The key to development of high-voltage P2-type Na 0.66 Ni 0.33 Mn 0.67 O 2 is the modification methods that can effectively improve its electrochemical reversibility. Herein, a doping-integrated coating strategy based on zinc element is proposed to modify P2-type Na 0.66 Ni 0.33 Mn 0.67 O 2 , which can be achieved by a facile one-step solid-state reaction. The formation mechanism of Na 0.66 Ni 0.26 Zn 0.07 Mn 0.67 O 2 @0.06ZnO (NNZM@ 0.06ZnO) is investigated, revealing that the spinel and P3 intermediate phases appear prior to the formation of the P2 phase. Ni 2+ can be preferentially incorporated into the P2 structure in competition with Zn 2+ at high temperature, resulting in a uniform enrichment of ZnO on the surface. A small amount of Zn 2+ doping significantly suppresses the Na + /vacancy ordering effect and improves the structural reversibility. Furthermore, the electrolyte decomposition is effectively reduced because of the presence of the ZnO coating layer, leading to the formation of a thin cathode electrolyte interphase film that is favorable to fast Na + diffusion. In virtue of the Zn 2+ doping and in situ formed ZnO coating, NNZM@0.06ZnO exhibits excellent cycling stability with a capacity retention of 83.7% after 100 cycles at 100 mA g −1 and rate performance with a discharge capacity of 56.4 mAh g −1 at 2000 mA g −1 , which significantly outperforms the uncoated Na 0.66 Ni 0.26 Zn 0.07 Mn 0.67 O 2 and the Na 0.66 Ni 0.26 Zn 0.07 Mn 0.67 O 2 /0.06ZnO with the coating layer introduced by mechanical milling. This work provides a new strategy to design high-performance cathode materials for sodium-ion batteries.

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