This paper presents the basic chemistry of oxygen recombination in lead-acid cells and briefly compares it with the more highly developed nickel-cadmium system, which also operates on the oxygen cycle.
Can recombination be used in lead-acid batteries?
Early attempts to use recombination in lead-acid batteries were unsuccessful due to excessive cost, size, and/or complexity, and none were effectively commercialized. However, over the past 20 years, recombination systems have been developed and are undergoing an extensive program of definition and refinement at many battery companies.
Oxygen-recombination chemistry is used in sealed or valve-regulated lead-acid batteries. Early attempts to incorporate this chemistry into lead-acid batteries were not successful due to excessive cost, size, and/or complexity, and none were effectively commercialized.
A recombination battery is a type of battery where the process of charging reverses the chemical reaction that occurs during discharge, allowing the oxygen and hydrogen gases produced to react and form water, reducing the need for maintenance. Recombination batteries were first used in aircraft applications in the late 1970s in the U.S.A., where individual cylindrical cells (with a C/1 capacity of 18 A h) were assembled in a rectangular outer case to give a 24 V battery.
How do battery technologists deal with gas recombination chemistry?
Instead, the focus is on the gas recombination chemistry and some of the ways battery technologists must deal with it in developing functional VRLA products. Sealed nickel-cadmium cell technology has been developed to optimize the efficiency of the oxygen-recombination process.
In lead-acid batteries of the vented design with „free“ electrolyte, it is practically impossible for the oxygen to move to the negative electrode. Immediately after having „left“ the positive electrode, it bubbles up and escapes through the vent plug. The oxygen oxidizes lead to lead oxide (formula (1)).
What is the operating voltage of a recombination battery?
The operating voltage of a recombination battery is higher than that of an equivalent battery with flooded electrolyte.nnA recombination battery is capable of giving 8 - 8.5 hours at a discharge current of 150 A (6 C/1) at ambient temperature.