Insight into the diffusion mechanism of sodium ion–polaron complexes in orthorhombic P2 layered cathode oxide Na_xMnO₂

Abstract

Small polaron and diffusion mechanism of Na ions in the layered orthorhombic cathode oxide NaxMnO2 applied for sodium-ion batteries.

Anionic Redox and Electrochemical Kinetics of the Na2Mn3O7 Cathode Material for Sodium-Ion Batteries

“…Na x MnO 2 was first investigated by Hagenmuller et al in 1971, where synthesis and structures of different sodium–manganese–oxygen systems from the tunnel to layered structures were reported . Later, many studies have explored the sodium insertion/disinsertion in this system including low-temperature α-NaMnO 2 , high-temperature β-NaMnO 2 , P2-Na x MnO 2 , , and tunnel-Na x MnO 2 . , Recently, Na 2 Mn 3 O 7 has attracted great attention as a potential cathode material for SIBs. This compound was first described by Chang et al in 1985, where they reported a synthesis method as well as an in-depth investigation of the structure using the Rietveld refinement of X-ray diffraction (XRD) data.…”

“…16,17 Na x MnO 2 was first investigated by Hagenmuller et al in 1971, where synthesis and structures of different sodium− manganese−oxygen systems from the tunnel to layered structures were reported. 18 Later, many studies have explored the sodium insertion/disinsertion in this system including lowtemperature α-NaMnO 2 , 19 high-temperature β-NaMnO 2 , 20 P2-Na x MnO 2 , 21,22 and tunnel-Na x MnO 2 . 23,24 Recently, Na 2 Mn 3 O 7 has attracted great attention as a potential cathode material for SIBs.…”

Effect of Mg Substitution on Structural Stabilization of NaxMnO2 Cathode for Na‐Ion Batteries

“…These values remain in agreement with DFT simulations by Maitra et al, [ 25 ] who reported energy bandgap of 1.3 eV for Na 2/3 Mg 1/3 Mn 2/3 O 2 . On the other hand, energy bandgap for Na 2/3 MnO 2 was reported to be 2.0 eV, [ 47 ] which justifies higher concentration of charge carriers for the Mg‐substituted compound and, consequently, higher electronic component of conductivity.…”

New family of layered N-based cathode materials for sodium-ion batteries

“…4 Following the success of cathode materials of lithium-ion batteries, various cathode materials for SIBs have been reported, such as layered transition metal oxides, polyanionic compounds, Prussian blue analogs and organic materials. 5 It is found that layered metal oxides, such as NaMO 2 (M = Co, Mn, Fe), [6][7][8] have high theoretical capacity. However, the multi-phase transition is easily induced in layered metal oxide during the charge and discharge processes, which badly hinders the diffusion of sodium ions.…”