B. V. Tilak

Electrochemical capacitors, also called supercapacitors, are unique devices exhibiting 20 to 200 times greater capacitance than conventional capacitors. The large capacitance exhibited by these systems has been demonstrated to arise from a combination of the double‐layer capacitance and pseudocapacitance associated with surface redox‐type reactions. The purpose of this review is to survey the published data of available electrode materials possessing high specific double‐layer or pseudocapacitance and examine their reported performance data in relation to their theoretical expectations.

Measurements on anodic surface oxidation of noble metals as a function of time and electrode potential show that the initial extension and subsequent thickening of such oxide films is directly logarithmic in time. A striking feature of this behavior is that the direct logarithmic extension law already applies to increase of coverage of Pt or Au electrodes with time well below the limit of formation of one monolayer of OH or O species on the metal surface. A direct logarithmic law of oxide film growth also applies to post-monolayer growth involving early stages of quasi-three-dimensional film formation. Eventually, as the oxide film thickens, the Mott–Cabrera ‘‘high-field’’ growth mechanism can apply. However, below the monolayer level of oxide film formation, electrochemisorption of two-dimensional (2D) structures of OH or O arises so that the Mott–Cabrera mechanism cannot be applicable to that situation. It is shown that the kinetic relation for direct electrodeposition of OH or O species onto available metal surface sites also cannot lead to a log law in time for extension of a 2D film. A new treatment, based on the changing surface-potential component of the electrode-solution potential difference, due to place exchange between metal atoms in the surface and electrosorbed OH or O species on the surface, is presented and shown to give rise to a direct log law for extension of the film in time. The relation derived has features in conformity with the experimentally demonstrated characteristics of submonolayer and early post-monolayer film extension.

Electrochemical Engineering Principles as Related to Electroorganic Processes (D. T. Chin & C. Y. Cheng). Performance of Two-Phase Electrolyte Electrolysis (H. Feess & H. Wendt). Design of a Multipurpose, Modularized Electrochemical Cell (L. Carlson et al.). Electrode Materials (B. V. Tilak et al.). Scale-Up of Electroorganic Processes: Some Examples for a Comparison of Electrochemical Syntheses with Conventional Syntheses (D. Degner). Experience in the Scale-Up of the Monsanto Adiponitrile Process (D. E. Danly & C. R. Campbell). The Phillips Electrochemical Flourination Process (W. V. Childs). Use of Rotating Electrodes for Small-Scale Electroorganic Processes (H. V. K. Udupa & K. S. Udupa). Electrochemical Engineering of Electroorganic Processes: Illustrated by an Energy Assessment of Some Large-Tonnage Process Chemicals (T. Beck et al.). Economics of Electroorganic Synthesis (K. B. Keating & V. D. Sutlic). Errata for Part I and Part II. Index.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Structure of the Electrical Double Layer at the Metal-Solution InterfaceM. A. V. Devanathan and B. V. K. S. R. A. TilakCite this: Chem. Rev. 1965, 65, 6, 635–684Publication Date (Print):December 1, 1965Publication History Published online1 May 2002Published inissue 1 December 1965https://pubs.acs.org/doi/10.1021/cr60238a002https://doi.org/10.1021/cr60238a002research-articleACS PublicationsRequest reuse permissionsArticle Views1971Altmetric-Citations165LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts