Robust NASICON-type iron-based Na4Fe3(PO4)2(P2O7) cathode for high temperature sodium-ion batteries

•Mesoporous sponge-like NFPP@C@rGO caged in cross-linked dual-carbon frameworks was fabricated via a feasible one-step solid state method.•Enhanced electrical conductivity and kinetics at high temperature has been achieved through nanoengineering and interface regulation.•86.7% capacity retention was obtained after 30,000 cycles at 20 C.•Full cells (NFPP@C@rGO//HC) exhibited outstanding electrochemical performances.