Nanosheet-Assembled Hierarchical Petal-like Na₄MnV(PO₄)₃@Carbonized-Polyaniline Microspheres for Stable Sodium-Ion Batteries

NASICON-structured Na4MnV(PO4)3 (NMVP) has been counted as one of the best alternatives to Na3V2(PO4)3 because of its higher redox voltage and less cost and toxicity, although it still suffers from poor conductivity. To overcome the disadvantage, this study designed nanosheet-assembled hierarchical petal-like NMVP microspheres with a nitrogen-doped carbon matrix via a facile dissolvent evaporation method and heat treatment. After morphological construction and carbonized-polyaniline decoration, the as-prepared NMVP-D@cPANI delivers a robust nanosheet-assembled framework and enhanced electrochemical reaction activity. As a result, the optimized NMVP-D@cPANI half-cell exhibits ultralong cyclability (conservation rate of 85.5% at 10 C (1 C = 111 mA h g–1) over 4000 cycles) and superior rate capability (61.68 mAh g–1 at 50 C). Furthermore, this work achieved a feasible strategy for a low-cost NMVP-D@cPANI//CHC full cell, which proves the possibility of the advancement and application in SIBs for NMVP.