Poster Session
Battery Section
Understanding the interaction of carbonates and binder in Na-ion batteries: A combined bulk and surface study
L.O. Vogt, M. El Kazzi, E. J. Berg, C. Villevieille
L.O. Vogt, M. El Kazzi, E. J. Berg, C. Villevieille
Na-Ion batteries are among the candidates for next generation battery systems and are under exploration at a fundamental level.
Electrodes for Na-Ion constising of intermetallics (Sn, Sb etc.) show impressive specific charge densitiy above 500 mAh/g. Furthermore, the cyclability
of the Na- battery electrodes improves if an additive such as FEC (fluoroethylene carbonate) is added. In order get from promissing electrode materials
to electrodes and battery cells, a mechanically and chemically stable electrode is required. In Li-ion battery systems PVDF (Polyvinylidenfluorid) is a
well established binder for the electrodes. Yet in Na-ion systems PDVF binder seems not to work. In this study the interface between the intermetallic (Sn)
electrode and the binder is inverstigated via XPS to explore the failure mechanisms.
Thermal Energy Section
High-Temperature Combined Sensible/Latent-Heat Storage
L. Geissbühler, M. Kolman, G. Zanganeh, A. Haselbacher, A. Steinfeld
L. Geissbühler, M. Kolman, G. Zanganeh, A. Haselbacher, A. Steinfeld
The outflow temperature of a thermal energy storage (TES) system with only sensible heat storage material drops during discharge if the
tank is not large enough and not sufficiently pre-charged. This can be mitigated if the sensible heat storage is combined with a latent
heat storage system. This approch is evaluated by exeriments and simulations.
Phase change material systems for high temperature heat storage
D. Perraudin, S. Haussener
D. Perraudin, S. Haussener
The development of technologies for energy storage has been intensified in recent years driven by the disparity between energy availability and demand,
which is expected to increase further as an increasing amount of energy is provided from renewable and intermittent sources. A large fraction of the end
energy is used in heating applications, in Switzerland amounting to about 50% of which an estimated 14% is used in high temperature applications
(temperatures >400°C). In order to cover this need for continuous availability of thermal energy with renewable sources or waste heat, advanced heat
storage technologies are required. Latent heat storage by means of phase change materials (PCM) has proven to be an attractive heat storage technology.
Key advantages include the high energy storage density, applicability to high temperatures, and the ability to store and release heat at a constant
temperature.
We developed a 1D numerical model of a basic latent heat storage material system composed of a metallic PCM and a metal-ceramic PCM encapsulation
Thermo-mechanical characterization of cellular ceramics in high-temperature environments
E. Rezaei, A. Ortona, S. Haussener
E. Rezaei, A. Ortona, S. Haussener
Cellular ceramics are attracting materials for high temperature applications such as high-temperature thermal storage systems, thermal protection systems, burners, reformers, and solar
radiation absorbers. These material structures are able to withstand oxidative environments at high temperatures and are particularly resistant to thermal shock. As typical for ceramic
materials, thermal stresses are one of the major reasons of failure in these components when used in high temperature applications. The study of this phenomena is a difficult task since
it couples the thermal physics and structural mechanics of ceramics with a possibly complex cellular structure.
X-ray computed tomography of a commercially available SiSiC foam produced by the replica method, was used to digitally reconstruct the cellular structure. We then used the finite element
method (FEM) as well as experiments to study the effect of structural features on ceramic foams’ mechanical and thermal properties. In a second step, models of lattice structures made of
ordered tetrakaidecahedral unit cells – a unit cell often used to represent the microstructure of commercial foams – were simulated and their morphology (e.g. strut shape, cross section, and thickness) optimized for enhanced thermo-mechanical properties.
Optimized structures made of SiSiC were produced using advanced additive manufacturing techniques in conjunction with the conventional replica method. Their mechanical properties were then
tested using non-destructive techniques (acoustical emission and electrical resistance) and compared to the FEM numerical modeling.
Hydrogen Section
Solvation of Formic Acid in Water and in Organic Solvents
C. Fink, G. Laurenczy
C. Fink, G. Laurenczy
A promising idea is to store hydrogen chemically bound to small molecules in a way that allows a quick hydrogen evolution or storage on demand.
CO2 has been proven to be suitable carrier molecule for hydrogen, by forming formic acid or formates. Beside the catalysts and carrier
substances, the solvent systems play a crucial role in these processes. It mediates the interactions between the reactants, catalysts, and the products.
For this purpose, we examined in detail the interactions of formic acid with some carefully selected solvents, using FT-IR, NMR spectroscopy and
calorimetric methods.
Conversion of electricity into hydrogen using a dual-circuit redox flow battery
P. Peljo, V. Amstutz, K. Toghill, H. Vrubel, H. H. Girault
P. Peljo, V. Amstutz, K. Toghill, H. Vrubel, H. H. Girault
Redox flow batteries (RFBs) are very well suited for storing the intermittent excess supply of renewable electricity.
However, conventional RFBs cannot in many situations utilize all the available “junk” electricity due to a limited storage capacity,
as they are charged and discharged electrochemically, with electricity stored as chemical energy in the electrolytes. In the RFB system reported here,
the electrolytes are conventionally charged but are then chemically discharged over catalytic beds in separate external circuits.
