Fuel cells

How gas impurities influence the alkaline fuel cell performance

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.

Effect of the catalyst layers structure on the pem fuel cell perfomance

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%

Catalytic activity oF LaLi0.1M0.1Fe0.8O3-d (M = Fe, Co, Ni) Oxides for molten carbonate fuel cell. Part 2. Reaction Mechanisms and Catalytic Activity in (Li0.62K0.38)2CO3 Melt

New mechanisms of oxygen reduction on perovskite related oxides LaLi0.1M0.1Fe0.8O3-d (M = Fe, Co, Ni) and a rock salt type oxide Li0.1Ni0.9O have been proposed. Based on these mechanisms, a comparison of catalytic activity of the oxides in the temperature range 820–1000 K has been done. It has been shown that catalytic activity of LaLi0.Co0.1Fe0.8O3-d oxide exceeds the activity of Li0.1Ni0.9O below 970 K

The application of graphene in biofuel cells

This work considers the application of graphene while forming the electrodes in biofuel cells. Graphene displays a number of important characteristics including first of all good mechanical properties, high thermal conductivity, high specific surface area, biocompatibility, structural peculiarities of a molecule, is available for chemical modification of the structure. Fabrication, properties of graphene and its oxide were considered and the peculiarities of the application of graphene as a basic material for electrodes in biofuel cells are also discussed.

Catalytic activity of LaLi0.1M0.1Fe0.8O3-d (M = Fe, Co, Ni) oxides for molten carbonate fuel cell. Part 1. Polarization Characteristics of Porous Gas Diffusion Electrodes in (Li0.62K0.38)2CO3 Melt. An Experimental Study

This paper presents polarization characteristics of porous gas diffusion cathodes prepared from LaLi0.1M0.1Fe0.8O3-d (M = Fe, Co, Ni) oxides with a perovskite related structure and Li0.1Ni0.9O oxide with a rock salt structure. The characteristics were measured in the laboratory scale fuel cell in the temperature range 820–1000 K. It has been shown that electrochemical activity of the cathodes with Co and Ni additives exceeds the activity of the Li0.1Ni0.9O cathode below 970 K.

Current-producing reactions in fuel cells with proton-conducting and anion-conducting electrolytes

Features of current generation processes in MEA of hydrogen-air (oxygen) fuel cells with proton-conducting (acidic) and anion-conducting (alkaline) solid polymer electrolytes were compared. Certain parameters of electrode reactions and characteristics of electrolytes and interaction effects of MEA’s components in FC operation and also destabilizing factors which deriving direct from current flow as well as from presence of impurities in the fuel and oxidant were discussed.

Electrochemical activity of the electrodes with electrocatalytic coatings

Electrochemical activity of electrodes for electrolysis of water is investigated. As catalysts coating Ni-S-Co, suspension LaNi2.5Co2.4Al0.1 or their combinations were applied. As electrolyte at test of electrodes 30% KOH or NaOH is used. Current density varied in a range from 10 to 600 мА/cm2 at temperature 20-80°C. When the temperature increases from 20 to 80°C the current density on cathodes with composite LaNi2.5Co2.4Alo.i/Ni-S-Co catalyst increases 4 times at constant potential E = –1.10 V (rel. Hg/HgO). When the current density of more than 100 mA/cm2 cathodes with all catalysts offered by us in this work have lower value of potential than the similar cathodes described in the scientific literature. In contrast to the cathodes, catalyst LaNi2.5Co2.4Al0.1/Ni–S–Co does not render influence on electrochemical activity of the anode.

The equilibrate concentration of the electro-active species in (Li0.62K0.38)2CO3 melt and reaction mechanisms of the oxygen reduction on the gold electrode

The concentrations of the main components of the (Li0.62K0.38)2CO3 melt have been evaluated by the thermodynamic modeling technique, and the Warburg coefficients of electroactive particles as a function of temperature and CO2/O2 gas mixture composition have been calculated. The same dependences of Warburg coefficient and charge transfer resistance were studied on Au cathode using coulostatic technique. It is shown that O2 ions and O2 molecules are the main electroactive species in the melt. Their relative concentration determines which reaction mechanism dominates.

Research and investigation of catalytic layers of proton-exchange membrane fuel cell

Composition and structure of proton-exchange membrane (PEM) fuel cell catalytic layers were investigated. The maximum FC efficiency was observed at the polymer content in a layer 25-30 vol.% at work on air and 30-35 vol. % at work on oxygen. At a variation of quantity of catalytic composition the maximum current density have been received at layer load 1.75 mg/sm2, thus decrease in it value in 2 times leads to falling of current density only on 10%.

The estimation of perfomanсe of exogenous redox mediators in the bioelectrochemical system glucose–Escherichia coli cells-mediator

The performance of several redox mediators (methylene blue, neutral red. and gallocyanine) in the bioelectrochemical system glucosc- Escherichia coli cells was estimated by means of the rotating disk electrode technique. The diffusion coefficients of the mediators under study were evaluated. Methylene blue and gallocyanine arc shown to be effective reversible electron carriers for the Escherichia coli-based bioanode.