Structural and Thermodynamic Understandings in Mn-Based Sodium Layered Oxides during Anionic Redox.

ABSTRACT: A breakthrough utilizing an anionic redox reaction (O^2-/O^n-) for charge compensation has led to the development of high-energy cathode materials in sodium-ion batteries. However, its reaction results in a large voltage hysteresis due to the structural degradation arising from an oxygen loss. Herein, an interesting P2-type Mn-based compound exhibits a distinct two-phase behavior preserving a high-potential anionic redox (≈4.2 V vs Na⁺/Na) even during the subsequent cycling. Through a systematic series of experimental characterizations and theoretical calculations, the anionic redox reaction originating from O 2p-electron and the reversible unmixing of Na-rich and Na-poor phases are confirmed in detail. In light of the combined study, a critical role of the a

SUBMITTER: Kang SM 

PROVIDER: S-EPMC7435253 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature