Measurement of the Electrochemical Diffusion Coefficient of Li-Ion in LiFePO4 by Constant Current Step

The lithium ions transferring into cathode material are similar as nonequilibrium carrier in semiconductor while the cell discharges at constant current small enough. The inpouring Li-ions can be called nonequilibrium Li-ions. The electrochemical diffusion coefficient, named as D, can be worked out approximately in terms of the relationship between the concentration of nonequilibrium Li-ions and the relevant potential difference. The D was found 3.21×10-10cm2/s for LiFePO4doped with 10% acetylene black.

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Synthesis and Electrochemical Properties of Spherical LiFePO4/C Composite via Spray Drying

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1120-1121.554 ◽

2015 ◽

Vol 1120-1121 ◽

pp. 554-558 ◽

Cited By ~ 1

Author(s):

Juan Mei Wang ◽

Bing Ren ◽

Ying Lin Yan ◽

Qing Zhang ◽

Yan Wang

Keyword(s):

Diffusion Coefficient ◽

Electrochemical Properties ◽

Spray Drying ◽

Electrochemical Impedance ◽

Retention Rate ◽

Lithium Ion ◽

Constant Current ◽

Ion Diffusion ◽

Electrochemical Tests ◽

Li Ion

In this work, spherical LiFePO4/C composite had been synthesized by co-precipitation and spray drying method. The structure, morphology and electrochemical properties of the samples were characterized by X-ray diffraction (XRD), scanning electron micrograph (SEM), transmission electron microscope (TEM), constant current charge-discharge tests and electrochemical impedance spectroscopy (EIS) tests. The spherical LiFePO4/C particles consisted of a number of smaller grains. The results showed that the morphology of LiFePO4/C particles seriously affected the Li-ion diffusion coefficient and electrochemical properties of lithium ion batteries. Electrochemical tests revealed the spherical LiFePO4/C composite had excellent Li-ion diffusion coefficient which was calculated to be 1.065×10-11 cm2/s and discharge capacity of 149 (0.1 C), 139 (0.2 C), 133 (0.5 C), 129 (1 C) and 124 mAhg-1(2 C). After 50 cycles, the capacity retention rate was still 93.5%.

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Estimation on diffusion coefficient of lithium ions at the interface of LiNi0.5Mn1.5O4/electrolyte in Li-ion battery

Ionics ◽

10.1007/s11581-014-1189-x ◽

2014 ◽

Vol 21 (2) ◽

pp. 335-344 ◽

Cited By ~ 7

Author(s):

H. Seyyedhosseinzadeh ◽

F. Mahboubi ◽

A. Azadmehr

Keyword(s):

Diffusion Coefficient ◽

Li Ion Battery ◽

Lithium Ions ◽

Li Ion

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Different strategies of introduction of lithium ions into nickel‑manganese‑cobalt carbonate resulting in LiNi0.6Mn0.2Co0.2O2 (NMC622) cathode material for Li-ion batteries

Solid State Ionics ◽

10.1016/j.ssi.2020.115273 ◽

2020 ◽

Vol 348 ◽

pp. 115273 ◽

Cited By ~ 4

Author(s):

Magdalena Zybert ◽

Hubert Ronduda ◽

Anna Szczęsna ◽

Tomasz Trzeciak ◽

Andrzej Ostrowski ◽

...

Keyword(s):

Cathode Material ◽

Li Ion Batteries ◽

Lithium Ions ◽

Cobalt Carbonate ◽

Li Ion ◽

Nickel Manganese

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Exploring the Effect of a MnO2 Coating on the Electrochemical Performance of a Li1.2Mn0.54Ni0.13Co0.13O2 Cathode Material

Micromachines ◽

10.3390/mi12111410 ◽

2021 ◽

Vol 12 (11) ◽

pp. 1410

Author(s):

Zhong Li ◽

Peiyue Yang ◽

Zhongxiang Zheng ◽

Qiyun Pan ◽

Yisi Liu ◽

...

Keyword(s):

Electrochemical Performance ◽

Cathode Material ◽

High Current Density ◽

Coated Sample ◽

Lithium Ions ◽

Capacity Loss ◽

A Value ◽

Electrochemically Active ◽

Li Ion ◽

Enhanced Electrochemical Performance

The effect of electrochemically active MnO2 as a coating material on the electrochemical properties of a Li1.2Mn0.54Ni0.13Co0.13O2 (LTMO) cathode material is explored in this article. The structural analysis indicated that the layered structure of the LTMO was unchanged after the modification with MnO2. The morphology inspection demonstrated that the rod-like LTMO particles were encapsulated by a compact coating layer. The MnO2 layer was able to hinder the electrolyte solution from corroding the LTMO particles and optimized the formation of a solid electrolyte interface (SEI). Meanwhile, lithium ions were reversibly inserted into and extracted from MnO2, which afforded an additional capacity. Compared with the bare LTMO, the MnO2-coated sample exhibited enhanced electrochemical performance. After the MnO2 coating, the first discharge capacity rose from 224.2 to 239.1 mAh/g, and the initial irreversible capacity loss declined from 78.2 to 46.0 mAh/g. Meanwhile, the cyclic retention climbed up to 88.2% after 100 cycles at 0.5 C, which was more competitive than that of the bare LTMO with a value of 71.1%. When discharging at a high current density of 2 C, the capacity increased from 100.5 to 136.9 mAh/g after the modification. These investigations may be conducive to the practical application of LTMO in prospective automotive Li-ion batteries.

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Analysis of the chemical diffusion coefficient of lithium ions in Li3V2(PO4)3 cathode material

Electrochimica Acta ◽

10.1016/j.electacta.2009.11.096 ◽

2010 ◽

Vol 55 (7) ◽

pp. 2384-2390 ◽

Cited By ~ 392

Author(s):

X.H. Rui ◽

N. Ding ◽

J. Liu ◽

C. Li ◽

C.H. Chen

Keyword(s):

Diffusion Coefficient ◽

Cathode Material ◽

Chemical Diffusion ◽

Chemical Diffusion Coefficient ◽

Lithium Ions

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Preliminary study of structural changes in Li2MnSiO4 cathode material during electrochemical reaction

Functional Materials Letters ◽

10.1142/s1793604716410034 ◽

2016 ◽

Vol 09 (04) ◽

pp. 1641003 ◽

Cited By ~ 2

Author(s):

Michał Świętosławski ◽

Marcin Molenda ◽

Marta Gajewska

Keyword(s):

Cathode Material ◽

Structural Changes ◽

Electrochemical Reaction ◽

Electrochemical Reactions ◽

Li Ion Batteries ◽

Lithium Ions ◽

Transmission Electron ◽

Working Cell ◽

Li Ion ◽

Preliminary Study

In this paper, we present exsitu observations of a structure of particular Li2MnSiO4 grains at different states of charge (SOC). The goal of these studies is structural analysis of Li2MnSiO4 cathode material for Li-ion batteries at different stages of electrochemical reaction using transmission electron microscopy. Performed analysis suggests that amorphization process of Li2MnSiO4 is not directly connected with lithium ions deintercalation but with additional electrochemical reactions running in the working cell.

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