Synergetic impact of high-entropy microdoping modification in Na3V2(PO4)3.

High entropy polyanionic Na3V1.9(Ca,Mg,Cr,Ti,Mn)0.1(PO4)3 was synthesized, which activated a reversible redox reaction of V4+/V5+ and reached a remarkable capacity of 116 mA h g-1 at 1C and maintained 90% capacity retention after 1000 cycles at 10C. Structure evolution and sodium storage mechanisms were revealed by an in situ XRD method, which disclosed the high-entropy effect of material design. Together with the full battery tests, these findings promote the wide applications of high-entropy polyanionic cathodes in SIBs.