ELECTRONIC STRUCTURE AND THERMODYNAMIC PROPERTIES OF LI-IONINSERTION IN SULFONAMIDES COMPOUNDS AS ORGANIC HIGH-ENERGY DENSITY CATHODES

The world’s ever-growing energy demand has evoked great interest in exploring renewable energy sources along with sustainable energy storage systems. While inorganic physics of rocking chair mechanism used in Li-ion battery have proven to provide high energy density and high performance, there are problems yet to be overcome in terms of sustainability and recyclability. This is why research in organic batteries has been on the rise, yet the diversity of organic battery frameworks remains limited and requires overcoming multiple obstacles that restrain the performance of an all-organic battery system. A recent advance in the design of organic electrode material by Wang et al. has shown the possibility of a new stable and tunable class of conjugated sulfonamides (CSA) with an experimental voltage range between 2.85V and 3.45V [5]. A theoretical approach to study these organic materials is taken in this thesis research where the effects of such compounds on the redox potential, physics of ion insertion, and other thermodynamical properties are examined. Density Functional Theory (DFT) is employed in this investigation along with an evolutionary algorithm to generate information about the crystal structure of mentioned systems, their density of states (DOS), and charge distribution in pristine form and after lithiation. Quinone systems with oxygen groups were investigated in a previous research project that complements this thesis which looks into a quinone system with sulfonamide compounds where a comparison between the two could offer more understanding of the electrochemistry of such systems for their application in batteries as high performing organic cathode materials on a par with other inorganic materials

Effect of Electronic Exchange-Correlation Interaction in the Physics of Ion Insertion in Organic Salts

The intense increase in energy consumption around the world has prompted a great deal of research on alternative and sustainable energy storage systems such as organic batteries. The fundamental understanding of the physics of organic salts and the ion insertion mechanism plays a key role in the development of electrode materials used in such sustainable batteries. The system studied in this project is of Lithium (2,5-dilithium-oxy)-terephthalate where a previous project studied this system from a different angle.  The electronic structure generation of the system is based on Density Functional Theory (DFT) along with an evolutionary algorithm to find the structures with minimum energy. The effects of varying the description of the exchange-correlation interaction were studied while introducing lithium ions to the system. This was done while also monitoring the repercussions of crystal structure optimization on the voltages, charge redistribution, and bonds of the system. The geometrical optimization of the hybrid functional resulted in the potential of the 2-electron step between Li2-p-DHT/ Li4-p-DHT of 2.6 V being closer to the experimental value recorded at 2.7 V

The Thermodynamic Interaction of Light with Matter

Light is electromagnetic radiation that could be shown in a spectrum with a wide range of wavelengths. Blackbody radiation is a type of thermal radiation and is an important topic to explore due to it being an ideal body that materials’ properties are often described in comparison to it. Therefore, it helps in understanding how materials behave on the quantum level. One must understand its interaction with light spectrum and how electron excitation happens. Thus, concepts such as Planck’s law, energy quantization and band theory will be discussed to try to grasp of how light interacts with materials

The Thermodynamic Interaction of Light with Matter

Light is electromagnetic radiation that could be shown in a spectrum with a wide range of wavelengths. Blackbody radiation is a type of thermal radiation and is an important topic to explore due to it being an ideal body that materials’ properties are often described in comparison to it. Therefore, it helps in understanding how materials behave on the quantum level. One must understand its interaction with light spectrum and how electron excitation happens. Thus, concepts such as Planck’s law, energy quantization and band theory will be discussed to try to grasp of how light interacts with materials

Exploring Metastable Phases During Lithiation of Organic Battery Electrode Materials

In this work, the Li-ion insertion mechanism in organic electrode materials is investigated through the lens of atomic-scale models based on first-principles theory. Starting with a structural analysis, the interplay of density functional theory with evolutionary and potential-mapping algorithms is used to resolve the crystal structure of the different (de)lithiated phases. These methods elucidate different lithiation reaction pathways and help to explore the formation of metastable phases and predict one- or multi-electron reactions, which are still poorly understood for organic intercalation electrodes. The cathode material dilithium 2,5-oxyterephthalate (operating at 2.6 V vs. Li/Li+) is investigated in depth as a case study, owing to its rich redox chemistry. When compared with recent experimental results, it is demonstrated that metastable phases with peculiar ring-ring molecular interactions are more likely to be controlling the redox reactions thermodynamics and consequently the battery voltage

Exploring Metastable Phases During Lithiation of Organic Battery Electrode Materials

In this work, the Li-ion insertion mechanism in organic electrode materials is investigated through the lens of atomic-scale models based on first-principles theory. Starting with a structural analysis, the interplay of density functional theory with evolutionary and potential-mapping algorithms is used to resolve the crystal structure of the different (de)lithiated phases. These methods elucidate different lithiation reaction pathways and help to explore the formation of metastable phases and predict one- or multi-electron reactions, which are still poorly understood for organic intercalation electrodes. The cathode material dilithium 2,5-oxyterephthalate (operating at 2.6 V vs. Li/Li+) is investigated in depth as a case study, owing to its rich redox chemistry. When compared with recent experimental results, it is demonstrated that metastable phases with peculiar ring-ring molecular interactions are more likely to be controlling the redox reactions thermodynamics and consequently the battery voltage

2023 Roadmap on molecular modelling of electrochemical energy materials

New materials for electrochemical energy storage and conversion are the key to the electrification and sustainable development of our modern societies. Molecular modelling based on the principles of quantum mechanics and statistical mechanics as well as empowered by machine learning techniques can help us to understand, control and design electrochemical energy materials at atomistic precision. Therefore, this roadmap, which is a collection of authoritative opinions, serves as a gateway for both the experts and the beginners to have a quick overview of the current status and corresponding challenges in molecular modelling of electrochemical energy materials for batteries, supercapacitors, CO2 reduction reaction, and fuel cell applications