The effect of grid configurations on potential and current density distributions in positive plate of lead–acid battery via numerical modeling


Abstract :

During the last decades, huge efforts have been made to enhance the efficiency as well as performanceof lead–acid batteries. The configuration of grid wires plays an important role in minimizing the ohmicdrop and hence, improving its current collecting ability. In the current study, numerical methods havebeen employed to investigate the effects of grid configuration on the performance of a positive electrodein lead–acid batteries. Potential and current density distributions have been modeled through grid wires,active material and adjacent electrolyte to the surface of each grid. The modeling results are consistentwith experimental findings in the literature saying that the optimized diagonal design for grid configu-ration provides lower total grid weight as well as enhanced current collecting role comparing to otherdesigns such as, conventional, diagonal and expanded metal. This confirms that numerical modeling is afast, inexpensive and effective method for optimization of the battery grid configuration.

Introduction :

During the last decade, huge efforts have been made to enhanceefficiency and performance of lead–acid batteries, i.e. incorporatingpromising alloying elements including Ca, Sn, Ag, into the grid alloy,optimizing the grid configuration and applying additives to bothactive material and battery electrolyte. Each grid of SLI (starting, lighting, and ignition) battery is usuallymade of two compartments; first, a rectangular frame surroundeda network of wires and second, a lug on top of the frame basi-cally used for carrying the current in or out of the plate. During thedischarge or charge process, electric current generated or appliedmoves through both lug and grid wires in opposite directions. While the battery grid is mainly a precursor for the activematerial and absorbent for mechanical stress specially caused byexternal forces or volume changes of active mass during cycling,it is also responsible for current distribution through the plate