Electrode material based on multilayer graphene oxide for chemical current sources

The results of the studies of the electrochemical synthesis of multilayer graphene oxide were presented, and the possibility of using it as an electrode material of the supercapacitor was shown. In an alcohol suspension the thickness of the particles of multilayer graphene oxide was less than 0.1 µm with an area of more than 100 µm2. The graphene oxide-based electrode has a high specific capacity of 107 F·g−1 and a high charge retention rate of 97% after 5000 cycles. It was shown that the graphene oxide electrode had a maximum specific energy of 8.7 W·h·kg−1 at the current density of 0.1 A·g−1 and had a maximum power of 2291.1 W·kg−1 at the current density of 4 A·g−1. The application of a lithium-thionyl chloride cell with a multilayer graphene oxide cathode on a nickel grid was tested. It was found that graphene oxide synthesized using the electrochemical method is a promising electrode material for creating a symmetric supercapacitor.

Electrochemical properties of quinones, antraquinones and their derivatives – potential redox-systems for flow batteries

Practical interest in redox flow batteries has arisen in recent decades as a result of intensive development in the field of alternative energy (such as solar and wind) and the control of peak loads in industrial electrical networks. It turned out that large-scale energy storage systems used to compensate fluctuations in the process of solar and wind generation of energy in the production of electric vehicles and power supply systems for large households, are more profitable when working on redox flow batteries. Firstly, they are easy to scale, and secondly, the energy stored in such batteries is cheaper. In recent years, the interest of researchers in the redox behavior of simple and substituted quinones and anthraquinones used as potential components of electrochemical energy storage systems has grown significantly. The main advantages of organic redox systems are scalability, kinetic advantages over the used redox systems based on inorganic substances, reconstructability (a wide possibility of changing electrochemical and chemical properties by introducing various functional groups into organic molecules) and environmental safety. Therefore, in this work, the electrochemical behavior of some promising organic systems based on quinone, anthraquinone and their analogs to be used as redox systems of flow batteries was studied using the method of cyclic voltammetry.

Electrodeposition of lead dioxide on titanium substrate

Modern technology causes the renewal of the interest to physical and chemical properties of solid oxide electrodes. Among these, PbO2/substrate has attracted considerable attention due to its application as an electrode in backup current sources. It was shown that the stable and active lead dioxide coating can be produced by appropriate pretreatment of the titanium substrate, including the coating of the substrate with colloidal graphite.

Solid proton-conducting ceramic electrolyte for energy storage units

The paper considers the electrochemical properties of potassium polytitanate synthesized at the values of pH varying from 3 to 8 in a wide temperature range from −26 to +80°C. The conductivity values and the activation energy were determined with the help of the method of impedance spectroscopy. The application of the obtained material used as a ceramic solid electrolyte in the energy storage units operating at low temperatures in the Far North is considered in the article.

Book review: Mahendra Rai, Anatoly Reshetilov, Yulia Plekhanova, Avinash P. Ingle, editors. Macro, Micro, and Nano-Biosensors: Potential Applications and Possible Limitation

The main idea of the book is that, depending on the addressed problem, different approaches are to be used; macro constructs are to be worked with in some cases, micro and nano in others. Biosensors considered are electrochemical, optical, atomic force microscopy-based; biofuel cells that develop the idea of electrochemical biosensors are intended for a double purpose of cleaning up the environment and working out electrical energy.

The role of vinylene carbonate in functioning of lithium-ion and sodium-ion batteries

The short review is devoted to the description of the effect of adding vinylene carbonate into the electrolyte of lithium-ion and sodium-ion batteries on the structure and properties of passive films on electrodes and on the behavior of batteries accordingly. The reviewed literature covers the works of the last 20 years mainly.

Study of the electrochemical properties of carbon materials for the negative electrode of a hybrid supercondenser with acid electrolyte

Electrochemical characteristics of electrodes based on various carbon materials such as expanded graphite, nanotubes, black carbon for hybrid supercapacitors C/PbO2 with acid electrolyte were investigated. It was shown that the highest values of the capacitive characteristics were obtained using TUBALL™ graphene nanotubes (LLC OCSiAl.ru, Novosibirsk).

Influence of impurities of the transitional metals Fe, Ni, and Co on the hydrolysis kinetics of BH− 4 ions in alkaline solutions

The influence of small amounts of the Fe, Co, and Ni impurities on the spontaneous hydrolytic process of borohydride was studied within a temperature range of 60–100°C. The object under study was a simulated solution containing 9.53 M of OH− ions and 0.14 M of BH− 4 ions, used as a fuel for borohydride fuel cells. The rate constant k of borohydride hydrolysis for a small amount of impurities at different temperature was estimated. The lowest non-accelerating concentrations of the impurities were established (∼10 ppm for iron; ∼1 ppm for cobalt). The strongest accelerating effect on the hydrolysis of BH− 4 ions was rendered by nickel impurities: self-hydrolysis was accelerated by 1.2 times for 1 ppm Ni. The ambiguous trend of the kinetic curves does not allow to accurately estimate the activation energy; however, the increased temperature enhances the catalytic effect of hydrolysis acceleration according to Arrhenius’ equation.

Composite C/MnO2 electrodes for electrochemical capacitors based on water electrolyte

The electrochemical properties of C/MnO2 composite materials in 1 M sodium sulfate solution were investigated using the methods of cyclic voltammetry, galvanostatic charge-discharge and impedance spectroscopy. It was shown that the capacitive characteristics of the electrodes depend on the nature and the method of obtaining manganese oxide nanoparticles. It was established that the material containing manganese oxide obtained using isoamyl alcohol as a reducing agent has high electrochemical characteristics.

The binder influence on the performance of positive electrodes of lithium-sulfur batteries

The comparison of performance of positive electrodes of lithium-sulfur batteries made using the binders based on fluoroplastic (PVDF Solef 5310 and Kynar) and polyethylene oxide (PEO) was carried out. The electrodes made using PVDF Kynar or limited amounts of PEO were shown to have certain advantages. It was also found that electrodes with PEO had an increased specific capacity during the initial period of cycling, whereas electrodes with Kynar were characterized by the minimum capacity fading during cycling.