Lithium secondary battery

A lithium secondary battery which is provided with: a positive electrode containing a positive electrode active material that are capable of absorbing and desorbing lithium; a negative electrode containing a negative electrode active material that are capable of absorbing and desorbing lithium; and a nonaqueous electrolyte solution. At least one of the positive electrode and the negative electrode contains a polymer that is a reaction product of a compound (A) and a compound (B), and the nonaqueous electrolyte solution contains an additive (X). The additive (X) is at least one compound that is selected from the group consisting of carbonate compounds having a carbon-carbon unsaturated bond, carbonate compounds having a halogen atom, alkali metal salts, sulfonic acid ester compounds, sulfuric acid ester compounds, nitrile compounds, dioxane compounds and substituted aromatic hydrocarbon compounds. The compound (A) is at least one compound that is selected from the group consisting of amine compounds, amide com