scholarly journals Operando Raman Shift Replaces Current in Electrochemical Analysis of Li-ion Batteries: A Comparative Study

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4667
Author(s):  
Mariusz Radtke ◽  
Christian Hess
Keyword(s):  
Charge Transfer ◽  
Diffraction Limit ◽  
Electrochemical Analysis ◽  
Electrode System ◽  
Raman Shift ◽  
Raman Intensity ◽  
Li Ion Batteries ◽  
Half Cell ◽  
Catalytically Active ◽  
Li Ion

Li-rich and catalytically active γ-LixV2O5 (x = 1.48) was investigated as a cathode for its heterogeneous charge transfer kinetics. Using a specially designed two-electrode system lithium half cell, Butler–Volmer analysis was performed, and Raman spectra were acquired in 18 mV intervals. A direct correlation was observed between the Raman shift of the active modes Ag,Bg, Au, and Bu, and the development of the Faraday current at the working electrode. The Raman intensity and the Raman shift were implemented to replace the current in a Tafel plot used for the analysis of Butler–Volmer kinetics. Striking similarities in the charge transfer proportionality constants α were found for current and Raman-based analysis. The potential of this new method of Raman-aided electrochemical detection at the diffraction limit is discussed.

Syntheses and Properties of Pyrrole Derivative as a Cathode Material for Li-Ion Batteries

2012 ◽  
Vol 236-237 ◽  
pp. 731-735
Author(s):  
Chang Su ◽  
Ling Min Wang ◽  
Li Huan Xu ◽  
Jun Lei Liu ◽  
Fang Yang ◽  
...  
Keyword(s):  
Chemical Structure ◽  
Specific Capacity ◽  
Lithium Ion ◽  
Particle Morphology ◽  
Side Chain ◽  
Li Ion Batteries ◽  
Galvanostatic Charge ◽  
Half Cell ◽  
Ft Ir ◽  
Li Ion

A copolymer of 4-(1H-pyrrol-1-yl)phenol (PLPY) and pyrrole ( P(PLPY-co-Py) )was synthesized. And the chemical structure and battery performance of the prepared materials were characterized comparably by 1H NMR, FT-IR spectra and galvanostatic charge-discharge testing using simulant lithium ion half-cell method, respectively. The results shows that the introduction of the phenol group to the pyrrole as a rigid side chain could prevent the polymer from agglomeration and optimize the particle morphology of the resulting polymers, all of which made it demonstrate a significantly improved specific capacity (73.9 mAh•g-1) compared with PPy (21.4 mAh•g-1)

scholarly journals Surface modified Li4Ti5O12 by paper templated approach for enhanced interfacial Li+ charge transfer in Li-ion batteries

RSC Advances ◽  
2018 ◽  
Vol 8 (67) ◽  
pp. 38391-38399 ◽  
Author(s):  
Ujjwala V. Kawade ◽  
Manish S. Jayswal ◽  
Anuradha A. Ambalkar ◽  
Sunil R. Kadam ◽  
Rajendra P. Panmand ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Electrochemical Performance ◽  
Template Synthesis ◽  
Li Ion Batteries ◽  
Interfacial Charge Transfer ◽  
Li Ion ◽  
Surface Modified ◽  
Interfacial Charge

The versatile paper template synthesis of LTO has been demonstrated with an interconnected nanoparticles network. The system exhibits accelerated interfacial charge transfer which in turn confers enhanced stable electrochemical performance in LIBs.

scholarly journals Impedance Characterization of an LCO-NMC/Graphite Cell: Ohmic Conduction, SEI Transport and Charge-Transfer Phenomenon

Batteries ◽  
2018 ◽  
Vol 4 (3) ◽  
pp. 43 ◽  
Author(s):  
Victoria Ovejas ◽  
Angel Cuadras
Keyword(s):  
Charge Transfer ◽  
Solid Electrolyte Interphase ◽  
Impedance Spectrum ◽  
Half Cell ◽  
Electrochemical Processes ◽  
Sei Layer ◽  
Current Densities ◽  
Li Ion ◽  
Impedance Characterization

Currently, Li-ion cells are the preferred candidates as energy sources for existing portable applications and for those being developed. Thus, a proper characterization of Li-ion cells is required to optimize their use and their manufacturing process. In this study, the transport phenomena and electrochemical processes taking place in LiCoO2-Li(NiMnCo)O2/graphite (LCO-NMC/graphite) cells are identified from half-cell measurements by means of impedance spectroscopy. The results are calculated from current densities, instead of absolute values, for the future comparison of this data with other cells. In particular, impedance spectra are fitted to simple electrical models composed of an inductive part, serial resistance, and various RQ networks—the parallel combination of a resistor and a constant phase element—depending on the cell. Thus, the evolution of resistances, capacitances, and the characteristic frequencies of the various effects are tracked with the state-of-charge (SoC) at two aging levels. Concretely, two effects are identified at the impedance spectrum; one is clearly caused by the charge transfer at the positive electrode, whereas the other one is presumably caused by the transport of lithium ions across the solid electrolyte interphase (SEI) layer. Moreover, as the cells age, the characteristic frequency of the charge transfer is drastically reduced by a factor of around 70%.

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