Poly(3,4-ethylenedioxythiophene:poly(styrenesulfonate) (PEDOT:PSS) water and toluene solutions were investigated in detail, taking into consideration their stability, wettability, transparency, and electrochemical properties, along with change polarity caused by dopant. As dopant, methanol, ethanol, and isopropanol were used with different dipole moments (1.70, 1.69, and 1.66 D) and dielectric constants (33.0, 24.5, and 18.0). Three techniques, i.e., spin coating, doctor blade coating, and spray coating, were employed to created PEDOT:PSS layers on glass, glass/indium tin oxide (ITO), and glass/fluorine-doped tin oxide (FTO) substrates with optimized technical parameters for each used equipment. All used PEDOT:PSS water and toluene solutions demonstrated good wetting properties with angles below 30° for all used surfaces. Values of the energy bandgap (Eg) of PEDOT:PSS investigated by cyclic voltammetry (CV) in solution showed increase energy Eg along with addition of alcohol to the mixture, and they were found in the range of 1.20 eV to 2.85 eV. The opposite tendency was found for the Eg value of the PEDOT:PSS layer created from water solution. The storage effect on PEDOT:PSS layers detected by CV affected only the lowest unoccupied molecular orbital (LUMO) level, thereby causing changes in the energy bandgap. Finally, simple devices were constructed and investigated by infrared (IR) thermographic camera to investigate the surface defects on the created PEDOT:PSS layers. Our study showed that a more stable PEDOT:PSS layer without pin-holes and defects can be obtained from water and toluene solutions with isopropanol via the spin coating technique with an optimal speed of 3000 rpm and time of 90 s.

The main idea of this work is based on the latest achievements in the commercialization of sodium-ion (Na-ion) batteries, which constitute a basis of analysis for military applications as energy storage systems. Technical, engineering, and ecological aspects were analyzed to find the optimal solution for using Na-ion batteries for military purposes. When selecting batteries for military applications, the following criteria are required: (a) they are more durable than standard batteries, (b) resistant to fire, (c) cannot explode, (d) cannot emit heat so as not to reveal their position, (e) equipped with safety elements and protective circuits to ensure safety, and (f) have the highest possible energy density, defined as the ratio of capacity to weight. The advantages and challenges of Na-ion batteries are discussed and compared to typical lithium-ion batteries, and also lithium iron phosphate, Ni-Cd, and Ni-MH batteries. The prospects for expanding the practical applications of Na-ion batteries in the military are presented. The unique properties of Na-ion batteries, such as their lower risk of ignition, more excellent thermal stability, and ability to work in extreme conditions, are essential from the point of view of military operations. Additionally, when considering environmental and logistical aspects, sodium-ion batteries may offer more sustainable and cost-effective solutions for the military. Therefore, this work aims not only to present the technological potential of these systems but also to draw attention to their strategic importance for the future of military operations. Battery discharge can result from leaving current receivers switched on or even from a drop in temperature. The discharge current should not exceed 1/10 of the battery capacity (1C). Discharging below the discharge voltage may result in irreversible damage. Sodium-ion batteries are safer to use than their lithium counterparts and allow for discharge to 0 V, eliminating the possibility of uncontrolled thermal discharge due to a short circuit (explosion, ignition), which is particularly important in the military.

Recently, use of supercapacitors as energy storage systems has attracted considerable attention. However, the literature is scarce of information about the optimization of hybrid systems, using supercapacitors as the main energy storage system. In our study, we focused step-by-step on the engineering concept of a photo-rechargeable energy storage system based on silicon solar cells and supercapacitors. In the first step, based on commercially available elements, we designed a solar charger and simulated its work in idealized conditions. Secondly, we designed appropriate electronic connections and control systems, allowing for the charging–discharging process of the energy storage system. After constructing three type of demonstrators of solar energy charger, we tested it. The novel design allowed us to achieve total available energy from solar panel energy conversion up to 93%.

The one of the most important issues in constructing light-harvesting photovoltaic (PV) systems with a charge storage element is its reliable and uninterrupted use in highly variable and weather-dependent conditions in everyday applications. Herein, we report the construction and applicability evaluation of a ready-to-use portable solar charger comprising a silicon solar cell and an enhanced energy hybrid supercapacitor using activated carbon electrodes and iodide-based aqueous electrolyte to stabilise the PV power under fluctuating light conditions. The optimised electrode/electrolyte combination of a supercapacitor was used for the construction of a 60 F/3 V module by a proper adjustment of the series and parallel connections between the CR2032 coin cells. The final photo-rechargeable device was tested as a potential supporting system for pulse electronic applications under various laboratory conditions (temperature of 15 and 25 °C, solar irradiation of 600 and 1000 W m⁻²).

This paper presents the investigations on the improvement of search object detection during search and rescue (SAR) action at sea using thermal imaging and radar sensors. The introduction of new materials in the construction of lifesaving appliances increasing their detectability has been studied for the selected example of a pneumatic life raft. The research was based on laboratory tests and open sea trials. The presented experimental investigations on the new materials that can be used for pneumatic life raft construction showed the enhancement of its thermal and radar signatures, which directly affect life raft detectability and influence reliability of SAR action and probability of success (POS). The improved detectability of a life raft related to the time to survive of a person in the water (PIW) allowed to present the modified search pattern for both PIW and life raft, significantly increasing POS.