Electrode for secondary battery
An electrode for a secondary battery includes a current collector, a first electrode mixture layer disposed on at least one surface of the current collector and including styrene butadiene rubber, and a second electrode mixture layer disposed on the first electrode mixture layer and including a second styrene butadiene rubber. The first styrene butadiene rubber and the second styrene butadiene rubber have a repeating unit of styrene derived structure and a repeating unit of a butadiene derived structure, the first styrene butadiene rubber containing 40 to 90 mol % of a butadiene monomer based on total content of a monomer, and the second styrene butadiene rubber having a lower content of a butadiene monomer than the content of the first styrene butadiene rubber.
1. An electrode for a secondary battery, comprising:
a current collector;
a first electrode mixture layer disposed on at least one surface of the current collector and including a first styrene-butadiene rubber; and
a second electrode mixture layer disposed on the first electrode mixture layer and including a second styrene-butadiene rubber,
wherein the first styrene-butadiene rubber and the second styrene-butadiene rubber include a repeating unit of a styrene-derived structure and a repeating unit of a butadiene-derived structure,
the first styrene-butadiene rubber contains 40 to 90 mol % of a butadiene monomer based on a total content of a monomer, and
the second styrene-butadiene rubber has a lower content of a butadiene monomer than the content of the first styrene-butadiene rubber.
2. The electrode for a secondary battery of claim 1 , wherein the second styrene-butadiene rubber contains 5 to 35 mol % of the butadiene monomer based on the total amount of the monomer.
3. The electrode for a secondary battery of claim 1 , wherein the content of the second styrene-butadiene rubber included in the second electrode mixture layer is the same as or lower than a content of the first styrene-butadiene rubber included in the first electrode mixture layer.
4. The electrode for a secondary battery of claim 1 , wherein the first electrode mixture layer comprises 2.0 to 5.0% by weight of the first styrene-butadiene rubber, based on a total weight of the first electrode mixture layer.
5. The electrode for a secondary battery of claim 1 , wherein the second electrode mixture layer contains 2.0% by weight or less of the second styrene-butadiene rubber, based on a total weight of the second electrode mixture layer.
6. The electrode for a secondary battery of claim 1 , wherein the first electrode mixture layer comprises 2.0 to 3.5% by weight of the first styrene-butadiene rubber, based on a total weight of the first electrode mixture layer, and the second electrode mixture layer comprises 1.5% by weight or less of the second styrene-butadiene rubber, based on a total weight of the second electrode mixture layer.
7. The electrode for a secondary battery of claim 1 , wherein at least one of the first and second styrene-butadiene rubbers includes at least one of a monomer having a structure derived from acrylate and a monomer having a structure derived from acrylonitrile.
8. The electrode for a secondary battery of claim 1 , wherein the thickness of the first electrode mixture layer is in the range of 10 to 40 μm.
9. The electrode for a secondary battery of claim 1 , wherein the thickness of the second electrode mixture layer is in the range of 10 to 100μm, and
the first electrode mixture layer and the second electrode mixture layer have a thickness ratio of 1:1 to 1:3.
10. The electrode for a secondary battery of claim 1 , wherein the electrode has an adhesive force of 0.15 to 0.38N/18 mm, between the current collector and a first electrode active material layer.
11. The electrode for a secondary battery of claim 1 , wherein the electrode is a negative electrode.
12. A secondary battery comprising the electrode of claim 1 .
13. The secondary battery of claim 12 , wherein the electrode is a negative electrode.