It consists of one or more cells, each containing a positive plate, an electrolyte, and a negative plate
. In the fully charged state the positive plate is lead dioxide, the electrolyte is sulfuric acid and the negative plate
Hammond's business is producing lead oxides and negative plate
expanders in service to the world's battery industry.
Two primary effects reduce the life of a lead-acid battery--corrosion of the battery's positive plate and sulfation of the battery's negative plate
. Kurt Kelly at Firefly Energy, Inc., Peoria, Ill., found a solution to both of these problems by incorporating carbon-graphite foam technology into a conventional battery structure, with the Carbon Foam Graphite Battery.
Additionally, negative plate
samples can be eliminated very quickly allowing the microbiologists time to focus their skills on the positive samples only.
The batteries include several other design features to prolong life such as a lead-calcium-tin alloy in both the positive and negative plate
grids allowing for efficient recharging, thick positive plates to reduce grid corrosion and a polypropylene case that prevents water loss.
NiMH (nickel-metal hydride) batteries consist of a positive plate containing nickel hydroxide as its principal active ingredient, a negative plate
composed primarily of hydrogen-absorbing alloys (such as NiFe and MgNi), a separator made of fine fibers, an alkaline electrolyte, a metal case, and a sealing plate with a self-resealing safety vent.
The number of plates in a cell is determined by the required capacity of the battery, but in common practice there is one more negative plate