scholarly journals Modeling galvanostatic charge-discharge of nanoporous supercapacitors

2021 ◽  
Author(s):  
Liang Zeng ◽  
Taizheng Wu ◽  
Ting Ye ◽  
Tangming Mo ◽  
Rui Qiao ◽  
...  
Keyword(s):  
Potential Method ◽  
Galvanostatic Charge ◽  
Galvanostatic Mode ◽  
Potentiostatic Mode ◽  
Realistic Description ◽  
Constant Potential ◽  
The Rich ◽  
Adsorption Desorption ◽  
Dynamics Process ◽  
Charge Discharge

Abstract Molecular modeling can study the energy storage of supercapacitors at the atomistic level and has become indispensable in this research. The constant potential method (CPM) allows keeping the electric potential uniform on the electrode, which is essential for a realistic description of the charge repartition and dynamics process in supercapacitors. Prior CPM studies have been limited to the potentiostatic mode. Though widely adopted in the experiment, the galvanostatic mode has been rarely investigated in CPM simulations due to a lack of effective methods. In this work, we developed a modeling approach to simulating the galvanostatic charge-discharge of supercapacitors under constant potential (GCD-CPM). We show that, for nanoporous electrodes, GCD-CPM can capture supercapacitor dynamics in excellent agreement with experimental measurements and delineate the ion adsorption-desorption dynamics underlying the hysteresis with molecular resolutions during charging and discharging. Therefore, this GCD-CPM modeling could open up new avenues for exploring the rich physics and electrochemistry of supercapacitor dynamics.

scholarly journals Modeling galvanostatic charge–discharge of nanoporous supercapacitors

2021 ◽  
Author(s):  
Liang Zeng ◽  
Taizheng Wu ◽  
Ting Ye ◽  
Tangming Mo ◽  
Rui Qiao ◽  
...  
Keyword(s):  
Potential Method ◽  
Discharge Process ◽  
Galvanostatic Charge ◽  
Galvanostatic Mode ◽  
Modeling Approach ◽  
Realistic Description ◽  
Constant Potential ◽  
Adsorption Desorption ◽  
Dynamics Process ◽  
Charge Discharge

AbstractMolecular modeling has been considered indispensable in studying the energy storage of supercapacitors at the atomistic level. The constant potential method (CPM) allows the electric potential to be kept uniform in the electrode, which is essential for a realistic description of the charge repartition and dynamics process in supercapacitors. However, previous CPM studies have been limited to the potentiostatic mode. Although widely adopted in experiments, the galvanostatic mode has rarely been investigated in CPM simulations because of a lack of effective methods. Here we develop a modeling approach to simulating the galvanostatic charge–discharge process of supercapacitors under constant potential. We show that, for nanoporous electrodes, this modeling approach can capture experimentally consistent dynamics in supercapacitors. It can also delineate, at the molecular scale, the hysteresis in ion adsorption–desorption dynamics during charging and discharging. This approach thus enables the further accurate modeling of the physics and electrochemistry in supercapacitor dynamics.

Li0.95Na0.05Ti2(PO4)3/C with Good Performance as Anode Material for Aqueous Rechargeable Lithium Batteries

2014 ◽  
Vol 989-994 ◽  
pp. 316-319 ◽  
Author(s):  
Jing Zhu ◽  
Yong Guang Liu ◽  
Qing Qing Tian ◽  
Ling Wang ◽  
Ji Lin Cao
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Performance ◽  
Anode Material ◽  
Lithium Batteries ◽  
Sol Gel ◽  
Nasicon Structure ◽  
Galvanostatic Charge ◽  
Rechargeable Lithium Batteries ◽  
Structure And Morphology ◽  
Charge Discharge

Li0.95Na0.05Ti2(PO4)3/C nanocomposite was prepared by sol-gel method.The structure and morphology of the samples were characterized by XRD, SEM which showed the particles had typical NASICON structure and diameter range from 400~500nm. The electrochemical performance were tested by cyclic voltammetry and galvanostatic charge–discharge. Results show Li0.95Na0.05Ti2(PO4)3/C nanocomposite exhibitsmuch better electrochemical performance than bare Li0.95Na0.05Ti2(PO4)3.

Preparation and Electrochemical Properties of LaMnO3 Powder as a Supercapacitor Electrode Material

2017 ◽  
Vol 727 ◽  
pp. 698-704 ◽  
Author(s):  
Xian Wei Wang ◽  
Xiao Er Wang ◽  
Hui Chao Zhang ◽  
Qian Qian Zhu ◽  
Dong Li Zheng ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Properties ◽  
Electrode Material ◽  
Raw Materials ◽  
Sol Gel ◽  
Galvanostatic Charge ◽  
Supercapacitor Electrode ◽  
Lanthanum Manganate ◽  
Pure Phase ◽  
Charge Discharge

The structural and electrochemical properties of lanthanum manganate (LaMnO3) powder prepared by the sol-gel method are researched in this article. The powder calcined at 600 °C showed amorphous, and the powder calcined at 700-800 °C showed the pure phase of the LaMnO3. The grains with the size of about 80-120 nm were agglomerating together. Cyclic voltammetry and galvanostatic charge-discharge were used to characterize the electrochemical properties in alkaline environment. The electrochemical properties calcined at 700 °C showed a specific capacitance of 73 F/g at the current density of 0.5 A/g. The raw materials for preparing the LaMnO3 powder are cheap, and the operation method is simple.

