Abstract: Provided is a cathode mix for lithium secondary batteries, comprising a cathode active material having a composition represented by the following Formula I: LiFe(P1-XO4) (I) wherein a molar fraction (1-x) of phosphorus (P) is in the range of 0.910 to 0.999, to allow operational efficiency of the cathode active material to be leveled to a lower operational efficiency of an anode active material and improve energy density of the cathode active material. The cathode mix maximizes operational efficiency of batteries, minimizes electrode waste and thus reduces manufacturing costs of batteries. Furthermore, The cathode active material, wherein a molar fraction (1-x) of phosphorus (P) is lower than 1, according to the present invention contains both Fe2+ and Fe3+, thus advantageously causing no structural deformation, improving ionic conductivity, exhibiting superior rate properties, inhibiting IR drop upon charge/discharge, thereby imparting high energy density to batteries.

Abstract: Disclosed herein is an electrolyte for lithium secondary batteries comprising: a chelating agent, which forms complexes with transition metal ions in the battery, and at the same time does not react and coordinate with lithium ions; a non-aqueous solvent; and an electrolyte salt, as well as a lithium secondary battery comprising the electrolyte. The chelating agent, which is contained in the electrolyte for lithium secondary batteries, can suppress a side reaction in which transition metal ions are reduced and deposited as transition metals on the anode. Also, the chelating agent can suppress internal short-circuits in the battery and the resulting voltage drop of the battery and a reduction in the safety and performance of the battery, which can occur when transition metals are deposited on the anode.

Abstract: Disclosed herein is an electrolyte for lithium secondary batteries comprising: a chelating agent, which forms complexes with transition metal ions in the battery, and at the same time does not react and coordinate with lithium ions; a non-aqueous solvent; and an electrolyte salt, as well as a lithium secondary battery comprising the electrolyte. The chelating agent, which is contained in the electrolyte for lithium secondary batteries, can suppress a side reaction in which transition metal ions are reduced and deposited as transition metals on the anode. Also, the chelating agent can suppress internal short-circuits in the battery and the resulting voltage drop of the battery and a reduction in the safety and performance of the battery, which can occur when transition metals are deposited on the anode.

Abstract: Disclosed herein is an electrolyte for lithium secondary batteries comprising: a chelating agent, which forms complexes with transition metal ions in the battery, and at the same time does not react and coordinate with lithium ions; a non-aqueous solvent; and an electrolyte salt, as well as a lithium secondary battery comprising the electrolyte. The chelating agent, which is contained in the electrolyte for lithium secondary batteries, can suppress a side reaction in which transition metal ions are reduced and deposited as transition metals on the anode. Also, the chelating agent can suppress internal short-circuits in the battery and the resulting voltage drop of the battery and a reduction in the safety and performance of the battery, which can occur when transition metals are deposited on the anode.