Applied Mechanics and Materials Vols. 672-674

Abstract: Hydrothermal method was successfully employed to synthesize LiNi_0.5Mn_0.5O₂ and the crystallinity of the resultant product was further improved by an annealing process. The structural information of the final product was analyzed by X-ray diffraction (XRD) and Rietveld refinement. The results showed that the Li/Ni exchange rate of hydrothermal samples was lower than traditional solid state method. Because of the improvement of the crystallinity the capacity of the annealed product was much better than that of the as prepared hydrothermal product. The capacity of annealed sample maintained 100mAh/g after 100 charge/discharge cycles. ICP-OES element analysis show that both hydrothermal and annealed samples are non-stoichiometric due to the existence of high valence Ni³⁺ and Mn⁴⁺ ions in LiNi_0.5Mn_0.5O₂ samples which might be largely responsible for the lower electrochemical capacity. Our work demonstrated that stoichiometric LiNi_0.5Mn_0.5O₂ with lower Li/Ni exchange could be synthesized by hydrothermal method when suitable oxidants were selected.

Abstract: The rapid development of lithium ion battery has provided a broad space for every profession and trade, but the temperature change of the lithium ion battery is relatively sensitive, should strengthen the lithium ion battery thermal management system. In this paper, using COMSOL MUTILPHYSICS software, the lithium-ion battery forced convection cooling numerical simulation research , comparing its temperature changes. We conclude: when forced convection temperature is high, the flow speed is high, the cooling effect is better; near the cooling entrance closer, the cooling effect is more obvious, and has important significance to the lithium ion battery radiating and rational utilization.

Abstract: As a new type of lithium-ion energy should be in a wide range of industries , the battery 's own battery temperature is facing a serious problem . Based on the three-dimensional applications based on COMSOL MUTILPHYSICS software was simulated using the control variable method and compared the results of its analysis. Application of COMSOL MUTILPHYSICS software to simulate the three-dimensional basis, using control variable method, and the results were compared. The results show that, when the temperature is high or when the battery discharge times, rising temperatures in the region better, faster and more; heat of reaction generated; also get a cell center along the radial direction, the temperature is gradually reduced.

Abstract: In proton exchange membrane (PEM) fuel cell cathode, oxygen reduction reaction (ORR) behavior have important effects on fuel cell performance. In this paper, the dynamic oxygen adsorption model and then the redox reaction model for hydrogen and oxygen system were established on the surface of the electricity catalyst Pt. The reaction process of hydrogen and oxygen on the surface of Pt was simulated by first-principles molecular dynamics method, and the influence of temperature on oxygen reduction reaction characteristics was analyzed. The simulation results show that the oxygen atom adsorption on the Pt (111) surface and reaction with the first hydrogen atom are the control step of the oxygen reduction reaction; and the oxygen reduction reaction accelerates with increasing temperature, but the temperature does not affect the geometric structure of the products in the oxygen reduction reaction steps. The results of the simulation agree well with our previous first-principles calclation, and this will be helpful for understanding the mechanism of oxygen reduction reaction in PEM fuel cell cathode.

Abstract: Pd-Cu-Ce composite membrane was prepared using an electroless plating technique. The effects of temperature and pressure on permeation were studied. The resistance to sulfidation was examined by exposing alloys to simulated syngas containing a combined gas of H₂ and H₂S. The alloys showed sings of slight sufidation at the 0.1% H₂S exposure level.

Abstract: Pyrolysis of Hailar lignite (moisture content ~ 34.81 wt%) was investigated at temperatures ranging from 700 °C to 900 °C in two different reactors: A tubular reactor (TR) and a continuous screw kiln reactor (CSKR). Under temperature programmed-heating conditions in the TR reactor, the auto-generated steam from the lignite moisture was vaporized and swept out of the reactor by the N₂ flow during the long heating process, leading to a weakened effect on the subsequent reactions. However, in the CSKR tests all the volatiles was generated continuously while avoid the carrier gas dilution , significant interactions between the in situ steam and the intermediate products occurred. Upon comparing the two pyrolysis processes, it was found the CSKR process exhibits higher H₂ yield of 23.23 mol/kg, H₂ proportion of 49.82 vol % than those (16.97 mol/kg, 41.51 vol %) from the TR process. The results demonstrated that inherent moisture in Hailar lignite had a significant influence on the product yield, depending on the pyrolysis conditions. It was also shown that increase in temperature led to rising dry gas yield and H₂ yield.

Abstract: Microwave pyrolysis of low rank coal is a new technology of cleaner production. The effect of microwave power and flow rate of N₂ on the yield of pyrolysis products under N₂ atmosphere was explored. The results showed that the higher microwave power was, the higher all the terminal temperature, the yield of liquid products and the weight loss rate were. The flow rate of N₂ had little influence on the yield of pyrolysis solid products, while it exerted a greater influence on the yield of pyrolysis liquid products. When the low rank coal was pyrolysised under the conditions of microwave power of 800W and flow rate of N₂ of 4.0×10^-4 m³/min, the yield of Bluecoke and liquid products respectively reached 65.8% and 18%.

Abstract: Due to the good chemical properties, polyoxymethylene dimethyl ethers (DMM_n) are regarded as an outstanding additive component of diesel fuel, which are efficient in reducing the formation of soot during the combustion when added to diesel fuel. The properties, synthetic methods and application of DMM_n are summarized and introduced in this paper. Furthermore, the development and application prospects of DMM_n in future are presented.

Abstract: Lead-acid batteries are widely used in all walks of life, the State-of-Charge is the most important part of the battery management system. On account of the strong coupling, multivariable, nonlinear characteristics of the batteries, this paper adopts the LS-SVM method to predict remaining battery capacity. The nonlinear POLYnomial (POLY) kernel is employed to design the LS-SVM. Aiming at predigesting the hardware requirement of the LS-SVM application, this paper uses the deduced induction of the input vector to simplify the POLY kernel, greatly reducing the memory capacity of the practical application. At last, simulation on MATLAB was done to verify the validity of the proposed model, the simulation results show that the LS-SVM based on the simplified PLOY kernel is applicable to battery SOC estimation, and the estimation error can be controlled within 5%.

Abstract: Two kinds of alkynoxymethyl benzyl quaternary ammonium salt (ABQAS) were synthesized by raw materials of paraformaldehyde, propiolic alcohol, organic amine, benzyl chloride and ethanol under nitrogen protection, toluene as carrying agent. The products were characterized by FTIR. According to the characteristics of blast furnace gas pipeline, quaternary ammonium salt type compound corrosion inhibitor formulas were designed, and their corrosion inhibition performance were evaluated by weight-loss method and electrochemical method. The results showed that the products were synthesized as expected, the two kinds of products had excellent inhibition performance to the cathode electrochemical process of A3 carbon steel, and the corrosion inhibition efficiency in simulative blast furnace gas reached to 100%.