Electroactivity of natural and synthetic triphylite

Ravet, Nathalie; Chouinard, Y.; Magnan, Jean-François; Besner, Simon; Gauthier, Michel; Armand, Michel

doi:10.1016/s0378-7753(01)00727-3

Cited by 884 publications

(716 citation statements)

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“…NMR is a valuable tool for probing the structural changes that arise in electrode materials during electrochemical battery cycling. The resonances of 7 Li in diamagnetic chemical environments like in an electrolyte and the SEI (surface electrolyte interphase) are shown at about ± 10 ppm. Alternatively, the resonances of 7 Li in paramagnetic phases can be made as large as −500 to +3000 ppm, since the unpaired electrons from the paramagnets are capable of hyperfine interaction with them.…”

Section: Introductionmentioning

confidence: 99%

“…However, the practical capacity of 100-110 mAh −1 g associated with LiFePO 4 differs from the theoretical value (170 mAh −1 g), since the number of Li atoms per unit of LiFePO 4 is 0.6 in reality. 7 To explain the correlation between the characteristics and microstructure of these various materials, Nuclear Magnetic Resonance (NMR) studies are needed. NMR is a valuable tool for probing the structural changes that arise in electrode materials during electrochemical battery cycling.…”

Section: Introductionmentioning

confidence: 99%

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Development of 600-MHz¹⁹F-⁷Li Solid-State NMR Probe for In-Situ Analysis of Lithium Ion Batteries

Jeong¹,

Park

Choi³

et al. 2013

Bulletin of the Korean Chemical Society

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Lithium is a highly attractive material for high-energy-concentration batteries, since it has low weight and high potential. Rechargeable lithium-ion batteries (LIBs), which have the extremely high gravimetric and volumetric energy densities, are currently the most preferable power sources for future electric vehicles and various portable electronic devices. In order to improve the efficiency and lifetime, new electrode compounds for lithium intercalation or insertion have been investigated for rechargeable batteries. Solid-state nuclear magnetic resonance (NMR) is a very useful tool to investigate the structural changes in electrode materials in actual working lithium-ion batteries. To detect the in-situ microstructural changes of electrode and electrolyte materials, 7 Li-19 F double-resonance solid-state NMR probe with a static solenoidal coil for a 600-MHz narrowbore magnet was designed, constructed, and tested successfully.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Development of 600-MHz¹⁹F-⁷Li Solid-State NMR Probe for In-Situ Analysis of Lithium Ion Batteries

Jeong¹,

Park

Choi³

et al. 2013

Bulletin of the Korean Chemical Society

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“…[1][2][3] However, the commercial application of LiFePO4 as a cathode for lithium secondary batteries has been limited because of its low electrical conductivity and poor rate capability. Recent research efforts have focused on improving the electrical conductivity of LiFePO 4 by coating carbonaceous conductors [4][5][6] and doping with metallic elements such as Cr, Mg, Ni, or Co. [7][8][9] Ravet et al 4 coated LiFePO4 using sucrose, cellulose acetate, and a modified polycyclic aromatic and achieved the initial discharge capacity up to 140 mAhg -1 . Prosini et al 5 investigated LiFePO4 coated with 10 wt % carbon black and obtained initial capacity up to 120 mAhg -1 .…”

Section: Introductionmentioning

confidence: 99%

“…Prosini et al 5 investigated LiFePO4 coated with 10 wt % carbon black and obtained initial capacity up to 120 mAhg -1 . Chung et al 7 reported that electrical conductivity of LiFePO 4 was enhanced by metal doping and the doped cathode delivered 140 mAhg -1 at 0.1 C. Wang et al 9 also reported the enhancement of rate performance of LiFePO 4 by metal doping without increasing the initial capacity. They suggested that the initial capacity is mainly improved by increasing the electrical conductivity of the LiFePO 4 , while the rate performance could be enhanced by metal doping.…”

Section: Introductionmentioning

confidence: 99%

“…Chung et al 7 reported that electrical conductivity of LiFePO 4 was enhanced by metal doping and the doped cathode delivered 140 mAhg -1 at 0.1 C. Wang et al 9 also reported the enhancement of rate performance of LiFePO 4 by metal doping without increasing the initial capacity. They suggested that the initial capacity is mainly improved by increasing the electrical conductivity of the LiFePO 4 , while the rate performance could be enhanced by metal doping. On the other hand, it was also suggested that the electrical conductivity of LiFePO 4 could be improved by the presence of residual carbon after synthesis.…”

