scholarly journals Nature of the Electrochemical Properties of Sulphur Substituted LiMn2O4 Spinel Cathode Material Studied by Electrochemical Impedance Spectroscopy

Materials ◽  
2016 ◽  
Vol 9 (8) ◽  
pp. 696 ◽  
Author(s):  
Monika Bakierska ◽  
Michał Świętosławski ◽  
Roman Dziembaj ◽  
Marcin Molenda
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Cathode Material ◽  
Electrochemical Properties ◽  
Electrochemical Impedance ◽  
Limn2o4 Spinel ◽  
Spinel Cathode

scholarly journals Studies on Anion Exchange Membrane and Interface Properties by Electrochemical Impedance Spectroscopy: The Role of pH

Membranes ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 771
Author(s):  
Wenjuan Zhang ◽  
Wei Cheng ◽  
Ramato Ashu Tufa ◽  
Caihong Liu ◽  
David Aili ◽  
...  
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Ion Exchange ◽  
Electrochemical Properties ◽  
Anion Exchange ◽  
Structural Changes ◽  
Electrochemical Impedance ◽  
Transport Processes ◽  
Anion Exchange Membranes ◽  
Interface Properties

Ion-exchange membranes (IEMs) represent a key component in various electrochemical energy conversion and storage systems. In this study, electrochemical impedance spectroscopy (EIS) was used to investigate the effects of structural changes of anion exchange membranes (AEMs) on the bulk membrane and interface properties as a function of solution pH. The variations in the physico/electrochemical properties, including ion exchange capacity, swelling degree, fixed charge density, zeta potentials as well as membrane and interface resistances of two commercial AEMs and cation exchange membranes (CEMs, as a control) were systematically investigated in different pH environments. Structural changes of the membrane surface were analyzed by Fourier transform infrared and X-ray photoelectron spectroscopy. Most notably, at high pH (pH > 10), the membrane (Rm) and the diffusion boundary layer resistances (Rdbl) increased for the two AEMs, whereas the electrical double layer resistance decreased simultaneously. This increase in Rm and Rdbl was mainly attributed to the deprotonation of the tertiary amino groups (-NR2H+) as a membrane functionality. Our results show that the local pH at the membrane-solution interface plays a crucial role on membrane electrochemical properties in IEM transport processes, particularly for AEMs.

Graphene-NiO Composite Electrode for Supercapacitors

2011 ◽  
Vol 345 ◽  
pp. 75-78 ◽  
Author(s):  
Wei Zhou ◽  
Man Lin Tan ◽  
Xiao Song Zhou
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Properties ◽  
Specific Capacitance ◽  
Composite Electrode ◽  
Electrochemical Impedance ◽  
Graphene Sheets ◽  
Supercapacitor Electrode ◽  
Scan Rate

In this paper, a facilesolution method was employed to synthesize the graphene-NiO composite. SEM and XRD results indicated the graphene sheets were covered by the NiO nanoplates. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to measure the electrochemical properties of the composite. The specific capacitance reached 1292F/g at a scan rate of 5mV/s. The results show that this composite is a promising material for supercapacitor electrode.

scholarly journals MODERN RESEARCH METHODS OF PHYSICOCHEMICAL AND ELECTROCHEMICAL PROPERTIES OF ELECTROLYTES IN FOR Li-ION BATTERIES AND HYBRID SUPERCAPACITIES

2021 ◽  
Vol 87 (6) ◽  
pp. 82-96
Author(s):  
Viktor Diamant
Keyword(s):  
Thermal Stability ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Properties ◽  
Power Density ◽  
Electrochemical Impedance ◽  
Aqueous Electrolytes ◽  
Li Ion Batteries ◽  
Power Sources ◽  
Li Ion

In review examineі base properties of modern non-aqueous electrolytes for li-ion batteries and hybrid supercapacities taking part in the formation of power density, electrochemical and thermal stability. Discussed such aspects as the electrolytes functions in electrochemical power sources, physicochemical and electrochemical properties of electrolytes for supercapacitors, the physicochemical and electrochemical properties of electrolytes for primary and secondary batteries, and methods of electrolytes research. As the base methodі for electrolytes studies considered: electrochemical impedance spectroscopy, voltammetry, amperometry, viscosimetry, and combined Ramman spectroscopy.  

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