High-quality Prussian blue crystals as superior cathode materials for room-temperature sodium-ion batteries

High-quality Prussian blue crystals with a small number of vacancies and a low water content are obtained by employing Na4Fe(CN)(6) as the single iron-source precursor. The high-quality Prussian blue shows high specific capacity and remarkable cycling stability as the cathode material for Na-ion batteries because of its excellent ion storage capability and impressive structure stability.