Abstract: Single-crystal cathode materials NCM90(LiNi_xCo_yMn_1-x-yO₂,x≥0.9) with different Zr doping contents were successfully synthesized by a facile co-precipitation and subsequent high-temperature solid-phase sintering method. The results show that the electrochemically inert Zr incorporated into the crystal structure enters both the lithium layer and the transition metal layer. On the one hand, the Zr entering the lithium layer effectively widens the interlayer spacing and accelerates the diffusion of lithium ions during cycling; on the other hand, the Zr entering the transition metal layer forms a higher bond through the bonding with the lattice oxygen. The active Zr-O bond can effectively stabilize the crystal structure of the material. As expected, the modified materials exhibit superior cycling stability, LiNi_0.9Co_0.05Mn_0.05O₂-0.5%Zr(NCM90-Zr2) doped with 0.5% Zr has the best electrochemical performance. The capacity retention of NCM90-Zr2 is 74.1% after 200 cycles in the voltage range of 2.95-4.30 V at a rate of 1C; further increasing the cut-off voltage to 4.50 V, the material releases an initial discharge specific capacity of 215.5 mAh·g^-1. It maintains 86.9% of the initial capacity after 100 cycles, showing excellent high-pressure stability. This study provides a certain reference for the subsequent development of high-voltage cathode materials for lithium-ion batteries.