P2-layered Na_0.5Li_0.07Mn_0.61Co_0.16Ni_0.16O₂ cathode boosted Na-storage properties via rational sub-group element doping

Abstract

P2-layered metal oxide cathodes exhibited greatly promising in sodium ion batteries due to their unique two-dimensional tunnel structure, high energy density and high redox potential, etc. However, the inferior structural...

A high-performance Na-storage cathode enabled by layered P2-type KxMnO2 with enlarged interlayer spacing and fast diffusion channels for sodium-ion batteries

“…For the pristine KMO electrode, the binding energy of Mn 2p revealed the coexistence of Mn 3+ (652.96 and 641.12 eV) and Mn 4+ (654.50 and 642.81 eV) with an area ratio of 2.15, which is consistent with the structural chemical formula of K 0.69 MnO 2 . 42 When fully charged to 4.3 V, the peaks of Mn 2p move to higher binding energies, and the deconvoluted results manifest the transitions of Mn 3+ to Mn 4+ upon K + extraction. Upon discharging to 1.8 V, a large number of Mn 3+ is produced from the reduction of Mn 4+ .…”

Surface Lattice‐Matched Engineering Based on In Situ Spinel Interfacial Reconstruction for Stable Heterostructured Sodium Layered Oxide Cathodes

“…[23][24][25][26] Compared with O-type, the P-type Na x TMO 2 is able to achieve a better rate and cycling performance because of the open prismatic structure which is a benefit to Na + mobility. [27][28][29] Whereas volume expansion occurring through irreversible P2-O2 phase translation at high voltage would result in the capacity decrease, which would hinder the achievement of high-energy density SIBs. [30,31] To solve these issues, a biphase intergrowth structure has been proposed such as P2/O3 and P2/P3 layered composited cathode materials, which implements the integration of merits of different structures to enhance electrochemical performance compared with separated counterparts.…”

Single-Crystal Growth of P2-Type Layered Oxides with Increased Exposure of {010} Planes for High-Performance Sodium-Ion Batteries

“…Moreover, SIBs exhibit considerable potential for cost reduction owing to the abundance of sodium resources. , Cathode materials considerably influence the performance of SIBs. Among the three types of promising cathode materials (layered oxides, − polyanionic compounds, − and Prussian blue analogs − ), layered oxides (Na x TMO 2 , where TM represents transition-metal elements) have the advantages of easy synthesis and high specific capacity as well as tap density. P2-type layered oxides have a lower energy barrier for sodium-ion migration than O3- and P3-type layered oxides .…”