The method for producing a surface-modified base material according to the present invention includes a step of bringing a base material having a polar group present on a surface thereof into contact with a hydrosilane compound having a molecular structure A and having a SiH group composed of a silicon atom of the molecular structure A and a hydrogen atom bonded to the silicon atom in the presence of a borane catalyst so as to allow a dehydrocondensation reaction to take place between the base material and the compound, thereby forming the base material surface-modified with the molecular structure A. This production method is capable of surface-modifying a base material at a lower temperature in a shorter time than conventional methods and allows a wide variety of options for the form, type, and application of the base material, the mode of the modification reaction, and the type of the molecular structure with which the base material is surface-modified.

A lithium secondary battery according to embodiments of the present disclosure may include a cathode including a lithium metal phosphate, an anode disposed opposite to the cathode, a lithium salt, an organic solvent, and a phosphonate-based additive represented by Formula 1. The lithium secondary battery according to exemplary embodiments of the present disclosure may exhibit reduced initial resistance and improved low-temperature capacity properties and high-temperature capacity properties.