Section: Introductionmentioning

confidence: 99%

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The Origin of the Residual Carbon in LiFePO₄Synthesized by Wet Milling

Park¹,

Park²,

Hwang³

et al. 2011

Bulletin of the Korean Chemical Society

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This study reports the origin of the electrochemical improvement of LiFePO4 when synthesized by wet milling using acetone without conventional carbon coating. The wet milled LiFePO4 delivers 149 mAhg -1 at 0.1 C, which is comparable to carbon coated LiFePO4 and approximately 74% higher than that of dry milled LiFePO4, suggesting that the wet milling process can increase the capacity in addition to conventional carbon coating methods. UV spectroscopy, elemental microanalysis, and evolved gas analysis are used to find the root cause of the capacity improvement during the mechanochemical reaction in acetone. The analytical results show that the improvement is attributed to the conductive residual carbon on the surface of the wet milled LiFePO4 particles, which is produced by the reaction of FeC2O4· 2H2O with acetone during wet milling through oxygen deficiency in the precursor.

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Intercalation Chemistry

Jacobson

Nazar

2005

Encyclopedia of Inorganic Chemistry

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The term ‘intercalation’ refers to a process whereby a guest molecule or ion is inserted into a host lattice. The structure of the guest–host or intercalation compound is only slightly perturbed from the host structure and the reaction used to form the compound is reversible. In this chapter, the major classes of host lattice are classified by both dimensionality and electronic properties. In three‐dimensional systems, the sizes of the guest species are constrained by the dimensions of the host lattice. In lower dimensional systems, no such restriction exists and the strongly bonded layers or chains can adjust their separation freely to accommodate guest species of different sizes. With increasing guest size, the structural correlation between layers or chains is diminished and in the limiting case, complete separation of single layers or chains occurs in solution, resulting in the formation of colloidal dispersions. Insulating host lattices undergo reactions that involve ion exchange, acid–base chemistry, solvent exchange, and sorption of neutral molecules from the gas phase. The insulating hosts have a fixed concentration of ionic guests that remains unchanged throughout subsequent reactions. The conducting host lattices have the feature that the concentration of ionic guest species can be altered by oxidation or reduction of the host. The chemistry of most compounds involves reduction and cation intercalation with the major exceptions of graphite and some layered oxides, which can be both reductively intercalated with cations and oxidized with anion insertion. The present understanding of the mechanism of intercalation with particular emphasis on layered structures is reviewed. Reactions involve adsorption of guest species on host crystals, exchange or insertion at the host surface, the formation of intermediate stages in layered compounds, and transport within the host lattice. Macroscopic effects such as variations in crystal size, dislocations, stacking faults, and pore mouth blockage can strongly influence the reaction kinetics. The major classes of host lattices in each category and their chemical behavior are described. The insulating materials discussed include zeolites, clays, layered double hydroxides, acid phosphates, and layered oxides while graphite, C 60 , carbon nanotubes, transition metal chalcogenides, metal phosphorus trisulfides, metal oxyhalides, metal nitride halides, and metal oxides are the major examples of conducting hosts. In the case of metal oxides, examples of both reductive intercalation of lithium ions and oxidative intercalation of oxide ions are discussed. These two types of intercalation reactions are important for lithium batteries and high‐temperature superconductivity, respectively.

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Electroactivity of natural and synthetic triphylite

Cited by 884 publications

References 1 publication

Development of 600-MHz¹⁹F-⁷Li Solid-State NMR Probe for In-Situ Analysis of Lithium Ion Batteries

Development of 600-MHz¹⁹F-⁷Li Solid-State NMR Probe for In-Situ Analysis of Lithium Ion Batteries

The Origin of the Residual Carbon in LiFePO₄Synthesized by Wet Milling

Intercalation Chemistry

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Electroactivity of natural and synthetic triphylite

Cited by 884 publications

References 1 publication

Development of 600-MHz19F-7Li Solid-State NMR Probe for In-Situ Analysis of Lithium Ion Batteries

Development of 600-MHz19F-7Li Solid-State NMR Probe for In-Situ Analysis of Lithium Ion Batteries

The Origin of the Residual Carbon in LiFePO4Synthesized by Wet Milling

Intercalation Chemistry

Contact Info

Product

Resources

About

Development of 600-MHz¹⁹F-⁷Li Solid-State NMR Probe for In-Situ Analysis of Lithium Ion Batteries

Development of 600-MHz¹⁹F-⁷Li Solid-State NMR Probe for In-Situ Analysis of Lithium Ion Batteries

The Origin of the Residual Carbon in LiFePO₄Synthesized by Wet Milling