Rheological behaviour of Na-CMC and Na-alginate as binders for lithium ion batteries

Lithium ion batteries are the current technology of choice for electric vehicles due to their light weight, high volumetric and gravimetric energy density, low selfdischarge rate, quick charge acceptance, excellent cycle life and wide operating temperature range. However the current manufacturing process requires the use of polyvinylidene fluoride (PVDF), in order to bind the anode components within the electrode which prevents the recycling of the electrode materials. Furthermore PVDF necessitate the application of N-methyl-2-pyrrolidone (NMP), an environmentally toxic material as a solvent during the manufacturing. The aim of this research was to investigate the suitability of using water soluble Na-alginate as an alternative binder for the anodes of lithium ion batteries to reduce the environmental impact from current manufacturing processes and to allow recycling of the active anode components. The main function of the binder is the improvement of the mechanical strength and the adhesion of the electrode on the current collector. The properties of the binder which are most important during manufacturing are the rheological characteristics of the slurries comprising binder and active materials. This was the focus of this investigation. The viscosity of Na-alginate suspensions at 1% or 1.5% loading in water were typically 1 to 8 Pa·s which are similar to PVDF suspensions with loadings of 2.5 to 3.0%. Comparing to the benchmark Na-CMC, the degree of flocculation shows that for the same concentration of binder in water, Na-alginate suspensions are more stable, Na-alginate has a degree of flocculation of 1.17 while for Na-CMC it was 1.90. The rheology measurements show that Na-alginate slurries have a higher viscosity than Na-CMC at a shear rate of 50 s-1 with that for a 1.5% of Na-alginate binder being 1.26 Pa·s while for Na-CMC it was for 0.20 Pa·s. The loss factor was lower for Na-alginate, between 2 and 3 against between 2.9 and 3.3 for Na-CMC, showing a more developed network structure. The casting and drying process, demonstrated that while 1.5% Na-CMC in water wasn´t sufficiently viscous to cast the slurries it was possible to do it with Naalginat

Large Induced Interface Dipole Moments without Charge Transfer: Buckybowls on Metal Surfaces

Charge carrier injection barriers at interfaces are crucial for the performance of organic electronic devices. In this respect, tuning the electronic interface potential or, in case of the metallic electrode, the work function for electronic level alignment is crucial. However, poor control over the interface structure and the work function of the combined materials is an obstacle for better device performance. Here we show that bowl-shaped molecules, based on buckminsterfullerene, induce very large interface dipole moments of up to 8.8 D on a copper surface. It is shown experimentally and theoretically that charge transfer between both components is negligible. The origin of the large dipole moments is revealed via dispersion-enabled density functional theory, displaying a strong rearrangement of charge in the metal underneath the molecular adsorbate

Behavior of heavy metals during fluidized bed combustion of poultry litter

In this study, we have examined the behavior of heavy metals during fluidized bed combustion of poultry litter. Heavy metals examined include As, Cd, Co, Cr, Cu, Hg, Mn, Mo, Ni, Pb, V, and Zn. Solid and gaseous streams were analyzed and compared with relevant guidelines to determine the potential environmental impact of combustion and subsequent land spreading or landfill of the resulting ash. The majority of heavy metals were associated with the solid ash fraction, with low gaseous emissions. Pb and As were concentrated in the fine baghouse ash (160 °C) due to their volatility. The remaining heavy metals, excluding Cd, were enriched in the heat exchangers and cyclone, where flue gas temperatures ranged from 580 to 220 °C. Under the waste acceptance criteria, all samples of process ash, excluding bed ash, exceeded the limits for nonhazardous landfill waste, as a result of high levels of water-soluble Cr. Water-soluble Cr indicated the presence of Cr(VI), and its presence was confirmed using X-ray absorption near-edge structure spectroscopy (18.4% to 38.3%). The source of Cr was identified as the bedding material (wood shavings), and its conversion to Cr(VI) was temperature-dependent and could be facilitated by the high alkali content found in poultry litter

The ELSI Infrastructure for Scalable Electronic Structure Theory

Lightning talk accompanying the poster describing the ELSI infrastructure in detail.<br