Poster: An analytical approach to modelling of mass transfer…

Presenter: René Lorenz
Title: An analytical approach to modelling of mass transfer effects in Redox Flow Batteries
Affiliation: DTU Energy, Technical University of Denmark

Abstract

Aiming at a simple and computationally inexpensive method for analyzing a single cell setup in terms of (pumping power corrected) net power, a combination of analytical models are evaluated. Regarding the fluid flow, simplification assumptions allow for relating the pressure drop to the applied flowrate with a single explicit equation, which is implemented for three configurations: Flow Through electrode, Serpentine Flow Field and Interdigitated Flow Field. Multiplying Δp with flow rate Q gives the minimum parasitic pumping loss. A first estimation of the power output is obtained by applying a Thin Film Electrode model, coupled with fluid flow by assuming a flow factor that relates stoichiometric flow rate to applied flow rate. In a second step, a differential expression of the overpotential across the electrode thickness, solved numerically, accounts for the 3D porous reaction volume. The results are compared to numerical and experimental studies.

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Poster: Developing Li-ion conducting passivation layers on metallic lithium…

Authors: Pushpaka B. Samarasingha and Mario Valvo
Title: Developing Li-ion conducting passivation layers on metallic lithium and their effect on electrochemistry
Affiliation: Uppsala University

Abstract

Li-ion battery (LIB) demand is unprecedented at present, mainly due to an exponential growth of consumer electronics and fast development of battery-powered vehicles. Currently, the general consensus is that conventional LIBs based on liquid electrolytes have reached a saturation point for fundamental and technical developments. Hence, increasing attention is paid to performance improvements. Yet, there is still room to increase the power and energy densities of LIBs by integrating metallic lithium (Li) as advanced negative electrode. Some early attempts to use metallic Li in LIBs occurred before their commercial introduction. Nevertheless, such efforts failed due to severe safety failures.
In this work, we try to develop Li-ion conducting passivation layers on metallic Li, which would be useful in addressing the safety issues posed by the highly reactive Li surface. In addition, these passivation layers could improve properties of the solid electrolyte interface (SEI) layer as well.

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Poster: Hemp-Derived Carbon as Bi-Functional Anode Material for Lithium…

Author: Prasanna Kadirvelayutham
Title: Hemp-Derived Carbon as Bi-Functional Anode Material for Lithium and Sodium Ion Batteries
Affiliation: DTU Energy, Technical University of Denmark

Abstract

Different parts of the hemp plant (Cannabis sativa) has different applications namely the seeds and flowers are used in preparing healthy foods, organic body care, and other nutraceuticals, the fibers and stalks are used in clothing, construction materials, paper, biofuel, plastic composites, and more. Similarly, in this research work, we have used hemp bast (HB) for application in energy storage devices like lithium and sodium ion batteries (LIBs and SIBs). From the HB we derived partially graphitized carbonaceous material (HBC) using simple pyrolysis process followed by washing with nitric acid. The chemical and physical properties of HBC are analysed using XRD, Raman spectroscopy, XPS, FE-SEM, and BET. The electrochemical properties of HBC are analysed using it as an anode in LIBs and SIBs. The anode electrode fabricated using HBC is found to have good cycling performance, capacity, and rate capability in both the LIBs and SIBs.

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Poster: DFT Modelling for boosting R&D of Magnesium Technology

Presenter: Piotr Jankowski
Title: DFT Modelling for boosting R&D of Magnesium Technology
Affiliation: DTU Energy, Technical University of Denmark

Abstract

Magnesium battery technology is one of the promising post-lithium technology, that has potential to reduce our lithium dependence and at the same time outperform current Li-ion technology. Magnesium is more abundant, hence cheaper, and comes with promises of higher energy density and lower tendency to dendrite formation – possibility of metallic anode application. Higher safety, together with easier recycling process, in respect to lithium, give environmental friendliness and sustainability to this technology and result overall in a very attractive set of properties. Unfortunately, several challenges come along with replacement of lithium by magnesium, and need to be resolved prior to successful commercialization of this technology: low diffusion of Mg-ions inside host materials; low potential of cathode materials; aggregation of ions inside Mg-based electrolytes.

Rational design of new materials is necessary and DFT calculations are shown to provide valuable support in it.

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Poster: SEI formation in Li-ion batteries studied by EIS/EQCM-D

Author: Paul Kitz
Title: SEI formation in Li-ion batteries studied by EIS/EQCM-D
Affiliation: Eidgenössische Technische Hochschule Zürich, ETH

Abstract

Considering the complex dynamics of the interphase formation process in Li-ion batteries, the SEI nm-sized dimension, as well as the intermediacy and instability of many interphase species, operando analysis methods of high surface sensitivity are of interest. Operando electrochemical quartz crystal microbalance with dissipation monitoring (EQCM D) coupled with simultaneous electrochemical impedance spectroscopy (EIS) was developed for this purpose to accurately measure the mechanical and electrochemical electrode-electrolyte interphase properties. The new technique was applied to study the SEI formation process on carbon based anodes. Indeed, combined EIS/EQCM-D provides unique pieces of information for understanding the highly dynamic structure-function relationships of electrode interphases in Li-ion batteries.

