Differential Capacitance Study on the Basal Plane of Stress-Annealed Pyrolytic Graphite

Abstract

The non-faradaic differential electrode capacity of the basal plane of high-pressure stress-annealed pyrolytic graphite has been examined in aqueous solution using an a.c. impedance bridge. The capacity has a near parabolic dependence on electrode potential with a minimum of approximately 3 microfarads/ sq cm in concentrated electrolytes and is pH independent. Studies in NaF solutions at concentrations in the range 0.9 to 0.00001M indicate that in the range of potential studied (+0.5 to -0.5 V vs NHE) the minimum capacity is best attributed to the space charge region within the graphite and not to the diffuse ionic layer. Apparently the potential of zero charge of the electrolyte is outside the potential range of the measurements.

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Document Details

Document Type
Technical Report
Publication Date
Jul 15, 1971
Accession Number
AD0739698

Entities

People

  • Ernest B. Yeager
  • Jean-paul Randin

Organizations

  • Case Western Reserve University

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Charge Carriers
  • Chemical Synthesis
  • Chemistry
  • Dispersions
  • Electrochemistry
  • Electrodes
  • Frequency
  • Materials
  • Measurement
  • Photoelectrochemical Cells
  • Physical Chemistry
  • Security
  • Semiconductors
  • Sine Waves
  • Sodium Compounds
  • Space Charge
  • Square Waves

Fields of Study

  • Materials science

Readers

  • Electrical Engineering
  • Electrochemical Engineering/ Fuel Cell Technologies

Technology Areas

  • Space
  • Space - Hall-Effect Thruster