scholarly journals Зависимость электрохимических параметров композитных SiO/C-анодов для литий-ионных аккумуляторов от состава и температуры синтеза

2022 ◽  
Vol 92 (3) ◽  
pp. 421
Author(s):  
Д.А. Ложкина ◽  
Е.В. Астрова ◽  
А.М. Румянцев
Keyword(s):  
Diffusion Coefficient ◽  
Discharge Capacity ◽  
Solid Phase ◽  
Rate Capability ◽  
Silicon Monoxide ◽  
Discharge Voltage ◽  
Lithium Oxide ◽  
Coulomb Efficiency ◽  
The Difference ◽  
Charge Discharge

The results of a study of anodes obtained by carbonization of silicon monoxide by means of a reaction with solid-phase fluorocarbon CF0.8 are presented. Charge/discharge voltage profiles were studied at different currents depending on the composition and temperature of the synthesis of composites. The irreversible losses of the 1st cycle and the contribution to them of intrinsic losses due to the formation of lithium oxide and its silicates and losses associated with the formation of SEI are analyzed. A difference has been established in the behavior of anodes made of SiO carbonized by annealing with CF0.8 at T=800°C (SiO/C composite) and silicon monoxide annealed with CF0.8 at T>1000°C, at which disproportionation occurs simultaneously with the carbonization of SiO (d-SiO/C composite). The difference consisting in a higher discharge capacity, a higher Coulomb efficiency, and better rate capability of d-SiO/C is explained by a change in the composition of the SiOx matrix that occurs during the disproportionation process. The effect of the formation of d-SiO/C anodes by preliminary lithiation with a low current, after which the electrodes can be charged and discharged with much higher currents, has been discovered. The effect is explained by the amorphization of silicon crystallites and the increasing diffusion coefficient of lithium

scholarly journals Формирование кремниевых нанокластеров при диспропорционировании моноокиси кремния

2021 ◽  
Vol 55 (4) ◽  
pp. 373
Author(s):  
Д.А. Ложкина ◽  
Е.В. Астрова ◽  
Р.В. Соколов ◽  
Д.А. Кириленко ◽  
А.А. Левин ◽  
...  
Keyword(s):  
Activation Energy ◽  
Solid Phase ◽  
Silicon Monoxide ◽  
Nanocrystalline Silicon ◽  
X Ray Diffraction ◽  
Isochronous Annealing ◽  
Transmission Electron ◽  
Amorphous Medium ◽  
The Difference ◽  
First Time

In this work, the processes of disproportionation of solid-phase silicon monoxide, accompanied by the formation of nanocrystalline silicon precipitates in the medium of amorphous SiOx suboxide (initial composition SiO0.9), have been studied. Based on the data of X-ray diffraction analysis and transmission electron microscopy, the dynamics of changes in the amount, concentration and size of phase precipitates of silicon with an increase in the temperature of isochronous annealing from 800 °C to 1200 °C is traced. It was found that with a monotonic increase in the total mass of the precipitated silicon, the number of its crystallization centers per unit volume nonmonotonically depends on temperature. The activation energy of diffusion of silicon atoms in the SiOx matrix was determined to be Ea1= 1.64 eV, and the activation energy of their transfer from the formed precipitates to the growth medium of SiOx was Ea2 = 2.38 eV. Anisotropic deformation of silicon crystallites precipitated during the disproportionation of SiO has been revealed for the first time. This phenomenon is associated with the difference in the specific volumes of the separated phases and the anisotropy of the growth rate of silicon precipitates formed in a solid amorphous medium.

