Early stage techno-economic and environmental analysis of aluminium batteries

For any proper evaluation of next generation energy storage systems technological, economic, and environmental performance metrics should be considered. Here conceptual cells and systems are designed for different aluminium battery (AlB) concepts, including both active and passive materials. Despite the fact that all AlBs use high-capacity metal anodes and materials with low cost and environmental impact, their energy densities differ vastly and only a few concepts become competitive taking all aspects into account. Notably, AlBs with high-performance inorganic cathodes have the potential to exhibit superior technological and environmental performance, should they be more reversible and energy efficient, while at the system level costs become comparable or slightly higher than for both AlBs with organic cathodes and lithium-ion batteries (LIBs). Overall, with continued development, AlBs should be able to complement LIBs, especially in light of their significantly lower demand for scarce materials

Initial Evolution of Passivation Layers in Non-Aqueous Aluminium Batteries

Aluminium batteries (AlBs) have gathered considerable attention, primarily due to the high capacity, the low cost, the large abundance in the Earth’s crust, and the recyclability of the Al metal anode. However, several hurdles must be surpassed to make AlBs a feasible energy storage technology and two of them are interconnected; the presence of an ionic and electronically insulating native oxide layer on the Al metal anode that calls for special non-aqueous, most often ionic liquid based acidic electrolytes, to enable reversible plating and stripping of Al. We here find the passivation layer initially formed in contact with an ionic liquid electrolyte (ILE) to have a porous and very complex nature, i.e. an outer inorganic/organic layer and an inner oxide-rich layer. Furthermore, it grows under open circuit voltage conditions by simultaneous dissolution and re-deposition of dissolved products, while during galvanostatic cycling this is exacerbated by an electrochemical etching that causes pitting corrosion of the Al metal itself. All of this leads to unstable interfaces being formed and the co-existence of several species at the Al metal anode surface, of which a proper understanding and mitigation are crucial to make AlBs a reality

Depth probing of the hydride formation process in thin Pd films by combined electrochemistry and fiber optics-based in situ UV/vis spectroscopy

We demonstrate a flexible combined electrochemistry and fiber optics-based in situ UV/vis spectroscopy setup to gain insight into the depth evolution of electrochemical hydride and oxide formation in Pd films with thicknesses of 20 and 100 nm. The thicknesses of our model systems are chosen such that the films are thinner or significantly thicker than the optical skin depth of Pd to create two distinctly different situations. Low power white light is irradiated on the sample and analyzed in three different configurations; transmittance through, and, reflectance from the front and the back side of the film. The obtained optical sensitivities correspond to fractions of a monolayer of adsorbed or absorbed hydrogen (H) and oxygen (O) on Pd. Moreover, a combined simultaneous readout obtained from the different optical measurement configurations provides mechanistic insights into the depth-evolution of the studied hydrogenation and oxidation processes

Inorganic polyphosphate (polyP) physiology 35 Caveats in studies of the physiological role of polyphosphates in coagulation

Abstract Platelet-derived polyphosphates (polyP), stored in dense granule and released upon platelet activation, have been claimed to enhance thrombin activation of coagulation factor XI (FXI) and to activate FXII directly. The latter claim is controversial and principal results leading to these conclusions are probably influenced by methodological problems. It is important to consider that low-grade contact activation is initiated by all surfaces and is greatly amplified by the presence of phospholipids simulating the procoagulant membranes of activated platelets. Thus, proper use of inhibitors of the contact pathway and a careful choice of materials for plates and tubes is important to avoid artefacts. The use of phosphatases used to degrade polyP has an important drawback as it also degrades the secondary activators ADP and ATP, which are released from activated platelets. In addition, the use of positively charged inhibitors, such as polymyxin B, to inhibit polyP in platelet-rich plasma and blood is problematic, as polymyxin B also slows coagulation in the absence of polyP. In conclusion we hope awareness of the above caveats may improve research on the physiological roles of polyP in coagulation

Gradient-dependent inhibition of stimulatory signaling from platelet G protein-coupled receptors

As platelet activation is an irreversible and potentially harmful event, platelet stimulatory signaling must be tightly regulated to ensure the filtering-out of inconsequential fluctuations of agonist concentrations in the vascular milieu. Herein, we show that platelet activation via G protein-coupled receptors is gradient-dependent that is determined not only by agonist concentrations per se but also by how rapidly concentrations change over time. We demonstrate that gradient-dependent inhibition is a common feature of all major platelet stimulatory G protein-coupled receptors, while platelet activation via the non- G protein- coupled receptor glycoprotein VI is strictly concentration-dependent. By systematically characterizing the effects of variations in temporal agonist concentration gradients on different aspects of platelet activation, we demonstrate that gradient-dependent inhibition of protease-activated receptors exhibit different kinetics, with platelet activation occurring at lower agonist gradients for protease-activated receptor 4 than for protease-activated receptor 1, but share a characteristic bimodal effect distribution, as gradient-dependent inhibition increases over a narrow range of gradients, below which aggregation and granule secretion is effectively shut off. In contrast, the effects of gradient-dependent inhibition on platelet activation via adenosine diphosphate and thromboxane receptors increase incrementally over a large range of gradients. Further, depending on the affected activation pathway, gradient- dependent inhibition results in different degrees of refractoriness to subsequent autologous agonist stimulation. Mechanistically, our study identifies an important role for the cyclic adenosine monophosphate-dependent pathway in gradient-dependent inhibition. Together, our findings suggest that gradient-dependent inhibition may represent a new general mechanism for hemostatic regulation in platelets

