# US 8,785,038 B2 · Negative electrode active material

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- Number: US 8,785,038 B2
- Document ID: US8785038B2
- Status: Granted
- Kind: B2
- Application number: 13/813,018
- Filed: 2010-11-19
- Published: 2013-05-23
- Granted: 2014-07-22
- Earliest claimed: 2010-07-30
- Assignees: Iljin Electric Co., Ltd.
- Applicants: Jae Woong Kim; Seung Chul Lee; Ki Duck Park; Chul Gyu Bae; Jong Goo Kang; Yoon Seong Cho
- Inventors: Jae Woong Kim; Seung Chul Lee; Ki Duck Park; Chul Gyu Bae; Jong Goo Kang; Yoon Seong Cho
- Web page: https://patentgrep.com/patent/US8785038B2

## CPC

- H01M 4/386: {Silicon or alloys based on silicon}
- H01M 4/134: Electrodes based on metals, Si or alloys
- H01M 4/364: {as mixtures}
- H01M 4/38: of elements or alloys
- H01M 4/525: of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
- H01M 4/581: {Chalcogenides or intercalation compounds thereof}
- H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
- H01M 2004/021: {Physical characteristics, e.g. porosity, surface area}
- Y02E 60/10: Energy storage using batteries
- Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product
- 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
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

## Abstract

A negative electrode active material and a secondary battery are provided. The negative electrode active material can be useful in maintaining excellent cell efficiency and lifespan while showing high-capacity properties, and the secondary battery may be manufactured using the negative electrode active material.

## Claims

### Claim 1

A negative electrode active material which is represented by the following Forumla 1, and which comprises
a phase A including active silicon; and
a phase B having a metal alloy matrix including silicon and a transition metal,
wherein the active silicon of the phase A forms a core and the alloy matrix of the phase B surrounds the core of the active silicon of the phase A,
wherein peaks other than a peak derived from the active silicon of the phase A observed by an ex situ XRD analysis before a charge/discharge cycle are also observed by an ex situ XRD analysis after the charge/discharge cycle,
the Formula 1 being aSi-bTi-cFe
wherein the sum of a, b, and c is 100 atom %, a is 67 atom % to 74 atom %, b is from 13 atom % to 16.5 atom %, and c is 13 atom % to 16.5 atom %.

### Claim 2 (depends on 1)

The negative electrode active material of claim 1, wherein the phase A is formed of a single phase of the active silicon.

### Claim 3 (depends on 1)

The negative electrode active material of claim 1, wherein the active silicon of the phase A has an average particle diameter of 1,000 nm or less.

### Claim 4 (depends on 1)

The negative electrode active material of claim 1, which has an electric conductivity of 5×101 S/cm or more, as measured at a load of 20 kN.

### Claim 5 (depends on 1)

A secondary battery comprising:
a positive electrode;
a negative electrode including the active material defined in claim 1; and
an electrolyte.

### Claim 6 (depends on 5)

The secondary battery claim 5, wherein the positive electrode includes a lithiated intercalation compound, elemental sulfur or a sulfur compound.

### Claim 7 (depends on 5)

The secondary battery claim 5, wherein the electrolyte includes a non-aqueous organic solvent and a lithium salt.

### Claim 8 (depends on 5)

The secondary battery claim 5, which is formed in a tubular, horn, coin or pouch shape.