• Energy Research

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.

An important direction in the development of energy saving policy is harvesting and conversion into electricity of low-grade waste heat. The present paper is devoted to the improvement of the efficiency of thermo-electrochemical cells based on carbon fiber electrodes and potassium ferri-/ferrocyanide redox electrolyte. The influence of the carbon fiber electrode surface modification (magnetron deposition of silver and titanium or infiltration implantation of nanoscale titanium oxide) on the output power and parameters of the impedance equivalent scheme of a thermo-electrochemical cell has been studied. Two kinds of cell designs (a conventional electrochemical cell with a salt bridge and a coin cell-type body) were investigated. It was found that the nature of the surface modification of electrodes can change the internal resistance of the cell by three orders of magnitude. The dependence of the equivalent scheme parameters and output power density of the thermoelectric cell on the type of electrode materials was presented. It was observed that the maximum power for carbon fiber modified with titanium metal and titanium oxide was 25.2 mW/m2 and the efficiency was 1.37%.

In this paper, the electrochemical and electrophysical properties of protonated potassium polytitanate synthesized at pH values varying from 3.11 to 8.88 depending on the magnitude of the polarization voltage and the magnitude of the measured signal were studied by the method of impedance spectroscopy. The values of effective conductivity, relaxation times, frequency dependences of the loss tangent, and dielectric permittivity are determined.

This article deals with the creation of a power supply system of wireless sensors which take measurements and transmit data at time intervals, the duration of which is considerably less than the activation period of sensors. The specific feature of the power supply system is the combined use of devices based on various physical phenomena. Electrical energy is generated by thermoelectrochemical cells. The temperature gradient on the sides of these cells is created by a vortex tube. A special boost DC/DC converter provides an increase in the output voltage of thermoelectrochemical cells up to the voltage that is necessary to power electronic devices. A supercapacitor is used to store energy in the time intervals between sensor activation. A study of an experimental sample of the power supply system for wireless sensors was conducted. Using the model in MATLAB + Simulink program, the possibility and conditions for creating the considered system for a particular type of wireless sensor were shown.