# US 2014/0197801 A1 · Silicon-based electrode for a lithium-ion cell

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- Number: US 2014/0197801 A1
- Document ID: US20140197801A1
- Status: Published application
- Kind: A1
- Application number: 14/118,690
- Filed: 2012-05-17
- Published: 2014-07-17
- Earliest claimed: 2011-05-20
- Assignees: The Board of Trustees of the University of Illinois
- Inventors: Ralph G. Nuzzo; Jason L. Goldman; Michael W. Cason
- Web page: https://patentgrep.com/patent/US20140197801A1

## CPC

- H02J 7/00: Circuit arrangements for charging or discharging batteries or for supplying loads from batteries
- H01M 4/134: Electrodes based on metals, Si or alloys
- H01M 4/1395: of electrodes based on metals, Si or alloys
- H01M 4/366: {as layered products}
- H01M 4/624: {Electric conductive fillers}
- H01M 4/628: {Inhibitors, e.g. gassing inhibitors, corrosion inhibitors}
- H01M 10/052: Li-accumulators
- H01M 2004/021: {Physical characteristics, e.g. porosity, surface area}
- Y02E 60/10: Energy storage using batteries
- H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

A silicon-based electrode includes a silicon layer on a substrate, an electrically conductive layer overlying a top surface of the silicon layer, an optional polymer layer overlying the top surface of the electrically conducting layer, and a plurality of channels extending through the electrically conductive layer and the silicon layer to the substrate. The channels define sidewalls in the silicon layer. The electrically conductive layer and the optional polymer layer act to inhibit lithium ion intercalation through the top surface of the silicon layer during charging of a lithium-ion cell, and the lithium ion intercalation into the silicon layer occurs through the sidewalls that are defined by the channels.

## Claims

### Claim 1

A silicon-based electrode for a lithium-ion cell, the electrode comprising:
a silicon layer on a substrate;
an electrically conductive layer overlying a top surface of the silicon layer; and
a plurality of channels extending through the electrically conductive layer and the silicon layer to the substrate, the channels defining sidewalls in the silicon layer;
wherein the electrically conductive layer inhibits lithium ion intercalation through the top surface of the silicon layer during charging of a lithium-ion cell, the lithium ion intercalation into the silicon layer occurring through the sidewalls defined by the channels.

### Claim 2 (depends on 1)

The electrode of claim 1, wherein the channels are substantially perpendicular to the top surface of the silicon layer.

### Claim 3 (depends on 1)

The electrode of claim 1, further comprising a polymer layer on the electrically conductive layer, wherein the polymer layer further inhibits lithium intercalation through the top surface of the silicon layer during charging of the cell.

### Claim 4 (depends on 3)

The electrode of claim 3, wherein the channels extend through the polymer layer.

### Claim 5 (depends on 3)

The electrode of claim 3, wherein the polymer layer comprises polyethylene.

### Claim 6 (depends on 1)

The electrode of claim 1, wherein the silicon layer comprises crystalline silicon.

### Claim 7 (depends on 6)

The electrode of claim 6, wherein the crystalline silicon has a (100) orientation.

### Claim 8 (depends on 1)

The electrode of claim 1, wherein the silicon layer comprises polycrystalline silicon.

### Claim 9 (depends on 8)

The electrode of claim 8, wherein the silicon layer comprises silicon particles in a binder.

### Claim 10 (depends on 9)

The electrode of claim 9, wherein the binder comprises copper.

### Claim 11 (depends on 1)

The electrode of claim 1, wherein the electrically conductive layer comprises copper.

### Claim 12 (depends on 1)

The electrode of claim 1, wherein the channels are arranged in an ordered array.

### Claim 13

(canceled)

### Claim 14 (depends on 1)

The electrode of claim 1, wherein each channel has a lateral dimension of between about 0.1 micron and about 10 microns.

### Claim 15 (depends on 1)

The electrode of claim 1, wherein a spacing between adjacent channels is between about 1 micron and about 25 microns.

### Claim 16 (depends on 1)

The electrode of claim 1, wherein the channels comprise a channel array pitch of between about 0.1 and 10.

### Claim 17

(canceled)

### Claim 18 (depends on 1)

The electrode of claim 1, wherein the silicon layer comprises a thickness of between about 1 micron and about 100 microns.

### Claim 19

A lithium-ion cell comprising:
a first electrode, a second electrode, and an electrolyte in contact with the first electrode and the second electrode, wherein the electrolyte conducts lithium ions and the first electrode comprises:
a silicon layer on a substrate;
an electrically conductive layer overlying a top surface of the silicon layer; and
a plurality of channels extending through the electrically conductive layer and the silicon layer to the substrate, the channels defining sidewalls in the silicon layer,
wherein the electrically conductive layer inhibits lithium ion intercalation through the top surface of the silicon layer during charging of the lithium-ion cell, the lithium ion intercalation into the silicon layer occurring through the sidewalls defined by the channels.

### Claim 20

A method of charging a lithium-ion cell, the method comprising:
providing a first electrode, a second electrode, and an electrolyte in contact with the first electrode and the second electrode, wherein the electrolyte conducts lithium ions and the first electrode comprises: a silicon layer on a substrate; an electrically conductive layer overlying a top surface of the silicon layer; and a plurality of channels extending through the electrically conductive layer and the silicon layer to the substrate, the channels defining sidewalls in the silicon layer; and
intercalating lithium ions into the silicon layer through the sidewalls thereof, the lithium ions being substantially blocked from intercalation through the top surface of the silicon layer.

### Claim 21 (depends on 20)

The method of claim 20, further comprising forming a solid electrolyte interface layer on the sidewalls of the silicon layer.

### Claim 22 (depends on 20)

The method of claim 20, wherein the channels are aligned in a thickness direction substantially perpendicular to the top surface of the silicon layer, and wherein the silicon layer expands in the thickness direction during the intercalating.