Understanding the structural phase transitions in lithium vanadium phosphate cathodes for lithium-ion batteries

2020 ◽  
Vol 8 (20) ◽  
pp. 10331-10336 ◽  
Author(s):  
Woong Oh ◽  
Hyunyoung Park ◽  
Bong-Soo Jin ◽  
Ranjith Thangavel ◽  
Won-Sub Yoon
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Lithium Ion Batteries ◽  
Structural Phase ◽  
Lithium Ion ◽  
Lithium Vanadium Phosphate ◽  
Phase Reaction ◽  
Structural Phase Transitions ◽  
Vanadium Phosphate ◽  
Two Phase

Inconspicuous two-phase reaction during Li0V2(PO4)3–Li2V2(PO4)3 phase transition in Li3V2(PO4)3 cathode.

scholarly journals The origin of the lattice thermal conductivity enhancement at the ferroelectric phase transition in GeTe

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Đorđe Dangić ◽  
Olle Hellman ◽  
Stephen Fahy ◽  
Ivana Savić
Keyword(s):  
Phase Transition ◽  
Thermal Conductivity ◽  
Phase Transitions ◽  
Thermoelectric Materials ◽  
Ferroelectric Phase Transition ◽  
Lattice Thermal Conductivity ◽  
Ferroelectric Phase ◽  
Structural Phase ◽  
High Symmetry ◽  
Structural Phase Transitions

AbstractThe proximity to structural phase transitions in IV-VI thermoelectric materials is one of the main reasons for their large phonon anharmonicity and intrinsically low lattice thermal conductivity κ. However, the κ of GeTe increases at the ferroelectric phase transition near 700 K. Using first-principles calculations with the temperature dependent effective potential method, we show that this rise in κ is the consequence of negative thermal expansion in the rhombohedral phase and increase in the phonon lifetimes in the high-symmetry phase. Strong anharmonicity near the phase transition induces non-Lorentzian shapes of the phonon power spectra. To account for these effects, we implement a method of calculating κ based on the Green-Kubo approach and find that the Boltzmann transport equation underestimates κ near the phase transition. Our findings elucidate the influence of structural phase transitions on κ and provide guidance for design of better thermoelectric materials.

X-ray diffraction and Raman study of DL-alanine at high pressure: revision of phase transitions

2012 ◽  
Vol 68 (4) ◽  
pp. 412-423 ◽  
Author(s):  
Nikolay A. Tumanov ◽  
Elena V. Boldyreva
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Structural Phase ◽  
Group Symmetry ◽  
Second Phase ◽  
Structural Phase Transitions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Raman Study

The effect of pressure on DL-alanine has been studied by X-ray powder diffraction (up to 8.3 GPa), single-crystal X-ray diffraction and Raman spectroscopy (up to ∼ 6 GPa). No structural phase transitions have been observed. At ∼ 1.5–2 GPa, cell parameters b and c become accidentally equal to each other, but the space-group symmetry does not change. There is no phase transition between 1.7 and 2.3 GPa, contrary to what has been reported earlier [Belo et al. (2010). Vibr. Spectrosc. 54, 107–111]. The presence of the second phase transition, which was claimed to appear within the pressure range from 6.0 to 7.3 GPa (Belo et al., 2010), is also argued. The changes in the Raman spectra have been shown to be continuous in all the pressure ranges studied.

Lithium vanadium phosphate as cathode material for lithium ion batteries

Ionics ◽  
2015 ◽  
Vol 21 (5) ◽  
pp. 1201-1239 ◽  
Author(s):  
Du Tao ◽  
Shengping Wang ◽  
Yongchao Liu ◽  
Yu Dai ◽  
Jingxian Yu ◽  
...  
Keyword(s):  
Cathode Material ◽  
Lithium Ion Batteries ◽  
Lithium Ion ◽  
Lithium Vanadium Phosphate ◽  
Vanadium Phosphate

Structural phase transitions coupled with prominent dielectric anomalies and dielectric relaxation in a one-dimensional organic–inorganic hybrid compound [C3H4NS][CdCl3]

2015 ◽  
Vol 3 (33) ◽  
pp. 8535-8541 ◽  
Author(s):  
Guang-Quan Mei ◽  
Wei-Qiang Liao
Keyword(s):  
Phase Transitions ◽  
Dielectric Relaxation ◽  
Structural Phase ◽  
Structural Phase Transitions ◽  
Two Phase ◽  
Hybrid Compound ◽  
Inorganic Hybrid ◽  
One Dimensional

A one-dimensional organic–inorganic hybrid exhibits two phase transitions at 288 and 215 K, coupled with remarkable dielectric performances.

Effects of nickel-doped lithium vanadium phosphate on the performance of lithium-ion batteries

2012 ◽  
Vol 542 ◽  
pp. 187-191 ◽  
Author(s):  
Yong Zhang ◽  
Qing-yuan Huo ◽  
Yan Lv ◽  
Li-zhen Wang ◽  
Ai-qin Zhang ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
Lithium Ion ◽  
Lithium Vanadium Phosphate ◽  
Vanadium Phosphate

Magnesium/chloride co-doping of lithium vanadium phosphate cathodes for enhanced stable lifetime in lithium-ion batteries

2018 ◽  
Vol 42 (16) ◽  
pp. 13667-13673 ◽  
Author(s):  
Shuting Sun ◽  
Ruhong Li ◽  
Deying Mu ◽  
Zeyu Lin ◽  
Yuanpeng Ji ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
Magnesium Chloride ◽  
Lithium Ion ◽  
Lithium Vanadium Phosphate ◽  
Vanadium Phosphate ◽  
Co Doping ◽  
Cl Atoms ◽  
Co Doped

Combining XRD with 31P NMR, it is demonstrated that the Mg and Cl atoms of the new Mg and Cl co-doped Li3V2(PO4)3/C material occupy V and O sites in its structure, respectively.

scholarly journals Computer simulation of the structural phase transitions in thin ferroelectric films

2017 ◽  
Vol 07 (01) ◽  
pp. 1750004 ◽  
Author(s):  
O. G. Maksimova ◽  
A. V. Maksimov ◽  
O. S. Baruzdina
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Boundary Conditions ◽  
Order Parameter ◽  
Mixed Boundary ◽  
Structural Phase ◽  
Film Surface ◽  
Mixed Boundary Conditions ◽  
Structural Phase Transitions ◽  
Ferroelectric Films

The influence of free surface and depolarizing field on structural phase transitions in thin ferroelectric films from an ordered state to a disordered one is investigated. The dependences of the order parameter on the distance from the free film surface are calculated. It is shown that with the presence of the depolarizing field and in its absence, the effective thickness of the surface layer depends on the temperature. Nearby the phase transition point, the thickness increases indefinitely. Calculations considering depolarizing field showed that the phase transition points for the bulk ferroelectrics and the film under given boundary conditions coincide. Also shown that in the absence of depolarizing field with mixed boundary conditions, the film thickness does not affect the order parameter, and in presence of the field, this influence is observed.

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