Synthesis and Characterization of Lithiated Nickel Based Metal Oxides as Positive Electrode Materials for Lithium Ion Batteries

1999 ◽  
Vol 575 ◽  
Author(s):  
S. Fujitani ◽  
H. Fujimoto ◽  
T. Nohma ◽  
K. Nishio
Keyword(s):  
Metal Oxides ◽  
Lithium Ion Batteries ◽  
Discharge Capacity ◽  
Electrode Materials ◽  
Lithium Ion ◽  
Cycle Performance ◽  
High Discharge Capacity ◽  
Discharge Cycle ◽  
The Difference ◽  
Charge Discharge

ABSTRACTLiNi1−xCoxO2(x=0.2, 0.3, 0.4) was synthesized through a sintering process from two different types of source materials of nickel and cobalt, namely each respective hydroxide and oxide, and composite hydroxide. Influence of the difference on charge-discharge characteristics, crystal structure and distribution of the metal elements was investigated.The composite hydroxides formulated in Ni1−xCox(OH)2 as the source material brought better homogenized composite lithiated nickel based metal oxides exhibiting the larger specific discharge capacity. Further modification of LiNi0.6Co0.4)2 by manganese through sintering from the composite hydroxide including manganese brought a good charge-discharge cycle performance as well as a high discharge capacity of 160mAh/g level.A cylindrical test cell of 18mm in diameter and 65mm in height using the LiNi0.6Co0.3Mn0.1O2 exhibited discharge capacity of 1700mAh which is larger than that using LiCoO2, and also exhibited a competitive charge-discharge cycle performance to commercialized lithium ion batteries.

scholarly journals The effect of cooling process on the structure and charge/discharge capacities of Li-rich solid-solution layered oxide cathode materials for the Li-ion battery

RSC Advances ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 1715-1728
Author(s):  
Fumihiro Nomura ◽  
Tatsuya Watanabe ◽  
Hiroya Ochiai ◽  
Takao Gunji ◽  
Takeshi Hagiwara ◽  
...  
Keyword(s):  
Solid Solution ◽  
Discharge Capacity ◽  
Li Ion Battery ◽  
Cooling Process ◽  
Slow Cooling ◽  
Oxide Cathode ◽  
Li Ion ◽  
The Difference ◽  
Discharge Capacities ◽  
Charge Discharge

The difference in discharge capacity = (discharge capacity of the LLO sample prepared by quenched cooling) − (discharge capacity of the LLO sample prepared by slow cooling). The difference in discharge capacity: > 10 mA h g−1, −10 mA h g−1 < <10 mA h g−1, < −10 mA h g−1.

scholarly journals Changes in Phenols, Polysaccharides and Volatile Profiles of Noni (Morinda citrifolia L.) Juice during Fermentation

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2604
Author(s):  
Zhulin Wang ◽  
Rong Dou ◽  
Ruili Yang ◽  
Kun Cai ◽  
Congfa Li ◽  
...  
Keyword(s):  
Octanoic Acid ◽  
Solid Phase ◽  
Principal Component ◽  
Hexanoic Acid ◽  
Morinda Citrifolia ◽  
Gas Chromatography Mass Spectrometry ◽  
Aroma Characteristics ◽  
Volatile Profiles ◽  
The Difference ◽  
Aroma Components

The change in phenols, polysaccharides and volatile profiles of noni juice from laboratory- and factory-scale fermentation was analyzed during a 63-day fermentation process. The phenol and polysaccharide contents and aroma characteristics clearly changed according to fermentation scale and time conditions. The flavonoid content in noni juice gradually increased with fermentation. Seventy-three volatile compounds were identified by solid-phase microextraction coupled with gas chromatography–mass spectrometry (SPME-GC-MS). Methyl hexanoate, 3-methyl-3-buten-1-ol, octanoic acid, hexanoic acid and 2-heptanone were found to be the main aroma components of fresh and fermented noni juice. A decrease in octanoic acid and hexanoic acid contents resulted in the less pungent aroma in noni juice from factory-scale fermentation. The results of principal component analysis of the electronic nose suggested that the difference in nitrogen oxide, alkanes, alcohols, and aromatic and sulfur compounds, contributed to the discrimination of noni juice from different fermentation times and scales.

scholarly journals dual-ion charge-discharge behaviors of Na-NiNc and NiNc-NiNc batteries

2021 ◽  
Author(s):  
Jinkwang Hwang ◽  
Rika Hagiwara ◽  
Hiroshi Shinokubo ◽  
Ji-Young Shin
Keyword(s):  
Discharge Capacity ◽  
Electrode Material ◽  
High Stability ◽  
Coulombic Efficiency ◽  
Active Electrode ◽  
High Discharge ◽  
High Discharge Capacity ◽  
Charge Discharge ◽  
High Coulombic Efficiency

Dual-ion sodium-organic secondary batteries were provided with antiaromatic porphyrinoid, NiNc as an active electrode material, which implemented inherent charge-discharge behaviors with high discharge capacity, high stability, high Coulombic efficiency with...

