Poster: Atomic-scale Modelling of Organic Electrode Materials

Author: C. Moyses Araujo
Title: Atomic-scale Modelling of Organic Electrode Materials
Affiliation: Uppsala University 

Abstract

The organic electrode materials (OEM) are emerging as a promising alternative to develop greener and sustainable battery technologies. However, the poor cycling stability and low energy densities hinders their fast implementation. To overcome these hurdles, it is essential to achieve a fundamental understanding at atomic-scale of the lithiation/delithiation processes. To contribute to this end, we are developing methodologies based on evolutionary algorithms (EA) and deep neural networks (DNN) at interplay with density functional theory (DFT). They EA has been employed to predict the structure and electrochemistry of a set of dicarboxylates while the DNN has been employed in a novel machine learning approach to obtain the redox potentials. A number of learning algorithms have been investigated along with different molecular representations based (e.g. the many-body tensor representation). This study provides a framework that can aid the designing of novel organic electrode materials.

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Poster: Electronic structure of amorphous poly(ethylene oxide)

Author: Mikael Unge
Title: Electronic structure of amorphous poly(ethylene oxide)
Affiliation: ABB

Abstract

Poly(ethylene oxide) (PEO) has been extensively studied with focus on usage as polymer electrolyte in solid state battery applications. Primarily Li ion conduction in PEO has been studied in the literature, but as the polymer electrolyte become thinner, to facilitate ion conduction, electronic leakage currents may be of increasing importance. Here we focus on electronic structure properties which will be of relevance for understanding electronic leakage currents in PEO. PEO is a semi crystalline material and here we focus on the amorphous part. Amorphous structures are generated and relaxed using molecular dynamics and electronic structure is calculated using linear-scaling DFT. First results indicate that the conduction states are inter chain states and occupies free volume pockets. Mobility edges are calculated for holes and electrons at 0 K and estimated to be 0.5 eV and 0.8 eV away from the band edges, respectively. At room temperature and 80 degC, these shift to 0.1 eV and 0.3 eV, respectively.

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Poster: Structural Studies of TiO2 Polymorphs as Electrode Materials…

Presenter: Martin Aaskov Karlsen
Title: Structural Studies of TiO2 Polymorphs as Electrode Materials in Rechargeable Batteries
Affiliation: University of Southern Denmark

Abstract

Titania has a comprehensive and diverse family of polymorphs, where differences in the connectivity of the TiO2 polyhedra give rise to channel structures with diverse channel dimensions, which is attractive for applications in intercalation-type batteries, e.g., the Li-ion battery technology. Members of the family of titania polymorphs are here studied to see how structure affects electrochemical properties.

Traditionally, electrode materials for intercalation-type batteries have been crystalline. However, nanosized or disordered materials show interesting electrochemical properties as well. To probe a more local structure and limited range of order, total scattering and pair distribution function (PDF) analysis is a powerful tool.

Therefore, PDF analysis is utilized in this study to explore some of the manifold titania polymorphs. X-ray total scattering and PDF analysis is used both for ex-situ studies of pristine TiO2 materials as well as for operando studies.

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Poster: Comparison of single crystal and polycrystalline lithiation for…

Author: Marianna Hietaniemi
Title: Comparison of single crystal and polycrystalline lithiation for NCM622 cathode materials
Affiliation: University of Oulu

Abstract

Single crystal cathode active materials are commercially available, and several reports indicate them having better cycle life and better high voltage cyclability.  Very few publications, however, compare single crystal material with traditional polycrystalline materials prepared from the same NCM precursor.
First, electrochemical performance under different conditions is compared to see the difference between normal lithiation and single crystal lithiation. Coin cells are assembled and tested at room temperature, at elevated temperature and with high voltage cycling. They were also tested before and after washing and milling treatment. Secondly, the effect of lithiation on different precursors and their suitability for single crystal lithiation was investigated. Several NCM622 precursors were precipitated and their performance after different lithiation conditions was compared. Materials varied in particle size, particle size distribution, tap density and purity.

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Poster: Effect of carbon coating on the electrochemical performance…

Author: Maria Valeria Blanco
Title: Effect of carbon coating on the electrochemical performance of SiO2/C Anodes for Li-Ion Batteries
Affiliation: Norwegian University of Science and Technology

Abstract

We analyzed the effect of carbon coating on the electrochemical performance of SiO2/C composites to be used as anode materials of Li-ion batteries. Composites were prepared by mixing silica nanoparticles with different amounts of glucose, sucrose and cornstarch and subjecting the resulting powders to high temperature annealing treatments at 850 °C, 1050 °C and 1200 °C. Structural, microstructural and textural differences on the composites were related to differences on the electrochemical performance of the electredes. A systematic effect of the different carbon precursors and heat treatments on the specific capacity displayed by the electrodes was observed and it allowed to identify the most suitable carbon precursor and its percentage on the composite to achieve the best electrochemical performance.

