Electrochemical behaviors of LiCo1/3Ni1/3Mn1/3O2 were examined in non-aqueous lithium cells and lithium-ion cells with Li[Li1/3Ti5/3]O4 at 30, 55, 75, and 95°C. Li/LiCo1/3Ni1/3Mn1/3O2 cells showed rechargeable capacity of 205mAhg−1 at 30°C, 210mAhg−1 at 55°C, and 225mAhg−1 at 75°C in voltages of 2.5–4.6V. Results on rate-capability tests at 55°C indicated that LiCo1/3Ni1/3Mn1/3O2 was capable to deliver 160mAhg−1 of capacity even at 4000mAg−1 while high-rate charge was very hard due to electrical shortage derived from lithium metal deposition. Lithium-ion cells of Li[Li1/3Ti5/3]O4 and LiCo1/3Ni1/3Mn1/3O2 could operate with rechargeable capacity of 150mAhg−1 at 1600mAg−1 without any electrical shortage during charge and discharge at 55°C. One-hundred cycle test of the lithium-ion cell with variation of temperature 55, 75, and 95°C, in voltages of 1.00–3.05V was also examined and shown that LiCo1/3Ni1/3Mn1/3O2 was the most promising positive-electrode material for advanced lithium-ion batteries.