Secondary battery and manufacturing method of the same

A method for manufacturing a secondary battery comprising the step of:

• performing a first charging and discharging while pressure is applied in a thickness direction of the secondary battery,
• wherein the secondary battery includes:
• a negative electrode;
• a positive electrode;
• an electrolyte solution;
• and
• a separator,
• wherein the negative electrode includes a negative electrode current collector and a negative electrode active material layer,
• wherein the negative electrode active material layer comprises SiOy (2>y>0),
• wherein the negative electrode active material layer includes a first projection, a first depression, a second projection and a second depression,
• wherein the negative electrode current collector includes a third projection, a third depression, a fourth projection and a fourth depression,
• wherein the first projection, the first depression, the third projection and the third depression overlap with each other, and
• wherein the second projection, the second depression, the fourth projection and the fourth depression overlap with each other.