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Recent studies on anatase TiO2 have demonstrated its capability of performing as an anode material for sodium-ion batteries (SIBs) even though, due to poor conductivity, realistic applications have not yet been foreseen. In order to try to address this issue, herein, we shall introduce a cost effective and facile route based on the co-precipitation method for the synthesis of Mo-doped anatase TiO2 nanoparticles with AlF3 surface coating. The electrochemical measurements demonstrate that the Mo-doped anatase TiO2 nanoparticles deliver an ∼40% enhanced reversible capacity compared to pristine TiO2 (139.8 vs. 100.7 mA h g−1 at 0.1 C after 50 cycles) due to an improved electronic/ionic conductivity. Furthermore, upon AlF3 coating, the overall system can deliver a much higher reversible capacity of 178.9 mA h g−1 (∼80% increase with respect to pristine TiO2) with good cycling stability and excellent rate capabilities of up to 10 C. The experimental results indicate that the AlF3 surface coating could indeed effectively reduce the solid electrolyte interfacial resistance, enhance the electrochemical reactivity at the surface/interface region, and lower the polarization during cycling. The improved performance achieved using a cost-effective fabrication approach makes the dually modified anatase TiO2 a promising anode material for high-performance SIBs.

The use of theory-based knowledge in machine learning models has a major impact on many engineering and physics problems. The growth of deep learning algorithms is closely related to an increasing demand for data that is not acceptable or available in many use cases. In this context, the incorporation of physical knowledge or a priori constraints has proven beneficial in many tasks. On the other hand, this collection of approaches is context-specific, and it is difficult to generalize them to new problems. In this paper, we experimentally compare some of the most commonly used theory-injection strategies to perform a systematic analysis of their advantages. Selected state-of-the-art algorithms were reproduced for different use cases to evaluate their effectiveness with smaller training data and to discuss how the underlined strategies can fit into new application contexts.

The role of maintenance in the industry has been shown to improve companies’ productivity and profitability. Industry 4.0 revolutionised this field by exploiting emergent cloud technologies and IoT to enable predictive maintenance. Significant benefits can be obtained by taking advantage of historical data and Industrial IoT streams, combined with high and distributed computing power. Many approaches have been proposed for predictive maintenance solutions in the industry. Typically, the processing and storage of enormous amounts of data can be effectively performed cloud-side (e.g., training complex predictive models), minimising infrastructure costs and maintenance. On the other hand, raw data collected on the shop floor can be successfully processed locally at the edge, without necessarily being transferred to the cloud. In this way, peripheral computational resources are exploited, and network loads are reduced. This work aims to investigate these approaches and integrate the advantages of each solution into a novel flexible ecosystem. As a result, a new unified solution, named SERENA Cloud Platform. The result addresses many challenges of the current state-of-the-art architectures for predictive maintenance, from hybrid cloud-to-edge solutions to intermodal collaboration, heterogeneous data management, services orchestration, and security.

Uncontrolled wildfires are dangerous events capable of harming people safety. To contrast their increasing impact in recent years, a key task is an accurate detection of the affected areas and their damage assessment from satellite images. Current state-of-the-art solutions address such problem through a double convolutional neural network able to automatically detect wildfires in satellite acquisitions and associate a damage index from a defined scale. However, such deep-learning model performance is strongly dependent on many factors. In this work, we specifically focus on a key parameter, i.e., the loss function, exploited in the underlying neural networks. Besides the state-of-the-art solutions based on the Dice-MSE, among the many loss functions proposed in literature, we focus on the Binary Cross-Entropy (BCE) and the Intersection over Union (IoU), as two representatives of the distribution-based and region-based categories, respectively. Experiments show that the BCE loss function coupled with a double-step U-Net architecture provides better results than current state-of-the-art solutions on a public labeled dataset of European wildfires.

