LiNi0.8Co0.15Al0.05O2 (NCA) has attracted much attention because of its high capacity and low cost. Herein, we report a facile wet-chemical route to prepare a Co3O4-modified NCA cathode material with enhanced electrochemical performance for lithium-ion batteries. The as-prepared Co3O4-coated NCA cathode material delivers a specific capacity of 207.6mAhg−1 with an initial Coulombic efficiency of 90.8% at 0.1C. The capacity retention of the Co3O4-coated NCA cathode material is as high as 91.6% at 1C between the potential from 2.8 to 4.3V after 100 cycles. More importantly, the capacity retention of the resulting Co3O4-coated NCA is higher than 94.7% after 100 cycles at 0.2C. In addition, the Co3O4-coated NCA cathode material exhibits good rate capability, especially a high discharge capacity at a high current density. The outstanding electrochemical performance of Co3O4-coated NCA is assigned to the surface coating of Co3O4 that may react with lithium-containing impurities on the surface and decrease the charge-transfer resistance.