Due to high specific capacity and cost performance, high-nickel cathode materials have received much attention. However, its further application is hindered by poor stability and safety performance during cycling. In this work, Ni-rich LiNi_0.8Mn_0.2O₂ materials were prepared through microwave-assisted co-precipitation followed by high-temperature solid-phase method, which can be further modified by doping different proportions of Co and Al. As a result, LiNi_0.8Mn_0.1Co_0.08Al_0.02O₂ (NMCA-2) exhibits the best electrochemical performance, whose capacity retention rate reaches 91.39% after 100 cycles at 1C in the voltage range between 2.75 and 4.35 V, and still owns a specific discharge capacity of 160.03 mAh∙g^-1 at 5C. Its excellent cyclic retention rate can be attributed to the restrained irreversibility of H2→H3 phase transition during cycling with Co and Al doping, and the lower reaction polarization which contributed to the decline of charge transfer resistance, resulting in good cycle and rate performance of the material. Furthermore, high thermal stability of NMCA-2 improves the safety of the material.