Recharchable lithium battery including protective layer for positive electrode and method of manufacturing same

The present invention refers to a rechargeable lithium battery including a positive electrode, a negative electrode and a separator between the positive and negative electrodes. A positive electrode protective layer is formed on a surface of the positive electrode and/or on a surface of the separator. The positive electrode protective layer comprises or consists of a polymer compound and an ionic liquid including a borate-based anion. A method of manufacturing the same and a positive electrode protective layer composition useful for the manufacturing method is also provided.