Na2Ru1−xMnxO3 as the cathode for sodium-ion batteries

Sodium-ion batteries (SIBs) have attracted a surge of attention as a potential alternative for replacing lithium-ion batteries (LIBs). However, the current cathodes of SIBs suffer from problems of limited capacity, capacity decay, inferior cycling performance and structural instability. Na2RuO3 is known for its high capacity including both cationic redox and anionic redox processes. Here, we show a general method for improving the sodium storage performance of Na2RuO3via Mn doping. A series of Na2Ru1−xMnxO3 are explored through X-ray diffraction (XRD), galvanostatic charge–discharge testing, electrochemical impedance spectroscopy (EIS) measurements and so on. The results exhibit that a suitable Mn doping (x = 0.1) enhances the kinetics and structural stability of the electrode, accounting for a superior electrochemical performance. Our findings provide a simple method to develop advanced cathodes for SIBs with a long lifespan and large capacity.