High Rate Charge/Discharge Characteristics in Composite Film of Mesoporous TiO2 and Polyaniline for Photorechargeable Battery

2014 ◽  
Vol 1606 ◽  
Author(s):  
Teruaki Nomiyama ◽  
Kenta Sakamoto ◽  
Tomohito Yoshida ◽  
Akinori Kagiyama ◽  
Yuji Horie
Keyword(s):  
Composite Film ◽  
High Performance ◽  
Specific Capacity ◽  
Electrical Energy ◽  
High Rate ◽  
Galvanostatic Charge ◽  
Discharge Characteristics ◽  
Electrical Energy Storage ◽  
Charging Rate ◽  
Charge Discharge

ABSTRACTOne of promising photorechargeable electrode, which has two functions of photovoltaic and electrical energy storage, is a composite film of mesoporous TiO2 and conducting polymer polyaniline. Galvanostatic charge/discharge characteristics of the TiO2-polyaniline composite were examined to reveal how fast the film was charged. The film with a specific capacity 60-120 mAh g–1 was found to be fully charged at high charging rate 20 mA cm–2 which is comparable to high performance solar cells. Such high charging rate was achieved by the compact polyaniline layer covering the large specific surface area of mesoporous TiO2 film.

Influence of Heating Temperature on Structure, Morphology and Electrochemical Performance of LiV3O8 Cathode for Lithium-Ion Batteries Application

2020 ◽  
Vol 1010 ◽  
pp. 314-320
Author(s):  
Mohamad Izha Ishak ◽  
Khairel Rafezi Ahmad ◽  
Rozana A.M. Osman ◽  
Mohd Sobri Idris
Keyword(s):  
Electrochemical Performance ◽  
Lithium Ion Batteries ◽  
Layered Structure ◽  
Heating Temperature ◽  
Lithium Ion ◽  
Galvanostatic Charge ◽  
Heat Treated ◽  
Structure Morphology ◽  
Performance Results ◽  
Charge Discharge

LiV3O8 layered structure was successfully synthesized by a conventional solid-state approach and subsequent heat-treated at 400, 450, 500 and 550 oC. The samples were characterized by XRD, SEM, TEM, BET. Electrochemical performance of LiV3O8 was investigated by cyclic voltammetry (CV) and galvanostatic charge-discharge. The results showed that high purity of LiV3O8 with layered structure was formed. The morphology of the samples were mixed between nanorods and nanosheets structure. For electrochemical performance, results showed that LiV3O8 heat-treated at 500 oC performed a highest charge and discharge capacity of 212 and 172 mAh g-1, respectively. From electrochemical performance results made them a good candidate for cathode material for lithium-ion batteries application.

scholarly journals How to Measure and Calculate Equivalent Series Resistance of Electric Double-Layer Capacitors

Molecules ◽  
2019 ◽  
Vol 24 (8) ◽  
pp. 1452 ◽  
Author(s):  
Rafael Vicentini ◽  
Leonardo Morais Da Silva ◽  
Edson Pedro Cecilio Junior ◽  
Thayane Almeida Alves ◽  
Willian Gonçalves Nunes ◽  
...  
Keyword(s):  
Double Layer ◽  
Electric Double Layer ◽  
Series Resistance ◽  
Voltage Drop ◽  
Equivalent Series Resistance ◽  
Galvanostatic Charge ◽  
Applied Current ◽  
Double Layer Capacitors ◽  
Charge Discharge ◽  
Electric Double Layer Capacitors

Electric double-layer capacitors (EDLCs) are energy storage devices that have attracted attention from the scientific community due to their high specific power storage capabilities. The standard method for determining the maximum power (Pmax) of these devices uses the relation Pmax = U2/4RESR, where U stands for the cell voltage and RESR for the equivalent series resistance. Despite the relevance of RESR, one can observe a lack of consensus in the literature regarding the determination of this parameter from the galvanostatic charge-discharge findings. In addition, a literature survey revealed that roughly half of the scientific papers have calculated the RESR values using the electrochemical impedance spectroscopy (EIS) technique, while the other half used the galvanostatic charge discharge (GCD) method. RESR values extracted from EIS at high frequencies (>10 kHz) do not depend on the particular equivalent circuit model. However, the conventional GCD method better resembles the real situation of the device operation, and thus its use is of paramount importance for practical purposes. In the latter case, the voltage drop (ΔU) verified at the charge-discharge transition for a given applied current (I) is used in conjunction with Ohm’s law to obtain the RESR (e.g., RESR = ΔU/ΔI). However, several papers have caused a great confusion in the literature considering only applied current (I). In order to shed light on this important subject, we report in this work a rational analysis regarding the GCD method in order to prove that to obtain reliable RESR values the voltage drop must be normalized by a factor of two (e.g., RESR = ΔU/2I).

