Accession Number : ADA158806
Title : Role of Additives in Minimizing Zinc Electrode Shape Change: The Effect of Lead on the Kinetics of Zn(II) Reduction in Concentrated Alkaline Media.
Descriptive Note : Final technical rept. 20 Sep 82-20 Sep 84,
Corporate Author : ALLIED CORP MORRISTOWN NJ
Personal Author(s) : Melnicki,L S ; Lazic,I ; Cipris,D
Report Date : Jul 1985
Pagination or Media Count : 88
Abstract : The kinetics of zinc deposition in various media is among the most widely studied systems, along with hydrogen and oxygen reactions. The importance of the zinc electrode originates from the use of zinc as an anode material in commerically important primary and secondary batteries. The Ag-Zn battery, commerically available for a long time, has the highest practical energy and power densities among conventional secondary batteries. The Ni-Zn secondary battery is still under development. Both zinc electrodes operate in concentrated alkaline electrolytes. In spite of the extensive number of studies, the mechanism of zinc reduction in alkaline media is not fully understood. The situation is further complicated in the presence of various metallic additives. which are commonly used in secondary alkaline batteries utilizing zinc anodes to suppress dendrite formation and/or facilitate uniform zinc deposition. Non-uniform zinc deposition leads to the phenomenon known as zinc electrode shape change in secondary batteries. The zinc electrode shape change is considered a leading factor in the premature loss of capacity of zinc batteries and to a generally unacceptably short cycle life. Of all the additives employed, lead appears to be the most commonly used in commercial practice, alone or in combination with other additives. While further work is in order (especially on the dissolution process of zinc, which is also affected by lead) our results point to the possibility of employing electrolyte additives, as opposed to additives to the ZnO paste in practical cells.
Descriptors : *REACTION KINETICS , *ELECTRODES , *STORAGE BATTERIES , *ZINC , *LEAD(METAL) , *REDUCTION(CHEMISTRY) , METALS , DENSITY , MATERIALS , SECONDARY , SHAPE , LONG RANGE(TIME) , HYDROGEN , REDUCTION , SHORT RANGE(TIME) , OXYGEN , DEPOSITION , CONCENTRATION(COMPOSITION) , COMMERCIAL EQUIPMENT , ADDITIVES , MEDIA , POWER , LOSSES , LIFE CYCLES , KINETICS , ELECTROLYTES , DENDRITIC STRUCTURE , ALKALINITY , ANODES , ALKALINE BATTERIES , PRIMARY BATTERIES , SILVER ZINC BATTERIES
Subject Categories : Physical Chemistry
Electrochemical Energy Storage
Distribution Statement : APPROVED FOR PUBLIC RELEASE