Dai Junyi, Li Jiahao, Yao Yu, Wang Yan-Ru, Ma Mingze, Bai Ruilin, Zhu Yinbo, Rui Xianhong, Wu Hengan, Yu Yan
Hefei National Research Center for Physical Sciences at the Microscale, Department of Materials Science and Engineering, CAS Key Laboratory of Materials for Energy Conversion, University of Science and Technology of China. Hefei, Anhui 230026, China.
CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Modern Mechanics, University of Science and Technology of China, Hefei, Anhui 230027, China.
ACS Nano. 2025 Mar 25;19(11):11197-11209. doi: 10.1021/acsnano.4c18526. Epub 2025 Mar 11.
P2-type layered oxides, such as NaNiMnO, represent a promising class of cathode materials for Sodium-ion batteries (SIBs) due to their high theoretical energy density. However, their cycling stability is often compromised by severe phase transitions and irreversible lattice oxygen redox reactions at high voltages. In this work, we develop a Zn and Al codoping approach to design a NaNiZnMnAlO (ZA-NNMO) cathode for stable SIBs. Geometric phase analysis reveals that the introduction of inert Zn significantly mitigates the lattice distortion and transition-metal-ion migration, thereby inhibiting detrimental phase transition and structural collapse. The doped Al element in the Mn site strengthens the Al-O interaction, facilitating reversible O-O (0 < < 4) reactions at high voltages and effectively curtailing irreversible lattice oxygen oxidation, as confirmed by differential electrochemical mass spectrometry. As a result, the ZA-NNMO cathode delivers superior electrochemical performance in terms of high output voltage of 3.6 V, highly competitive energy density of 470 W h kg and good cyclability (80.2% of capacity retention after 1400 cycles at 1.0 A g). This work presents a robust methodology for improving the reversibility and stability of layered oxide cathodes in SIBs.
