In this work, carbon nanotube–intertwined Na3V2(PO4)2F3 nanospheres (notated as NVPF@CNTs) are successfully synthesized by a solvothermal method and subsequent heat treatment.

2020年3月1日 · Incorporation of high energy NVPF, stable NVP, highly conductive V 2 O 3, and sodium ion active Na 3 VF 6, NVPF/NVP/C composite exhibits high energy, high rate, and long cycle performances. These findings can enrich the understanding of vanadium-based polyanion cathode materials for energy storage and may trigger interest in hybrid cathode ...

2022年9月1日 · Na 3 V 2 (PO 4) 2 F 3 nanosheets coated by a layer of carbon are self-assembled into micron particles which disperse in the three-dimensional network formed by carbon nanotubes. NVPF@C/CNTs nanocomposites exhibit better structure stability and improved electronic conductivity, cycling stability and rate capacity.

NVPF/rGO shows 119 mAh g −1 discharge capacity at 0.5 C, with an excellent rate capability of 71 mAh g −1 at 20 C and 114 mAh g −1 when charged back at 0.5 C.

2023年3月1日 · The leached NVPF powders were discharged to 2 V (0% state of charge) vs. Na metal for FTIR measurement. FTIR spectra were recorded on a Nicolet iS5 FTIR spectrometer, mounted with a diamond Attenuated Total Reflectance accessory (iD1 ATR).

Figure 1 b displays the Fourier transform infrared (FTIR) spectrum of the prepared Na 3 V 2 (PO 4 ) 2 O 2 F. The broad band at 1000-1150 cm −1 can be ascribed to the asymmetric stretching ...

2018年7月7日 · Here, a cross-linked graphene-caged Na 3 V 2 (PO 4) 2 F 3 microcubes (NVPF@rGO) composite via a one-pot hydrothermal strategy followed by freeze drying and heat treatment is reported. As a cathode for a sodium-ion half-cell, the NVPF@rGO delivers excellent cycling stability and rate capability, as well as good low temperature adaptability.

Here, we propose a water based hydrothermal route to prepare well-crystallized NVPF, without any extra heat treatment process. In this route, all the raw materials (H 3 PO 4, NH 4 VO 3, NaF, and oxalic acid) are common and cheap, and NVPF@C tetragons can be one-step synthesized at 180°C with deionized water as solvent.

The phase con rmations of NVPF-(002) and pure-NVPFs (NVPF) were characterized and analyzed by synchrotron radiation X-ray diffraction (SRXRD), Fourier transform infrared (FTIR) spec-troscopy, and Raman spectroscopy. As shown in Fig. 1a and b, the SRXRD patterns of the synthesized samples accorded with

2021年12月31日 · Na 3 V 2 (PO 4) 2 F 3 (NVPF) is one of the Na-containing superionic conducting crystals, but it has a disadvantage of low intrinsic electronic conductivity. To improve this issue, NVPF@C/G with a three-dimensional conductive structure from bio-carbon (buckwheat) and graphene is fabricated via a straightforward carbothermal reduction method. We ...