Formic acid can be selectively decomposed into CO free carbon dioxide and hydrogen. It has been shown, that beside the ruthenium(II)-mtppts systems,
the iron(II) – hydrido tris[(2-diphenyl-phosphino)ethyl]-phosphine complex also catalyses formic acid cleavage with an exceptionally high rate and
efficiency. This opens the way for cheap, non-noble metal based catalysts for this reaction.
Entirely rechargeable hydrogen storage devices have been developed based on the hydrogenation of bicarbonates, or CO2 – amine systems and
decomposition of formates in aqueous solution or organic solvents with the same catalysts, [{RuCl2(mtppms)2}2][4] or [RuH2(dppm)2],
in both directions without needing to isolate either the formates or bicarbonate salts to start new cycles.
For the first time, the direct hydrogenation of CO2 into formic acid using a homogeneous ruthenium catalyst, in aqueous solution and in
dimethyl sulfoxide without any additives, have been realised.
Synthetic Fuel Section
Electrochemical setup for online FTIR and Differential Electrochemical Mass Spectrometry studies of CO2-electroreduction on model metal surfaces
Y. Paratcha, T. J. Schmidt, J. Herranz, J. Durst
Y. Paratcha, T. J. Schmidt, J. Herranz, J. Durst
The electrochemical reduction of CO2 is an interesting pathway
since a broad range of useful products can be formed. Nevertheless, on top of the high overpotential required to drive this reaction, the electrochemical
reduction of CO2 suffers from a poor yield/selectivity of valuable products.
In order to overcome these two barriers, a better fundamental understanding of this reaction is urgently needed.
Especially, the yield of each reaction product should be quantified as a function of several parameters. For this purpose, we have designed a Differential
Electrochemical Mass Spectrometry (DEMS) setup coupled with an electrochemical flow cell that allows
the in-operando quantification of the volatile species produced in the course of the reaction. Alternatively, this reaction is studied also using an online Fourier Transformed
Infra-Red (FTIR) spectroscopy setup coupled with an electrochemical cell where information about adsorbed reaction intermediates could be earned.
A Kinetic Study of CO2 Electroreduction on Metallic Electrodes in Aprotic Media
A. Rudnev, M. Ehrenburg, U. Zhumaev, E. Molodkina, I. Botriakova, M. Rahman, A. Danilow, T. Wandslowski
A. Rudnev, M. Ehrenburg, U. Zhumaev, E. Molodkina, I. Botriakova, M. Rahman, A. Danilow, T. Wandslowski
Electrocatalytic conversion of CO2 into gaseous and liquid fuels has a great potential. However, significant conceptual and technological advances are still needed to make this
process economically viable. Most studies on CO2 electroreduction were carried out using aqueous electrolytes. The solubility of CO2 in water is rather low,
which leads to an undesirably low rate of mass transfer to the cathode. The use of non-aqueous electrolytes has the advantage of a significant increase in the CO2 solubility
and allows avoiding intensive hydrogen evolution.
In this work, we investigate electrocatalytic activity of Au, Pt, Cu electrodes as well as of Cu-modified Pt(hkl) single crystal electrodes in electroreduction of CO2 in aprotic solvents, such as acetonitrile and propylene carbonate.
Technology Interaction Section
Combined Storage of Electricity, Heat and Cold
A. Stamatiou, A. Amman, L. Fischer, J. Worlitschek
A. Stamatiou, A. Amman, L. Fischer, J. Worlitschek
A promising storage system based on the combination of a heat pump, heat
engine, cold and hot storage is presented. This site-independent technology can
provide flexibility between power and heat while supplying electricity efficiently in
the interesting power range of approximately 0.3-100 MW for several hours.
Within the SCCER framework, HSLU is reviewing and extending the existing
variations, as well as developing new ones. The goal is to adapt this flexible
technology in order to provide application-specific, optimized storage solutions for
a variety of cases from bulk electricity storage to district heating, cooling and
electricity storage.
The process of Power-to-Methane transforms excess electrical
energy to chemical energy in the form of methane. This
process is conducted in two stages: In the 1st stage, the electrolysis,
water is split into oxygen and hydrogen
the latter is transformed in a 2nd stage into methane in using
carbon dioxide from a suitable source.
This gas can be transported over long distances in the natural
gas grid and it can be stored in storages already existing
today.
It is the aim of our project, to demonstrate existing technologies of the Power-to-Methane process to the public and interested expert groups.
It is the aim of our project, to demonstrate existing technologies of the Power-to-Methane process to the public and interested expert groups.
The objective of this research (conducted in WP5 of SCCER-Storage) is to develop a uniform techno-economic and environmental assessment method for electrical and thermal storage. This assessment is intrinsically flexible because it can be applied to different energy storage (ES) technologies for both heat and electricity, for different applications and sectors. The analysis will integrate different levels including:
- the storage unit, e.g. battery unit or hot water tank.
- the application, e.g. renewable energy (RE) time-shift and demand shifting.
- the system interactions, e.g. energy prices and reference scenarios.