A proton exchange membrane (PEM) fuel cell, an alternative to combustion processes that consume fossil resources, is used to convert energy stored in the form of hydrogen into electricity. The ...membrane-electrode assembly (MEA), the core of this system, contains platinum, a noble metal, which is a limited resource. This paper presents an environmental assessment of a recycling process for the platinum catalyst contained in the MEA of a PEM fuel cell. During this study, four hydrometallurgical platinum recovery processes from Pt/C particles have been developed at the laboratory scale. The considered process alternatives are composed of the four following steps: leaching, separation, precipitation and filtration. Approximately 76% of the platinum can be recovered as NH42PtCl6 salt using the most efficient process alternatives. In this case, platinum leaching is carried out with a mixture of H2O2 and HCl, followed by liquid/liquid platinum extraction and a precipitation step.
The environmental assessment was performed using the SimaPro 8 tool coupled with the EcoInvent 3.1 database. The environmental impacts were estimated for a 25 cm2 active area MEA considering the production and end-of-life stages of the MEA life-cycle using the CML-IA baseline V3.02 method. The results show that more than half of the main impacts of the MEA life-cycle can be avoided for four relevant impact categories if platinum is recovered in the end-of-life of the product.
•Membrane electrode assembly life-cycle assessment has been performed.•Platinum production has a significant environmental impact.•Platinum recovering processes environmental impacts have been compared.•An incineration scenario has been compared to a platinum recycling scenario.
The Li-ion batteries are currently the technology of choice for the future generation of Hybrid and Electric Vehicles. New generation of these batteries based on less noble materials are currently in ...development. That is why the new approaches to their recycling are necessary and lithium recovery will become economically interesting. Indeed, this study deals with lithium separation from solution and is part of a larger project dealing with the recycling of the future generation of Li-ion batteries. In this study, the sorption/desorption technique was selected to evaluate lithium separation from lithium aqueous solutions. Four types of commercially available materials were used as sorbents: Amberlite IR 120 resin, molecular sieve 13X, aluminosilicate MCM 41 and activated carbons. Under the experimental conditions used in this study, the maximum lithium uptake ranging between 20 and 25mg Li g−1 has been reached for Amberlite IR 120 resin and molecular sieve 13X. All equilibrium and kinetics data have been described by a single-site ion exchange model.
•Sorption/desorption technique was used to recover Li from aqueous solutions.•Four different commercially available solids were tested as sorbents.•A maximum uptake capacity of 20–25mg Li g−1 was reached.•A simple ion-exchange model was developed to describe experimental points.•Model fits well both equilibrium and sorption/desorption kinetics experimental data
The binder used in the formulation of sulfur electrodes for Li/S batteries plays a crucial role in their electrochemical performance. In the present study, the impact of using a polyelectrolyte ...binder (poly(diallyldimethylammonium) bis(trifluromethane sulfonyl)imide) on the morphological degradation of sulfur electrodes is evaluated by in situ dilatometry, acoustic emission (AE) and synchrotron X-ray tomography (XRT), and compared to more conventional binders (poly(vinylidene difluoride) (PVdF) and carboxymethylcellulose (CMC)). The dilatometry study shows that during the initial sulfur dissolution process, the polyelectrolyte-based electrode displays a lower irreversible thickness contraction of ~16% compared to ~22% and ~31% for CMC and PVdF, respectively. This is confirmed by the XRT measurements showing a reduced thickness variation for the polyelectrolyte electrode compared to the CMC electrode. The same trend is found in the AE results, where a lower acoustic activity attributed to the rupture of the binder/carbon/sulfur network is detected during the 1st discharge plateau for the polyelectrolyte electrode. All these results confirm the major role of the binder for the Li/S system. Thanks to its multifunctionality, it impacts both the diffusion of the active material outside the electrode and the electrode integrity and therefore the conduction paths and accessible active surface for electrochemical processes.
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•The impact of the binder on the morphological change of sulfur electrodes is studied.•PVdF, CMC and cationic polyelectrolyte binders are compared.•In situ dilatometry, acoustic emission and X-ray tomography are used.•The better mechanical strength of the polyelectrolyte based electrode is highlighted.
•Simplification of a reference battery degradation model with a formulation based on state of health successive updates and normalized exchange energy.•Integration of the model in an energy ...management strategy and tradeoff between storage degradation and overall system performances.•Tailored Dynamic Programming used to compute optimal battery State of Health trajectories over long period of time for given system configurations.•Optimal storage sizing and energy management of an isolated microgrid while accounting fot storage degradation and replacement.
Li-ion batteries are being increasingly used in stationary applications, allowing for greater autonomy and facilitating the integration of renewable energies. However, these devices lose their capacity over time, especially during their so-called second life. This degradation affects the operation of the system and its cost, and must be taken into consideration if an optimal management is to be found. In this work, we present a framework for the integration of the battery aging in a microgrid design and energy management problem. To do so, we first propose a method to simplify a reference model for cyclic degradation of batteries. The results show that the battery loss of capacity shall be compute on a weekly to monthly basis to accurately keep track of degradation effects. Also, at a first order, we show that ageing is dependent with the initial battery State of Health at every update and the energy exchanged normalized by the nominal capacity. This simplified model formulated with Mixed Integer Linear Programming is integrated in a management problem of an isolated energy system for cost minimization. Optimization results show the necessary trade-off between storage degradation and overall system performances. Finally, a tailored dynamic programming is proposed to simulate successive years for the optimal sizing of the considered system in terms of battery capacity and its replacements. Compared to the proposed pproach, not accounting for the storage degradation leads to inaccurate results and significant cost underestimations (>20 %).
