Local structure and redox energies of lithium phosphates with olivine- and Nasicon-like structures

Salah, A. Ait; Jóźwiak, P.; Garbarczyk, Jerzy E.; Benkhouja, K.; Zaghib, Karim; Giligny, François; Julien, C.

doi:10.1016/j.jpowsour.2004.08.029

Cited by 140 publications

(112 citation statements)

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“…The high rate of discharge capacity, excellent columbic efficiency and high structural stability (strong P -O covalent bond in the orthorhombic lattice) has made the olivine -type compounds as attractive cathode materials than the layered (or) spinel oxides for high energy rechargeable batteries [5]. The olivine crystal structure has an orthorhombic lattice with hexagonally closed packed (hcp) oxygen atoms, corner-shared MO 6 octahedra, edge-shared LiO 6 and tetrahedrally coordinated PO 4 polyanions Since 1997, heaps of work has been performed to establish this olivine-type cathode LiMPO 4 with different transition metal cation substitutions, such as M = Fe, Mn, Co and Ni [6][7][8][9] for energy storage applications. It is well known that the conventionally available nonaqueous electrolyte falls within the voltage stability window ranging between 3.5 and 4.5 V.…”

Section: Introductionmentioning

confidence: 99%

Role of structural defects in olivine cathodes

Kandhasamy

Kalaiselvi

Minakshi

2012

Progress in Solid State Chemistry

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The high rate capability and structural stability of the olivine phosphates attracted a lot of interest as promising cathode materials for high energy density batteries. Alteration on these cathode materials, for instance, reducing particle size, conductive coating and metal ion doping were performed in order to improve the conductivity and to obtain high specific Li + diffusion. However, the drastic improvement in electrical conductivity for the aliovalent doping is still unclear. Rather writing a lengthy standard review, this manuscript intends to describe briefly the lattice defects owing to metal ion doping and its influence in improving the cathode performance of the olivine phosphates. This gives a new approach in this field.

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Section: Introductionmentioning

confidence: 99%

Role of structural defects in olivine cathodes

Kandhasamy

Kalaiselvi

Minakshi

2012

Progress in Solid State Chemistry

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“…When an impurity such as Li 3 PO 4 (sample A) is present, the FTIR spectrum displays some modifications in the shape of the doublets and an additional IR band grows at 424 cm -1 . The presence of an impurity was also observed in the high-wave number region of the symmetric and asymmetric (ν 1 -ν 3 ) modes of PO 4 due to the symmetric stretching mode of P 2 O 7 pyrophosphate groups, while the high-frequency band at 1180 cm -1 is assigned to the vibration of the PO 3 terminals [17][18][19]. These two spectral features are fingerprints of the diphosphate impurity.…”

Section: Introductionmentioning

confidence: 99%

Enhanced Electrochemical Properties of LiFePO<sub>4</sub> as Positive Electrode of Li-Ion Batteries for HEV Application

Julien¹,

Zaghib²,

Mauger³

et al. 2012

ACES

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LiFePO 4 materials synthesized using FePO 4 (H 2 O) 2 and Li 2 CO 3 blend were optimized in view of their use as positive electrodes in Li-ion batteries for hybrid electric vehicles. A strict control of the structural properties was made by the combination of X-ray diffraction, FT-infrared spectroscopy and magnetometry. The impact of the ferromagnetic clusters (γ-Fe 2 O 3 or Fe 2 P) on the electrochemical response was examined. The electrochemical performances of the optimized LiFePO 4 powders investigated at 60˚C are excellent in terms of capacity retention (153 mAh·g -1 at 2C) as well as in terms of cycling life. No iron dissolution was observed after 200 charge-discharge cycles at 60˚C for cells containing Li foil, Li 4 Ti 5 O 12 , or graphite as negative electrodes.

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“…Following from Figure 3, no significant differences were observed in the FTIR spectra of the as-prepared Na1+yVPO4F1+y samples. In all the spectra, the characteristic vibrations of the PO4 groups (the Td point group) were predominant [27]. In the spectral region of the internal modes of the PO4 anion, symmetric ν1 (a singlet) and asymmetric ν3 (triply degenerated) stretching modes were located in the high-wavenumber region (900-1150 cm −1 ) and were well separated from the bands due to asymmetric ν4 (triply degenerated) and symmetric ν2 (a doublet) bending vibrations that appeared in the low-wavenumber region (400-500 cm −1 ).…”

Section: Crystal Structure and Morphologymentioning

confidence: 98%

Na1+yVPO4F1+y (0 ≤ y≤ 0.5) as Cathode Materials for Hybrid Na/Li Batteries

Косова

Rezepova

2017

Inorganics

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Using Rietveld-refined X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and electrochemical cycling, it was established that among sodium vanadium fluorophosphate compositions Na 1+y VPO 4 F 1+y (0 ≤ y ≤ 0.75), the single-phase material Na 1.5 VPO 4 F 1.5 or Na 3 V 2 (PO 4 ) 2 F 3 with a tetragonal structure (the P4 2 /mnm S.G.) is formed only for y = 0.5. The samples with y < 0.5 and y > 0.5 possessed different impurity phases. Na 3 V 2 (PO 4 ) 2 F 3 could be considered as a multifunctional cathode material for the fabrication of lithium-ion and sodium-ion high-energy batteries. The reversible discharge capacity of 116 mAh·g −1 was achieved upon cycling Na 3 V 2 (PO 4 ) 2 F 3 in a hybrid Na/Li cell. Decrease in discharge capacity for the other samples was in accordance with the amount of the electrochemically active phase Na 3 V 2 (PO 4 ) 2 F 3 . Na 3 V 2 (PO 4 ) 2 F 3 showed good cycleability and a high rate of performance, presumably due to operation in the mixed Na/Li electrolyte. The study of the structure and composition of charged and discharged samples, and the analysis of differential capacity curves showed a negligible Na/Li electrochemical exchange, and a predominant sodium-based cathode reaction. To increase the degree of the Na/Li electrochemical exchange in Na 3 V 2 (PO 4 ) 2 F 3 , it needs to be desodiated first in a Na cell, and then cycled in a lithium cell. In this case, the electrolyte would be enriched with the Li ions.

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Local structure and redox energies of lithium phosphates with olivine- and Nasicon-like structures

Cited by 140 publications

References 10 publications

Role of structural defects in olivine cathodes

Role of structural defects in olivine cathodes

Enhanced Electrochemical Properties of LiFePO<sub>4</sub> as Positive Electrode of Li-Ion Batteries for HEV Application

Na1+yVPO4F1+y (0 ≤ y≤ 0.5) as Cathode Materials for Hybrid Na/Li Batteries

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Local structure and redox energies of lithium phosphates with olivine- and Nasicon-like structures

Cited by 140 publications

References 10 publications

Role of structural defects in olivine cathodes

Role of structural defects in olivine cathodes

Enhanced Electrochemical Properties of LiFePO&lt;sub&gt;4&lt;/sub&gt; as Positive Electrode of Li-Ion Batteries for HEV Application

Na1+yVPO4F1+y (0 ≤ y≤ 0.5) as Cathode Materials for Hybrid Na/Li Batteries

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Enhanced Electrochemical Properties of LiFePO<sub>4</sub> as Positive Electrode of Li-Ion Batteries for HEV Application