A novel research on the positive effects of oxygen vacancies for interstitial N-doped MnO2 on 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.

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Nanoscale Mapping of Lithium-Ion Diffusion in a Cathode within an All-Solid-State Lithium-Ion Battery by Advanced Scanning Probe Microscopy Techniques

ACS Nano ◽

10.1021/nn305648j ◽

2013 ◽

Vol 7 (2) ◽

pp. 1666-1675 ◽

Cited By ~ 54

Author(s):

Jing Zhu ◽

Li Lu ◽

Kaiyang Zeng

Keyword(s):

Solid State ◽

Lithium Ion Battery ◽

Scanning Probe Microscopy ◽

Lithium Ion ◽

Scanning Probe ◽

Ion Diffusion ◽

Probe Microscopy ◽

Microscopy Techniques ◽

Lithium Ion Diffusion

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

Science and Technology Development Journal ◽

10.32508/stdj.v22i1.462 ◽

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.

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