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Table 2 Atomic positions and isotopic displacement parameters for a-NazNizFe(PO,)z from X-ray powder diffraction data at 300 K

Table 2 Atomic positions and isotopic displacement parameters for a-NazNizFe(PO,)z from X-ray powder diffraction data at 300 K

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Table 1 Crystallographic and structure refinement data for a-NazNizFe (POa)3 volume transmission grating, holographic notch filter and thermoelectrically cooled CCD detector (Physics Spectra). The spectrometer was regularly calibrated by using neon lines. A Ti**-sapphire laser pumped by an argon ion laser was tuned at 700 nm. The acquisition time was 60 s.
Table 1 Crystallographic and structure refinement data for a-NazNizFe (POa)3 volume transmission grating, holographic notch filter and thermoelectrically cooled CCD detector (Physics Spectra). The spectrometer was regularly calibrated by using neon lines. A Ti**-sapphire laser pumped by an argon ion laser was tuned at 700 nm. The acquisition time was 60 s.
Fig. 1 Final observed, calculated and difference plots for the XRPD (Cu-K, radiation) refinement of «-NazNi2Fe(PO,)3. The inset corresponds to a zoom of the 20 = 10 to 50° area.
Fig. 1 Final observed, calculated and difference plots for the XRPD (Cu-K, radiation) refinement of «-NazNi2Fe(PO,)3. The inset corresponds to a zoom of the 20 = 10 to 50° area.
Fig. 2. Projection views of the structure of a-NazNi2Fe(PO.)z along the b-axis (a), and the a-axis (b). In the [(Ni2/Fe2)O,] octahedra the dyiz/re2-0 distances range from 2.007 to 2.054 A with an average distance of 2.0227 A, whereas in the [(Ni1/Fe1)O,] octahedra, the dyii/re1-0 distances range from 2.027 to 2.086 A with an average value of 2.0617 A. Such Ni?'/Fe** coordination and distance values have been
Fig. 2. Projection views of the structure of a-NazNi2Fe(PO.)z along the b-axis (a), and the a-axis (b). In the [(Ni2/Fe2)O,] octahedra the dyiz/re2-0 distances range from 2.007 to 2.054 A with an average distance of 2.0227 A, whereas in the [(Ni1/Fe1)O,] octahedra, the dyii/re1-0 distances range from 2.027 to 2.086 A with an average value of 2.0617 A. Such Ni?'/Fe** coordination and distance values have been
Fig. 3 Coordinations of the sodium atoms in a-Na2NizFe(PO,)s.
Fig. 3 Coordinations of the sodium atoms in a-Na2NizFe(PO,)s.
“Bond valence sum, B.V. = e”°~”? with the following parameters: b = ) 0.37, To (Na'-O) = 1.803, rp (NiO) = 1.654, ro (Fe''-O) = 1.759, and To (PY-O) = 1.617 A??? Table 3 Interatomic distances (in A) and bond valences (B.V.) for a-NazNizFe(PO,)3. Average distances are given in brackets
“Bond valence sum, B.V. = e”°~”? with the following parameters: b = ) 0.37, To (Na'-O) = 1.803, rp (NiO) = 1.654, ro (Fe''-O) = 1.759, and To (PY-O) = 1.617 A??? Table 3 Interatomic distances (in A) and bond valences (B.V.) for a-NazNizFe(PO,)3. Average distances are given in brackets
Fig. 4 Projections of the structure of B-NazNi,Fe(PO,)z along the c-axis (a), view of the infinite chains of the edge-sharing octahedra (b), and surroundings of the sodium atoms (c, d).
Fig. 4 Projections of the structure of B-NazNi,Fe(PO,)z along the c-axis (a), view of the infinite chains of the edge-sharing octahedra (b), and surroundings of the sodium atoms (c, d).
Table 4 Fitted °’Fe Mossbauer parameters obtained for the a-Na2Ni2Fe- (PO4)z phase (5 = isomeric shift, 7 = full width at half maximum, and A = quadrupole splitting)
Table 4 Fitted °’Fe Mossbauer parameters obtained for the a-Na2Ni2Fe- (PO4)z phase (5 = isomeric shift, 7 = full width at half maximum, and A = quadrupole splitting)
Fig. 5 57Fe Mossbauer experimental and fitted spectra of a-Na2NizFe- (PO,)3 collected at room temperature. The corresponding fitted para- meters are given in Table 4.
Fig. 5 57Fe Mossbauer experimental and fitted spectra of a-Na2NizFe- (PO,)3 collected at room temperature. The corresponding fitted para- meters are given in Table 4.
Fig. 7. The charge—discharge curves of «-NazNizFe(PO,)z at a current density of 50 mA g™t. The inset corresponds to a zoom of the first dis- charge curve in the capacity area 0 to 60 mAhg™.
Fig. 7. The charge—discharge curves of «-NazNizFe(PO,)z at a current density of 50 mA g™t. The inset corresponds to a zoom of the first dis- charge curve in the capacity area 0 to 60 mAhg™.
Fig. 6 Magnetic susceptibility y vs. temperature and the corresponding 71 vs. T plots of a-NazNi2Fe(PO,)3 measured with the applied field H = 100 Oe.
Fig. 6 Magnetic susceptibility y vs. temperature and the corresponding 71 vs. T plots of a-NazNi2Fe(PO,)3 measured with the applied field H = 100 Oe.
Fig. 9 Galvanostatic charge/discharge profiles of NazNizFe(PO,)z in an Na-ion cell ata 5 mA g™ current rate in the voltage range 1.8—4.5 V. During the first charge, Na3Ni,Fe(PO,)3 delivers a capacity of 160 mA h g™* in good agreement with the theoretical
Fig. 9 Galvanostatic charge/discharge profiles of NazNizFe(PO,)z in an Na-ion cell ata 5 mA g™ current rate in the voltage range 1.8—4.5 V. During the first charge, Na3Ni,Fe(PO,)3 delivers a capacity of 160 mA h g™* in good agreement with the theoretical
Fig. 8 Performance of «-NazNizFe(PO.4)z as a negative electrode in the voltage range 0.03-3 V vs. Na*/Na, at 20 °C.
Fig. 8 Performance of «-NazNizFe(PO.4)z as a negative electrode in the voltage range 0.03-3 V vs. Na*/Na, at 20 °C.
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Inorganic ChemistryElectrochemical Energy Storage DeviceLithium-Ion Battery
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