Structural Evolution in P2‐type Layered Oxide Cathode Materials for Sodium‐Ion Batteries

Abstract

Sodium‐ion batteries (SIBs) have attracted much attention due to their abundance, easy accessibility, and low cost. P2‐type layered oxide materials, as one of the most potential cathode candidates for SIBs, have been widely studied. However, various kinds of structural evolution during cycling are harmful to the stability. In the present Minireview, the phase transitions occurring in the process of charge/discharge are summarized, and the mechanism of structural rearrangement and phase transition are introduced. This Minireview is aimed at helping researchers understand the detailed structural evolution, and propose strategies of designing the P2‐type layered oxide cathodes with low strain.

Entropy modulation strategy of P2-type layered transition metal oxide cathodes for sodium-ion batteries with a high performance

“…Compared with the O3-type material, the P2-type Na x TMO 2 has a more stable structure and higher ionic conductivity. 20–22…”

Structural and electrochemical progress of O3-type layered oxide cathodes for Na-ion batteries

“…The internal factors affecting the structural evolution of layered oxides are the number and distribution of sodium-ions within the lattice. 46 Arcelus et al 47 developed a model system using density functional theory calculations to examine the Pn ↔ On transition from an atomic point of view and confirmed that the sliding-driven P → O transition might be successfully prevented at high Na content. The structural evolution during sodium-ion de-embedding can be verified by ex situ XRD tests in different charge and discharge states.…”

Research Progress and Modification Measures of Anode and Cathode Materials for Sodium‐Ion Batteries

“…The electrochemical characteristics of the cathode material affect the electrochemical characteristics of the whole battery. The theoretical energy density of the cathode material is the upper limit of the energy density of the battery cell, and the cathode material affects the power density of the SIBs by affecting the ability to accommodate sodium ions and the fluency of the transmission channel [69–71] . At the same time, the loss of active substances in the cathode material and the impurity composition will affect the life of the battery.…”