Core-Shell Composites for Sulfur-Based Cathodes in Metal-Ion Batteries

• US 20130224594A1
• Filed: 02/25/2013
• Published: 08/29/2013
• Est. Priority Date: 02/28/2012
• Status: Active Grant

• Current Assignee: Sila Nanotechnologies Inc.
• Original Assignee: Sila Nanotechnologies Inc.
• Inventors: Yushin, Gleb Nikolayevich, Zdyrko, Bogdan, Luzinov, Igor, Svoboda, Vojtech, Jacobs, Alexander Thomas, Berdichevsky, Eugene Michael
• Granted Patent: US 8,932,764 B2
• Time in Patent Office: Days
• US Class Current: 429/218.1
• 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 2004/028 Positive electrodes
• CPC Class Codes: H01M 4/0421 involving vapour deposition
• 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 4/1397 of electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
• CPC Class Codes: H01M 4/366 as layered products
• CPC Class Codes: H01M 4/38 of elements or alloys
• CPC Class Codes: H01M 4/5815 Sulfides
• CPC Class Codes: H01M 4/5825 Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines
• CPC Class Codes: H01M 4/625 Carbon or graphite
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A battery cathode electrode composition is provided comprising core-shell composites. Each of the composites may comprise a sulfur-based core and a multi-functional shell. The sulfur-based core is provided to electrochemically react with metal ions during battery operation to store the metal ions in the form of a corresponding metal-sulfide during discharging or charging of the battery and to release the metal ions from the corresponding metal-sulfide during charging or discharging of the battery. The multi-functional shell at least partially encases the sulfur-based core and is formed from a material that is (i) substantially permeable to the metal ions of the corresponding metal-sulfide and (ii) substantially impermeable to electrolyte solvent molecules and metal polysulfides.

Claims

1. A battery electrode composition comprising core-shell composites, each of the composites comprising:

a sulfur-based core provided to electrochemically react with metal ions during battery operation to store the metal ions in the form of a corresponding metal-sulfide during discharging or charging of the battery and to release the metal ions from the corresponding metal-sulfide during charging or discharging of the battery; and

a multi-functional shell at least partially encasing the sulfur-based core, the shell being formed from a material that is (i) substantially permeable to the metal ions of the corresponding metal-sulfide and (ii) substantially impermeable to electrolyte solvent molecules and metal polysulfides.

2. The battery electrode composition of claim 1, wherein at least a portion of the composites are formed with a substantially spherical, particle morphology of the core and shell.

3. The battery electrode composition of claim 1, wherein at least a portion of the composites are formed with a substantially planar, flake morphology of the core and shell.

4. The battery electrode composition of claim 3, wherein at least a portion of the substantially planar, flake morphology composites are aggregated together into a three-dimensional agglomeration.

5. The battery electrode composition of claim 1, wherein at least a portion of the composites are formed with external open channel pores extending from an outer edge of the composite towards the core and providing channels for faster diffusion of the metal ions from outside of the composite into the core by reducing the average diffusion distance of the metal ions within the composite, and wherein the open channel pores are formed external to the shell in relation to the core.

6. The battery electrode composition of claim 1, wherein at least a portion of the composites have electrically interconnected sulfur-based cores such that at least one layer of their corresponding shells only partially encases the interconnected sulfur-based cores in such a way that the electrical interconnectivity is maintained between the individual sulfur-based cores and the at least one layer substantially conformally covers a majority of the interconnected cores.

7. The battery electrode composition of claim 1, wherein the sulfur-based core comprises pores mixed in with a sulfur material.

8. The battery electrode composition of claim 1, wherein the sulfur-based core comprises conductive carbon provided to enhance electrical conductivity of the sulfur-based core.

9. The battery electrode composition of claim 8, wherein the conductive carbon is provided in the form of carbon nanoflake(s), graphene segment(s), multi-layered graphene segment(s), graphite ribbon(s), carbon nanotube(s), nanostructured dendritic carbon, nanoporous carbon, carbon black particle(s), carbon onion particle(s), fullerene(s), and/or carbon nanofiber(s).

10. The battery electrode composition of claim 1, wherein the sulfur-based core comprises a dense metal-sulfide.

11. The battery electrode composition of claim 10, wherein the metal-sulfide comprises individual nano-sized or micro-sized grains of metal-sulfide linked together with a metal-ion-conductive material.

12. The battery electrode composition of claim 10, wherein the sulfur-based core further comprises conductive carbon provided in the form of carbon nanoflake(s), graphene segment(s), multi-layered graphene segment(s), graphite ribbon(s), carbon nanotube(s), nanostructured dendritic carbon, nanoporous carbon, carbon black particle(s), carbon onion particle(s), fullerene(s), and/or carbon nanofiber(s).

13. The battery electrode composition of claim 1, wherein the material from which the multi-functional shell is formed comprises at least one material selected from the group consisting of (i) a metal-ion-conductive ceramic coating, (ii) a polymer coating, (iii) an electrically-conductive carbon coating, and (iv) a semiconductor coating.

14. The battery electrode composition of claim 13, wherein the material from which the multi-functional shell is formed comprises a composite coating of two or more materials selected from the group.

15. The battery electrode composition of claim 14, wherein the composite coating materials are arranged in an interpenetrating configuration such that at least two of the composite coating materials contact the sulfur-based core.

16. The battery electrode composition of claim 14, wherein the composite coating materials are arranged in a layered configuration such that at least one of the composite coating materials does not contact the sulfur-based core.

17. The battery electrode composition of claim 1, wherein the material from which the multi-functional shell is formed comprises at least one material selected to electrochemically react with metal ions during battery operation to store the metal ions in the shell during discharging or charging of the battery and to release the metal ions from the shell during charging or discharging of the battery.

18. The battery electrode composition of claim 1, wherein the material from which the shell is formed remains (i) substantially permeable to the metal ions of the corresponding metal-sulfide and (ii) substantially impermeable to electrolyte solvent molecules and metal polysulfides during battery operation.

19. A battery comprising the battery electrode composition of claim 1.

20. A method of producing a battery electrode composition, comprising:

forming a sulfur-based core for electrochemically reacting with metal ions during battery operation, whereby the electrochemical reaction stores the metal ions in the form of a corresponding metal-sulfide during discharging or charging of the battery and releases the metal ions from the corresponding metal-sulfide during charging or discharging of the battery; and

at least partially encasing the sulfur-based core with a multi-functional shell to form core-shell composites, the shell being formed from a material that is (i) substantially permeable to the metal ions of the corresponding metal-sulfide and (ii) substantially impermeable to electrolyte solvent molecules and metal polysulfides.

21. The method of claim 20, further comprising:

dispersing core-shell composites in a binder solution;

applying the dispersion of core-shell composites to a conductive metal substrate; and

air or vacuum drying the metal substrate to yield a substantially uniform coating of core-shell composites bonded with a binder on the metal substrate.

22. The method of claim 20, further comprising:

dispersing core particles in a binder solution;

applying the dispersion of core composites to a conductive metal substrate;

air or vacuum drying the metal substrate to yield a substantially uniform coating of core particles bonded with a binder on the metal substrate; and

depositing the multi-functional shell in a substantially conformal coating to at least partially encase the sulfur-based cores and form the core-shell composites.

23. The method of claim 20, wherein the at least partially encasing comprises depositing the multi-functional shell by a vapor deposition method selected from the group consisting of chemical vapor deposition, atomic layer deposition, and thermal decomposition of precursor molecules in a gas phase.