Prevention of Catalyst Plug Deterioration in Lead-Acid Batteries

Catalyst plugs, developed to obviate the need for adding water to the electrolyte in a battery, re-combine oxygen and hydrogen gases generated from the battery during float-charging to form water. This paper describes the deactivation mechanism for the catalyst (Pd-Al2O3) and the deactivation-prevention techniques. The analysis of catalyat plugs used for several years at telephone offices has revealed that the catalyst plugs fail due to adsorption of the water onto the catalyst, and that the catalytic reaction is interfered with by the water physisorbed on the catalyst surface. A method for covering the catalyst surface with hydrophobic film was studied. Results revealed that the method reduced the amount of water physisorbed on the catalyst to one-fiftieth that on untreated catalyst.