Negative electrode and lithium secondary battery

Abstract

Negative electrode for a lithium secondary battery, comprising: a current collector and an active material layer of the negative electrode provided on at least one surface of the current collector, wherein the active material layer of the negative electrode comprises a first region corresponding to 50% of the total thickness of the active material layer of the negative electrode from a surface facing the current collector, and a second region corresponding to 50% of the total thickness of the active material layer of the negative electrode from a surface opposite the surface facing the current collector, wherein the active material layer of the negative electrode comprises two or more types of active materials of the negative electrode having different D50 values, and the following equations 1 and 2 satisfied:−3≤((D50,total−D50,1st)÷D50,total×100≤3−3≤((D50,total−D50,2nd)÷D50,total×100≤3, and where in equation 1 and equation 2, D50,totalD50 of the active material of the negative electrode in the entire active material layer of the negative electrode, D50,1stD50 of the active material of the negative electrode in the first region, and D50,2ndD50 of the active material of the negative electrode in the second region, and the average particle diameter (D50) is measured using a laser diffraction method.