Anode electrode composition of li-ion battery cell

Patent metadata

Field	Value
Publication number	US-2019123339-A1
Application number	US-201816164704-A
Country	US
Kind code	A1
Filing date	Oct 18, 2018
Priority date	Oct 19, 2017
Publication date	Apr 25, 2019
Grant date	—

Abstract

In an embodiment, a Li-ion battery cell comprises an anode electrode with an electrode coating that (1) comprises Si-comprising active material particles, (2) exhibits an areal capacity loading in the range of about 3 mAh/cm 2 to about 12 mAh/cm 2 , (3) exhibits a volumetric capacity in the range from about 600 mAh/cc to about 1800 mAh/cc in a charged state of the cell, (4) comprises conductive additive material particles, and (5) comprises a polymer binder that is configured to bind the Si-comprising active material particles and the conductive additive material particles together to stabilize the anode electrode against volume expansion during the one or more charge-discharge cycles of the battery cell while maintaining the electrical connection between the metal current collector and the Si-comprising active material particles.

First claim

1 . A Li-ion battery cell, comprising:
anode and cathode electrodes; an electrolyte ionically coupling the anode electrode and the cathode electrode; and a separator electrically separating the anode electrode and the cathode electrode, wherein the anode electrode comprises a metal current collector and an electrode coating, wherein the electrode coating:
(1) comprises Si-comprising active material particles that exhibit an average particle size in the range from about 0.2 microns to about 10 microns and exhibit a volume expansion in the range of about 8 vol. % to about 180 vol. % during one or more charge-discharge cycles of the Li-ion battery cell,
(2) exhibits an areal capacity loading in the range of about 3 mAh/cm 2 to about 12 mAh/cm 2 ,
(3) exhibits a volumetric capacity in the range from about 600 mAh/cc to about 1800 mAh/cc in a charged state of the Li-ion battery cell,
(4) comprises conductive additive material particles, and
(5) comprises a polymer binder that is configured to bind the Si-comprising active material particles and the conductive additive material particles together to stabilize the anode electrode against the volume expansion during the one or more charge-discharge cycles of the Li-ion battery cell while maintaining an electrical connection between the metal current collector and the Si-comprising active material particles.

2 . The Li-ion battery cell of claim 1 , wherein at least a portion of the polymer binder is chemically bonded to at least a portion of the Si-comprising active material particles

3 . The Li-ion battery cell of claim 2 , wherein the chemical bonding is formed prior to the electrode coating being arranged on the metal current collector.

4 . The Li-ion battery cell of claim 1 , wherein at least a portion of the polymer binder is deposited on one or more surfaces of the Si-comprising active material particles by chemical vapor deposition (CVD).

5 . The Li-ion battery cell of claim 1 , wherein the polymer binder covers less than about 75% of an external surface area of the Si-comprising active material particles in the electrode coating with an average thickness of more than about 5 nm.

6 . The Li-ion battery cell of claim 5 , wherein the polymer binder comprises nanofibers.

7 . The Li-ion battery cell of claim 1 , wherein the electrode coating is casted from an aqueous suspension.

8 . The Li-ion battery cell of claim 1 , wherein the metal current collector includes roll-thinned metal foils.

9 . The Li-ion battery cell of claim 8 , wherein the roll-thinned metal foils are configured to sustain mechanical elongation of at least about 1% prior to fracture.

10 . The Li-ion battery cell of claim 8 , wherein the roll-thinned metal foils comprise crystalline grains elongated in an area parallel to a foil surface and exhibit an average grain size in the range from about 0.4 micron to about 400 microns.

11 . The Li-ion battery cell of claim 8 , wherein the metal current collector that comprises the roll-thinned metal foils exhibit surface roughness features in the range from about 20 nm to about 10,000 nm.

12 . The Li-ion battery cell of claim 8 , wherein the roll-thinned metal foils are perforated.

13 . The Li-ion battery cell of claim 8 , wherein at least a portion of the roll-thinned metal foil is chemically bonded to the polymer binder in the anode electrode or an interlayer located between the roll-thinned metal foils and an active electrode layer

14 . The Li-ion battery cell of claim 1 ,
wherein the conductive additive material comprises carbon nanotubes or carbon nanofibers, and wherein a total content of the conductive additive material is below about 5 wt. % of the electrode coating and/or below about 5 vol. % of the electrode coating.

15 . The metal-ion battery cell of claim 14 , wherein a total weight of all inactive components in the electrode coating is in the range between about 2.0 wt % and 8.0 wt. % of the electrode coating.

16 . The Li-ion battery cell of claim 14 , wherein the conductive additive material is chemically bonded to the Si-comprising active material particles either by using chemically bonded polymer binders or by growing the conductive additive material directly on surfaces of the Si-comprising active material particles.

17 . The Li-ion battery cell of claim 14 ,
wherein the conductive additive material comprises two or more types of carbon particles, and wherein at least one type of carbon particle in the conductive additive material exhibits an average length of about 4 times to about 100 times larger than an average length of at least one other type of carbon particle in the conductive additive material.

18 . The Li-ion battery cell of claim 14 ,
wherein the conductive additive material includes a first conductive carbon additive and a second conductive carbon additive, and wherein the first conductive carbon additive has a higher affinity to the Si-comprising active material particles relative to the second conductive carbon additive.

19 . The Li-ion battery cell of claim 1 , wherein at least a portion of at least one of the electrodes is bent so as to exhibit a bending radius in the range from about 2 mm to about 40 mm.

20 . The Li-ion battery cell of claim 1 , wherein at least a portion of at least one of the electrodes comprises grooves that propagate from an electrode surface towards a respective metal current collector and that are spaced about 0.2 mm to about 10 mm apart from each other to help alleviate stresses occurring in the respective electrode during cell manufacturing and/or during cell operation.

21 . The Li-ion battery cell of claim 20 , where the grooves propagate from about 50% to about 100% of a respective electrode coating thickness.

Assignees

• Sila Nanotechnologies Inc

Inventors

• Yushin Gleb
• Gerber Laura
• Kajdos Adam
• Yen Justin
• Doane Justin
• Steiger Jens

Classifications

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M4/661

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

• H01M4/622

  being polymers · CPC title

• H01M2004/027

  Negative electrodes · CPC title

• H01M4/386

  Silicon or alloys based on silicon · CPC title