Layered high-entropy oxides as highly stable cathodes for Na-ion batteries

Reducing dependence on lithium-ion batteries (LIBs) represents one of the most significant challenges in the energy transition towards a more sustainable world. Thanks to the great abundance of sodium in nature, Na-ion batteries (NIBs) represent a valid alternative to LIBs. The development of high-performance cathode materials could contribute to their broad market penetration. This contribution focuses on the preparation of layered high-entropy oxides (LHEOs) by a simple and scalable technique and their evaluation as NIB cathode materials. The effect of changes in the microstructure of LHEOs produced by the variation of the calcination conditions (CCs), at fixed Na content (xNa), and of xNa, for fixed CCs, on their electrochemical performance is investigated.