топливный элемент

Concentrated water-alkaline mixtures of sodium and potassium borohydrides and borates are used as fuel and a hydrogen source in hydrogen power engineering, including low-temperature fuel cells. The performance of such mixtures is determined by their physicochemical properties. An algorithm to calculate the density, viscosity, and specific electric conductivity of mixed solutions of the five-component water + salt system (Na,K)BH₄ + (Na,K)BO₂ + (Na,K)OH + H₂O based on the quasiadditivity of these properties is proposed.

Composition and structure of proton-exchange membrane fuel cell catalytic layers were investigated. Modelling of catalytic layer vas considered. This model allows to calculate layers containing particles of polymer and the catalyst of various forms and sizes. Dependence of conductivity and active layer surface area on concentration of polymer particles is shown. Best performance of a fuel cell is observed at the polymer concentration in a layer of 30–35% vol.

The paper deals with some questions concerning carbonization and decarbonization of alkaline electrolyte in matrix fuel cell (FC). It is shown that there is an equilibrium ultimate level of carbonization that depends on CO₂ content in gases delivered into FC and FC electric loading. Electrolyte decarbonization takes place at the increase of FC load current with CO₂ emission at hydrogen electrode end. The possible mechanisms of electrolyte carbonization and decarbonization are suggested.

The article contains the review of scientific-technical publications concerning a use of borohydrides in fuel cells and chemical generator over a period of 2000–2009. Their scientific basis principles of operation, prospects of utilization, and possible technologies are examined.

In the current paper electrospun nanofiber mats were derived from polyacrylonitrile (PAN). The temperature influence on the volumetric and surface composition of the resulting pyropolymers was studied by means of elemental analysis and X-ray photoelectron spectroscopy.

Electrochemical activity of anodes on the basis of a nickel mesh grid for water electrolysis is investigated. Activation of anodes was made by three ways:
1) chemical covering sulfur-containing compounds of nickel and iron;
2) immersing in solution Na₂S₂O₃ + H₂SO₄ (till pH=3);
3) immersing in solution Na₂S + H₂SO₄ (till pH=3).

Using complex models, including the solution percolation problem and electrochemical kinetics calculations are considered the features of a solid polymer fuel cell catalyst layers with a catalyst based on nanoscale carbon materials, including graphene nanowires. These calculations are consistent with the experimental data presented by optimizing the composition of the catalyst layers. It is shown that the addition of 20 wt.\% nanofibres graphene can reduce ohmic losses from the ion current and improve the performance of the fuel cell is 20%

В работе рассмотрена металлизация электролитной матрицы щелочного матричного топливного элемента, обусловленная растворением платинового катализатора на кислородном электроде этого элемента. Показано, что уровень металлизации зависит от условий функционирования топливного элемента и структурных особенностей его составляющих.

The work reviews the influence of gas impurities in fuel and oxidizing chemical on the alkaline oxyhydrogen fuel cell functioning. It shows that methane impurities act differently on anode and cathode, while other gases (except noble gases), including carbon monoxide, which is a poison for fuel cell with acid solution, influence the operation of alkaline fuel cell through the reaction with potassium hydroxide (KOH). Substitution electrolyte for fresh recovers fuel cell performance.

DOI: 10.18500/1608-4039-2015-15-4-175-179

The reasons, that lead to the performance loss of alkaline matrix electrochemical generator (ECG) based on hydrox cell and therefore reduce the fuel cell stack cycle life, are highlighted in this article. It is shown that storage of ECG, preserved with a special gas mixture within up to 20 years, doesn't lead to noticeable characteristic fluctuation.