近日，北京大学肖荫果团队研究了电化学性能优异的钠层状阴极材料相形成的结构分析。2025年7月8日出版的《德国应用化学》杂志发表了这项成果。

钠离子电池（SIB）层状阴极材料的电化学性能与其结构特性密切相关。然而，通过相位工程实现相位结构的精确调节是具有挑战性的，主要是由于受限的合成方法和对专门相位结构的理解存在差距。

研究组基于对P'2相结构的深入了解，成功合成了一系列具有突出电化学性能的P'2-Na_0.67Fe_0.05Ti_0.1Mn_0.85O₂阴极材料。通过分析合成过程中的结构演变和Mn价态变化，他们发现氧空位在决定P'2-P2相变中起着重要作用。此外，这些结构见解不仅确定了相形成中的氧气释放和吸收行为，还扩展了合成策略，提高了操作可行性。 

得益于电化学循环过程中Mn氧化还原范围的扩大和稳定的氧空位，获得的P'2-Na_0.67Fe_0.05Ti_0.1Mn_0.85O₂在0.1℃下的容量增加了约40 mAh g^-1，即使在10℃下循环1000次后仍保持约93 mAh g^-1，保留率高达87.5%。该研究显著推进了对P'2相材料的合成机理和电化学性能优化机理的理解，为提高SIB材料的性能提供了一种实用的策略。

附：英文原文

Title: Structural Insights into Phase Formation of Sodium Layered Cathodes Materials with Prominent Electrochemical Performances

Author: Haocheng Ji, Hengyu Ren, Guojie Chen, Wenhai Ji, Feng Zhou, Haotian Qu, Hui Fang, Mihai Chu, Rui Qi, Jingjun Zhai, Wen Zeng, Tiefeng Liu, Guangmin Zhou, Yinguo Xiao, Jun Lu

Issue&Volume: 2025-07-08

Abstract: The electrochemical performances of layered cathode materials for sodium-ion batteries (SIBs) are intimately dependent on their structural characteristics. However, realizing accurate regulation of phase structure by phase engineering is challenging, primarily due to constrained synthesis methods and the existing gaps in understanding of specialized phase structures. In this study, a series of P'2-Na0.67Fe0.05Ti0.1Mn0.85O2 cathode material with prominent electrochemical performances were successfully synthesized, based on an in-depth understanding of structural insights into P'2 phase. By analyzing the structural evolution and Mn-valence changes during synthesis process, we found that oxygen vacancies play a significant role in determining the P'2-P2 phase transition. Moreover, these structural insights not only identified the oxygen release and uptake behaviors in phase formation but also expanded synthesis strategy with enhanced operational feasibility. Benefits from expanded Mn redox range and stable oxygen vacancies during electrochemical cycling, the obtained P'2-Na0.67Fe0.05Ti0.1Mn0.85O2 demonstrated a capacity increase of over ~40 mAh g-1 at 0.1 C, maintaining ~93 mAh g-1 even after 1000 cycles at 10 C, with an impressive retention rate of 87.5%. This research significantly advances the comprehension of both synthesis mechanism and electrochemical properties optimization mechanisms of P'2 phase materials, offering a pragmatic strategy for elevating the performance of SIB materials.

DOI: 10.1002/anie.202510981

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202510981