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

Abstract

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.

High-Rate-Capacity Cathode Based on Zn-Doped and Carbonized Polyacrylonitrile-Coated Na4MnV(PO4)3 for Sodium-Ion Batteries

“…Meanwhile, the Zn 2p spectrum (Figure d) exhibits two conspicuous peaks at 1022.2 and 1045.2 eV, corresponding to Zn 2p 3/2 and Zn 2p 1/2 , respectively. The result shows that Zn is bivalent. − The C 1s spectrum (Figure e) exhibits three peaks corresponding to the C–C bond (284.8 eV), C–O bond (286.4 eV), and O–CO bond (288.6 eV). ,, The N 1s XPS spectrum (Figure f) shows the peaks for three different states of N, including pyridinic nitrogen (398.6 eV), pyrrolic nitrogen (400.8 eV), and graphitic nitrogen (402.4 eV) . The presence of N is mostly attributed to PAN. , The disorder states of nitrogen provide more defects and vacancies for the carbonized PAN layer.…”

“…53−55 The C 1s spectrum (Figure 2e) exhibits three peaks corresponding to the C−C bond (284.8 eV), C−O bond (286.4 eV), 56 and O−C�O bond (288.6 eV). 32,57,58 The N 1s XPS spectrum (Figure 2f) shows the peaks for three different states of N, including pyridinic nitrogen (398.6 eV), pyrrolic nitrogen (400.8 eV), and graphitic nitrogen (402.4 eV). 59 The presence of N is mostly attributed to PAN.…”

“…More specifically, dimethylformamide (DMF) was used during the dissolution process of the raw material because it could homogenize all ingredients. Furthermore, the nitrogen content of PAN provides extra defects and active sites, which enhance the electrochemical reactivity of the material. , Particularly, the modification mechanism of Zn substitution was studied using experimental studies and density functional theory (DFT) calculations. − Predictably, NMZVP@cPAN exhibited distinguished fast charge–discharge properties and cycling stability.…”

NASICON-Type Na3V1.5Cr0.4Fe0.1(PO4)3: High-Voltage and High-Rate Cathode Materials for Sodium-Ion Batteries

“…The growing concerns related to adverse climatic changes and associated remedies in the form of renewable energy have resulted in an increasing need for new energy storage technologies. 1,2 The use of high-energy density lithium-ion batteries (LIBs) in long-range electric vehicles is almost inevitable; 3,4 however, consumer utilities and demands on secondary batteries as a storage hub for wind and solar energy confirm that sodium-ion batteries (SIBs) are a promising alternative for large-scale energy storage applications owing to the abundance and cost efficiency of sodium resources. 5,6 Cathode material development is challenging for SIBs because of the larger size and high charge density of sodium ions, which limit their mobility and diffusion kinetics.…”

Synergistic Strain Suppressing and Interface Engineering in Na4MnV(PO4)3/C for Wide-Temperature and Long-Calendar-Life Sodium-Ion Storage

“…Moreover, morphology control of the NMVP cathode is on designing hierarchical micro/nanostructures, like the hierarchical bayberry-like NMVP@NC and hierarchical petal-like NMVP-D@cPANI, offering rich electron/ion transport pathways and excellent interface compatibility. 30,31 Herein, a series of Zr-doped and surface carbon-coated Na 4−x MnV 1−x Zr x (PO 4 ) 3 /C (x = 0, 0.025, 0.05, 0.075, and 0.1) materials were synthesized by a combination of sol−gel and annealing methods. As a functional ion with rich free electrons on the d-orbital, Zr 4+ -doping can not only effectively enrich the local electron density of NMVP and interface engineering but also improve the reaction kinetics, greatly increasing the electrochemical performances of NMVP materials.…”