Negative electrode composition, negative electrode for lithium secondary battery comprising same, lithium secondary battery comprising negative electrode, and method for preparing negative electrode composition

1 . A negative electrode composition comprising:

a silicon-containing active material;

a negative electrode conductive material; and

a negative electrode binder,

wherein the silicon-containing active material comprises silicon-containing particles having a particle size distribution of 0.01 μm or more and 30 μm or less,

the silicon-containing active material comprises 1 part by weight or more and 5 parts by weight or less of the silicon-containing particles having a particle size of 1 μm or less based on 100 parts by weight of the silicon-containing active material, and

the silicon-containing active material satisfies a particle size ratio of the following Equations 1, 2 and 3:

20≤( X 1 /Y )×100(%)  [Equation 1]

( X 2/ Y )×100(%)≤230  [Equation 2]

10≤( X 1/ X 2)×100(%)  [Equation 3]

in Equations 1, 2 and 3,

X1 denotes a D5 particle size of the silicon-containing active material,

X2 denotes a D95 particle size of the silicon-containing active material, and

Y denotes a median particle size (D50) of the silicon-containing active material.

2 . The negative electrode composition of claim 1 , wherein the silicon-containing particles comprise one or more selected from the group consisting of SiOx, wherein x=0, SiOx, wherein 0<x<2, SiC, and a Si alloy.

3 . The negative electrode composition of claim 1 , wherein the silicon-containing particles comprise one or more selected from the group consisting of SiOx, wherein x=0 and SiOx, wherein 0<x<2, and comprise 70 parts by weight or more of the SiOx, wherein x=) based on 100 parts by weight of the silicon-containing active material.

4 . The negative electrode composition of claim 1 , wherein the silicon-containing active material is present in an amount of 60 parts by weight or more based on 100 parts by weight of the negative electrode composition.

5 . The negative electrode composition of claim 1 , wherein the silicon-containing particles having a particle size distribution of 0.01 μm or more and 30 μm or less have a full width at half maximum of 1 μm or more and 5 μm or less.

6 . The negative electrode composition of claim 1 , wherein the negative electrode conductive material comprises a planar conductive material and a linear conductive material.

7 . A method for preparing a negative electrode composition, the method comprising:

mixing a negative electrode conductive material and a negative electrode binder to form a mixture;

performing a first mixing by adding water to the mixture; and

performing a second mixing by adding a silicon-containing active material to the first mixed mixture,

wherein the silicon-containing active material comprises silicon-containing particles having a particle size distribution of 0.01 μm or more and 30 μm or less,

the silicon-containing active material comprises 1 part by weight or more and 5 parts by weight or less of the silicon-containing particles having a particle size of 1 μm or less based on 100 parts by weight of the silicon-containing active material, and

the silicon-containing active material satisfies particle size ratios of the following Equations 1 and 2:

20≤( X 1 /Y )×100(%)  [Equation 1]

( X 2/ Y )×100(%)≤230  [Equation 2]

in Equations 1 and 2,

X1 denotes a D5 particle size of the silicon-containing active material,

X2 denotes a D95 particle size of the silicon-containing active material, and

Y denotes a median particle size (D50) of the silicon-containing active material.

8 . The method of claim 7 , wherein in the first mixing and second mixing steps, mixing is performed at 2,000 rpm to 3,000 rpm for 10 minutes to 60 minutes.

9 . A negative electrode for a lithium secondary battery, comprising:

a negative electrode current collector layer; and

a negative electrode active material layer comprising the negative electrode composition according to claim 1 on one surface or both surfaces of the negative electrode current collector layer.

10 . The negative electrode of claim 9 , wherein the negative electrode current collector layer has a thickness of 1 μm or more and 100 μm or less, and

the negative electrode active material layer has a thickness of 20 μm or more and 500 μm or less.

11 . A lithium secondary battery comprising:

a positive electrode;

the negative electrode for a lithium secondary battery according to claim 9 ;

a separator between the positive electrode and the negative electrode; and

an electrolyte.

12 . A negative electrode composition comprising:

a silicon-containing active material;

a negative electrode conductive material; and

a negative electrode binder,

wherein the silicon-containing active material comprises silicon-containing particles having a particle size distribution of 0.01 μm or more and 30 μm or less have a full width at half maximum of 1 μm or more and 5 μm or less,

the silicon-containing active material comprises 1 part by weight or more and 5 parts by weight or less of the silicon-containing particles having a particle size of 1 μm or less based on 100 parts by weight of the silicon-containing active material, and

the silicon-containing active material satisfies a particle size ratio of the following Equations 1 and 2:

20≤( X 1 /Y )×100(%)  [Equation 1]

( X 2/ Y )×100(%)≤230  [Equation 2]

in Equations 1 and 2,

X1 denotes a D5 particle size of the silicon-containing active material,

X2 denotes a D95 particle size of the silicon-containing active material, and

Y denotes a median particle size (D50) of the silicon-containing active material.

13 . A negative electrode composition comprising:

a silicon-containing active material;

a negative electrode conductive material; and

a negative electrode binder,

wherein the silicon-containing active material comprises silicon-containing particles having a particle size distribution of 0.01 μm or more and 30 μm or less,

the silicon-containing active material comprises 1.3 parts by weight or more and 4 parts by weight or less of the silicon-containing particles having a particle size of 1 μm or less based on 100 parts by weight of the silicon-containing active material, and

the silicon-containing active material satisfies a particle size ratio of the following Equations 1 and 2:

20≤( X 1 /Y )×100(%)  [Equation 1]

( X 2/ Y )×100(%)≤230  [Equation 2]

in Equations 1 and 2,

X1 denotes a D5 particle size of the silicon-containing active material,

X2 denotes a D95 particle size of the silicon-containing active material, and

Y denotes a median particle size (D50) of the silicon-containing active material.

14 . A negative electrode composition comprising:

a silicon-containing active material;

a negative electrode conductive material; and

a negative electrode binder,

wherein the silicon-containing active material comprises silicon-containing particles having a particle size distribution of 0.01 μm or more and 30 μm or less,

the silicon-containing active material comprises 1 part by weight or more and 5 parts by weight or less of the silicon-containing particles having a particle size of 1 μm or less based on 100 parts by weight of the silicon-containing active material, and

the silicon-containing active material satisfies a particle size ratio of the following Equations 1 and 2:

20≤( X 1 /Y )×100(%)  [Equation 1]

( X 2/ Y )×100(%)≤230  [Equation 2]

in Equations 1 and 2,

X1 denotes a D5 particle size of the silicon-containing active material,

X2 denotes a D95 particle size of the silicon-containing active material, and

Y denotes a median particle size (D50) of the silicon-containing active material.

15 . A negative electrode composition comprising:

a silicon-containing active material;

a negative electrode conductive material; and

a negative electrode binder,

wherein the silicon-containing active material comprises silicon-containing particles having a particle size distribution of 0.01 μm or more and 30 μm or less,

the silicon-containing active material comprises 1 part by weight or more and 5 parts by weight or less of the silicon-containing particles having a particle size of 1 μm or less based on 100 parts by weight of the silicon-containing active material, and

the silicon-containing active material satisfies a particle size ratio of the following Equations 1 and 2:

20≤( X 1 /Y )×100(%)  [Equation 1]

( X 2/ Y )×100(%)≤230  [Equation 2]

in Equations 1 and 2,

X1 denotes a D5 particle size of the silicon-containing active material,

X2 denotes a D95 particle size of the silicon-containing active material, and

Y denotes a median particle size (D50) of the silicon-containing active material.