Lithium secondary battery

A lithium secondary battery comprising:

• a positive electrode;
• and a negative electrode,
• wherein,
• the positive electrode comprises from −30 parts by weight to 75 parts by weight of a first positive electrode active material having a D50 of 9 μm or greater, based on 100 parts by weight of a total positive electrode active material, and further comprises a second positive electrode active material having a D50 of 6 μm or less;
• the negative electrode comprises a silicon-based active material;
• a resistance ratio represented by Equation 1 below is within a range of from 100% to 140%:
• [SOC 5% discharge resistance]/[SOC 50% discharge resistance]×100−100 (1), wherein the SOC 5% discharge resistance and the SOC 50% discharge resistance are resistances measured when a discharge pulse is applied at states of charge (SOC) of 5% and 50%, 2.5 C and 25° C. for 10 seconds, respectively;
• and
• a resistance ratio represented by Equation 2 below is within a range of from 90% to 110%:
• [SOC 5% discharge resistance]/[SOC 20% discharge resistance]×100−100 (2), wherein the SOC 5% discharge resistance and the SOC 20% discharge resistance are resistances measured when a discharge pulse is applied at states of charge (SOC) of 5% and 20%, 2.5 C and 25° C. for 10 seconds, respectively.