Electrode structure having structured conductive buffer layer

Patent metadata

Field	Value
Publication number	US-10199655-B2
Application number	US-201514954510-A
Country	US
Kind code	B2
Filing date	Nov 30, 2015
Priority date	Nov 30, 2015
Publication date	Feb 5, 2019
Grant date	Feb 5, 2019

Abstract

An electrode comprises a current collector, a conductive buffer layer formed on the current collector that has at least one geometrically configured region and an active material layer formed on the conductive buffer layer. The geometrically configured conductive buffer region can expand and contract between the non-lithiated and lithiated states.

First claim

What is claimed is:

1. An electrode comprising:
a current collector having a surface;
a conductive buffer layer formed on the current collector, the conductive buffer layer having at least two sublayers in furrowed overlying relationship to the current collector and to each other, the at least two sublayers forming a plurality of discrete chambers in the conductive buffer layer; and
an active material layer formed on the conductive buffer layer opposite the current collector.

2. The electrode of claim 1 , wherein at least one first sublayer of the conductive buffer layer is a continuous elongated sheet having a plurality of discrete current collector contact regions in direct contact with the surface of the current collector and a plurality of distal regions located at spaced overlying distances from the surface of the current collector, and wherein at least one second sublayer is a continuous elongated sheet having a plurality of discrete sublayer contact regions such that discrete regions of the at least one second sublayer are in direct contact with respective distal regions of the at least one first sublayer.

3. The electrode of claim 1 , wherein at least one sublayer is an elongated sheet connected to the surface of the current collector and form a plurality of discrete chambers therebetween, and wherein the at least two sublayers form a plurality of discrete chambers therebetween.

4. The electrode of claim 1 , wherein the buffer layer is composed of at least one of carbon, graphene, metals, metal alloys, carbon composites.

5. The electrode of claim 1 , wherein the at least two sublayers are independently composed of at least one of carbon, graphene, metal, metal alloys, carbon composites.

6. The electrode of claim 1 , wherein at least a portion of the chambers contain one or more materials selected from the group consisting of silicon, tin, lithium, sodium and their compounds.

7. The electrode of claim 1 wherein the current collector one or more materials selected from the group consisting of nickel, stainless steel, copper, aluminum and carbon.

8. The electrode of claim 1 , wherein the buffer layer is at least two microns in thickness.

9. The electrode of claim 1 , wherein the active material layer comprises one or more materials selected from the group consisting of silicon, tin, lithium, sodium germanium, cobalt, manganese, nickel and their compounds, and wherein the at least two sublayers of the buffer layer flex between an expanded shape and a compressed shape.

10. The electrode of claim 9 , wherein the buffer layer has a first contact area value with the current collector when the at least two sublayers are in the expanded shape and a second contact area value when the at least two sublayers are in the compressed shape, and wherein the first contact area value is less that the second contact area value.

11. The electrode of claim 9 , wherein the at least two sublayers in the buffer layer compress when energy density enhancing materials present in the active material layer expand in volume, wherein the energy density enhancing material includes at least one of the following; silicon, tin, germanium, cobalt, manganese, nickel and their compounds.

12. A lithium ion battery comprising the electrode of claim 1 , wherein the electrode is an anode, the active material layer comprises at least one of silicon, tin, lithium, sodium and their compounds, wherein at least one first sublayer of the conductive buffer layer is a continuous elongated sheet having a plurality of discrete current collector contact regions in direct contact with the surface of the current collector and a plurality of distal regions located at spaced overlying distances from the surface of the current collector, and wherein at least one second sublayer is a continuous elongated sheet having a plurality of discrete sublayer contact regions in direct contact with respective distal regions of the at least one first sublayer.

13. The lithium ion battery of claim 12 , further comprising:
a separator in operative contact to the active material, wherein the separator has a separator flexibility value and the buffer layer has a buffer layer flexibility value, the buffer layer flexibility value greater than the separator flexibility value.

14. The lithium ion battery of claim 13 , wherein the first sublayer and the surface of the current collector form a plurality of discrete flexible chambers, and wherein the first and second sublayers form a plurality of discrete flexible chambers.

15. The lithium ion battery of claim 13 , wherein silicon, tin, lithium, sodium and their compounds are present in the active layer at a concentration that varies in response to battery function, and wherein the at least two sublayers in the buffer layer compress when the concentration of silicon or tin in the active material layer is increased.

16. The lithium ion battery of claim 13 , wherein the at least two sublayers of the buffer layer flex between an expanded shape and a compressed shape.

17. The lithium ion battery of claim 16 , wherein the buffer layer has a first contact area value with the current collector when the at least two sublayers are in the expanded shape and a second contact area value when the at least two sublayers are in the compressed shape, and wherein the first contact area value is less that the second contact area value.

Assignees

• Nissan North America Inc

Inventors

• Dale Nilesh

Classifications

• H01M4/70 Primary

  characterised by shape or form · CPC title

• H01M2004/027

  Negative electrodes · CPC title

• H01M2220/20

  Batteries in motive systems, e.g. vehicle, ship, plane · CPC title

• H01M4/382

  Lithium (H01M4/405 takes precedence) · CPC title

• H01M4/661

  Metal or alloys, e.g. alloy coatings (H01M4/669 take precedence) · CPC title