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This article presents an analysis of the capacity and the state of health (SoH) of 3-Ah lithium battery cells operating in a real case vibration stress scenario based on drones. An unmanned aerial vehicle (quad-copter) is adopted to acquire real vibration profiles during different phases of flight. First, the possible capacity fade and aging effect on lithium cells are investigated by considering vibrations applied to the radial and longitudinal battery axes with both short-term and long-term (aging) tests. Then, the cruise-flight vibration profiles are applied and characterized. A comparison with standard (no vibrations) cycling aging is also presented and discussed. The experimental results show that no significant effect on capacity fade can be observed between standard and real case vibrating operating conditions.

In the current work, electrochemical impedance spectroscopy is applied to lithium batteries with different power size, shape and technology in order to monitor the state of health of the cells. The employed approach shows that the frequency analysis can provide the aging state evaluation. This is particularly evident for a narrow frequency range, and even a single frequency readout can be exploited to quickly and reliably evaluate the state of health of the cell. Therefore, the presented method results promising for many practical applications, such as for battery management strategies and cell monitoring purposes.

This paper investigates the Lithium battery behavior and possible aging effects in presence of current ripple during the operation. In the context of a research funded project aimed at increasing the safety level of Lithium batteries for the naval propulsion, we present the results of an experimental analysis aimed at investigating the effect of current ripple on cell performances. An ad-hoc experimental setup is developed to test the batteries and the effect of current ripple on battery capacity and cell aging is discussed throughout the paper.

During the last decades, the increase of the world energy consumption promoted the renewable resource development and use. Together with wind, solar and hydro energy, biomasses play a key role in the reduction of the industrial environmental impact; moreover, the biomass combustion systems are very attractive for micro-generation purpose. In this paper, experimental tests on a 140kW small size fixed bed biomass boiler were carried out. The main goal was to study the thermal behavior and some chemical products, such as CO, CO2, Methane and Ethylene, from the combusting fixed bed of the system. In fact, despite the wide amount of literature for the laboratory scale systems, the commercial scale boilers have been seldom studied by the experimental point of view. The data were obtained by varying the operational parameters of the boiler, that are the air excess and the secondary to primary air feeding ratio. Furthermore, the collected data were analyzed and the relationship between the thermal-chemical data and the control variables was discussed.

In the recent years the progressive decrease in fossil petroleum resources and gradual deprivation of the environment have attracted increasing interest towards the use of biomass as renewable carbon source for the production of chemicals and transportation fuels. In particular, lignocellulosic biomass represents an abundant and inexpensive renewable resource with high carbon sequestration ability and non-polluting. In this paper, the valorisation of mixtures made of n-butanol (n-BuOH), butyl levulinate (BL) and dibutyl ether (DBE), in different percentages, as additive fuel for compression ignition (CI) internal combustion engine (ICE) was studied. These mixtures can be directly obtained from the catalytic alcoholysis reaction of the cellulosic fraction of raw and pre-treated lignocellulosic biomasses. Moreover, the possibility to recycle and reutilize the excess alcohol (n-Butanol), during the catalytic alcoholysis reaction, has been considered since it represents an opportunity to reduce the overall costs of the process. Therefore, a blend constituted only by BL and DBE has been also tested. The model mixtures were prepared by using commercial reactants, characterized by compositions analogous to those of the reaction mixtures. These model mixtures were tested as blend with Diesel fuel in a CI-ICE with the measurement of pollutant emission and performance. Results have been compared with those obtained fuelling the engine with a commercial Diesel fuel. As a whole, tests results have evidenced the potentiality of these novel blending mixtures to reduce the emissions of particulate without any significant increase in the other pollutants and negligible changes in engine power and efficiency.

A Computational Fluid Dynamic model of oxy-coal devolatilization experiments in a pilot-scale entrained flow reactor is proposed to gain insight into the thermal histories of the cloud of solid fuel particles and to investigate sources of uncertainties that may affect the analysis of devolatilization. Solid fuel particles experience different paths and are characterized by a temperature which is lower than the reactor nominal one at some of the sampling locations used for investigating devolatilization rates. Indeed, neglecting the quick heating up of the particles by assuming their temperature to be equal to the reactor one for calculating kinetics leads to an underestimation of devolatilization rates. A simple hypothesis on a linear dependence of the particle temperature on residence time through an average heating rate, with residence time and heating rate estimated from the numerical model, was found to largely improve the reliability of devolatilization kinetics even with a simple Single First Order ...

Since safety hazards can occur during the life of a Li-ion battery, understanding its behaviour under abusive conditions is important for the development of a safe cell. In this work, overcharge tests on commercial Li-polymer cells were conducted, resulting in gas evolution. A comprehensive postmortem analysis of the abused cells was planned to be carried out by means of several analytical techniques: gas phase chromatography for the identification of the exhaust gases, scanning electron microscopy and energy X-ray spectrometry for the investigation of the cathode and anode materials, Fourier-transform infrared spectroscopy for the study of the electrolyte composition, etc.). First interesting results, regarding the characterization of a high temperature overcharged cell and the detection of flammable and toxic species produced by the cell, are presented in this paper.