NOVELTY - Battery comprises: a positive electrode comprising a lithium-cobalt composite oxide and a lithium-manganese composite oxide; a negative electrode comprising a lithium titanium composite oxide; and a nonaqueous electrolyte, where the ratio (Qp/Qn) of a charge capacity (mAh/m2) of the positive electrode per unit area (Qp) and a charge capacity (mAh/m2) of the negative electrode per unit area (Qn) is greater than 1.1, an open circuit voltage of the positive electrode is greater than or equal to 3.6 V (lithium versus lithium(I)) when the battery is discharged to 1.8 V at 0.2 C.    USE - The battery is useful in automobiles.    ADVANTAGE - The battery: suppresses the increase in resistance during the charge and discharge cycle, thus exhibiting improved capacity retention rate; exhibits higher charge and discharge efficiency; has a long life; avoids radiation from the electrode group caused by the increase of the positive electrode thickness, thus exhibiting high safety; and has light weight, a high power, and long-term reliability.    DETAILED DESCRIPTION - Battery comprises: a positive electrode comprising a lithium-cobalt composite oxide and a lithium-manganese composite oxide; a negative electrode comprising a lithium titanium composite oxide; and a nonaqueous electrolyte, where the charge capacity (mAh/m2) of the positive electrode per unit area (Qp) and a charge capacity (mAh/m2) of the negative electrode per unit area (Qn) are in a ratio (Qp/Qn) of greater than 1.1, an open circuit voltage of the positive electrode is greater than or equal to 3.6 V (lithium versus lithium(I)) when the battery is discharged to 1.8 V at 0.2 C, a charge and discharge range of the positive electrode is 3-4.25 V (lithium versus lithium(I)), and a charge and discharge range of the negative electrode is 1.4-2 V (lithium versus lithium(I)).    DESCRIPTION OF DRAWING(S) - The figure shows a partial cutaway perspective view of the battery.    Electrode group (11)    Container (12)    Lid body (13)    Negative electrode tab (14)    Negative electrode terminal (15)