A lithium secondary battery contains a negative electrode binder containing a polyimide resin having a structure represented by the following chemical formula (1), and the polyimide resin having a molecular weight distribution such that the weight ratio of a polyimide resin having a molecular weight of less than 100,000 and a polyimide resin having a molecular weight from 100,000 to less than 200,000 is from 50:50 to 90:10: where n is an integer equal to or greater than 1, and R is a functional group represented by the following chemical formula (2) or (3):