Preparation and Characterisation of the Compounds MFePO5 (M = Ni, Cu)
About: This article is published in Advanced Materials Research.The article was published on 1994-09-01. It has received 6 citations till now.
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TL;DR: In this article, the performance of composite anode material NiFeOPO4/C (NFP/C) vs. Li+/Li0 were investigated at C/5 current rate and in a wide voltage window 0.01-3.0
15 citations
TL;DR: In this article, a cobalt iron oxyphosphate CoFeOPO4@C (abbreviated as CFP@C) anode was prepared via a solid-state route, and its electrochemical performance was investigated vs Li+/Li over a wide voltage range of 0.01-3.0 V at different current rates C/n (n = 20, 10, 5, 2, and 1).
Abstract: A cobalt iron oxyphosphate CoFeOPO4@C (abbreviated as CFP@C) anode was prepared via a solid-state route, and its electrochemical performance was investigated vs Li+/Li over a wide voltage range of 0.01–3.0 V at different current rates C/n (n = 20, 10, 5, 2, and 1). This anode material is able to intercalate more than six lithium ions into the structure at the C/10 current rate, delivering a specific capacity of 748.23 mAh g–1, which is much higher than the theoretical capacity (593.7 mAh g–1) calculated when the insertion of a five lithium ions is considered. A reversible capacity of 200 mAhg–1 was maintained after 30 cycles. Raman spectroscopy confirmed the incorporation of carbon layers into the CoFeOPO4@C composite. Scanning electronic microscopy revealed that CFP@C particles have an angular-flake shape with particle sizes ranging between 1 and 5 μm. In situ X-ray absorption spectroscopy of Fe and Co at the K-edge showed that both transition metals are active during the whole discharge and charge. In o...
14 citations
TL;DR: In this paper, double phosphates (V) Zn3Cr4(PO4)6 and Mg3c4-PO4-6 were synthesized by non-waste solid-state reaction, performed in the temperature range 350-1150°C, and the change in phase composition of samples during the synthesis, depending on the heating temperature, was examined using the XRD method.
Abstract: For the first time, double phosphates(V) Zn3Cr4(PO4)6 and Mg3Cr4(PO4)6 were synthesized by non-waste solid-state reaction, performed in the temperature range 350–1150 °C. The change in the phase composition of samples during the synthesis, depending on the heating temperature, was examined using the XRD method. The results of the DTA measurements enabled both the correct selection of the heating temperatures of the samples and the determination of the thermal stability of the phases obtained. Zn3Cr4(PO4)6 and Mg3Cr4(PO4)6 have relatively high thermal stability in air, i.e. they melt incongruently at 1340 °C and about 1450 °C, respectively. Crystallites of the obtained double phosphates, observed by SEM method, are similar in shape, when their sizes are of the order of 0.5–6 µm. IR spectra of both double phosphates are presented. A new solid solution of the formula Zn1.5Mg1.5Cr4(PO4)6 was also obtained. It is stable in air up to 1412 °C. The energy gaps of Zn3Cr4(PO4)6, Mg3Cr4(PO4)6 and Zn1.5Mg1.5Cr4(PO4)6 are 4.00, 3.60 and 3.75 eV, respectively, as estimated from their UV–Vis DR spectra. The colour of all phases expressed in the coordinates of CIE L*C*h* colour space is very similar, and according to the RAL system, it can be described as boulder brown. All the obtained phases are good candidates to be as inorganic pigments.
5 citations
Cites background from "Preparation and Characterisation of..."
...The second absorption band in the wavenumber range 700–490 cm−1 probably comes from the stretching vibrations of M–O bonds in the MO5 (M = Mg, Zn) and MO6 (M = Cr, Mg, Zn) polyhedra coupled with the vibrations in PO4 tetrahedra [19, 20, 23]....
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2 citations
TL;DR: In this paper, the electrochemical activity of CoFeOPO4@C in half-cells and evaluate its potential use as an anode material for sodium ion batteries was evaluated.
2 citations