Electrode for lithium secondary battery having specific composition condition and lithium secondary battery comprising the same

An electrode for a lithium secondary battery comprising:

• a current collector;
• and
• an electrode material layer containing an active material and a binder formed on at least one surface of the current collector,
• wherein, when the electrode material layer is divided in half based on a thickness, an upper layer located away from the current collector having a half thickness of the electrode material layer is referred to as an electrode material layer A, and a lower layer located close to the current collector having a half thickness of the electrode material layer is referred to as an electrode material layer B, each of the electrode material layer A and the electrode material layer B contains one or more active material layers, and satisfies all of the following conditions (1) to (3):
• (1) the electrode material layer A contains artificial graphite as the active material in an amount of 75% by weight or more based on a total weight of the active material contained in the electrode material layer A, and the electrode material layer B contains an expansion-suppressing natural graphite as the active material in an amount of 80% by weight or more based on a total weight of the active material contained in the electrode material layer B,
• (2) the artificial graphite in the electrode material layer A has a specific surface area (BET) of 0.6 to 1.4 m2/g, and the expansion-suppressing natural graphite in the electrode material layer B has a specific surface area (BET) of 1.4 to 3.6 m2/g,
• (3) when a weight % occupied by the binder contained in the electrode material layer A based on the total weight of the electrode material layer is referred to as a, and a weight % occupied by the binder contained in the electrode material layer B based on the total weight of the electrode material layer is referred to as b, a>b, 3≤a+b≤5, 2≤a≤3, and 1≤b≤2, and
• (4) when a concentration of the binder contained in an entire electrode material layer is 1, the electrode material layer A is divided in half based on the thickness, a concentration of the binder contained in an area A′ located close to a surface of the electrode is referred to as a′, and a concentration of the binder contained in a region A″ located inside the electrode is referred to as a″, and
• when the electrode material layer B is divided in half based on the thickness, and a concentration of the binder contained in a region B′ located close to the electrode material layer A is referred to as b′, and a concentration of the binder contained in the area B″ located near the current collector is referred to as b″, and
• a value of a′/(a″+b′+b″) is 1/3 to 1.5.