Aluminum anode active material

• US 10,367,192 B2
• Filed: 04/06/2017
• Issued: 07/30/2019
• Est. Priority Date: 04/07/2016
• Status: Active Grant

• Current Assignee: StoreDot Ltd.
• Original Assignee: StoreDot Ltd.
• Inventors: Burshtain, Doron, Kedem, Nir, Aronov, Daniel
• Primary Examiner(s): Walls, Cynthia K
• Application Number:
  US15/480,911
• Publication Number:
  US 20170294644A1
• Time in Patent Office: 845 Days
• 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 2004/021 Physical characteristics, e.g. porosity, surface area
• CPC Class Codes: H01M 4/0471 involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis
• CPC Class Codes: H01M 4/134 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 4/366 as layered products
• CPC Class Codes: H01M 4/38 of elements or alloys
• CPC Class Codes: H01M 4/621 Binders
• CPC Class Codes: H01M 4/624 Electric conductive fillers
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

Improved anodes and cells are provided, which enable fast charging rates with enhanced safety due to much reduced probability of metallization of lithium on the anode, preventing dendrite growth and related risks of fire or explosion. Anodes and/or electrolytes have buffering zones for partly reducing and gradually introducing lithium ions into the anode for lithiation, to prevent lithium ion accumulation at the anode electrolyte interface and consequent metallization and dendrite growth. Various anode active materials and combinations, modifications through nanoparticles and a range of coatings which implement the improved anodes are provided.

Claims

1. An anode comprising anode active material particles which comprise aluminum particles, wherein a lithium-containing layer replaces a native oxide on the surface of the aluminum particles.

2. The anode of claim 1, wherein the lithium-containing layer comprises a buffering zone configured to receive lithium ions from an interface of the anode active material particles with an electrolyte, partially reduce the received lithium ions, and enable the partially reduced lithium ions to move into an inner zone of the anode active material particles for lithiation therein.

3. The anode of claim 1, wherein the aluminum particles are consolidated to form the anode without forming an oxidation layer on the aluminum particles.

4. The anode of claim 1, wherein the lithium-containing layer comprises any of lithium polyphosphate, lithium poly(acrylic acid), lithium carboxyl methyl cellulose, poly(lithium-4-styrenesulfonate) and lithium alginate.

5. The anode of claim 1, wherein the lithium-containing layer comprises a lithium-aluminum compound having formula Li_xAl_y.

6. The anode of claim 5, wherein the lithium-aluminum compound comprises Li₉Al₄.

14. The anode of claim 1, wherein the anode active material particles further comprise a coating by a polymer which is conductive and/or lithiated.

15. The anode of claim 14, wherein the anode active material particles are 20-500 nm in diameter and the coating is 2-200 nm thick.

16. A lithium ion cell comprising the anode of claim 1.

7. An anode comprising anode active material particles which comprise aluminum particles, wherein a layer of B₂O₃ replaces a native oxide on the surface of the aluminum particles.

8. The anode of claim 7, wherein the anode active material particles further comprise a coating by a polymer which is conductive and/or lithiated.

9. The anode of claim 8, wherein the anode active material particles are 20-500 nm in diameter and the coating is 2-200 nm thick.

10. A lithium ion cell comprising the anode of claim 7.

11. An anode for a lithium-ion device comprising an anode active material comprising aluminum nanoparticles from which a native oxide has been removed from a surface thereof and having a lithium-containing layer on the surface of the aluminum nanoparticles from which the native oxide has been removed;

said nanoparticles being consolidated, without forming an oxidation layer, with at least one additive selected from the group consisting of a particulate conductive filler, a plasticizer, and a binder, to form an anode.

12. A lithium ion energy storage device comprising a cathode, an electrolyte, a separator permeable to lithium ions, and the anode of claim 11, further comprising a current collector in contact with the anode active material.

13. The lithium ion energy storage device of claim 12, wherein the lithium aluminum compound is Li₉Al₄ and the anode comprises nanoparticles of Li₉Al₄ having a particle size in a range of 50 nm to 1 μ

m.