Electrode with conductive interlayer and method thereof

Patent metadata

Field	Value
Publication number	US-2020083542-A1
Application number	US-201916563791-A
Country	US
Kind code	A1
Filing date	Sep 6, 2019
Priority date	Sep 6, 2018
Publication date	Mar 12, 2020
Grant date	—

Abstract

In an embodiment, a Li-ion battery electrode comprises a conductive interlayer arranged between a current collector and an electrode active material layer. The conductive interlayer comprises first conductive additives and a first polymer binder, and the electrode active material layer comprises a plurality of active material particles mixed with a second polymer binder (which may be the same as or different from the first polymer binder) and second conductive additives (which may be the same as or different from the first conductive additives). In a further embodiment, the Li-ion battery electrode may be fabricated via application of successive slurry formulations onto the current collector, with the resultant product then being calendared (or densified).

First claim

1 . A Li-ion battery electrode, comprising:
a current collector; a conductive interlayer arranged on the current collector, the conductive interlayer including first conductive additives and a first polymer binder; and an electrode active material layer arranged on the conductive interlayer, the electrode active material layer including a plurality of active material particles mixed with a second polymer binder and second conductive additives, the plurality of active material particles exhibiting an average particle size in the range from about 0.2 microns to about 10 microns, an average 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, and an average areal capacity loading in the range of about 3 mAh/cm 2 to about 12 mAh/cm 2 .

2 . The battery electrode of claim 1 , wherein the first polymer binder comprises at least one component of the second polymer binder.

3 . The battery electrode of claim 1 , wherein the first conductive additives comprise at least one component of the second conductive additives.

4 . The battery electrode of claim 1 , wherein the plurality of active material particles comprise Si.

5 . The battery electrode of claim 1 , wherein the electrode active material layer comprises water-soluble or water-dispersible binders.

6 . The battery electrode of claim 1 , wherein the electrode active material layer comprises a plurality of binder components.

7 . The battery electrode of claim 5 , wherein at least one of the plurality of binder components comprises particles or fibers of an elastomeric material with a maximum elongation in the range from about 50% to about 5,000%.

8 . The battery electrode of claim 7 , wherein the particles or fibers of the elastomeric material comprise around 60 wt. % to around 95 wt. % of all binder in the electrode active material layer.

9 . The battery electrode of claim 7 , wherein a smallest average dimension of the particles or fibers of the elastomeric material ranges from around 30 nm to around 600 nm.

10 . The battery electrode of claim 1 , wherein the second conductive additives comprise single walled, double-walled and/or multi-walled carbon nanotubes.

11 . The battery electrode of claim 10 , wherein a weight fraction of all carbon nanotubes of the second conductive additives ranges from around 0.1 wt. % to around 5 wt. % of the electrode active material layer.

12 . The battery electrode of claim 1 , wherein the first conductive additives single walled, double-walled and/or multi-walled carbon nanotubes.

13 . The battery electrode of claim 12 , wherein a weight fraction of all carbon nanotubes of the first conductive additives ranges from around 0.1 wt. % to around 5 wt. %.

14 . The battery electrode of claim 1 , wherein a first weight fraction of the first conductive additives in the conductive interlayer exceeds a second weight fraction of the second conductive additives in the electrode active material layer by at least about 2 times.

15 . The battery electrode of claim 1 , wherein, upon separation of the current collector from the conductive interlayer, Raman spectroscopy mapping detects at least about 2 times more conductive additives on an exposed surface of the separated current collector or an exposed surface of the separated conductive interlayer than a top surface of the electrode active material layer.

16 . The battery electrode of claim 1 , wherein an average thickness of the conductive interlayer ranges from around 25 nm to around 500 nm.

17 . The battery electrode of claim 1 , wherein a current collector is a metal foil with a thickness in the range from around 4 micron to around 15 micron.

18 . A Li-ion battery comprising the battery electrode of claim 1 .

19 . A process of manufacturing of a Li-ion battery electrode, comprising:
mixing a first polymer binder, a first solvent and first conductive additives to form a first uniform conductive interlayer slurry; coating a current collector with the first slurry at a first thickness to form a conductive interlayer; drying the first slurry coating to attain a conductive interlayer on the current collector; mixing a second polymer binder, a second solvent, second conductive additives and active material particles to form a second uniform active material slurry; coating the conductive interlayer with the second slurry at a second thickness; drying the second slurry coating to attain an electrode active material layer; and calendaring the conductive interlayer and/or the electrode active material layer until a desired density is achieved.

20 . The method of claim 19 , wherein the first polymer binder comprises at least one component of the second polymer binder.

Assignees

• Sila Nanotechnologies Inc

Inventors

• Yushin Gleb
• Yen Justin
• Steiger Jens
• Zsoldos Eniko
• Fevre Mareva
• Kajdos Adam
• Wang Weimin

Classifications

• H01M4/625

  Carbon or graphite · CPC title

• H01M4/386

  Silicon or alloys based on silicon · CPC title

• H01M10/0525 Primary

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

• H01M4/134

  Electrodes based on metals, Si or alloys · CPC title

• H01M4/661

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