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Poster: Creating Automotive Renewal Project

Presenter: Lukasz Hupka
Title: Creating Automotive Renewal Project
Affiliation: Gdansk University of Technology

Abstract

Creating Automotive Renewal (CAR) project has the goal of promoting the large-scale implementation of electric mobility in the countries around the South Baltic. There are ten partners with complementary competencies and resources from Sweden, Denmark, Germany, and Poland.
Project activities aim to fulfil two overall goals:

1. Implementing six pilot investments, each one of those driven by one partner.
2. Building a network of companies, public organizations, universities, research institutes, and clusters that want to contribute to the increase in systems for electric mobility.

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Poster: Magnesium borohydride composites as an electrolyte for all-solid-state…

Presenter: Lasse Skov
Title: Magnesium borohydride composites as an electrolyte for all-solid-state magnesium batteries
Affiliation: Aarhus University

Abstract

Solid-state electrolytes can increase the stability and safety of batteries, compared to organic solvents in existing high voltage batteries. High ionic conductivity at room temperature has been a challenge for magnesium-ion electrolytes.
Mg(BH4)2 ∙ 1.6NH3 – MgO has been synthesised by our group with high ionic conductivity of 2.2e–6 < Mg-ion < 3.6e–3 S cm–1 in the temperature range of 20 to 90 degree C. This study includes a structural analysis and a theoretical explanation, based on DFT calculations, for the cation conductivity promotion observed, and a reversible electrochemical magnesium stripping/plating.

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Poster: Phosphites as precursors in thin film synthesis. Using…

Author: Kristian B. Kvamme
Title: Phosphites as precursors in thin film synthesis. Using LiPO as cathode coating in Li-ion batteries
Affiliation: University of Oslo

Abstract

Phosphate based materials show great promise as electrolytes in solid state batteries. The ideal solid state electrolyte should be thin and uniform. For these reasons Atomic layer deposition (ALD) has been suggested as a good synthesis route for solid state electrolytes. In this work a new route for synthesising phosphorous based material using ALD is demonstrated. Phosphite precursors have been used for the synthesis of LiPO and AlPO materials. This is done by replacing phosphate precursors with phosphite precursors in established ALD synthesis routes. Furthermore the LiPO product has been deposited as a coating layer onto LiFePO4 cathodes to improve kinetics and low current density cycling performance. We have shown that there is indeed an improvement at coating thicknesses of 1 nm or less. The materials themselves have been characterised using XPS and XRF for composition analysis, and cyclic voltammetry and galvanostatic cycling for electrochemical analysis.

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Poster: Post mortem analysis of stoichiometric, over-lithiated and doped…

Presenter: Katja Lahtinen
Title: Post mortem analysis of stoichiometric, over-lithiated and doped LiCoO2 electrode materials for Li-ion batteries
Affiliation: Aalto University

Abstract

Lithium cobalt oxide (LiCoO2, LCO) is one of the most used materials in Li-ion batteries for portable applications. However, the consumption of Li-ion batteries is quickly increasing and as a result, the availability of the raw materials and the amount of waste batteries is increasing rapidly. Therefore, recycling of the used battery materials is an important factor to investigate. In this work, stoichiometric, over-lithiated and Mg-Ti doped LCOs prepared using the same precursors and synthesis method are aged in LCO/graphite pouch cells, and their aging behaviour is investigated and compared. The cells are then opened, the electrodes are collected, and assembled to half-cells. The LCOs are relithiated and their reuse is investigated. The results indicate that the capacity loss is caused by structural changes and loss of lithium. The Mg-Ti doped LCO withstands the changes the best because of a stabilized structure and an enhanced conductivity. Therefore it shows promising reusability.

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Poster: LiFSI as electrolyte salt for silicon anodes and…

Author: Karina Asheim
Title: LiFSI as electrolyte salt for silicon anodes and NMC cathodes
Affiliation: Norwegian University of Science and Technology

Abstract

Silicon is a promising high capacity anode material for Li-ion batteries. The challenge is electrode degradation and continuous solid-electrolyte interphase (SEI) growth due to volume expansion during lithiation. A stable and strong SEI is then crucial for the performance. The commercially used LiPF6 salt is susceptible to hydrolysis, forming HF which etches the SiO2 layer. An alternative salt, lithium bis(fluorosulfonyl)imide (LiFSI), has been found to improve performance of Si electrodes compared to when using LiPF6. In this work, LiFSI is evaluated as electrolyte salt for Si anode and NMC cathode in half-cell configuration. Through post mortem characterization, involving cross sectional analysis, using FIB in combination with SEM, TEM to evaluate crystallinity of particles and acquire element maps of the SEI, and XPS of the electrode surface to determine which oxidation state of elements are present, the improved performance of Si when using LiFSI is attempted explained.

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