Negative electrode and secondary battery

Abstract

Negative electrode for a secondary battery, comprising: a current collector; a first active material layer of the negative electrode provided on the current collector and comprising a silicon-carbon composite; and a second active material layer of the negative electrode provided on the first active material layer of the negative electrode and comprising a silicon oxide, wherein a ratio (D50,2nd / D50,1st) of an average particle diameter (D50,2nd) of the second active material layer of the negative electrode to an average particle diameter (D50,1st) of the first active material layer of the negative electrode is 0.75 to 1.5, wherein the average particle diameter is measured by a laser diffraction method.