Supercapacitors based on carbide-derived carbons synthesised using HCl and Cl2 as reactants

Micro- and mesoporous carbide-derived carbons (CDCs) were synthesised from TiC powder via a gas-phase reaction using HCl and Cl₂ within the temperature range of 700–1,100 °C. Analysis of X-ray diffraction results show that TiC-CDCs consist mainly of graphitic crystallites. The first-order Raman spectra showed the graphite-like absorption peaks at ~1,577 cm^?1 and the disorder-induced peaks at ~1,338 cm^?1. The low-temperature N₂ sorption experiments were performed, and specific surface areas up to 1,214 and 1,544 m²?g^?1 were obtained for TiC-CDC (HCl) synthesised at T?=?800 °C and TiC-CDC (Cl₂) synthesised at T?=?900 °C, respectively. For the TiC-CDC powders synthesised, a bimodal pore size distribution has been established with the first maximum in the region up to 1.5 nm and the second maximum from 2 to 4 nm. The energy-related properties of supercapacitors based on 1 M (C₂H₅)₃CH₃NBF₄ in acetonitrile and TiC-CDC (Cl₂) and TiC-CDC (HCl) as electrode materials were also investigated by cyclic voltammetry, impedance spectroscopy, galvanostatic charge/discharge and constant power methods. The specific energy, calculated at U?=?3.0 V, are maximal for TiC-CDC (Cl₂ 800 °C) and TiC-CDC (HCl 900 °C), which are 43.1 and 31.1 W?h?kg^?1, respectively. The specific power, calculated at cell potential U?=?3.0 V, are maximal for TiC-CDC (Cl₂ 1,000 °C) and TiC-CDC (HCl 1,000 °C), which are 805.2 and 847.5 kW?kg^?1, respectively. The Ragone plots for CDCs prepared by using Cl₂ or HCl are quite similar, and at high power loads, the TiC-CDC material synthesised using Cl₂ at 900 °C, i.e. the material with optimal pore structure, delivers the highest power at constant energy.     

Zn(ClO4)2 aqueous solution–based Zn thin foil|carbon cloth two-electrode single-cell characteristics

Journal of Solid State Electrochemistry - Asymmetrical Zn thin foil|carbon cloth two-electrode cells based on 1 M Zn(ClO4)2 aqueous solution have been tested using cyclic voltammetry,...     

The review of advances in interfacial electrochemistry in Estonia: electrochemical double layer and adsorption studies for the development of electrochemical devices

The electrochemistry nowadays has many faces and challenges. Although the focus has shifted from fundamental electrochemistry to applied electrochemistry, one needs to acknowledge that it is impossible to develop and design novel green energy transition devices without a comprehensive understanding of the electrochemical processes at the electrode and electrolyte interface that define the performance mechanisms. The review gives an overview of the systematic research in the field of electrochemistry in Estonia which reflects on the excellent collaboration between fundamental and applied electrochemistry.