High nickel ternary cathode materials are less expensive, more productive, and less environmentally harmful than conventional cathode materials. Thus, it becomes one of the best cathode materials for lithium-ion batteries. However, there are also clear drawbacks to high nickel ternary materials, for instance its inadequate cycle life, poor structural and heat stability, which limit its future development. In this work, LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811) material was studied and modified using Li₃BO₃, a lithium-ion conductor-type compound, as its coating layer. Studies reveal that after 1 wt percent -Li₃BO₃ coating, the first discharge capacity at a 2 C rate rose from 162.7 mAh g^-1 to 185.9 mAh g^-1. After 250 cycles, the capacity retention of the Li₃BO₃-coated sample was 87%, compared to just 82.5% for the uncoated sample. The introducing of Li₃BO₃ coating material of NCM811 can significantly improve the electrochemical performance of materials for lithium-ion battery cathodes that are high in nickel ternary.