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Internal resistance

About: Internal resistance is a research topic. Over the lifetime, 5740 publications have been published within this topic receiving 64201 citations.


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Proceedings ArticleDOI
01 Sep 2007
TL;DR: In this paper, an easy-to-use battery model applied to dynamic simulation software is presented, which uses only the battery State-Of-Charge (SOC) as a state variable in order to avoid the algebraic loop problem.
Abstract: This paper presents an easy-to-use battery model applied to dynamic simulation software. The simulation model uses only the battery State-Of-Charge (SOC) as a state variable in order to avoid the algebraic loop problem. It is shown that this model, composed of a controlled voltage source in series with a resistance, can accurately represent four types of battery chemistries. The model's parameters can easily be extracted from the manufacturer's discharge curve, which allows for an easy use of the model. A method is described to extract the model's parameters and to approximate the internal resistance. The model is validated by superimposing the results with the manufacturer's discharge curves. Finally, the battery model is included in the SimPowerSystems (SPS) simulation software and is used in the Hybrid Electric Vehicle (HEV) demo. The results for the battery and for the DC-DC converter are analysed and they show that the model can accurately represent the general behaviour of the battery.

1,102 citations

Journal ArticleDOI
TL;DR: It is demonstrated that power densities can be increased to over 1 W/m2 by changing the operating conditions or electrode spacing, which should lead to further improvements in power generation and energy recovery in single-chamber, air-cathode MFCs.
Abstract: Power density, electrode potential, coulombic efficiency, and energy recovery in single-chamber microbial fuel cells (MFCs) were examined as a function of solution ionic strength, electrode spacing and composition, and temperature. Increasing the solution ionic strength from 100 to 400 mM by adding NaCl increased power output from 720 to 1330 mW/m2. Power generation was also increased from 720 to 1210 mW/m2 by decreasing the distance between the anode and cathode from 4to 2 cm. The power increases due to ionic strength and electrode spacing resulted from a decrease in the internal resistance. Power output was also increased by 68% by replacing the cathode (purchased from a manufacturer) with our own carbon cloth cathode containing the same Pt loading. The performance of conventional anaerobic treatment processes, such as anaerobic digestion, are adversely affected by temperatures below 30 degrees C. However, decreasing the temperature from 32 to 20 degrees C reduced power output by only 9%, primarily as a result of the reduction of the cathode potential. Coulombic efficiencies and overall energy recovery varied as a function of operating conditions, but were a maximum of 61.4 and 15.1% (operating conditions of 32 degrees C, carbon paper cathode, and the solution amended with 300 mM NaCl). These results, which demonstrate that power densities can be increased to over 1 W/m2 by changing the operating conditions or electrode spacing, should lead to further improvements in power generation and energy recovery in single-chamber, air-cathode MFCs.

911 citations

Journal ArticleDOI
TL;DR: A clear relation between the electrochemical performance and the microbial composition of MFCs is demonstrated and the potential to generate useful energy by means of M FCs is substantiated.
Abstract: Connecting several microbial fuel cell (MFC) units in series or parallel can increase voltage and current; the effect on the microbial electricity generation was as yet unknown Six individual continuous MFC units in a stacked configuration produced a maximum hourly averaged power output of 258 W m(-3) using a hexacyanoferrate cathode The connection of the 6 MFC units in series and parallel enabled an increase of the voltages (202 V at 228 W m(-3)) and the currents (255 mA at 248 W m(-3)), while retaining high power outputs During the connection in series, the individual MFC voltages diverged due to microbial limitations at increasing currents With time, the initial microbial community decreased in diversity and Gram-positive species became dominant The shift of the microbial community accompanied a tripling of the short time power output of the individual MFCs from 73 W m(-3) to 275 W m(-3), a decrease of the mass transfer limitations and a lowering of the MFC internal resistance from 65 +/- 10 to 39 +/- 05 omega This study demonstrates a clear relation between the electrochemical performance and the microbial composition of MFCs and further substantiates the potential to generate useful energy by means of MFCs

851 citations

Journal ArticleDOI
TL;DR: In this article, a mathematical model of a lead-acid battery is presented, which takes into account self-discharge, battery storage capacity, internal resistance, overvoltage, and environmental temperature.
Abstract: A mathematical model of a lead-acid battery is presented. This model takes into account self-discharge, battery storage capacity, internal resistance, overvoltage, and environmental temperature. Nonlinear components are used to represent the behavior of the different battery parameters thereby simplifying the model design. The model components are found by using manufacturers specifications and experimental tests. A comparison between the model and experimental results obtained from a battery evaluation test system was used for verification. This model can be used to accurately evaluate battery performance in electrical systems. >

637 citations

Journal ArticleDOI
TL;DR: Si composite negative electrodes for lithium secondary batteries degrade in the dealloying period with an abrupt increase in internal resistance that is caused by a breakdown of conductive network made between Si and carbon particles as discussed by the authors.
Abstract: Si composite negative electrodes for lithium secondary batteries degrade in the dealloying period with an abrupt increase in internal resistance that is caused by a breakdown of conductive network made between Si and carbon particles. This results from a volume contraction of Si particles after expansion in the previous alloying process. Due to the large internal resistance, the dealloying reaction is not completed while Si remains as a lithiated state. The anodic performance is greatly improved either by applying a pressure on the cells or loading a larger amount of conductive carbon in the composite electrodes.

603 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023109
2022228
2021115
2020266
2019360
2018379