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Omar N.,Vrije Universiteit Brussel | Omar N.,Erasmus University College Brussels | Monem M.A.,Vrije Universiteit Brussel | Firouz Y.,Vrije Universiteit Brussel | And 8 more authors.
Applied Energy

From these analyses, one can derive the impact of the working temperature on the battery performances over its lifetime. At elevated temperature (40. °C), the performances are less compared to at 25. °C. The obtained mathematical expression of the cycle life as function of the operating temperature reveals that the well-known Arrhenius law cannot be applied to derive the battery lifetime from one temperature to another.Moreover, a number of cycle life tests have been performed to illustrate the long-term capabilities of the proposed battery cells at different discharge constant current rates. The results reveal the harmful impact of high current rates on battery characteristics.On the other hand, the cycle life test at different depth of discharge levels indicates that the battery is able to perform 3221 cycles (till 80% DoD) compared to 34,957 shallow cycles (till 20% DoD). To investigate the cycle life capabilities of lithium iron phosphate based battery cells during fast charging, cycle life tests have been carried out at different constant charge current rates. The experimental analysis indicates that the cycle life of the battery degrades the more the charge current rate increases. From this analysis, one can conclude that the studied lithium iron based battery cells are not recommended to be charged at high current rates. This phenomenon affects the viability of ultra-fast charging systems.Finally, a cycle life model has been developed, which is able to predict the battery cycleability accurately. © 2013 Elsevier Ltd. Source

Khan M.R.,Vrije Universiteit Brussel | Mulder G.,Vlaamse Instelling voor Technologisch Onderzoek | Van Mierlo J.,Vrije Universiteit Brussel
Journal of Power Sources

In this article, an online state of charge (SoC) estimation framework is proposed, designed and implemented using the system identification approaches. The techniques are composed of cross combination between two modified nonlinear optimisation algorithms (modified Genetic Algorithm and modified Levenberg Marquardt) adapted for battery cell parameter estimation. Subsequently a linear recursive Kalman filter is employed to estimate the state parameters of the battery cell. Moreover, a newly statistical approach is developed to encounter hysteresis phenomena within the cell. The prerequisite for the SoC determination in the electrical vehicle (EV) is challenging as the battery can be composed of hundreds of cells while the load current changes dramatically inside the cells and the required elapsed time for SoC determination should be as short as possible to extend the expected lifetime of the battery pack. Thus, the accurate estimation of the SoC of the cells in a battery pack is one of the key factors for using them effectively. The framework is found to be robust, optimal and implementable in time constrained environment with acceptable accuracy. © 2013 Elsevier Ltd. All rights reserved. Source

Welkenhuysen K.,Royal Belgian Institute Of Natural Sciences | Piessens K.,Royal Belgian Institute Of Natural Sciences | Baele J.-M.,University of Mons | Laenen B.,Vlaamse Instelling voor Technologisch Onderzoek | Dusar M.,Royal Belgian Institute Of Natural Sciences
Energy Procedia

Potential CO2 reservoirs in Belgium are poorly explored. Consequently, the estimated storage capacities are theoretical capacities. The total theoretical storage capacity for Belgium is conservatively estimated at about 1Gt, additional exploration and research are needed to make better capacity assessments. An onset towards prioritising such actions is given here. Deep saline aquifers and coal sequences have created the geological storage options for CO2 in Belgium. The main criteria for reservoir selection and evaluation are reservoir properties, sealing, depth and the occurrence of trapping structures. Aquifer storage opportunities are the Houthem and Maastricht Formations, the Buntsandstein Formation, the Neeroeteren Formation, the Carboniferous Limestone Group (Dinantian) and the Devonian, the latter two in both the north and the south of the country. Of these, the Buntsandstein and the Dinantian reservoirs appear the most promising. Unmined coal sequences have a relatively large capacity, but the low permeability will pose technical difficulties. Storage in abandoned coal mines is likely feasible but pressure and sealing issues will have to be solved. © 2010 Elsevier Ltd. © 2011 Published by Elsevier Ltd. Source

Mulder G.,Vlaamse Instelling voor Technologisch Onderzoek | Ridder F.D.,Vrije Universiteit Brussel | Six D.,Vlaamse Instelling voor Technologisch Onderzoek
Solar Energy

Classically electricity storage for PV panels is mostly designed for stand-alone applications. In contrast, we focus in this article on houses connected to the grid with a small-scale storage to store a part of the solar power for postponed consumption within the day or the next days. In this way the house owner becomes less dependent on the grid and does only pay for the net shortage of his energy production. Local storage solutions pave the way for many new applications like omitting over-voltage of the line and bridging periods of power-line black-out. Since 2009 using self-consumption of PV energy is publicly encouraged in Germany, which can be realised by electric storage. This paper develops methods to determine the optimal storage size for grid-connected dwellings with PV panels. From measurements in houses we were able to establish calculation rules for sizing the storage. Two situations for electricity storage are covered: - the storage system is an optimum to cover most of the electricity needs; - it is an optimum for covering the peak power need of a dwelling. After these calculation rules a second step is needed to determine the size of the real battery. The article treats the aspects that should be taken into consideration before buying a specific battery like lead-acid and lithium-ion batteries. © 2010 Elsevier Ltd. All rights reserved. Source

Da Ponte G.,Vlaamse Instelling voor Technologisch Onderzoek | Ghosh A.K.,SIM Researcher | Kakaroglou A.,Vrije Universiteit Brussel | Van Hemelrijck D.,Vrije Universiteit Brussel | And 2 more authors.
Plasma Processes and Polymers

3-Aminopropyltriethoxysilane coatings have been deposited on stainless steel (SS) samples by means of an atmospheric pressure dielectric barrier discharge as an adhesive promotion layer in epoxy resin/SS composites. A multi-diagnostic analytical approach (FTIR, XPS) was used for the chemical characterization of the deposited coating with regard to improvement of adhesively bonded joint strength. The effect of a plasma post-treatment after the plasma coating deposition was compared to a thermal post-treatment. Both enhanced the siloxane networking resulting in a significant adhesion improvement. Fracture strength between SS and epoxy was increased with more than 20MPa. Atmospheric plasma deposited siloxane coatings including a plasma post treatment improve the adhesion strength in stainless steel/epoxy hybrids with 20MPa compared to untreated steel samples. Therefore these plasma coatings can be seen as worthy alternatives to more conventional wet chemical coatings with a thermal post treatment. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

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