Accession Number : AD0718831

Title :   Electrochemistry of Redox Couples on Lithiated Nickel Oxide Electrodes.

Descriptive Note : Technical rept.,

Corporate Author : CASE WESTERN RESERVE UNIV CLEVELAND OHIO ELECTROCHEMISTRY RESEARCH LAB

Personal Author(s) : Tench,Dennis M. ; Yeager,Earnest

Report Date : 15 SEP 1970

Pagination or Media Count : 211

Abstract : The kinetics of redox couples (Fe(CN)6(-4)/Fe(CN)6(-3), FE(+2)/Fe(+3), Cr(+2)/Cr(+3) and quinhydrone) have been investigated on mosaic NiO(Li) electrodes (0.5 - 0.5 cation % Li), in aqueous sulfate solutions at various pH, using rotating flat electrodes and linear sweep voltammentry. To summarize the redox data, no oxidation or reduction processes occur at potentials very cathodic (>200 mV) to that of the reversible surface reaction (Ni(+2) - Ni(+3)). For oxidation reactions, all of the change in electrode potential is across the Helmholtz region, except at low overvoltages (< 100 mV) and possible when specific adsorption occurs. For reductions, most of this potential change usually occurs across the space charge region of the semiconductor, depending on pH and the system considered. In the absence of redox couples, the differential capacitance exhibits a maximum at the potential of the reversible surface reaction (Ni(+2) - Ni(+3)). At more cathodic potentials,1/C - E plots are linear with essentially the proper slope for the carrier concentration in the semiconductor, although some frequency dispersion is observed. (Author)

Descriptors :   (*SEMICONDUCTORS, *ELECTRODES), (*ELECTROCHEMISTRY, *NICKEL COMPOUNDS), SURFACE PROPERTIES, LITHIUM, DOPING, FREE ENERGY, IRON, PH FACTOR

Subject Categories : Physical Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE