The Control of Insoluble Magnesium Compounds Resulting from Sea Water Battery Operation

摘要

The capacity of low rate multicell silver chloride/magnesium sea water batteries is often limited by a flocculent precipitate that clogs the inlet ports and fills the space between the electrodes. The results of this investigation show that the flocculent precipitate is formed only when magnesium ions (Mg(++)) are initially present in the electrolyte solution. In magnesium free salt solutions, with a salinity equal to sea water, the precipitate is granular. The magnesium-ion effect can be controlled by passing the incoming sea water electrolyte through a filter of thallous fluoride (TlF) or disodium ethylenediaminetetraacetate (disodium EDTA). The magnesium ions in the sea water electrolyte apparently react with the TlF to form a granular precipitate, and with disodium EDTA to form a soluble magnesium complex. Batteries containing filters of these types were discharged in 3.5% salinity sea water and showed capacity increases ranging from 12 to 60 percent over batteries having no filter. With TlF filters the capacity increase was typically 12 percent and with disodium EDTA the increase was typically 45 percent. (Author)