scholarly journals Online diagnosis of supercapacitors using extended Kalman filter combined with PID corrector

Author(s):  
Zoubida Bououchma ◽  
Jalal Sabor

<span>Supercapacitors are electrical energy storage devices with a high specific power density, a long cycle life and a good efficiency, which make them attractive alternative storage devices for various applications. However, supercapacitors are subject to a progressive degradation of their perfor-mance because of aging phenomenon. Therefore, it is very important to be able to estimate their State-of-Health during operation. Electrochemical Impedance Spectroscopy (EIS) is a very recog-nized technique to determine supercapacitors’ state-of-health. However, it requires the interrup-tion of system operation and thus cannot be performed in real time (online). In this paper, a new online identification method is proposed based on extended Kalman observer combined with a complementary PID corrector. The proposed method allows to accurately estimating supercapacitor resistance and capacitance, which are the main indicators of supercapacitor state-of-health. The new online identification method was applied for two voltage/current profiles using two different supercapacitors. The resistance/capacitance estimated by the new method and the conventional EKF were compared with those obtained by an experimental offline method. In comparison with conventional EKF, the capacitance obtained by the new method is significantly more accurate.</span>

2021 ◽  
Author(s):  
Cong Wang ◽  
Zehao Song ◽  
Pei Shi ◽  
Lin Lv ◽  
Houzhao Wan ◽  
...  

With the rapid development of portable electronic devices, electric vehicles and large-scale grid energy storage devices, it needs to reinforce specific energy and specific power of related electrochemical devices meeting...


MRS Advances ◽  
2018 ◽  
Vol 3 (22) ◽  
pp. 1261-1267 ◽  
Author(s):  
Belqasem Aljafari ◽  
Arash Takshi

ABSTRACTRecently, gel polymer electrolytes (GPEs) have been drawn noteworthy attention for different applications, specifically, for supercapacitors. GPEs could become an excellent substitute to liquid electrolytes (LEs) for making flexible and more durable devices. The performance of two different electrolytes (GPEs and LEs) in multi-wall carbon nanotube based supercapacitors were investigated. In spite of significantly lower conductivity of GPEs than LEs, devices with the gel electrolyte presented a superior performance. More focused has been given in this work on demonstrating the performance of supercapacitors based on GPEs and LEs at different concentrations of the acids ranging from 1M to 3M. Both electrolytes have been characterized at room temperature by making supercapacitors and using cyclic voltammetry, charging-discharging, electrochemical impedance spectroscopy, and leakage tests. The experimental results showed that GPE devices had much better capacitances and resistances compare to the LE based devices. Moreover, the capacitances of all devices were increased proportionally with the increase in the concentration from 1M to 3M, and the resistances were increased inversely with the decreased of concentration. The promising results from the gel electrolytes is encouraging for further development of flexible and high capacitance energy storage devices.


2013 ◽  
Vol 78 (12) ◽  
pp. 2141-2164 ◽  
Author(s):  
Vladimir Panic ◽  
Aleksandar Dekanski ◽  
Branislav Nikolic

Porous electrochemical supercapacitive materials, as an important type of new-generation energy storage devices, require a detailed analysis and knowledge of their capacitive performances upon different charging/discharging regimes. The investigation of the responses to dynamic perturbations of typical representatives, noble metal oxides, carbonaceous materials and RuO2-impregnated carbon blacks, by electrochemical impedance spectroscopy (EIS) is presented. This presentation follows a brief description of supercapacitive behavior and origin of pseudocapacitive response of noble metal oxides. For all investigated materials, the electrical charging/discharging equivalent of the EIS response was found to obey the transmission line model envisaged as so-called ?resistor/capacitor (RC) ladder?. The ladder features are correlated to material physicochemical properties, its composition and the composition of the electrolyte. Fitting of the EIS data of different supercapacitive materials to appropriate RC ladders enables the in-depth profiling of the capacitance and pore resistance of their porous thin-layers and finally the complete revelation of capacitive energy storage issues.


Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6008
Author(s):  
Tahira Yaqoob ◽  
Malika Rani ◽  
Arshad Mahmood ◽  
Rubia Shafique ◽  
Safia Khan ◽  
...  

MXene/Ag2CrO4 nanocomposite was synthesized effectively by means of superficial low-cost co-precipitation technique in order to inspect its capacitive storage potential for supercapacitors. MXene was etched from MAX powder and Ag2CrO4 spinel was synthesized by an easy sol-gel scheme. X-Ray diffraction (XRD) revealed an addition in inter-planar spacing from 4.7 Å to 6.2 Å while Ag2CrO4 nanoparticles diffused in form of clusters over MXene layers that had been explored by scanning electron microscopy (SEM). Energy dispersive X-Ray (EDX) demonstrated the elemental analysis. Raman spectroscopy opens the gap between bonding structure of as-synthesized nanocomposite. From photoluminence (PL) spectra the energy band gap value 3.86 eV was estimated. Electrode properties were characterized by applying electrochemical observations such as cyclic voltammetry along with electrochemical impedance spectroscopy (EIS) for understanding redox mechanism and electron transfer rate constant Kapp. Additionally, this novel work will be an assessment to analyze the capacitive behavior of electrode in different electrolytes such as in acidic of 0.1 M H2SO4 has specific capacitance Csp = 525 F/g at 10 mVs−1 and much low value in basic of 1 M KOH electrolyte. This paper reflects the novel synthesis and applications of MXene/Ag2CrO4 nanocomposite electrode fabrication in energy storage devices such as supercapacitors.


