Lg Energy Solution, Ltd.

Min Ji Heo

Jeong Woo Lee

Joo Sung Lee

Ho June Kim

The present invention relates to a lithium secondary battery having excellent battery performance at high voltage, wherein the lithium secondary battery according to the present invention includes a positive electrode which includes a positive electrode active material layer including a lithium nickel cobalt manganese-based oxide having an average particle diameter of primary particles of 3 μm or more and a lithium cobalt-based oxide, a negative electrode which includes a negative electrode active material layer including a negative electrode active material, and an electrolyte, wherein a ratio of negative electrode capacity to positive electrode capacity is in a range of 1.06 to 1.15.

Lithium secondary battery

The present invention provides a positive electrode for a lithium secondary battery, including a first positive electrode active material including a lithium cobalt-based oxide, and a second positive electrode active material including a lithium composite transition metal oxide containing at least two selected from the group consisting of nickel (Ni), cobalt (Co), and manganese (Mn), wherein, when the state of charge (SOC) of the first positive electrode active material in which the voltage of the lithium secondary battery reaches a constant voltage (CV) at 1 C-rate is referred to as SOC, and the state of charge (SOC) of the second positive electrode active material in which the voltage of the battery reaches a constant voltage (CV) at 1 C-rate is referred to as SOC, the SOCand the SOCsatisfy the relationship represented by Equation 1 below.SOC&#x3c;SOC&#x3c;1.1&#xd7;SOC&#x2003;&#x2003;[Equation 1]

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Daejeon, South Korea

Min Ji Heo