Katarzyna Lota

Supercapacitors Based on Nickel Oxide/Carbon Materials Composites

In the thesis, the properties of nickel oxide/active carbon composites as the electrode materials for supercapacitors are discussed. Composites with a different proportion of nickel oxide/carbon materials were prepared. A nickel oxide/carbon composite was prepared by chemically precipitating nickel hydroxide on an active carbon and heating the hydroxide at 300 ∘C in the air. Phase compositions of the products were characterized using X-ray diffractometry (XRD). The morphology of the composites was observed by SEM. The electrochemical performances of composite electrodes used in electrochemical capacitors were studied in addition to the properties of electrode consisting of separate active carbon and nickel oxide only. The electrochemical measurements were carried out using cyclic voltammetry, galvanostatic charge/discharge, and impedance spectroscopy. The composites were tested in 6 M KOH aqueous electrolyte using two- and three-electrode Swagelok systems. The results showed that adding only a few percent of nickel oxide to active carbon provided the highest value of capacity. It is the confirmation of the fact that such an amount of nickel oxide is optimal to take advantage of both components of the composite, which additionally can be a good solution as a negative electrode in asymmetric configuration of electrode materials in an electrochemical capacitor.

Zastosowanie kompozytowych materiałów polimerowo-metalicznych jako materiału elektrodowego w ogniwach niklowo-metalowodorkowych

Praca powstala dzieki wsparciu finansowemu Polskiego Narodowego Centrum Nauki, w ramach grantu nr DEC-2013/09/N/ST5/00910 oraz projektu DS 3787/E-138/S/2017 finansowanego przez Ministerstwo Nauki i Szkolnictwa Wyzszego.

The effect of carbon additives on the capacitive properties of AB(5) type electrodes

Badania zostaly cześciowo wykonane w ramach projektu nr POIG.01.01.02-00-015/09, pt. „Zaawansowane materialy i technologie ich wytwarzania”, wspolfinansowanego przez Unie Europejską z Europejskiego Funduszu Rozwoju Regionalnego, Program Operacyjny Innowacyjna Gospodarka oraz kontynuowane w ramach projektu DS 3787/E-138/S/2017, finansowanego przez Ministerstwo Nauki i Szkolnictwa Wyzszego.

The modification of anode material for direct borohydride fuel cell

The direct borohydride fuel cell (DBFC) is a promising device that converts chemical energy into electricity by electrochemical reactions. This type of power source is technically more simple than traditional fuel cells, because it does not require any hydrogen container and noble metals. Hydrogen evolution during hydrolysis can be inhibited by modification of anode materials. Extensive studies are focused on various specific electrocatalysts and their impact on oxidation and hydrolysis of borohydride. The aim of the study is to determine the effect of anode material composition using borohydride as a fuel. In order to enhance the utilization of borohydride fuel, AB5-type alloy (LaMnNi3.55Al0.30Mn0.40Co0.75) was modified by adding Si or two kinds of carbon materials using the ball milling method. The most proper electrolyte was selected. The physical and electrochemical properties of anode materials were evaluated by scanning electron microscopy (SEM), cyclic voltammetry, chronopotentiometric measurements and electrochemical impedance spectroscopy. Studies showed that graphite was the best additive to anode material due to its density, compact structure and improvement of conductivity.