# US 11,309,541 B2 · Negative electrode slurry for lithium secondary battery and method of preparing the same

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- Number: US 11,309,541 B2
- Document ID: US11309541B2
- Status: Granted
- Kind: B2
- Application number: 16/641,114
- Filed: 2018-08-31
- Published: 2021-04-29
- Granted: 2022-04-19
- Earliest claimed: 2017-09-01
- Assignees: LG Energy Solution, Ltd.
- Applicants: LG Chem, Ltd.
- Inventors: Dong Hyun Kim; Houng Sik Yoo; Byoung Hoon Ahn; Sang Hoon Choy; Hyeon Choi
- Web page: https://patentgrep.com/patent/US11309541B2

## CPC

- H01M 4/485: of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence)
- H01M 4/622: {being polymers}
- H01M 4/04: Processes of manufacture in general
- H01M 4/131: Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
- H01M 4/1391: of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
- H01M 4/62: Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
- H01M 4/623: {fluorinated polymers}
- 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}
- H01M 2004/027: {Negative electrodes}
- Y02E 60/10: Energy storage using batteries
- 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 negative electrode slurry including a lithium titanium oxide, a dispersant including a polar OH group and a non-polar alkyl group, a binder, and a solvent, and a method of preparing the same.

## Claims

### Claim 1

A negative electrode slurry comprising:
a lithium titanium oxide;
a dispersant comprising a polar OH group and a non-polar alkyl group;
a binder; and
an organic solvent,
wherein the negative electrode slurry satisfies Equation 1:
A
B
·
C
≥
0.06
[
Equation
⁢
⁢
1
]
wherein, in Equation 1,
A is an amount (wt %) of a repeating unit derived from a monomer containing the polar OH group in the dispersant, in the range of 1 to 50,
B is a weight-average molecular weight (Kg/mol) of the dispersant, and
C is a weight (parts by weight) of the dispersant based on 100 parts by weight of the lithium titanium oxide.

### Claim 2 (depends on 1)

The negative electrode slurry of claim 1, wherein the negative electrode slurry satisfies Equation 2:
0.05
≤
Dispersant
⁢
⁢
amount
Binder
⁢
⁢
amount
≤
3.5
[
Equation
⁢
⁢
2
]
wherein, in Equation 2, the amount of the dispersant and the amount of the binder respectively represent parts by weight of the dispersant and the binder based on 100 parts by weight of the negative electrode slurry.

### Claim 3 (depends on 1)

The negative electrode slurry of claim 1, wherein the negative electrode slurry comprises particles having a diameter of 2 μm or more in an amount of 10 vol % or less.

### Claim 4 (depends on 1)

The negative electrode slurry of claim 1, wherein the lithium titanium oxide is a secondary particle which is formed by agglomeration of primary particles comprising lithium titanium oxide, and
the secondary particle has an average particle diameter (D50) of 0.01 μm to 1 μm.

### Claim 5 (depends on 1)

The negative electrode slurry of claim 1, wherein the lithium titanium oxide has a specific surface area, which is measured by a Brunauer-Emmett-Teller (BET) method, of 0.1 m2/g to 50 m2/g.

### Claim 6 (depends on 1)

The negative electrode slurry of claim 1, wherein the lithium titanium oxide is represented by Formula 1:
LixTiyO4 [Formula 1]
wherein, in Formula 1, 0.5≤x≤3 and 1≤y≤2.5.

### Claim 7 (depends on 1)

The negative electrode slurry of claim 1, wherein the dispersant comprises a polymer having a repeating unit derived from one selected from the group consisting of polyvinyl butyral (PVB), polyvinyl alcohol (PVA), ethylene vinyl alcohol (EVOH), vinyl butyral, vinyl acetate, and vinyl alcohol, or a copolymer having repeating units derived from two or more selected therefrom.

### Claim 8 (depends on 1)

The negative electrode slurry of claim 1, wherein the negative electrode slurry has a viscosity of 0.1 Pa·s to 2 Pa·s at 25° C.

### Claim 9 (depends on 1)

The negative electrode slurry of claim 1, wherein the negative electrode slurry, has a solid content of 45 wt % or more.

### Claim 10 (depends on 1)

A method of preparing the negative electrode slurry of claim 1, the method comprising steps of:
(1) preparing a premixed slurry by mixing the binder, the lithium titanium oxide, the dispersant, and the organic solvent; and
(2) stirring the premixed slurry, to which the dispersant is added, to disperse the premixed slurry.

### Claim 11 (depends on 10)

The method of claim 10, wherein the step (1) comprises steps of:
(1-A) preparing a dispersant solution by mixing the dispersant comprising the polar OH group and the non-polar alkyl group with the organic solvent; and
(1-B) preparing a premixed slurry by mixing the binder and the lithium titanium oxide with the dispersant solution,
wherein the premixed slurry comprises the lithium titanium oxide in an amount of 45 wt % or more based on a total weight of the premixed slurry.

### Claim 12 (depends on 1)

A negative electrode for a lithium secondary battery, comprising the negative electrode slurry of claim 1.

### Claim 13 (depends on 12)

A lithium secondary battery comprising the negative electrode of claim 12.

### Claim 14 (depends on 1)

The negative electrode slurry of to claim 1, wherein the dispersant comprises a repeating unit derived from a monomer containing the polar OH group and a repeating unit derived from a monomer containing the non-polar alkyl group.