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To reduce the side reactions and increase olefin selectivity in the dehydrogenation process, a series of low-loaded Pt-based catalysts supported on -Al2O3 (with or without potassium (K) modification) were prepared. The K modification effect on the n-hexane dehydrogenation performances of Pt/Al2O3 catalysts was investigated using various techniques. The added K species selectively occupied the strong acid sites on the Pt/Al2O3 surface, leading to not only the regulated surface acid properties but also the modified metallic function. Specifically, adding an appropriate amount of K reduced the number of acid sites and increased the electron cloud density of Pt sites, leading to enhanced selectivity and stability. Furthermore, the moderate amount of acid sites kept Pt highly dispersed and provided a suitable geometric structure, resulting in good activity. Herein, the Pt–0.8K/Al2O3 catalyst with suitable metal–acid site balance shows an n-hexane conversion of 25% with over 70% C6 olefin selectivity. More importantly, a significantly low deactivation rate at 500 °C for 30 h is superior to most previously reported ones. [ABSTRACT FROM AUTHOR]

Nowadays, the poor conductivity and unstable structure have become obstacles for the popularization of Na3V2(PO4)3 (NVP). In the current work, a dual-modified Mn0.1Cl0.3-NVP composite doped with Mn and Cl is prepared by a facile sol–gel method. When Mn2+ with a large ionic radius replaces small V3+, it can improve the stability of the NVP crystal structure. In addition, the replacement of V3+ by Mn2+ in a low valence state can generate redundant hole carriers, which is conducive to the rapid transport of electrons. The substitution of PO43− by Cl−, which is more electronegative, can reduce the impedance and facilitate the movement of Na+. Owing to the synergistic effect of Mn and Cl co-substitution, the structural stability of NVP was systematically enhanced, and the electron transfer and ion diffusion were effectively improved. Consequently, the optimized Mn0.1Cl0.3-NVP sample demonstrated superior electrochemical performance and kinetic properties. It exhibited a high reversible capacity of 109.2 mA h g−1 at 0.1C. Even at 15 and 30C, high discharge capacities of 70.3 mA h g−1 and 68.2 mA h g−1 were observed after 2000 cycles with capacity retention above 80%. Moreover, it delivered remarkable capacities of 77.1 and 73.4 mA h g−1 at 100 and 200C with retained capacity values of 50.3 and 47 mA h g−1, respectively, after 2000 cycles. Furthermore, the assembled Mn0.1Cl0.3-NVP//HC full cell delivered a high value of 94.7 mA h g−1 and lit LED bulbs, indicating its excellent application potential. [ABSTRACT FROM AUTHOR]

The purpose of this study is to establish a life prediction model of lithium-thiocarbonyl chloride batteries by semi-empirical method. In the experiment, accelerated life tests on several groups of batteries at different temperatures were conducted. After a period of operation in the range from 25 °C to 74 °C, it was found that the higher the temperature, the less the remaining capacity of the batteries. According to the study of the battery aging mechanism, the characteristic parameter impedance of an aging battery would change exponentially with the increase of storage time and environmental temperature. The established life prediction model showed that the change in battery impedance spectrum had a good law, which made it possible to predict the state of charge (SOC) of the battery according to the local change characteristics of the electrochemical impedance spectroscopy (EIS) spectrum. The experimental data were compared with the fitted prediction curve, and the maximum deviation of the prediction was only 4.1036%, which indicated that the constructed model had high accuracy. [ABSTRACT FROM AUTHOR]