Supercapacitors (electrochemical capacitors)

International audienceRapid development of the technologies based on electric energy in the last decades have stimulated intensive research on efficient power sources. Electrochemical energy conversion and storage systems are based on Faradaic reactions (charge transfer) and electrostatic attraction of ions at the electrode/electrolyte interface. The latter might be an interesting solution for applications requiring moderate energy density, high power rates, and long cycle life. Electrochemical capacitors (ECs) store the charge in a physical manner, hence, their energy density is moderate. At the same time, the lack of electrochemical reactions ensures very high power and long cycle life compared to batteries. Activated carbons with their versatile properties (like specific surface area, well-developed and suitable porosity, heteroatoms in the graphene matrix) are the most popular materials in EC application. This chapter provides a comprehensive overview of the carbon-based materials recently developed, with special attention devoted to those obtained by biomass carbonization and activation. Electrochemical properties demonstrated by such carbons are discussed in respect to their physicochemical characteristic

The next step in the strategy–as–practice evolution: A comparative typology matrix

K.S. executed the study independently in partial fulfillment of her PhD under the supervision and oversight of M.P.ORIENTATION : In 2009, Strategy-as-Practice (S-as-P) research, as a subfield of strategy research, was grouped into nine different domains, and researchers were advised to frame their research within these domains. The papers or works (herein used interchangeably) published with S-as-P as subject, were counted, categorised, and a typology matrix was constructed. Researchers use this count to indicate a need for research in a specific domain. RESEARCH PURPOSE : The main purpose of this study is to construct a comparative S-as-P typology matrix which accurately depicts the number of papers published in each domain between 2008 and 2015. MOTIVATION FOR THE STUDY : The S-as-P typology matrix was first published in 2009 (Jarzabkowski & Spee 2009), and at the present moment, six years later, researchers still use the dated number of papers counted in each of the S-as-P domains to indicate a research gap. RESEARCH DESIGN, APPROACH AND METHOD : A content analysis of all papers, listed by researchers on the official S-as-P website, was conducted. The papers were disseminated and key variables were counted. MAIN FINDINGSain findings: The comparative typology matrix shows that relative to other domains, domain D appears overly researched, whilst no research has been carried out on domains C and H from 2008 to 2015. PRACTICAL/MANAGERIAL IMPLICATIONS : The comparative S-as-P typology matrix allows researchers to accurately evaluate the need for current research within the chosen domain. CONTRIBUTION/VALUE-ADD : The comparative typology matrix should prevent, as is the case currently with domain D, that domains are over-researched, whilst others receive no research attention.http://www.actacommercii.co.za/am2016Business Managemen