of the active layer, and wherein a ratio of the D₅₀ particle diameter of the plurality of carbon particles (ii) to the D₅₀ 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 m²/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 D₅₀ particle diameter of the plurality of carbon particles (ii) is at least 2 μ

m and no more than 45 μ

m.

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/cm³.

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 μ

m to 2 mm.

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

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 D₅₀ particle diameter in a range of 0.5 to 18 μ

m, 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 D₅₀ particle diameter in a range of from 1 to 50 μ

m,

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 D₅₀ particle diameter of the plurality of carbon particles (ii) to the D₅₀ 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.

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

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 D₅₀ particle diameter in a range of from 0.5 to 18 μ

m, 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 D₅₀ particle diameter in a range of from 1 to 50 μ

m,

wherein the plurality of carbon particles (ii) makes up at least 50% by weigh of the active layer, and wherein a ratio of the D₅₀ particle diameter of the plurality of carbon particles (ii) to the D₅₀ 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.