Policy Options for Sustainable Food Consumption – Review and Recommendations for Sweden. Mistra Sustainable Consumption report 1:10

The environmental impact of the average Swede’s diet exceeds the planetary limits for the food system in most areas. Over 15% of consumption-based greenhouse gas emissions come from food in Sweden. Sweden’s agricultural landscape has the largest proportion of European Red List species of all landscape types in Sweden and food imports are associated with high rates of land use, pesticides and veterinary antibiotics in other countries. Our diet is also not sustainable in terms of health – for example, 51% of Swedes are overweight and many of the most common diseases and causes of death are linked to diet.This report identifies and discusses policy instruments that the state and other public actors could introduce to steer food consumption in Sweden towards a more environmentally sustainable diet. Seventeen policy instruments operating either through knowledge and support, changes in relative prices, or regulation and requirements have been identified and previous research on policy effectiveness, costs and acceptance has been mapped out in a way that we hope is clear and easy to understand. Based on the current state of knowledge, we have formulated three recommendations on what public actors could do to accelerate the transition to a more sustainable food system.1.Intensify work in the public sector2.Develop national targets for sustainable food consumption3.Develop and implement effective and attractive policy instrument packagesThe mapping and analysis show that there is a need for research on policy instruments for environmentally sustainable food consumption, particularly when it comes to combinations of instruments. However, there is a sufficient evidence base for the immediate development and implementation of policy instruments to deal with the climate, environmental and health impacts of food. A focus on targets and policy instruments in the food area, as outlined above, is also fully in line with the EU’s new Farm-to-Fork strategy. The policy instruments discussed in the report can probably achieve only part of the huge, transformative changes required to limit the production and consumption of food to planetary limits, but a central issue is how to do this. Part of the answer lies in a change in food consumption and here we believe that we know where the answer lies: public actors ought to develop and implement a variety of policy instruments and systematically evaluate them – it is in this more large-scale implementation that the real need for research lies. The challenge of reducing the environmental impact of food consumption in Sweden is considerable, but there are good opportunities for nudging the trend towards more environment-friendly and health-friendly sustainable food consumption through the deployment of new policy instruments

Surface Composition of a Highly Active Pt3Y Alloy Catalyst for Application in Low Temperature Fuel Cells

Currently, platinum is the most widely used catalyst for low temperature proton exchange membrane fuel cells (PEMFC). However, the kinetics at the cathode are slow, and the price of platinum is high. To improve oxygen reduction reaction (ORR) kinetics at the cathode, platinum can be alloyed with rare earth elements, such as yttrium. We report that Pt3Y has the potential to be over 2 times more active for the ORR compared with Pt inside a real fuel cell. We present detailed photoemission analysis into the nature of the sputtered catalyst surface, using synchrotron radiation photoelectron spectroscopy (SRPES) to examine if surface adsorbates or impurities are present and can be removed. Pretreatment removes most of the yttrium oxide in the surface leaving behind a Pt overlayer which is only a few monolayers thick. Evidence of a substochiometric oxide peak in the Y 3d core level is presented, this oxide extends into the surface even after Ar+ sputter cleaning in-situ. This information will aid the development of new highly active nanocatalysts for employment in real fuel cell electrodes

Templated Growth of Covalently Bonded Three-Dimensional Carbon Nanotube Networks Originated from Graphene

A template-assisted method that enables the growth of covalently bonded three-dimensional carbon nanotubes (CNTs) originating from graphene at a large scale is demonstrated. Atomic force microscopy-based mechanical tests show that the covalently bonded CNT structure can effectively distribute external loading throughout the network to improve the mechanical strength of the material

Determination of the Bending Rigidity of Graphene via Electrostatic Actuation of Buckled Membranes

The small mass and atomic-scale thickness of graphene membranes make them highly suitable for nanoelectromechanical devices such as e.g. mass sensors, high frequency resonators or memory elements. Although only atomically thick, many of the mechanical properties of graphene membranes can be described by classical continuum mechanics. An important parameter for predicting the performance and linearity of graphene nanoelectromechanical devices as well as for describing ripple formation and other properties such as electron scattering mechanisms, is the bending rigidity, {\kappa}. In spite of the importance of this parameter it has so far only been estimated indirectly for monolayer graphene from the phonon spectrum of graphite, estimated from AFM measurements or predicted from ab initio calculations or bond-order potential models. Here, we employ a new approach to the experimental determination of {\kappa} by exploiting the snap-through instability in pre-buckled graphene membranes. We demonstrate the reproducible fabrication of convex buckled graphene membranes by controlling the thermal stress during the fabrication procedure and show the abrupt switching from convex to concave geometry that occurs when electrostatic pressure is applied via an underlying gate electrode. The bending rigidity of bilayer graphene membranes under ambient conditions was determined to be $35.5^{+20}_{-15}$ eV. Monolayers have significantly lower {\kappa} than bilayers