Sustainable alternative cathodes of sodium-ion batteries using hybrid P2/O3 phase Na0.67Fe0.5Mn0.5−xMgxO2

The Na0.67Fe0.5Mn0.5−xMgxO2 compound with x = 0.02, 0.04, 0.06, 0.08, 0.1, 0.15 was synthesized by solid state reaction. The structure of the samples gradually transformed from P2 phase to O3 phase with the increase of Mg content. The hybrid P2/O3 phase transition metal oxides with high performance was prepared to promote the application of sodium-ion batteries. Na0.67Fe0.5Mn0.46Mg0.04O2 exhibited a hybrid P2/O3 phase structure, which showed high electrochemical performance. Due to the synergy of P2 and O3 phase, the conductivity for the migration of Na ions in the experimental cell, exhibited the highest ion diffusivity. Here, Fe and Mn-based transition metal oxide materials as a cathode material can have great application potential for sodium-ion batteries and can be one of the most promising alternatives to the limited lithium-ion battery. •The introduction of Mg2+ in P2-Na0.67Fe0.5Mn0.5O2 will cause the transformation of P2 phase to O3 phase with a tremendous influence to the electrochemical performance.•Owing to the synergetic effect of hybrid P2 and O3 phases, the hybrid P2/O3 phase Na0.67Fe0.5Mn0.46Mg0.04O2 exhibits superior sodium-ion diffusivity and exceptional cycling performance.•The LED and tunner can bedriven by the prepared sodium-ion batteries.