Recent studies on anatase TiO

Wildfires are one of the natural hazards that the European Union is actively monitoring through the Copernicus EMS Earth observation program which continuously releases public information related to such catastrophic events. Such occurrences are the cause of both short- and long-term damages. Thus, to limit their impact and plan the restoration process, a rapid intervention by authorities is needed, which can be enhanced by the use of satellite imagery and automatic burned area delineation methodologies, accelerating the response and the decision-making processes. In this context, we analyze the burned area severity estimation problem by exploiting a state-of-the-art deep learning framework. Experimental results compare different model architectures and loss functions on a very large real-world Sentinel2 satellite dataset. Furthermore, a novel multi-channel attention-based analysis is presented to uncover the prediction behaviour and provide model interpretability. A perturbation mechanism is applied to an attention-based DS-UNet to evaluate the contribution of different domain-driven groups of channels to the severity estimation problem.

Germanium (Ge) nanocrystals combined with multiwalled carbon nanotube (Ge–MWCNT) composites were synthesized via a solvothermal approach and characterized through X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and scanning and transmission electron microscopy (SEM and TEM). The electrochemical behaviour during lithium insertion and de-insertion was investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge–discharge measurements. The as prepared Ge–MWCNT nanocomposite exhibits improved cycling performance with higher capacity retention than pristine Ge. The Ge–MWCNTs exhibit a discharge capacity of ∼1160 mA h g−1 after 60 cycles at a current rate of 0.1C. Furthermore, they showed an excellent rate performance at a current rate of 5C (where 1C is 1600 mA g−1) by delivering a specific capacity of ∼406 mA h g−1 over 400 charge–discharge cycles.

We report the fabrication of binder-free anodes for lithium-ion batteries (LIBs) based on graphene nanoflakes on-demand designed and produced by liquid phase exfoliation of graphite. A solvent exchange process is exploited to first remove the N-methyl-2-pyrrolidone used for the exfoliation of graphite and then to re-disperse the exfoliated single-(SLG) and few-layer (FLG) graphene flakes, at a high concentration (∼5 g L−1), in an environmentally friendly solvent, i.e., ethanol. Anodes are realized by drop-casting the SLG- and FLG-based ink in ethanol under ambient conditions on a Cu foil without any binder or conductive agents, typically used for the fabrication of conventional LIBs. We tested our SLG- and FLG-based anodes in a half-cell configuration, achieving a reversible specific capacity of ∼500 mA h g−1 after 100 cycles at a current density of 0.1 A g−1, with coulombic efficiency >99.5%. We also tested the SLG- and FLG-based anode in a full-cell configuration, exploiting commercial LiNi0.5Mn1.5O4 as a cathode. The battery operates around 4.7 V with a flat-plateau voltage profile and a reversible specific capacity of ∼100 mA h g−1. The proposed electrode fabrication process is fast, low cost and industrially scalable opening the way to the optimization of energy and power densities, lifetime and safety of LIBs, while minimizing their cost and environmental impact.

Despite the considerable initial optimism behind its development and prospective commercialization, the Li/air battery chemistry has now reached a mature stage of development, which has served to highlight the main underlying technological limitations, as well as what can realistically be expected from it. One of the main challenges is the control of the discharge product morphology, that is, Li2O2, onto the positive electrode. In this article, we show how the three‐phase configuration required to ensure cell operation can be induced in a two‐phase system made of mesoporous carbon and an ionic liquid electrolyte [N‐butyl‐N‐methylpyrrolidinium bis(trifluoromethane sulfonyl)imide, Pyr14TFSI] by means of an oxygen‐bubbling device (OBD) and a peristaltic pump. The use of a non‐flammable, non‐volatile electrolyte ensures long‐term, extensive discharging (up to 4.78 mAh cm−2), as well as operation at temperatures higher than room temperature., The authors acknowledge the support of the European Commission FP7 Project “Lithium‐Air Battery with Split Oxygen Harvesting and Redox Processes” (LABOHR) (FP7‐NMP‐2010, grant agreement No. 265971). P.P. acknowledges a FPI‐UCM fellowship (BE45/10).

