Year: 1966
Type: article
Abstract: In o rder to obta in the concent ra t ion and act ivat ion overpotent ia l for a ro ta t ing d isk e lect rode it is neces-sary to subt ract f rom the measured overpotent ia l the ohmic potent ia l drop between the re ference e l c t rode probe and the disk. The ohmic drop for a smal l d isk is concent ra ted in the so lut ion near the d isk (Fig. 1). Rather than t ry to put the probe f rom a re ference e lect rode very near the sur face and thus d is tor t the potent ia l and ve loc i ty d is t r ibut ions, one can es t imate the ohmic drop f rom the res i s tance between a d isk imbedded in the sur face of an insu la tor and a counter e lect rode at inf inity. Th is p rocedure does not account for dev ia t ions f rom the pr imary cur rent d is t r ibut ion. For the purpose of ca lcu la t ing the potent ia l d is-t r ibut ion f rom Lap lace 's equat ion, we use ro ta t iona l e l l ipt ic coord inates I ~ and,] re la ted to cy l indr ica l co-5 rd inates by z = a~ r = a~ / (1 + ~ 2) (1--~] 2) [1] where a is the rad ius of the disk, z is the normal d is-tance f rom the disk, and r is the d is tance f rom the axis of symmetry (see Fig. 1, where l ines of constant r are also l ines of constant ~). In th is c05rd inate sys-tem Lap lace 's equat ion is 0 [ 0o] 0 [ 0o] and the boundary condi t ions are 1 These are re la ted to "ob la te sphero ida l coSrd inates " by } = s inh~ and ~1 = cos 0.
DOI: 10.1149/1.2424003
Author: John Newman
Language: English
Field: Energy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W1982072818