scholarly journals The impact of carbon additives on lithium ion diffusion kinetic of LiFePO4/C composites

2019 ◽  
Vol 22 (1) ◽  
pp. 173-179
Author(s):  
Thanh Dinh Duc ◽  
Anh My-Thi Nguyen ◽  
Tru Nhi Nguyen ◽  
Hang Thi La ◽  
Phung My Loan Le
Keyword(s):  
Electrochemical Performance ◽  
Lithium Ion ◽  
Second Phase ◽  
Potential Candidate ◽  
Scale Production ◽  
X Rays ◽  
Ion Diffusion ◽  
Diffusion Kinetic ◽  
The Impact ◽  
Lithium Ion Diffusion

Introduction: LiFePO4/C composites were synthesized via physical mixing assisted solvothermal process. Different kinds of carbon materials were investigated including 0D (carbon Ketjen black), 1D (carbon nanotubes) and 2D (graphene) materials. X-rays diffraction patterns of carbon coated LiFePO4 synthesized by solvothermal was indexed to pure crystalline phase without the emergence of second phase. LiFePO4 platelets and rods were in range size of 80-200 nm and dispersed well in carbon matrix. The lithium ion diffusion kinetics was evaluated through the calculated diffusion coefficients to explore the impact of carbon mixing. Methods: In this work, we studied the structure, morphologies and the lithium ion diffusion kinetic of LiFePO4/C composites for Li-ion batteries. Different characterization methods were used including powder X-rays (for crystalline structure); Transmission Electron Microscopy (for particle and morphologies observation) and Cyclic voltammetry (for electrochemical kinetic study). Results: The study indicated LiFePO4/C composites were successfully obtained by mixing process and the electrochemical performance throughout the calculated diffusion coefficient was significantly improved by adding the carbon types. Conclusion: The excellent ion diffusion was obtained for composites LiFePO4/Ketjen black (KB) and LiFePO4/CNT compared to LiFePO4/Graphene. KB could be a potential candidate for large-scale production due to low-cost, stable and high electrochemical performance.  

scholarly journals Exploring Aliovalent Substitutions in the Lithium Halide Superionic Conductor Li3-xIn1-xZrxCl6 (0 ≤ X ≤ 0.5)

2021 ◽  
Author(s):  
Bianca Helm ◽  
Roman Schlem ◽  
Bjöern Wankmiller ◽  
Ananya Banik ◽  
Ajay Gautam ◽  
...  
Keyword(s):  
Ionic Conductivity ◽  
Three Dimensional ◽  
Lithium Ion ◽  
Ion Diffusion ◽  
Cation Site ◽  
Diffusion Channel ◽  
Cation Disorder ◽  
Site Disorder ◽  
The Impact ◽  
Lithium Ion Diffusion

<p>In recent years, ternary halides Li<sub>3</sub><i>MX</i><sub>6</sub> (<i>M</i> = Y, Er, In; <i>X</i> = Cl, Br, I) have garnered attention as solid electrolytes due to their wide electrochemical stability window and favorable room-temperature conductivities. In this material class, the influences of iso- or aliovalent substitutions are so far rarely studied in-depth, despite this being a common tool for correlating structure and transport properties. In this work, we investigate the impact of Zr substitution on the structure and ionic conductivity of Li<sub>3</sub>InCl<sub>6</sub> (Li<sub>3-<i>x</i></sub>In<sub>1-<i>x</i></sub>Zr<i><sub>x</sub></i>Cl<sub>6</sub> with 0 ≤ <i>x</i> ≤ 0.5) using a combination of neutron diffraction, nuclear magnetic resonance and impedance spectroscopy. Analysis of high-resolution diffraction data shows the presence of an additional tetrahedrally coordinated lithium position together with cation site-disorder, both of which have not been reported previously for Li<sub>3</sub>InCl<sub>6</sub>. This Li<sup>+</sup> position and cation disorder lead to the formation of a three-dimensional lithium ion diffusion channel, instead of the expected two-dimensional diffusion. Upon Zr<sup>4+</sup> substitution, the structure exhibits non-uniform volume changes along with an increasing number of vacancies, all of which lead to an increasing ionic conductivity in this series of solid solutions.</p>

scholarly journals Exploring Aliovalent Substitutions in the Lithium Halide Superionic Conductor Li3-xIn1-xZrxCl6 (0 ≤ X ≤ 0.5)

