Na2Ru1−xMnxO3 as the cathode for sodium-ion batteries

Abstract

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 Na₂Ru_1−xMn_xO₃ 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.