scholarly journals The Use of Succinonitrile as an Electrolyte Additive for Composite-Fiber Membranes in Lithium-Ion Batteries

Membranes ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 45 ◽  
Author(s):  
Jahaziel Villarreal ◽  
Roberto Orrostieta Chavez ◽  
Sujay A. Chopade ◽  
Timothy P. Lodge ◽  
Mataz Alcoutlabi
Keyword(s):  
Ionic Liquid ◽  
Ionic Conductivity ◽  
Lithium Ion Batteries ◽  
Specific Capacity ◽  
Lithium Ion ◽  
Composite Fiber ◽  
Galvanostatic Charge ◽  
Lithium Anode ◽  
Charge Discharge ◽  
Licoo2 Cathode

In the present work, the effect of temperature and additives on the ionic conductivity of mixed organic/ionic liquid electrolytes (MOILEs) was investigated by conducting galvanostatic charge/discharge and ionic conductivity experiments. The mixed electrolyte is based on the ionic liquid (IL) (EMI/TFSI/LiTFSI) and organic solvents EC/DMC (1:1 v/v). The effect of electrolyte type on the electrochemical performance of a LiCoO2 cathode and a SnO2/C composite anode in lithium anode (or cathode) half-cells was also investigated. The results demonstrated that the addition of 5 wt.% succinonitrile (SN) resulted in enhanced ionic conductivity of a 60% EMI-TFSI 40% EC/DMC MOILE from ~14 mS·cm−1 to ~26 mS·cm−1 at room temperature. Additionally, at a temperature of 100 °C, an increase in ionic conductivity from ~38 to ~69 mS·cm−1 was observed for the MOILE with 5 wt% SN. The improvement in the ionic conductivity is attributed to the high polarity of SN and its ability to dissolve various types of salts such as LiTFSI. The galvanostatic charge/discharge results showed that the LiCoO2 cathode with the MOILE (without SN) exhibited a 39% specific capacity loss at the 50th cycle while the LiCoO2 cathode in the MOILE with 5 wt.% SN showed a decrease in specific capacity of only 14%. The addition of 5 wt.% SN to the MOILE with a SnO2/C composite-fiber anode resulted in improved cycling performance and rate capability of the SnO2/C composite-membrane anode in lithium anode half-cells. Based on the results reported in this work, a new avenue and promising outcome for the future use of MOILEs with SN in lithium-ion batteries (LIBs) can be opened.

Effect of Synthesis Conditions on Pseudocapacitance Properties of Nitrogen-Doped Porous Carbon Materials

2019 ◽  
Vol 59 ◽  
pp. 112-125
Author(s):  
Volodymyr Boichuk ◽  
Volodymyr Kotsyubynsky ◽  
Andrii Kachmar ◽  
Sergiy Budzulyak ◽  
Ivan Budzulyak ◽  
...  
Keyword(s):  
Carbon Materials ◽  
Aqueous Electrolyte ◽  
Electrochemical Impedance ◽  
Galvanostatic Charge ◽  
Discharge Data ◽  
Synthesis Conditions ◽  
Capacitive Properties ◽  
Charge Discharge ◽  
Redox Capacitance

The electrochemical properties of the nitrogen-enriched carbons obtained by plant raw treatment as electrode material for supercapacitors were investigated by electrochemical impedance spectroscopy, cycling voltammetry and galvanostatic charge-discharge cycling in KOH aqueous electrolyte. The effect of activation agent (NaOH) concentration and carbonization temperature were analyzed. The separation of double layer and redox capacitance components was done. The dominating role of microporosity for capacitive properties was demonstrated. The capacitance of model capacitors based on carbons obtained at different modes was calculated from both from cycling voltammetry and galvanostatic charge-discharge data. The maximal values of specific capacitance of carbon materials carbonized at 600°C and 900°C are about 100 and 120 F/g, respectively.

Galvanostatic charge–discharge tests, 57Fe and 119Sn Mössbauer and XRD measurements on novel Sn-Ni-Fe electrodeposits

2012 ◽  
Vol 218 (1-3) ◽  
pp. 145-150 ◽  
Author(s):  
G. B. Lak ◽  
E. Kuzmann ◽  
M. El-Sharif ◽  
C. U. Chisholm ◽  
S. Stichleutner ◽  
...  
Keyword(s):  
Galvanostatic Charge ◽  
Charge Discharge

scholarly journals Electrochemical behavior of Bi4B2O9towards lithium-reversible conversion reactions without nanosizing

2018 ◽  
Vol 20 (4) ◽  
pp. 2330-2338 ◽  
Author(s):  
Florian Strauss ◽  
Gwenaëlle Rousse ◽  
Dmitry Batuk ◽  
Mingxue Tang ◽  
Elodie Salager ◽  
...  
Keyword(s):  
Electrochemical Behavior ◽  
Galvanostatic Charge ◽  
Conversion Reaction ◽  
Voltage Hysteresis ◽  
Small Voltage ◽  
Charge Discharge ◽  
Discharge Curves

Galvanostatic charge–discharge curves for a Bi4B2O9/C macrocomposite, highlighting the small voltage hysteresis for the conversion reaction around 300 mV.

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