The proposed model shows that the electrode polarization, oxygen evolution, and loss of water can be inhibited by using a pulse charge and/or prolonging the rest time between the pulses. Guo and coworkers under pulse charging conditions. The kinetic processes of both lead(II) sulfate (PbSO 4 ) oxidation and the oxygen evolution in the positive plate of the VRLA batteries were studied by Y. Journal of the Electrochemical Society 135: 278–285. Courtesy of the Electrochemical Society, Reproduced with permission from Dimpault-Darcy EC, Nguyen TV, and White RE (1988) A two-dimensional mathematical model of a porous lead dioxide electrode in a lead–acid cell. X cc and x th are, respectively, the half-thickness of the grid/electrode region and the electrode. Schematic of a lead dioxide electrode with the model boundary shown by dashed line. Electrochemical Models of Porous Electrodesįigure 10. To date, owing to the availability of commercial codes that can provide accurate numerical solutions and the computation power in personal computers, electrochemical models are becoming useful for the growing battery engineering exercise toward short-term energy management and automotive vehicle hybridization. Nevertheless, these models are the only ones able to provide close-to-reality simulations of LAB over a wide range of operating conditions, especially to assist battery design.
#Battery pulse chargers code
The variables used in the model are the acid concentration, electrode porosity, current density in the electrolyte, and potentials in solid and liquid phases.Įlectrochemical models, also called first-principle mathematical models, are not commonly used in the industry because of the complexity involved in the numerical model development and the parameterization, which usually demand an intensive code development and an immense experimental data collection and require high computation power to run simulation. In most of the cases, it includes the porosity variation, Ohm's law in solution and in solid phases, and the mass balance of transport phenomena (as those depicted by Fick's second law) and electrode kinetics (as described by Butler–Volmer equations). Liaw, in Encyclopedia of Electrochemical Power Sources, 2009 Electrochemical Models Introduction to Electrochemical ModelsĪn electrochemical model is constructed from first-principle equations governing the physicochemical processes occurring in the LAB. It requires much more sophisticated charger hardware, which reflects its cost, and the practical benefits are questionable. In summary, pulse charging is technically challenging. Most of the benefits are disputable and have not been generally accepted by the scientific community. With the same average current, it causes higher joule losses and battery temperature. Application of this technique with the same maximal charge rate results in longer charge duration.
Some reports claim dislodging gas bubbles from the porous electrodes active mass. It is supposed to lower electrode polarization during charging and reduce gassing.
The pulse charging with a short reverse polarization pulse prior to each charging pulse is called ‘negative pulse charging’. Installation of durable and reliable reference electrode would increase the battery cost significantly. For better control of pulse charging, individual electrodes’ potential control would be desirable however, this is technically challenging. Pulse charging has no influence on diffusion however, it leads to lower gassing and higher negative electrode polarization at the end of charging. On the contrary, in comparison with equivalent average CC, pulse current generates higher joule losses and longer charging time at the same maximal current rate.
Thus, such pulse charging might reduce gassing.
Once it reaches gassing voltage, the pulse current is interrupted. Battery voltage during the pulse is monitored. During a pulse switch on current, voltage increases, reflecting the same voltage fractions as at the current interruption with nearly the same time constants. Other benefits of pulse charging were claimed some are supported by experimental measurements, some are rather vague and disputable.
#Battery pulse chargers free
Svoboda, in Encyclopedia of Electrochemical Power Sources, 2009 Pulse chargingĪs mentioned earlier, pulse charging is convenient for IR free charging.
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