Self-diffusion coefficient of lithium in lithium oxide

1979 ◽  
Vol 87 (2-3) ◽  
pp. 341-344 ◽  
Author(s):  
Y. Oishi ◽  
Y. Kamei ◽  
M. Akiyama ◽  
T. Yanagi
Keyword(s):  
Diffusion Coefficient ◽  
Lithium Oxide ◽  
Self Diffusion ◽  
Self Diffusion Coefficient

Diffusion of Zn into Gaas 0.6 P0.4:Te From Zn-Doped Oxide Films By Rapid Thermal Processing

1987 ◽  
Vol 92 ◽  
Author(s):  
A. Usami ◽  
Y. Tokuda ◽  
H. Shiraki ◽  
H. Ueda ◽  
T. Wada ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Thermal Processing ◽  
Rapid Thermal Processing ◽  
Oxide Films ◽  
Zn Diffusion ◽  
Enhanced Diffusion ◽  
Conventional Furnace ◽  
Zn Concentration ◽  
The Difference ◽  
Doped Oxide

ABSTRACTRapid thermal processing using halogen lamps was applied to the diffusion of Zn into GaAs0.6 P0.4:Te from Zn-doped oxide films. The Zn diffusion coefficient of the rapid thermal diffused (RTD) samples at 800°C for 6 s was about two orders of magnitude higher than that of the conventional furnace diffused samples at 800°C for 60 min. The enhanced diffusion of Zn by RTD may be ascribed to the stress field due to the difference in the thermal expansion coefficient between the doped oxide films and GaAs0.6P0.4 materials, and due to the temperature gradient in GaAs0.6P0 4 materials. The Zn diffusion coefficient at Zn concentration of 1.0 × l018 cm−3 was 3.6 × 10−11, 3.1 × 10−11 and 5.0 × 10−12 cm2 /s for the RTD samples at 950°C for 6 s from Zn-, (Zn,Ga)- and (Zn,P)-doped oxide films, respectively. This suggests that Zn diffusibility was controlled by the P in the doped oxide films.

Trapping Effect on the Kinetic Critical Radius in Nucleation and Growth Processes

2014 ◽  
Vol 790-791 ◽  
pp. 97-102
Author(s):  
Zoltán Erdélyi ◽  
Zoltán Balogh ◽  
Gabor L. Katona ◽  
Dezső L. Beke
Keyword(s):  
Critical Nucleus ◽  
Solid Phase ◽  
Kinetic Monte Carlo ◽  
Mean Field ◽  
Transformation Process ◽  
Nucleus Size ◽  
Critical Nucleus Size ◽  
Acta Mater ◽  
Order Of Magnitude ◽  
The Difference

The critical nucleus size—above which nuclei grow, below dissolve—during diffusion controlled nucleation in binary solid-solid phase transformation process is calculated using kinetic Monte Carlo (KMC). If atomic jumps are slower in an A-rich nucleus than in the embedding B-rich matrix, the nucleus traps the A atoms approaching its surface. It doesn’t have enough time to eject A atoms before new ones arrive, even if it would be favourable thermodynamically. In this case the critical nucleus size can be even by an order of magnitude smaller than expected from equilibrium thermodynamics or without trapping. These results were published in [Z. Erdélyi et al., Acta Mater. 58 (2010) 5639]. In a recent paper M. Leitner [M. Leitner, Acta Mater. 60 (2012) 6709] has questioned our results based on the arguments that his simulations led to different results, but he could not point out the reason for the difference. In this paper we summarize our original results and on the basis of recent KMC and kinetic mean field (KMF) simulations we show that Leitner’s conclusions are not valid and we confirm again our original results.

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