SECONDARY BATTERIES – LEAD– ACID SYSTEMS | Flooded Batteries

Flooded lead–acid batteries (LAB) have been used for more than 140 years in various applications, which include automotive, traction, and stationary. Although valve-regulated lead–acid batteries have gained significant market shares over the past decades, the flooded design is still the major part of all manufactured LAB. The essential components of a LAB are the positive and negative electrodes (grids and active materials), the electrolyte (diluted sulfuric acid), the highly porous separators between the plates, the current collector system (top bars, terminals, and intercell connectors for block batteries), and the container with the lid. Flat plate design is used virtually for all negative and most of the positive electrodes. However, there are also batteries with positive plates of the tubular or Plante design. Over the decades, there have been many improvements on the flooded types, which include the reduction or even elimination (for certain applications) of antimony in the grid alloys, the use of modern plastic materials for container and lid, inter-cell connection for block batteries rather than connecting cells outside the lids, separators with higher porosity, lighter and thinner grids, alloys with lower corrosion rate, and active materials with better utilization and cycling performance.