Optimization of grid configuration by investigating its effect on positive


Abstract :

With increasing the applications of lead-acid batteries, the demand for efficient, low resistant and inexpensive batteries has increased drastically. As discharge rates increase, ohmic voltage losses in current collecting system become more important. In this study, numerical methods are employed to investigate the effect of grid configuration, lug position, diagonal wire angles and tapering wires towards the plate’s lug on the performance of positive electrode of lead-acid batteries via modeling the current and potential distribution through gird wires, active material and adjacent electrolyte to the surface of each grid. 18 distinct grid designs with same weights are designed to achieve this task. The results indicate that double-diagonal configuration offers up to 43% increased current distribution uniformity. It is also shown that locating the lug near the midpoint of the frame, increasing the degree of parallel diagonal wires and tapering the wires towards the lug increases the uniformity of the current distribution up to 14%, 1.6% and 5.6%, respectively. It is noteworthy that manufacturing and practical limitations has been taken into account in this work as well.

Introduction :

Applications of lead-acid batteries have increased significantly during the last decades. Most of these applications require batteries to work on partial state of charge (PSoC) status and deliver high currents in short periods more frequently. It is well known that as the discharge rate increases, ohmic losses in current collecting system become more important and even dominant in some cases. Therefore optimization of grid configuration may contribute to enhance the overall performance of the lead-acid batteries (LAB) for these new and more demanding applications with reducing ohmic losses through the current path. Many attempts have been exerted during the last 9 decades to investigate the effect of different parameters on current and potential distribution through electrodes of LABs

Source :