Recently, intensive efforts are dedicated to convert and store the solar energy in a single device. Herein, dye-synthesized solar cell technology is combined with lithium-ion materials to investigate light-assisted battery charging. In particular we report the direct photo-oxidation of lithium iron phosphate nanocrystals in the presence of a dye as a hybrid photo-cathode in a two-electrode system, with lithium metal as anode and lithium hexafluorophosphate in carbonate-based electrolyte; a configuration corresponding to lithium ion battery charging. Dye-sensitization generates electron–hole pairs with the holes aiding the delithiation of lithium iron phosphate at the cathode and electrons utilized in the formation of a solid electrolyte interface at the anode via oxygen reduction. Lithium iron phosphate acts effectively as a reversible redox agent for the regeneration of the dye. Our findings provide possibilities in advancing the design principles for photo-rechargeable lithium ion batteries., Photo-rechargable energy storage cells can provide plug-free power for various applications. Here the authors integrate a photo-absorbing dye complex with LiFePO4 nanocrystals as a lithium-ion battery cathode in a two-electrode system demonstrating its photo-charging and galvanostatic discharging.

We demonstrate that few-layer graphene (FLG) flakes combined with ultra-small (below 10 nm) amorphous silicon nanoparticles (SiNPs) improve the performance of Li-ion battery anodes compared to both amorphous carbon and graphene oxide additives. The FLG flakes are produced by liquid phase exfoliation of pristine graphite, while the SiNPs are synthesized by means of a plasma-assisted aerosol synthesis technique. These novel hybrid electrodes are realized by drop casting, onto a copper current collector, a slurry paste with a 1 : 1 : 1 mass ratio of FLG, SiNPs and a polyacrylic acid (PAA) binder followed by annealing in a H2 atmosphere. The as-produced anode displays a capacity loss of only 8% over 300 cycles, reaching a maximum specific capacity of 1500 mA h gSi−1 and a coulombic efficiency exceeding 99% and 99.8% in the 20th and 300th cycles, respectively. The obtained results highlight the optimal synergy between FLG flakes and ultra-small SiNPs, allowing the best capacity retention to be achieved upon cycling. The observed stability coupled with the scalability of both the FLG and SiNP production methods offers a viable approach for the development of next generation Li-ion battery anodes based on nano-engineered hybrid materials.

In this work, the electrochemical stability and lithium plating/stripping performance of N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (Pyr14TFSI) are reported, by investigating the behavior of Li metal electrodes in symmetrical Li/electrolyte/Li cells. Electrochemical impedance spectroscopy measurements and galvanostatic cycling at different temperatures are performed to analyze the influence of temperature on the stabilization of the solid electrolyte interphase (SEI), showing that TFSI-based ionic liquids (ILs) rank among the best candidates for long-lasting Li–air cells.

Li/O 2 batteries are a breakthrough in battery technology for powering long-range electric vehicles. The viability of high efficiency, rechargeable Li/O 2 battery is demonstrated by the use of catalyst-free meso-macroporous carbon cathode and N-butyl-N-methyl pyrrolidinium bis(trifluoromethanesulfonyl)imide ionic liquid-based electrolyte. The carbon electrode, obtained by a simple, low-cost template method, features a high specific capacity of 2500 mAh g −1 at 2.6 V vs. Li + /Li and, more importantly, a recharge potential lower than 3.8 V vs Li + /Li that prevents secondary reactions in the ionic liquid detrimental for battery rechargeability and makes it possible to reach a recharge efficiency of 90%.

LiMnPO4 is an attractive cathode material for the next-generation high power Li-ion batteries, due to its high theoretical specific capacity (170 mA h g(-1)) and working voltage (4.1 V vs Li(+)/Li). However, two main drawbacks prevent the practical use of LiMnPO4: its low electronic conductivity and the limited lithium diffusion rate, which are responsible for the poor rate capability of the cathode. The electronic resistance is usually lowered by coating the particles with carbon, while the use of nanosize particles can alleviate the issues associated with poor ionic conductivity. It is therefore of primary importance to develop a synthetic route to LiMnPO4 nanocrystals (NCs) with controlled size and coated with a highly conductive carbon layer. We report here an effective surface etching process (using LiPF6) on colloidally synthesized LiMnPO4 NCs that makes the NCs dispersible in the aqueous glucose solution used as carbon source for the carbon coating step. Also, it is likely that the improved exposure of the NC surface to glucose facilitates the formation of a conductive carbon layer that is in intimate contact with the inorganic core, resulting in a high electronic conductivity of the electrode, as observed by us. The carbon coated etched LiMnPO4-based electrode exhibited a specific capacity of 118 mA h g(-1) at 1C, with a stable cycling performance and a capacity retention of 92% after 120 cycles at different C-rates. The delivered capacities were higher than those of electrodes based on not etched carbon coated NCs, which never exceeded 30 mA h g(-1). The rate capability here reported for the carbon coated etched LiMnPO4 nanocrystals represents an important result, taking into account that in the electrode formulation 80% wt is made of the active material and the adopted charge protocol is based on reasonable fast charge times.

