Enhanced Rate Capability in Two Phase Reaction in LiFePO4 By Interfacial Modification Between Cathode and Electrolyte

Science ◽  
2020 ◽  
Vol 367 (6481) ◽  
pp. 1030-1034 ◽  
Author(s):  
Wei Zhang ◽  
Dong-Hwa Seo ◽  
Tina Chen ◽  
Lijun Wu ◽  
Mehmet Topsakal ◽  
...  

Fast-charging batteries typically use electrodes capable of accommodating lithium continuously by means of solid-solution transformation because they have few kinetic barriers apart from ionic diffusion. One exception is lithium titanate (Li4Ti5O12), an anode exhibiting extraordinary rate capability apparently inconsistent with its two-phase reaction and slow Li diffusion in both phases. Through real-time tracking of Li+ migration using operando electron energy-loss spectroscopy, we reveal that facile transport in Li4+xTi5O12 is enabled by kinetic pathways comprising distorted Li polyhedra in metastable intermediates along two-phase boundaries. Our work demonstrates that high-rate capability may be enabled by accessing the energy landscape above the ground state, which may have fundamentally different kinetic mechanisms from the ground-state macroscopic phases. This insight should present new opportunities in searching for high-rate electrode materials.


Author(s):  
Qiao Luo ◽  
Xiaobing Zhang

Purpose – In engineering applications, gas-solid two-phase reaction flow with multi-moving boundaries is a common phenomenon. The launch process of multiple projectiles is a typical example. The flow of adjacent powder chambers is coupled by projectile’s motion. The purpose of this paper is to study this flow by numerical simulation. Design/methodology/approach – A one-dimensional two-phase reaction flow model and MacCormack difference scheme are implemented in a computational code, and the code is used to simulate the launch process of a system of multiple projectiles. For different launching rates and loading conditions, the simulated results of the launch process of three projectiles are obtained and discussed. Findings – At low launching rates, projectiles fired earlier in the series have little effect on the launch processes of projectiles fired later. However, at higher launching rates, the projectiles fired first have a great influence on the launch processes of projectiles fired later. As the launching rate increases, the maximum breech pressure for the later projectiles increases. Although the muzzle velocities increase initially, they reach a maximum at some launching rate, and then decrease rapidly. The muzzle velocities and maximum breech pressures of the three projectiles have an approximate linear relationship with the charge weight, propellant web size and chamber volume. Originality/value – This paper presents a prediction tool to understand the physical phenomenon of the gas-solid two-phase reaction flow with multi-moving boundaries, and can be used as a research tool for future interior ballistics studies of launch system of multiple projectiles.


2017 ◽  
Vol 19 (20) ◽  
pp. 4804-4810 ◽  
Author(s):  
S. H. Shinde ◽  
C. V. Rode

A new and effective unique two-phase reaction system for the high yield production of tri(furyl)methane from furfural and furan.


2019 ◽  
Vol 34 (S1) ◽  
pp. S8-S13
Author(s):  
T. Konya ◽  
Y. Shiramata ◽  
T. Nakamura

Structural variation of LiMn1.5Ni0.5O4 spinel cathode during the Li+ extraction/insertion reaction was studied using operando X-ray diffraction. It was found that the reaction in the voltage range from 3.5 to 4.9 V consisted of two consecutive two-phase reactions, where three spinel phases of LiMn1.5Ni0.5O4, Li0.5Mn1.5Ni0.5O4 and Mn1.5Ni0.5O4 were identified and the lattice volume change in the whole reaction was evaluated as 6%. The reactions were symmetric and reversible under low-current conditions, but some asymmetries were detected during high current operation. Furthermore, a two-phase reaction between cubic and tetragonal phases was observed in the low-voltage reaction at 2.1–3.5 V, where the lattice volume change was approximately 4.9%. The rate-determining step was discussed based on these operando results.


2018 ◽  
Vol 6 (21) ◽  
pp. 9962-9970 ◽  
Author(s):  
Meng Li ◽  
Zonglin Zuo ◽  
Jianqiu Deng ◽  
Qingrong Yao ◽  
Zhongmin Wang ◽  
...  

A rhombohedral structured two-phase Na2LiV2(PO4)3/C nanocomposite was synthesized and employed as both cathode and anode material.


1991 ◽  
Vol 70 (5) ◽  
pp. 2181-2187 ◽  
Author(s):  
B. Kocsis ◽  
L. Fedina ◽  
E. Pasztor

The performance of the sympathetic nervous system during sustained moderate cerebral ischemia (CI) was examined in the present study. For this purpose, a Cushing response was elicited repeatedly during incomplete global CI in anesthetized artificially ventilated cats after vagotomy and baroreceptor denervation. In control animals without CI, sympathetic activity in response to brief elevation of intracranial pressure (ICP) showed a well-repeatable two-phase reaction. During CI there was a progressive deterioration of background sympathetic nerve discharge (SND) over a period of 30 min. SND response to repeated elevation of ICP was initially similar to control response but later with progression of CI was seriously changed. 1) Instead of the usual hyperactivation, sympathetic nerve activity was depressed during intracranial hypertension. 2) The characteristic desynchronized activity either appeared later during the reperfusion period or remained absent. The progressive loss of SND response to raised ICP in developed CI was compared with the changes seen in experiments in which repeated ICP elevations were superimposed on asphyxia. These findings suggest that the sympathetic component of the Cushing reaction strongly depends on the actual state of brain stem autonomic circuits and may be seriously altered in pathological situations involving ischemic brain injury.


Blood ◽  
1964 ◽  
Vol 23 (1) ◽  
pp. 27-37 ◽  
Author(s):  
JULIA GIDÁLI ◽  
IMRE FEHÉR ◽  
Julia Osgyáni

Abstract 1. In rabbits irradiated with 150 to 600 r, granulocytosis is preceded by a prompt significant granulocytopenia developing 5-15 minutes after irradiation but persisting for a short time. 2. The plasma taken at the minimum of the initial granulocytopenia produced a similar two-phase reaction when injected into normal animals: a promptly developing significant granulocytopenia persisting for a short period followed by prolonged granulocytosis. Prolonged thrombocytopenia might be induced by the very same plasma. 3. The above-mentioned reactions may he reproduced satisfactorily with the administration of dilute starch solutions. 4. On the basis of the results obtained, it seems likely that the agent demonstrable in the plasma after irradiation, and influencing the level of circulating granulocytes and thrombocytes, is not a toxin (leukotoxin) but a substance that may be formed following physiologic stimuli as well.


2018 ◽  
Vol 5 (10) ◽  
pp. 22123-22127 ◽  
Author(s):  
Yoshimitsu Uemura ◽  
Fon Yee Han ◽  
Thanh Tien Nguyen ◽  
Thanh Hoai Trinh ◽  
Katsuki Kusakabe

1984 ◽  
Vol 13 (5) ◽  
pp. 725-728 ◽  
Author(s):  
Takashi Ando ◽  
Takehiko Kawate ◽  
Junko Ichihara (nee Yamawaki) ◽  
Terukiyo Hanafusa

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