2021 ◽  
Author(s):  
Bianca Helm ◽  
Roman Schlem ◽  
Bjöern Wankmiller ◽  
Ananya Banik ◽  
Ajay Gautam ◽  
...  
Keyword(s):  
Ionic Conductivity ◽  
Three Dimensional ◽  
Lithium Ion ◽  
Ion Diffusion ◽  
Cation Site ◽  
Diffusion Channel ◽  
Cation Disorder ◽  
Site Disorder ◽  
The Impact ◽  
Lithium Ion Diffusion

<p>In recent years, ternary halides Li<sub>3</sub><i>MX</i><sub>6</sub> (<i>M</i> = Y, Er, In; <i>X</i> = Cl, Br, I) have garnered attention as solid electrolytes due to their wide electrochemical stability window and favorable room-temperature conductivities. In this material class, the influences of iso- or aliovalent substitutions are so far rarely studied in-depth, despite this being a common tool for correlating structure and transport properties. In this work, we investigate the impact of Zr substitution on the structure and ionic conductivity of Li<sub>3</sub>InCl<sub>6</sub> (Li<sub>3-<i>x</i></sub>In<sub>1-<i>x</i></sub>Zr<i><sub>x</sub></i>Cl<sub>6</sub> with 0 ≤ <i>x</i> ≤ 0.5) using a combination of neutron diffraction, nuclear magnetic resonance and impedance spectroscopy. Analysis of high-resolution diffraction data shows the presence of an additional tetrahedrally coordinated lithium position together with cation site-disorder, both of which have not been reported previously for Li<sub>3</sub>InCl<sub>6</sub>. This Li<sup>+</sup> position and cation disorder lead to the formation of a three-dimensional lithium ion diffusion channel, instead of the expected two-dimensional diffusion. Upon Zr<sup>4+</sup> substitution, the structure exhibits non-uniform volume changes along with an increasing number of vacancies, all of which lead to an increasing ionic conductivity in this series of solid solutions.</p>

scholarly journals Effects of Mg Doping at Different Positions in Li-Rich Mn-Based Cathode Material on Electrochemical Performance

Nanomaterials ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 156
Author(s):  
Elena Makhonina ◽  
Lidia Pechen ◽  
Anna Medvedeva ◽  
Yury Politov ◽  
Aleksander Rumyantsev ◽  
...  
Keyword(s):  
Solid State ◽  
Electrochemical Performance ◽  
Solid State Reaction ◽  
Lithium Ion ◽  
Layered Oxides ◽  
Ion Diffusion ◽  
Capacity Fading ◽  
Mg Doping ◽  
Voltage Decay ◽  
Lithium Ion Diffusion

Li-rich Mn-based layered oxides are among the most promising cathode materials for next-generation lithium-ion batteries, yet they suffer from capacity fading and voltage decay during cycling. The electrochemical performance of the material can be improved by doping with Mg. However, the effect of Mg doping at different positions (lithium or transition metals) remains unclear. Li1.2Mn0.54Ni0.13Co0.13O2 (LR) was synthesized by coprecipitation followed by a solid-state reaction. The coprecipitation stage was used to introduce Mg in TM layers (sample LR-Mg), and the solid-state reaction (st) was used to dope Mg in Li layers (LR-Mg(st)). The presence of magnesium at different positions was confirmed by XRD, XPS, and electrochemical studies. The investigations have shown that the introduction of Mg in TM layers is preferable in terms of the electrochemical performance. The sample doped with Mg at the TM positions shows better cyclability and higher discharge capacity than the undoped sample. The poor electrochemical properties of the sample doped with Mg at Li positions are due to the kinetic hindrance of oxidation of the manganese-containing species formed after activation of the Li2MnO3 component of the composite oxide. The oxide LR-Mg(st) demonstrates the lowest lithium-ion diffusion coefficient and the greatest polarization resistance compared to LR and LR-Mg.

