Dual stabilization in potassium Prussian blue and cathode/electrolyte interface enables advanced potassium-ion full-cells

•1. A synergistic stabilization strategy in KPB and cathode/electrolyte interface is developed to boost the potassium storage performance of KPB cathode.•2. The structure of KPB is stabilized through adjusting the co-precipitation process and inhibiting nucleation and growth by adding EDTA-2 K.•3. The cathode/electrolyte interface is stabilized in KFSI electrolyte to further enhance the CE and cyclic stability of KPB.•4. The KPB//graphite full-cell device is constructed to demonstrate its practical use, exhibiting high capacity, high-rate and superior cyclic stability.