Ultralow‐Strain Zn‐Substituted Layered Oxide Cathode with Suppressed P2–O2 Transition for Stable Sodium Ion Storage

Abstract

Layered transition metal oxides have drawn much attention as a promising candidate cathode material for sodium‐ion batteries. However, their performance degradation originating from strains and lattice phase transitions remains a critical challenge. Herein, a high‐concentration Zn‐substituted NaxMnO2 cathode with strongly suppressed P2–O2 transition is investigated, which exhibits a volume change as low as 1.0% in the charge/discharge process. Such ultralow strain characteristics ensure a stable host for sodium ion storage, which significantly improves the cycling stability and rate capability of the cathode material. Also, the strong coupling between the highly reversible capacity and the doping content of Zn in NaxMnO2 is investigated. It is suggested that a reversible anionic redox reaction can be effectively triggered by Zn ions and is also highly dependent on the Zn content. Such an ion doping strategy could shed light on the design and construction of stable and high‐capacity sodium ion host.

Boron-doped sodium layered oxide for reversible oxygen redox reaction in Na-ion battery cathodes

“…Further comparison of extended X-ray absorption fine structure (EXAFS) spectra at Ni, Fe, and Mn K-edge are made between NLNFMB and NLNFM to gain the local coordination information 54 . The significant changes of EXAFS peak intensity in discharge cutoff state and initial state for NLNFM indicate the obvious structural changes (Supplementary Fig.…”

Bulk O2 formation and Mg displacement explain O-redox in Na0.67Mn0.72Mg0.28O2

“…8,9 However, the presence of a shortened plateau during subsequent charge of such a honeycomb-ordered compound is a feature observed only upon cycling of P2-Na 0.67 Mn 0.72 Mg 0.28 O 2 , P3-Na 0.67 Mn 0.67 Mg 0.33 O 2 , and P2-Na 0.67 Mn 0.78 Zn 0.22 O 2 . 13,14…”

Pseudo‐Bonding and Electric‐Field Harmony for Li‐Rich Mn‐Based Oxide Cathode

“…[14] Besides, the clear and distinct splitting diffraction peaks of (006)/(012) and (018)/(110) reveal that the layered structure of all samples is maintained and the bulk structure is not dramatically changed after linkage-functionalized modification, which could boost the Li + shuttling ( Figure 2B). [15] As shown in Figure 2C, the (003) and (104) diffraction peaks of the modified samples are slightly shifted to lower angles compared with the pristine sample, implying that the lattice parameters of a and c are increased, which may be attributed to the insertion of some Ce 3+ into the bulk structure. In addition, it is worth noting that some shoulder peaks appear on the left of the (101) and (104) peaks in the modified samples ( Figure 2D; Figure S1A, Supporting Information).…”