моделирование

The possibility of determining the charge state of lithium-sulfur batteries using the ANFIS model was estimated. Easily measurable in practice physical quantities were used as input parameters of the model. They are the battery voltage, the rate of its change and the number of previous cycles. The analysis of ANFIS models with various parameters (the number and type of membership functions) was carried out. It was shown that ANFIS is a model that makes it possible to estimate the charge state of a lithium-sulfur battery with the accuracy of more than 95%.

To model the characteristics of lithium-sulfur batteries based on the experimental evaluation of the electrochemical properties of electrode materials, the software "Battery Designer", included in the software package “ElChemLab”, was developed. The possibilities of software are described. The specific energy of lithium-sulfur batteries is compared for different surface capacitances of a positive electrode and for different amounts of electrolyte.

Computer modelling of the mechanical stress state originating at manufacturing and heating to a working temperature of cells of the SOFC of a tubular design with classical functional materials (Ni-YSZ)/YSZ/LSM is developed. Electrolyte-supported and anode-supported cells are observed, and also the residual stresses originating by manufacture of the module a cone-cone with direct anode-cathode contact are simulated. Simulation of process of manufacturing anode-supported cells display that there is no the stress, able to lead to cell rupture. However, the high level of the strain energy stored in the thin electrolyte layer, under certain conditions constitute the driving force for interfacial delamination. Manufacturing of electrolyte-supported cell leads to a high tension stress in an anode layer that leads the anode layer cracking. Heating of cells to a working temperature and reduction of anode material partially removes residual stress in the cell. Lines of boundary of the thin layers with a supporting tube concentrate significant radial stresses and can serve as the centres of delamination. The stress state of a cone electrolyte-supported cell does not exceed dangerous level.

By the example of tubular oxygen-permeable membrane of mixed-conducting LaGa_0.65Mg_0.15Ni_0.20O_3-Δ operating under oxygen chemical potential gradients in the regime of hydrocarbon oxidation, modeling of chemically induced strains in the dense ceramic material has been carried out. The membranes with various radii in different reactor configurations were simulated. Analysis of the distributions of oxygen chemical activity and chemically induced stresses showed that, for minimization of mechanical stresses, the most advantageous basic configuration involves supplying atmospheric air inside a tubular membrane and opposite directions of the gas flows. The maximum stresses are observed in the region of reducing gas mixture injection, where a zone with an essentially constant oxygen chemical potential on the membrane surface may exist for many reactor configurations. The size of such zones formed due to specific features of the gaseous phase component distribution and/or ceramic reactor configurations, has a significant effect on the mechanical stress distribution.

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 thermal model of the power plant based on the solid oxide fuel cells (SOFC) fed with methane is developed. The power plant includes three heat-generating zones: a fuel-cell stack, a reactor of partial oxidation (RPO), and an afterburner. It is shown that temperature distribution along the battery depends on three factors: a methane consumption, a methane to air relation in the flow fed to the RPO, and a battery current. Results of modeling well correlate with the experimental data received on the power plant prototype with the SOFC stack consisted on 16 tubular cells.

It is shown that the nonlinear structural model of the battery can be used for modeling the voltage relaxation processes after a charge of batteries. The solution obtained is valid for alkaline, acid and lithium-ion batteries. Comparison of solutions, with the experimental data for nickel-cadmium batteries, showed, that the relative error does not exceed 3%.