Positive electrode for rechargeable lithium battery and rechargeable lithium battery including same

A rechargeable lithium battery comprising:

• a positive electrode comprising a positive active material, a binder, and a conductive material, wherein a weight ratio of the binder and conductive material to the positive active material, ranges from 3:97 to 4:96, and a weight ratio of the binder to the conductive material ranges from 1.6 to 2:1;
• a negative electrode comprising a negative active material;
• and
• a non-aqueous electrolyte, and wherein the positive active material satisfies the following:
• LixMyO2−z
• wherein M is Ni1−a−b(Ni1/2Mn1/2)aCob, 0.65≤a+b≤0.85, and 0.1≤b≤0.4,
• 0.95≤x≤1.05,
• x+y≈2, and
• 0≤z≤0.05.

A method of forming a positive electrode for a rechargeable lithium battery, the method comprising:

• mixing a positive active material, a binder, and a conductive material in a solvent to form a positive active material slurry;
• and
• coating the positive active material slurry on a metal-foil current collector to form the positive electrode,
• wherein a weight ratio of the binder and conductive material, and the positive active material, ranges from 3:97 to 5:95 wt %, and
• a weight ratio of the binder and the conductive material ranges from 1.5 to 3:1, and
• wherein the positive active material satisfies the following:
• LixMyO2−z
• wherein M is Ni1−a−b(Ni1/2Mn1/2)aCob, 0.65≤a+b≤0.85, and 0.1≤b≤0.4,
• 0.95≤x≤1.05,
• x+y≈2, and
• 0≤z≤0.05.