Reliable renewable energy – application of electrochemical capacitors for electrical energy storage

W artykule przedstawiono urządzenia służące do magazynowania energii, jakim są kondensatory elektrochemiczne, i przybliżono zasadę ich działania. Omówiono również najważniejsze materiały elektrodowe wykorzystywane w technologii wytwarzania superkondensatorów. W części doświadczalnej opisano badania własne nad nowym nanokompozytem składającym się z wielościennych nanorurek węglowych oraz polimeru przewodzącego, a także przedstawiono wyniki badań nad możliwością oraz zaletami zastosowania komercyjnych superkondensatorów do akumulowania energii elektrycznej wytworzonej w ogniwach fotowoltaicznych.This paper presents electrical energy storage devices such as electrochemical capacitors, their principle of operation and electrode materials most commonly used in their manufacturing technology. Moreover, our research on development of new nanocomposite materials based on multi-walled carbon nanotubes and conducting polymer is shown. Additionally, the possibility and advantages of application of supercapacitors for accumulation of electrical energy generated by photovoltaic cells are presented

New insights on lithium storage in silicon oxycarbide/carbon composites: Impact of microstructure on electrochemical properties

In this work, we study the impact of the preceramic precursor vinyltriethoxysilane (VTES) on the electrochemical performance of silicon oxycarbide (SiOC) glass/graphite composites. We apply an innovative approach based on high-power ultrasounds in order to obtain highly homogenous composites with a uniform distribution of small graphitic flakes. This procedure enhances gelation and drying of VTES-based preceramic polymer/graphite blends. The SiOC/graphite composites reveal stable capacities (up to 520 mAh g-1 after 270 cycles), which are much higher than the sum derived from the ratio of the components. Additionally, the first cycle Coulombic efficiencies obtained for the composites are 15% higher than that of the pristine VTES-based SiOC ceramic. These properties are identified as the synergistic effect, originated from the addition of graphite to VTES-based SiOCs. Interestingly, such improvement in electrochemical performance is not noticed in the case of analogous SiOC/ graphite composites based on phenyltriethoxysilane (PhTES) precursor. The microstructural investigation of the composites based on two different preceramic precursors using solid-state 29Si NMR and Raman Spectroscopy unveils the reason for such discrepancy in their electrochemical behaviour. Keyword