Structural insights into the dynamic and controlled multiphase evolution of layered-spinel heterostructured sodium oxide cathode

Abstract

Concepts in sodium oxide cathode composite structures have captured widespread attention; however, the detailed monitoring and accurate control of composite structural evolution during charge and discharge process remain challenging, especially for complex triphases and other similar systems. Here, we report the accurate manipulation of multiphase structural evolution during high-voltage cycling with improved electrochemical performance and adjustable sodium ion intercalation/deintercalation electrochemical behavior via rational chemical element substitution using a series of Fd -3 m spinel and layered P2/P3 heterostructures as proof-of-concept materials. Multiphase evolutions as a function of chemical substitution during high-voltage cycling are demonstrated. Meanwhile, we also monitor the dynamic formation process during calcination and observe the atomic arrangement of triphase heterostructure through various advanced characterization techniques. Overall, this study reveals controllable multiphase structural evolution in a model system and explores the related fundamental science required for future development of high-performance sodium-ion batteries. A series of spinel and P2/P3 heterostructures are studied Dynamic structural evolution and controllable multiphase transition are confirmed The architecture of controlled multiphase structural evolution is demonstrated Xiao et al. demonstrate the accurate manipulation of multiphase structural evolution during high-voltage cycling using a series of Fd-3 m spinel and layered P2/P3 heterostructures as proof-of-concept materials. The concept of controllable multiphase structural evolution architecture in a model system is realized, which may have implications for design of high-performance sodium-ion batteries.