Device and method of forming a device

Patent metadata

Field	Value
Publication number	US-10008716-B2
Application number	US-201314436186-A
Country	US
Kind code	B2
Filing date	Oct 31, 2013
Priority date	Nov 2, 2012
Publication date	Jun 26, 2018
Grant date	Jun 26, 2018

Abstract

A multilayer electrode suitable for use in a secondary battery is disclosed. The major active component of one layer is different to a major active component of an adjacent layer. The use of layered electrodes improves both the capacity retention and cycle life of batteries including such layered electrodes.

First claim

The invention claimed is:

1. A multilayer electrode comprising, in sequence, a conductive layer, a first composite electrode layer and a second composite electrode layer, each composite electrode layer comprising a particulate material suitable for use as an active material in a metal ion battery and a binder, wherein a major component of the active material of the first composite electrode layer (first major active component) is an active carbon and a major component of the active material of the second composite electrode layer (second major active component) is selected from the group consisting of silicon and tin, and wherein
the binder of the first composite electrode layer is polyvinylidene fluoride (PVDF), or a polyimide (PI), or a mixture of PVDF and PI, and
the binder of the second composite electrode layer is (i) polyacrylic acid (PAA) or a salt thereof, or (ii) carboxymethylcellulose (CMC) or a salt thereof, or (iii) styrene butadiene rubber (SBR), or (iv) a binary or tertiary mixture of two or more of (i), (ii), and (iii).

2. The multilayer electrode according to claim 1 , which comprises an interface between the first composite layer and the second composite layer.

3. The multilayer electrode according to claim 1 , wherein each composite electrode layer comprises one or more sub-layers, optionally wherein a concentration of the major active component of one sub-layer differs from a concentration of a major active component in an adjacent sub-layer within a composite layer of the multilayer electrode.

4. The multilayer electrode according to claim 3 , wherein a concentration of the first major active component decreases between a current collector and an interface with the second composite electrode layer, and/or wherein a concentration of the second major active component decreases in a direction between an interface with the first composite electrode layer and an upper surface of the second composite electrode layer.

5. The multilayer electrode according to claim 3 , wherein a porosity of the first composite electrode layer is different to a porosity of the second composite electrode layer, optionally wherein the porosity of the first composite electrode layer is less than the porosity of the second composite electrode layer.

6. The multilayer electrode according to claim 3 , wherein a porosity of the first composite electrode layer is greater than 5 vol % and less than 30 vol %, optionally 20 to 25 vol %; and/or wherein a porosity of the first composite electrode layer is less than 30 vol % and less than 80 vol %, optionally 30 to 70 vol %.

7. The multilayer electrode according to claim 1 , wherein doped or undoped silicon is the major active component of the second composite electrode layer.

8. The multilayer electrode according to claim 1 , wherein a concentration of the major active component in the first composite anode layer is higher than a concentration of the major active component in the second composite anode layer.

9. The multilayer electrode according to claim 1 , wherein the second composite electrode layer contains no more than 20 grams per square meter of the major active component of that layer, and/or wherein the first composite electrode layer contains at least 30 grams per square meter of the major active component of that layer.

10. The multilayer electrode according to claim 1 , wherein the active carbon is selected from one or more of hard carbon, carbon nano-tubes and graphite.

11. The multilayer electrode according to claim 1 , wherein active carbon is the only active component of the first composite electrode layer, and/or wherein doped or undoped silicon is the only active component of the second composite electrode layer.

12. The multilayer electrode according to claim 1 , wherein the second composite electrode layer further comprises an active carbon material.

13. The multilayer electrode according to claim 1 , wherein one or more of the composite electrode layers further comprises a conductive particulate additive.

14. A metal ion battery comprising:
an anode according to claim 1 ;
a cathode providing a source of metal ions; and
an electrolyte between the anode and the cathode.

15. The multilayer electrode according to claim 10 , wherein the graphite is natural or synthetic graphite selected from flakes, meso-carbon micro-beads and massive artificial graphite.

16. The multilayer electrode according to claim 1 , wherein the particulate material of the second composite electrode layer comprises a silicon-containing particulate material.

17. The multilayer electrode according to claim 16 , wherein the silicon-containing particulate material comprises flakes, particles, fibres, ribbons, scaffold structures or tubes.

18. The multilayer electrode according to claim 17 , wherein the particles comprise native particles, pillared particles, porous particles, porous particle fragments and mixtures thereof.

Assignees

• Nexeon Ltd

Inventors

• Abdelsalam Mamdouh
• Coowar Fazil
• Macklin William

Classifications

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M4/0428

  Chemical vapour deposition · CPC title

• H01M4/625

  Carbon or graphite · CPC title

• H01M4/587

  for inserting or intercalating light metals · CPC title

• H01M4/386

  Silicon or alloys based on silicon · CPC title