LITHIUM SECONDARY BATTERY INCLUDING EXCESS AMOUNT OF ELECTROLYTE

摘要

PURPOSE: A secondary battery is provided to use electrolytes in excess to minimize the increase in resistance caused by a side reaction product during a charging and discharging process and a secondary side reaction and delay a rapid decrease in capacity due to depletion in electrolytes. CONSTITUTION: A lithium secondary battery comprises: an electrode assembly composed of an anode, and a cathode, and a separator interposed between the anode and cathode; and an electrolyte. The cathode contains a lithium nickel manganese complex oxide as a cathode active material. The amount of the electrolyte contained is greater than 130 weight% and less than 200 weight% based on the electrode of the electrolyte and the gap in the separator. The lithium nickel manganese composite oxide is indicated as LixNiyMn(2-y)O represented by the chemical formula 1. Here, it is 0.9<=x<=1.2, 0