Author(s):  
Сергей Николаевич Пронькин ◽  
Нина Юрьевна Шокина

Представлена новая обобщенная лестничная модель электрохимического импеданса для пористых материалов электродов в устройствах хранения энергии. Дано краткое описание существующих моделей межфазного импеданса и их ограничений. Новая модель основана на общепринятой “лестничной” модели импеданса цилиндрических пор. Однако новая модель учитывает сложную пористую структуру электродных материалов. В частности, модель описывает импеданс электродов с иерархической пористой разветвленной структурой, в которой широкие поры разветвляются в более узкие. Новая модель позволяет вычислить импеданс межфазной границы электрод/электролит в присутствии как нефарадеевских, так и фарадеевских процессов. Модель успешно опробована для пор с простой геометрией, для которых существуют точные решения. Изучено влияние структурных параметров модельных пористых электродов на их характеристики работы в суперконденсаторах. Проанализировано влияние диаметра пор, величины расширения начал пор и разветвления пор. Сформулированы критерии направленного дизайна электродных материалов для суперконденсаторов A new generalized staircase model of the electrochemical impedance is presented for porous electrode materials in energy storage devices. A brief overview on existing models of interfacial impedance and their limitations is given. The new model is based on the conventional staircase model of the impedance in cylindrical pores. However, the new model takes into account the complex porous structure of electrode materials. In particular, the impedance of hierarchical branching porous electrodes is described, i.e. the wide pores branching into the narrower pores. The new model allows to evaluate the impedance of the electrode/electrolyte interface in the presence of both non-faradaic and faradaic processes. The model is validated using the available exact solutions and experimental data for simple pore geometries. The influence of the parameters of structure of model porous electrodes on their performance in supercapacitors is studied. In particular, the influence of the diameter of the pores, width of pore openings, branching of pores is analyzed. The guideline for focused design of electrode materials of supercapacitors is outlined


2008 ◽  
Vol 80 (11) ◽  
pp. 2327-2343 ◽  
Author(s):  
V. Subramanian ◽  
Hongwei Zhu ◽  
Bingqing Wei

Manganese oxides have been synthesized by a variety of techniques in different nanostructures and studied for their properties as electrode materials in two different storage applications, supercapacitors (SCs) and Li-ion batteries. The composites involving carbon nanotubes (CNTs) and manganese oxides were also prepared by a simple room-temperature method and evaluated as electrode materials in the above applications. The synthesis of nanostructured manganese oxides was carried out by simple soft chemical methods without any structure directing agents or surfactants. The prepared materials were well characterized using different analytical techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), surface area studies, etc. The electrochemical properties of the nanostructured manganese oxides and their composites were studied using cyclic voltammetry (CV), galvanostatic charge-discharge, and electrochemical impedance spectroscopic (EIS) studies. The influence of structural/surface properties on the electrochemical performance of the synthesized manganese oxides is reviewed.


In this study, graphene-molybdenum oxide composite materials were prepared via green hydrothermal synthesis method and evaluated as supercapacitor electrodes. The morphology and structure of the composite were examined by using Scanning Electron Microscopy (SEM), Raman spectroscopy. The electrochemical performances of the composite were evaluated by cyclic voltammetry (CV), galvanostatic chargedischarge (CD) method, and electrochemical impedance spectroscopy (EIS). The electrochemical results show that the composite electrodes possess improved specific capacitance of 122 F/g at a scan rate of 5 mV/s, which is about 22% higher that of pure graphene. Additionally, the composite electrodes exhibit good capacitive properties and a high specific energy with superior capacitive retention after 1000 cycles. In contrast to the previously reported systems that are usually complicated and costly, the present work potentially provides a readily scalable technological platform for economic mass production of energy storage devices.


2013 ◽  
Vol 1547 ◽  
pp. 69-74 ◽  
Author(s):  
Navjot K. Sidhu ◽  
Ratheesh R. Thankalekshmi ◽  
A.C. Rastogi

ABSTRACTOrdered one dimensional polypyrrole conducting polymer structure as a shell over TiO2 nanotube arrays at the core were formed by pulsed current electropolymerization. TiO2 nanotubes with rippled wall structure are designed by action of water in the anodizing medium. This provides open tube structure supporting short diffusion length and increased accessibility of ions involved in redox transition for energy storage. Electrochemical properties evaluated by cyclic voltammetry and electrochemical impedance spectroscopy show specific capacitance of 34-44 mF.cm-2 and extremely low bulk and charge transfer resistances.


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