We investigated the influence of the core diameter, shell thickness, and ligand length on the spectroscopic and electrochemical signature of CdSe-ZnS core−shell quantum dots and on the ability of these nanoparticles to exchange electrons with complementary acceptors or donors upon excitation. Our studies demonstrate that the core diameter controls the absorption and emission wavelengths of the quantum dots as well as the potentials for their oxidation and reduction. Both wavelengths increase monotonically and both redox potentials shift in the negative direction with an increase in diameter. The presence of a ZnS shell enhances significantly the luminescence quantum yield and shifts both reduction potentials in the positive direction. Interestingly, the shell thickness has negligible influence of the position of the absorption and emission wavelengths, but controls the electrochemical band gap energy. Specifically, an increase in thickness translates into a decrease in the electrochemical band gap energy,...

Carbon-doped TiO2-bronze nanowires were synthesized via a facile doping mechanism and were exploited as active material for Li-ion batteries. We demonstrate that both the wire geometry and the presence of carbon doping contribute to the high electrochemical performance of these materials. Direct carbon doping for example reduces the Li-ion diffusion length and improves the electrical conductivity of the wires, as demonstrated by cycling experiments, which evidenced remarkably higher capacities and superior rate capability over the undoped nanowires. The as-prepared carbon-doped nanowires, evaluated in lithium half-cells, exhibited lithium storage capacity of ∼306 mA h g(-1) (91% of the theoretical capacity) at the current rate of 0.1C as well as excellent discharge capacity of ∼160 mAh g(-1) even at the current rate of 10 C after 1000 charge/discharge cycles.

LiNi 0.5 Mn 1.5 O 4 (LNMO) composite electrodes having the same formulation as to percentage of active material mass, binder and carbons, including reduced graphene oxide, were characterized in EC: DMC – 1M LiPF 6 by cyclic voltammetry, charge/discharge cycles and impedance spectroscopy. The results demonstrate the beneficial effect on the electrode cycling stability in increasing C-rate to 1C, in limiting the charge voltage at 4.8 V and in covering the LNMO by partially reduced graphene oxide. The paper also discusses the evaluation of lithium diffusion coefficient in LNMO from cyclic voltammetry data in regard to the discrepancies reported in literature on this matter.

Structural, morphological and electrochemical characterizations in EC:DMC-LiPF 6 of carbon-coated LiMnPO 4 and LiMn 1− x Fe x PO 4 ( x = 0.2, 0.3) cathode materials synthesized via a cost-effective procedure based on sol–gel (from partially or totally soluble precursors in water), pyrolysis and ball milling steps are reported. Carbon-coated LiMnPO 4 obtained from totally soluble precursors featuring at 0.1 C 125 mAhg −1 at 50 °C and 95 mAhg −1 at 30 °C, with a capacity fade per cycle of 0.5% at 50 °C and 0.4% at 30 °C, is a very promising material, particularly in consideration of the inexpensive procedure that was pursued for its synthesis.

The development of a pseudorotaxane motif capable of performing unidirectional threading and dethreading processes under control of external stimuli is particularly important for the construction of processive linear motors based on rotaxanes and, at least in principle, it discloses the possibility to access to rotary motors based on catenanes. Here, we report a strategy to obtain the solvent-controlled unidirectional transit of a molecular axle through a molecular wheel. It is based on the use of appropriately designed molecular components, the essential feature of which is their non-symmetric structure. Specifically they are an axle containing a central electron-acceptor 4,4'-bipyridinium core functionalized with a hexanol chain at one side, and a stilbene unit connected through a C6 chain at the other side, and a heteroditopic tris(phenylureido)-calix[6]arene wheel. In apolar solvents the axle threads into the wheel from its upper rim and with the end carrying the OH group, giving an oriented pseudorotaxane structure. After a stoppering reaction, which replaces the small hydroxy group with a bulky diphenylacetyl moiety, and replacement of the apolar solvent with a polar one, dethreading occurs through the slippage of the stilbene unit from the lower rim of the wheel, that is, in the same direction of the threading process. The essential role played by the stilbene unit to achieve the unidirectional transit of the axle through the wheel, and to tune the dethreading rate by light is also demonstrated.