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Poster: An operando cell for dynamic X-ray diffraction with…

Author: Olof Gustafsson
Title: An operando cell for dynamic X-ray diffraction with controlled stack pressure
Affiliation: Uppsala University

Abstract

Designing an operando X-ray diffraction cell can be challenging from both an electrochemical and a diffraction point of view. The cell needs to perform in a similar electrochemical manner as typical lab scale devices, such as pouch cells or coin cells. At the same time, the cell must be suitable for diffraction, i.e. give a pattern with as little contribution from background and secondary phases as possible in order to study the active material. An often overlooked parameter for operando studies of electrode materials which can impact the electrochemical performance is the stack pressure.
Utilizing our own modified version of the AMPIX cell, stack pressure can easily be set with the use of an external wave spring. The cell was utilized on the P02.1 beam line at the Petra III synchrotron. Phase behaviour in the active material could be tracked accurately using X-ray diffraction, while simultaneously obtaining good electrochemical performance comparable to that seen with pouch cells.

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Poster: Affordable porous silicon composite anode from agricultural residue

Author: Nathiya Kalidas
Title: Affordable porous silicon composite anode from agricultural residue
Affiliation: University of Eastern Finland 

Abstract

Silicon has been considered as the most promising high-capacity anode material for lithium-ion batteries (LIB). Si-based anode suffers from capacity loss stemming from the large volume changes (300%) during the lithiation/delitiation process.  Porous silicon (PSi) structures can solve the problem and provide stable anodes for the future LIBs. The cost and environmental impact of the anode material can be reduced by using agricultural residues. Barley husk is rich in phytoliths that are amorphous nanostructures of porous silica. In the present study, PSi was prepared from barley husk ash containing nanostructured SiO2 and reduced to silicon through magnesiothermic reduction so that the nanostructure formed by the nature remains. To enhance the electrical conductivity of the PSi anode, carbon nanotubes (CNTs) were conjugated to the thermally carbonized surface of PSi particles. Due to the conjugated CNTs the rate performance of the silicon anode was essentially improved.

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Poster: Operando observations of the early stages of Electrode/Electrolyte…

Author: Nataliia Mozhzhukhina
Title: Operando observations of the early stages of Electrode/Electrolyte Interphase formation in Li-ion battery model systems
Affiliation: Uppsala University

Abstract

The Electrode/Electrolyte Interphase is the vital component for successful Li-ion battery operation. Yet after several decades of research, fundamental understanding of the nature and formation mechanism of the Solid Electrolyte Interphase (SEI) remain incomplete. While the anode/electrolyte interphase has been studied intensively over the years, the cathode/electrolyte interphase has received much less attention. Although ex situ measurements were traditionally used to study the Interphase formation, the use of real time operando techniques is today mandatory in order to provide a new insight into these complex processes. We have employed Operando Surface Enhanced Raman Spectroscopy to reveal the processes occurring in the Electrical Double Layer on the gold based model systems relevant to the Li-ion batteries. Preliminary results of both anodic and cathodic electrolyte decomposition processes will be presented in the poster.

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Poster: Synthesis and performance of Nb-doped Li2ZnTi3O8 as anode…

Author: Naila Firdous
Title: Synthesis and performance of Nb-doped Li2ZnTi3O8 as anode material for lithium ion batteries
Affiliation: DTU Energy, Technical University of Denmark

Abstract

Li2ZnTi3O8 (LZTO) is recently considered as a promising anode material for lithium ion batteries (LIBs) due to its low cost and cycling stability. LZTO has lithiation voltage plateau at about 0.5 V vs Li/Li+ which avoids the formation of lithium dendrites. Its practical applications are limited due to its low conductivity and poor lithium ion diffusion coefficient. In order, to overcome its drawbacks many studies are undertaken such as doping with ions (Ni+2, Cu+2, Al+3, V+5), coating with conductive phases, altering morphology, and so on. In this study to overcome the drawbacks we had doped LZTO with appropriate amount of Nb+5 by simple solid-state synthesis. In particular, among the doped Li2-X NbxZnTi3O8 (x=0, 0.05, 0.1) materials, Li1.95 Nb0.05ZnTi3O8 showed narrow particle size distribution, uniform morphology, lower charge transfer resistance, highest discharge capacity, and good reversibility, making it more attractive as a potential anode electrode for commercialization.

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Poster: The Effect of Transition Metal Counter Ion on…

Author: Muhammad Abdelhamid
Title: The Effect of Transition Metal Counter Ion on the Super Lithiation of Benzenedipropiolate Anode Material
Affiliation: Uppsala University

Abstract

Nowadays, most of energy storage solutions for mobile applications are based on Li-ion technology since its commercialisation in the early 1990s. This is due to its unsurpassed gravimetric and volumetric energy density. However, the production of Li-ion batteries (LiBs) requires large amount of non-renewable resources (e.g. inorganic ores and petroleum based materials), energy, and toxic chemicals, which raise concerns about their environmental impact and resource depletion effect. As a result, research on organic battery electrode materials for organic Li-ion batteries (OLiBs) has grown with significant results.  Iron(II) benzenedipropiolate is presented and investigated as a potential negative electrode material for OLiBs. This material undergoes a reversible reduction and oxidation, first, through the iron(II) ion to iron metal, and its carbonyls. Furthermore, its unsaturated carbon–carbon bonds can be reversibly reduced and oxidized leading to a 1:1 Li:C ratio.

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