Mitigating Internal Gliding of a High-Voltage O3-Type Cathode via Na-Site Doping with High Ionic Potential Cations.

Zhang, Shuai; Wang, Jiexi; Xu, Zhangyi; Xu, Zhengwei; Wang, Zhixing; Guo, Huajun; Li, Xinhai; Peng, Wenjie et al. · Nano Lett · 2026

basic_science · Level V

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Abstract

High-voltage O3-type cathodes promise higher energy densities for sodium-ion batteries but suffer from severe lattice strain, interlayer gliding, and structural degradation during cycling. Here, we report that Te<sup>4+</sup> doping into the Na 3a sites of NaNi<sub>0.35</sub>Fe<sub>0.2</sub>Mn<sub>0.3</sub>Cu<sub>0.05</sub>Ti<sub>0.1</sub>O<sub>2</sub> markedly improves its high-voltage cycling stability. Te<sup>4+</sup> doping suppresses stress accumulation, interlayer gliding, and intragranular cracking, thereby enhancing structural reversibility and electrochemical performance. Extending this strategy, Ca<sup>2+</sup>, Y<sup>3+</sup>, and Sm<sup>3+</sup> with similarly high ionic potentials preferentially occupy Na 3a sites, all exhibiting reduced lattice degradation and improved durability, confirming a universal "pinning effect". Notably, Ca<sup>2+</sup> doping enables kilogram-scale production, and the assembled 18650 cylindrical cell retains 89.9% capacity after 500 cycles. Mechanistically, strong ion-oxygen interactions stiffen the Na layer lattice, stabilizing the framework during Na (de)intercalation and suppressing (003) gliding. This work establishes high ionic potential Na-site doping as a broadly applicable design principle for durable high-voltage O3 cathodes.