Negative Electrode for Secondary Battery and Secondary Battery Including the Same
Provided are a negative electrode for a secondary battery including: a current collector; a first coating layer including a point-type conductive material and a binder, formed on the current collector; and a second coating layer including a silicon-based active material, formed on the first coating layer, and a lithium secondary battery including the same.
1 . A negative electrode for a secondary battery comprising:
a current collector;
a first coating layer including a point-type conductive material and a binder, formed on the current collector; and
a second coating layer including a silicon-based active material, formed on the first coating layer.
2 . The negative electrode for a secondary battery of claim 1 , wherein
a ratio between an average particle diameter (D50) of the point-type conductive material and an average particle diameter (D50) of the silicon-based active material is 1:60 to 1:20.
3 . The negative electrode for a secondary battery of claim 1 , wherein
the average particle diameter (D50) of the point-type conductive material is 100 to 200 nm.
4 . The negative electrode for a secondary battery of claim 1 , wherein
the point-type conductive material includes at least one selected from carbon black and graphite-based materials.
5 . The negative electrode for a secondary battery of claim 1 , wherein
the binder is carboxymethyl cellulose, a carboxymethyl cellulose derivative, polyvinyl alcohol, polyacrylic acid, a polyacrylic acid derivative, or a combination thereof.
6 . The negative electrode for a secondary battery of claim 1 , wherein
the first coating layer has a thickness of 0.05 to 2 μm.
7 . The negative electrode for a secondary battery of claim 1 , wherein
the average particle diameter (D50) of the silicon-based active material is 2 to 10 μm.
8 . The negative electrode for a secondary battery of claim 1 , wherein
the second coating layer further includes a carbon-based active material, a binder, and a conductive material.
9 . The negative electrode for a secondary battery of claim 1 , further comprising:
a third coating layer including a silicon-based active material, formed on the second coating layer.
10 . The negative electrode for a secondary battery of claim 9 , wherein
a content of the silicon-based active material in the second coating layer (wt % with respect to a total weight of the second coating layer) is higher than a content of the silicon-based active material in the third coating layer (wt % with respect to a total weight of the third coating layer).
11 . A secondary battery comprising: the negative electrode of claim 1 ; a positive electrode; a separator disposed between the negative electrode and the positive electrode; and an electrolyte solution.
12 . The secondary battery of claim 11 , wherein
the positive electrode includes:
a current collector;
a first positive electrode coating layer including a point-type conductive material and a binder, formed on the current collector; and
a second positive electrode coating layer including a Ni-based active material represented by the following Chemical Formula 1, formed on the first positive electrode coating layer:
Li a Ni x Co y Mn 1−x−y O 2 [Chemical Formula 1]
wherein a, x, and y satisfy: 0.9≤a≤1.05, 0.80<x≤1, 0≤y<0.2.
13 . The secondary battery of claim 12 , wherein
a ratio between an average particle diameter (D50) of the point-type conductive material and an average particle diameter (D50) of the N-based active material included in the positive electrode is 1:60 to 1:20.