Battery Cell of Improved Excellent Low-Temperature Output Property and Middle or Large-sized Battery Back Comprising the Same

摘要

The present invention relates to a battery cell having an electrode assembly in a structure with a cathode, an anode, and a separator interposed between the cathode and the anode, wherein the electrode assembly is impregnated in the electrolyte and built in a battery case. Provided are a battery cell having a cathode active material of the cathode, wherein the cathode active material consists of a lithium metal oxide having an operating voltage region of 3.5 to 4.3 V, represented by the chemical formula 1 and has an output at a state of charge (SOC) in a range of 10 to 20% is 65 to 90% of an output at SOC of 65% under the conditions of 25 degrees Celsius and a middle and large size battery back comprising the same. The chemical formula 1 is represented by Li(Co_(1-x)M_x)O_(2-a)A_a. In the formula, 0 = x =0.2, 0 = a = 0.2; M is at least one element selected from a group consisting of Mg, Ti, Zr, and Si; and A is at least one negative monovalent or negative divalent anion.