LiMnPO4 is an attractive cathode material for the next-generation high power Li-ion batteries, due to its high theoretical specific capacity (170 mA h g−1) and working voltage (4.1 V vs Li+/Li). Two main drawbacks prevent the practical use of LiMnPO4: (i) its low electronic conductivity and (ii) the limited lithium diffusion rate, responsible for the poor rate capability of the cathode. The use of nano-particles can alleviate the issues associated with poor ionic conductivity while the electronic resistance is usually lowered by coating the particles with a carbon layer. It is therefore of primary importance to develop a synthetic route to LiMnPO4 nanocrystals (NCs) with controlled size and coated with a highly conductive carbon layer. Here we report an effective surface etching process (using LiPF6) on colloidally synthesized LiMnPO4 NCs that makes the NCs more hydrophilic and dispersible in the aqueous glucose solution used as carbon source for the carbon coating step. The carbon coated etched LiMnPO4-based electrode exhibited a specific capacity of 118 mA h g−1 at 1C, with a stable cycling performance and a capacity retention of 92% after more than 100 cycles at different C-rates. The delivered capacities were higher than those of not etched carbon coated NCs, which never exceeded 30 mA h g−1. The adopted etching process allowed: (i) The efficient removal of the hydrophobic passivated surfactants shell, present on NCs surface after the colloidal synthesis. This increases the nanoparticles’ solubility in the aqueous glucose solution used as carbon source for NCs coating, enabling the formation of a good conductive carbon layer. (ii) The possibility to prepare composite electrodes with a reduced amount of carbon additive and polymeric binder (less than 20% wt. in total), with a consequent benefit on the energy density of LMP-based cathodes. The protocol reported here enabled the preparation of LMP/NCs-based cathodes with high rate capability and which can be charged with a fast CC−CV procedure (of maximum 2 h at 1C-rate), which is of paramount importance for the future development of high rate and high power Li-ion batteries.

P2-Na2/3[NixMny]O2-based cathode materials are promising candidates for Na-ion batteries. The cycling performance of these cathodes was usually reported to drop at working voltages over 4.2 V, due to the P2/O2 irreversible phase transition. Here we demonstrate a colloidally assisted two-step synthesis to phase pure P2-Na0.43Ni0.25Mn0.75O1.9. The adopted synthetic route and the chosen Na:Ni:Mn ratio (0.43:0.25:0.75) leads to a cathode material that can withstand long charge/discharge cycles at working voltages up to 4.4 V. The XRD pattern recorded on the de-sodiated electrode (4.4 V) does not evidence the presence of any peak related to the O2 phase, corroborating the effective suppression of the P2/O2 phase transition upon Na+ intercalation/deintercalation. The discharge capacity delivered at relatively low current (C/10) is 109 mAh g-1, with a capacity retention exceeding the 93% in 20 cycles. At the high current of 1C the delivered discharge capacity is 94 mAh g-1.

The use of ionic liquid (IL)-based electrolytes and porous carbonaceous cathodes is today one of the most promising strategies for the development of rechargeable Li/O2 batteries. Enhancing Li/O2 battery cyclability at high discharge rate is a key issue for automotive applications. O2 reduction at a meso-macroporous carbon electrode in N-butyl-N-methyl pyrrolidinium bis(trifluoromethanesulfonyl)imide (PYR14TFSI):LiTFSI 9:1 is here investigated. The study demonstrates that oxygen electrode response in IL at high discharge currents is dominated by O2 mass transport in IL. A novel configuration of flow-Li/O2 battery that operates at high discharge rate is reported.