Non-stoichiometric synthesis and electrochemical performance of LiFe1-xPO4/C cathode materials for lithium ion batteries

2014 ◽  
Vol 07 (02) ◽  
pp. 1450016 ◽  
Author(s):  
Chenglin Hu ◽  
Yuping Wu ◽  
Yongnian Dai
Keyword(s):  
Electrochemical Performance ◽  
Lithium Ion Batteries ◽  
Sol Gel ◽  
Lithium Ion ◽  
Ion Diffusion ◽  
X Ray Diffraction ◽  
X Ray ◽  
Capacity Loss ◽  
Fe Content ◽  
Lithium Ion Diffusion

Non-stoichiometric LiFe 1-x PO 4/ C composites were synthesized by a simple sol–gel method. Different impurities were detected in the X-ray diffraction measurements with the change of Fe content. The effects of Fe -poor on the structure and electrochemical performance of LiFePO 4 were investigated. Compared with stoichiometric LiFePO 4/ C , non-stoichiometric samples show better electrochemical performance because they have smaller impedance and faster lithium ion diffusion. Among these non-stoichiometric samples, LiFe 0.94 PO 4/ C cathode delivers the highest capacity of 149 mAh g-1 at 0.2 C and 103 mAh g-1 at 5 C and no capacity loss was found after 100 full cycles.

scholarly journals The Synergetic Effect Induced High Electrochemical Performance of CuO/Cu2O/Cu Nanocomposites as Lithium-Ion Battery Anodes

2021 ◽  
Vol 9 ◽  
Author(s):  
Lin-Hui Wang ◽  
Shang Gao ◽  
Long-Long Ren ◽  
En-Long Zhou ◽  
Yu-Feng Qin
Keyword(s):  
Electrochemical Performance ◽  
Synergetic Effect ◽  
Rate Capability ◽  
Lithium Ion ◽  
Reversible Capacity ◽  
Ion Diffusion ◽  
Storage Mechanism ◽  
Cuo Nanowires ◽  
Lithium Ion Diffusion ◽  
High Electric Conductivity

Due to the high theoretical capability, copper-based oxides were widely investigated. A facile water bath method was used to synthesis CuO nanowires and CuO/Cu2O/Cu nanocomposites. Owing to the synergetic effect, the CuO/Cu2O/Cu nanocomposites exhibit superior electrochemical performance compared to the CuO nanowires. The initial discharge and charge capacities are 2,660.4 mAh/g and 2,107.8 mAh/g, and the reversible capacity is 1,265.7 mAh/g after 200 cycles at 200 mA/g. Moreover, the reversible capacity is 1,180 mAh/g at 800 mA/g and 1,750 mAh/g when back to 100 mA/g, indicating the excellent rate capability. The CuO/Cu2O/Cu nanocomposites also exhibit relatively high electric conductivity and lithium-ion diffusion coefficient, especially after cycling. For the energy storage mechanism, the capacitive controlled mechanism is predominance at the high scan rates, which is consistent with the excellent rate capability. The outstanding electrochemical performance of the CuO/Cu2O/Cu nanocomposites indicates the potential application of copper-based oxides nanomaterials in future lithium-ion batteries.

Lithium Ion Diffusion Through Glassy Carbon Plate

1997 ◽  
Vol 496 ◽  
Author(s):  
M. Inaba ◽  
S. Nohmi ◽  
A. Funabiki ◽  
T. Abe ◽  
Z. Ogumi
Keyword(s):  
Diffusion Coefficient ◽  
Glassy Carbon ◽  
Lithium Ion ◽  
Ion Diffusion ◽  
Irreversible Capacity ◽  
Oxidation Current ◽  
Current Curve ◽  
Carbon Plate ◽  
Lithium Ion Diffusion

ABSTRACTThe electrochemical permeation method was applied to the determination of the diffusion coefficient of Li+ion (DLi+) in a glassy carbon (GC) plate. The cell was composed of two compartments, which were separated by the GC plate. Li+ions were inserted electrochemically from one face, and extracted from the other. The flux of the permeated Li+ions was monitored as an oxidation current at the latter face. The diffusion coefficient was determined by fitting the transient current curve with a theoretical one derived from Fick's law. When the potential was stepped between two potentials in the range of 0 to 0.5 V, transient curves were well fitted with the theoretical one, which gaveDLi+ values on the order of 10−8cm2s−1. In contrast, when the potential was stepped between two potentials across 0.5 V, significant deviation was observed. The deviation indicated the presence of trap sites as well as diffusion sites for Li+ions, the former of which is the origin of the irreversible capacity of GC.

Sign in / Sign up

Export Citation Format

Share Document