Formulating High‐Rate and Long‐Cycle Heterostructured Layered Oxide Cathodes by Local Chemistry and Orbital Hybridization Modulation for Sodium‐Ion Batteries

• Published in: Advanced materials (Weinheim) Vol. 34; no. 33; pp. e2202695 - n/a
• Main Authors: Xiao, Yao, Wang, Hong‐Rui, Hu, Hai‐Yan, Zhu, Yan‐Fang, Li, Shi, Li, Jia‐Yang, Wu, Xiong‐Wei, Chou, Shu‐Lei
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01.08.2022
• Subjects: Cathodes; Cycles; Density functional theory; Electrochemical analysis; Electrode materials; Evolution; heterostructured biphasic layered oxide cathodes; Heterostructures; Hybridization; local chemistry; Materials science; Modulation; orbital hybridization; Sodium; Sodium-ion batteries; structural evolution
• ISSN: 0935-9648; 1521-4095; 1521-4095
• DOI: 10.1002/adma.202202695

It is still very urgent and challenging to simultaneously develop high‐rate and long‐cycle oxide cathodes for sodium‐ion batteries (SIBs) because of the sluggish kinetics and complex multiphase evolution during cycling. Here, the concept of accurately manipulating structural evolution and formulating high‐performance heterostructured biphasic layered oxide cathodes by local chemistry and orbital hybridization modulation is reported. The P2‐structure stoichiometric composition of the cathode material shows a layered P2‐ and O3‐type heterostructure that is explicitly evidenced by various macroscale and atomic‐scale techniques. Surprisingly, the heterostructured cathode displays excellent rate performance, remarkable cycling stability (capacity retention of 82.16% after 600 cycles at 2 C), and outstanding compatibility with hard carbon anode because of the integrated advantages of intergrowth structure and local environment regulation. Meanwhile, the formation process from precursors during calcination and the highly reversible dynamic structural evolution during the Na+ intercalation/deintercalation process are clearly articulated by a series of in situ characterization techniques. Also, the intrinsic structural properties and corresponding electrochemical behavior are further elucidated by the density of states and electron localization function of density functional theory calculations. Overall, this strategy, which finely tunes the local chemistry and orbitals hybridization for high‐performance SIBs, will open up a new field for other materials. An abnormal heterostructured biphasic layered oxide cathode for sodium‐ion batteries (SIBs) is successfully constructed, and its dynamic formation process, intrinsic structural properties, and electrochemical behavior are elucidated by a series of in situ characterization techniques and density functional theory calculations. The concept of accurately manipulating structural evolution and formulating heterostructured cathode materials by local chemistry and orbital hybridization modulation is further demonstrated.