Optical or electrochemical excitation of an Ir(III) cyclometalated complex bearing photochromic and acid-sensitive dithienylethene ligands generates a phosphorescence emission that can be switched on/off by light and chemical stimulation.

The oxygen redox reaction (ORR) in pyrrolidinium-based ionic liquids (ILs) without and with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) is investigated at different temperatures for lithium/oxygen battery application. Results obtained by cyclic voltammetry, rotating disk electrode, and ultramicroelectrode potential steps at glassy carbon are reported and discussed in relation to the physical–chemical properties of the investigated ILs. Diffusion coefficients and solubility of oxygen in the ILs and tentative values of ORR heterogeneous rate constant in ILs without LiTFSI are reported. The effect of lithium salt on the ORR in IL is also discussed in view of lithium/oxygen battery application.

In the last few years, much research effort is being focused on rechargeable lithium–air (O2) batteries which feature a theoretical specific energy comparable to that of gasoline. While these cutting-edge batteries are at their early stage of development with many challenges to be overcome, they are the most promising candidates to power electric vehicles with long driving range. In the frame of the European LABOHR Project we are investigating the use of hydrophobic ionic liquid (IL)-based electrolytes in these batteries. Basic studies of the oxygen redox reaction in N-butyl-N-methyl pyrrolidinium bis(trifluoromethanesulfonyl)imide at home-made catalyst-free porous carbon electrode demonstrated that O2mass transport in IL becomes crucial at the fastest battery discharge rates, which are of interest for automotive applications. The study also demonstrated that it is possible to overcome this limitation by new flow-cell designs, and the main achievements are reported and discussed. Acknowledgement Work funded by the European Commission in the 7th Framework Programme FP7-2010-GC-ELECTROCHEMICAL STORAGE, under contract no. 265971 “Lithium-Air Batteries with split Oxygen Harvesting and Redox processes” (LABOHR). All the partners of the LABOHR Project are acknowledged for the fruitful discussions on Li/O2 batteries with ionic liquids. References [1] www.labohr.eu [2] S. Monaco, A. M. Arangio, F. Soavi, M. Mastragostino, E. Paillard, S. Passerini, Electrochimica Acta 83 (2012) 94–104. [3] F. Soavi, S. Monaco, M. Mastragostino, Journal of Power Sources 224 (2013) 115 – 119. [4] S. Monaco, F. Soavi, M. Mastragostino, J. Phys. Chem. Lett. 4 (2013) 1379−1382.

Low volatility, thermal and electrochemical stability and good conductivity of ionic liquids (ILs) make them “key electrolytes” for the development of Li/O2 batteries which are considered the most promising high-energy systems for a market success of electric vehicles of long driving range. Particularly, hydrophobic pyrrolidinium salts of bis(trifluoromethanesulfonyl)imide feature a high stability toward superoxide that is formed during the discharge/recharge of Li/O2 batteries. Under the European LABOHR Project, the oxygen redox reaction (ORR) and O2 diffusion coefficient and solubility, which are crucial parameters for Li/O2 battery operation, have been investigated in such ILs and related to the physical-chemistry properties of the electrolytes. It has also been demonstrated that ILs provide a real possibility for the development of rechargeable Li/O2 batteries that can safely operate even above room temperature. The main achievements of this study are here reported and discussed Acknowledgement Work funded by the European Commission in the 7th Framework Programme FP7-2010-GC-ELECTROCHEMICAL STORAGE, under contract no. 265971 “Lithium-Air Batteries with split Oxygen Harvesting and Redox processes” (LABOHR). All the partners of the LABOHR Project are acknowledged for the fruitful discussions on Li/O2 batteries with ionic liquids. References [1] www.labohr.eu [2] S. Monaco, A. M. Arangio, F. Soavi, M. Mastragostino, E. Paillard, S. Passerini, Electrochimica Acta 83 (2012) 94–104. [3] F. Soavi, S. Monaco, M. Mastragostino, Journal of Power Sources 224 (2013) 115 – 119. [4] S. Monaco, F. Soavi, M. Mastragostino, J. Phys. Chem. Lett. 4 (2013) 1379−1382.