In this study, we investigate the use of the ohmic drop compensation method during battery discharges at different rates. Four different types of NMC Li-ion batteries are compared and three 18,650 ...cells of each type are tested to evaluate the performance dispersion. The cell type that shows significant performance improvement thanks to ohmic drop compensation in this first experimental part is then selected to complete the exploration. A drone-type usage profile is set up and demonstrates without any doubt the interest of using this type of protocol in such usage. Finally, a preliminary aging study is also performed on this type of cells: ohmic drop compensation use has no effect on low-power performance decrease during aging and has a moderate impact on high-power performances.
All-solid-state batteries have been developed to increase energy density by replacing the lithiated graphite negative electrode by a lithium metal foil and to increase safety by removing the organic ...compounds. However, the safety issues of these batteries have received little attention up to now.
The behavior of a reassembled all-solid-state battery under thermal stress was recorded by X-ray radiography and a high-speed camera. The thermal runaway (TR) lasted about 5 ms, thus extremely fast reaction kinetics. In comparison, the TR of a lithium-ion battery is about 500 ms. Furthermore, a 188-mbar aerial overpressure was measured using a piezoelectric sensor. Although this cell is not an explosive, 2.7 g TNT equivalent was calculated for it.
This atypical behavior could have an impact on the casing or the battery pack. Therefore, it must be studied in greater detail.
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•The safety of the Li|LLZO|NMC811 cell has been assessed•An extremely fast thermal runaway about 5 ms is measured for Li|LLZO|NMC811 cell•A 188 mBar aerial overpressure has been measured for the Li|LLZO|NMC811 cell•Li|LLZO|NMC811 cell has a 2.7 g equivalent TNT however it is not an explosive
Applied sciences; Energy systems; Energy materials
This work addresses the surface characterization of an organic salt based on a piperidinium cation and a halide anion, similar to a first generation ionic liquid, using the Inverse Gas Chromatography ...(IGC) technique. IGC was employed in order to assess the dispersive surface energy and the acid/base character of 1-butyl-1-ethylpiperidinium bromide, C2C4PIPBr at a temperature range (313.15–343.15 K) well below its melting point, where the retention mechanism is governed by the surface adsorption of the probes. This type of characterization was possible due to the high melting point of C2C4PIPBr, namely 413.15 K. The dispersive component of the surface energy was estimated with the aid of the Schultz method and the Dorris-Gray method. Results obtained using the first method were higher than the ones obtained by the latter. The discrepancy between the two methods was found to increase with the increase of temperature. The acid/base characterization was implemented by using the Flour and Papirer approach as well as the Brookman and Sawyer method. The acidity and basicity constants of the surface of C2C4PIPBr revealed that it is amphoteric with a predominantly basic character.
•1-butyl-1-ethyl piperidinium bromide, C2C4PIPBr is solid at room temperature.•Surface characterization of C2C4PIPBr was performed with the IGC technique below its melting point.•The dispersive component of the surface energy calculated with the Schultz and the Dorris-Gray methods.•γsd results of C2C4PIPBr are comparable with similar piperidinium based ionic liquids.•The surface of C2C4PIPBr is amphoteric with a basic character bearing both weak Lewis acidic and basic sites.
•An antiscaling electrochemical fluidized bed reactor is investigated.•The fluidized balls between the electrodes substantially reduce scale deposits.•The fluidized balls act as bipolar electrodes ...increasing the electrochemical surface area.
A new kind of electrochemical antiscaling device using a fluidized bed constituted of 1 mm in diameter 316 stainless steel balls was investigated. The presence of the fluidized bed between the two electrodes substantially increased the antiscaling power of the device of nearly 90%. The balls act as bipolar electrodes where the anodic and cathodic electrochemical reactions responsible of the antiscaling properties also took place, allowing a treatment in the entire volume of the water. The influence of current density, operating time and height of the fluidized bed (or electrode surface area) on the efficiency of the device was studied.
All-solid-state batteries (ASSBs) are expected to be a relevant solution to increase the energy density in lithium-ion battery (LiB) technology. However, the energy management requires high-energy ...storage capacities, which make the safety a crucial issue. Unfortunately, it is difficult so far to assess the safety of nonfully mature battery technologies. In this paper, we describe a methodology to study the thermal runaway of a wide range of ASSB technologies. We specifically designed a closed calorimeter to be used in operando experiments with high-speed synchrotron X-ray radiography for the validation of the principle. Electrodes removed from LiB at 100% state of charge have been reassembled in ASSB, with an LLZO (lithium lanthanum zirconium niobium oxide) electrolyte. For the first time, we were able to observe and compare the thermal runaway of ASSB and liquid electrolyte (LiB) using this methodology. An 11% decrease of heat release was measured in comparison with LiB during the thermal runaway. Such a methodology can assist in the development of future battery technologies, by evaluating battery safety from the start of the design to battery composition to cell shape.
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