Cui, Yanyan (2023)
Synthesis and Processing of High Entropy Materials and their Integration into Lithium Batteries.
Technische Universität Darmstadt
doi: 10.26083/tuprints-00024209
Ph.D. Thesis, Primary publication, Publisher's Version
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Item Type: | Ph.D. Thesis | ||||
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Type of entry: | Primary publication | ||||
Title: | Synthesis and Processing of High Entropy Materials and their Integration into Lithium Batteries | ||||
Language: | English | ||||
Referees: | Hahn, Prof. Dr. Horst ; Xu, Prof. Dr. Bai-Xiang | ||||
Date: | 14 July 2023 | ||||
Place of Publication: | Darmstadt | ||||
Collation: | 114 Seiten | ||||
Date of oral examination: | 2 December 2022 | ||||
DOI: | 10.26083/tuprints-00024209 | ||||
Abstract: | With the increasing demand for renewable energy sources such as solar, geothermal, and wind energy, the development of efficient energy storage devices is necessary. Lithium-ion batteries (LIBs) have been considered a potentially revolutionary technology for storing renewable energy due to their advantages of low self-discharge, long life span, high output voltage, and high energy density. Over the past few decades, LIBs have undergone extensive development in both industry and academia. In current LIB technology, the cell voltage and capacity are primarily determined by the electrode materials, which also dominate the battery cost. Therefore, exploring alternative electrode materials and investigating their structure-composition-performance relationships is essential for further development. Recently, the use of the high entropy concept to develop materials is gaining significant interest. The high entropy concept is derived from high entropy alloys (HEAs), which possess high configurational entropy (Sconfig) by incorporating 5 or more elements into a single-phase structure, leading to the so-called “cocktail effect”, where the multiple synergies among the constituent elements may result in additional or changed properties. That means HEMs can have the potential to outperform the parent material system. Inspired by the high entropy concept, high entropy oxides (HEOs) were investigated as a new class of conversion electrode materials for LIBs, which show unexpected reversibility due to their unique structural stability. These unexpected findings have stimulated many recent studies on the performance of high entropy materials in electrochemical energy storage devices. In this work, a new photonic curing method was used to synthesize high entropy oxides for more rapid and efficient synthesis. The material was used as a binder-free electrode material for LIBs. Since HEO has a high mixed lithium-ion and electronic conductivity at room temperature, HEO was also synthesized by the photonic curing method for coating on NCM851005. In addition, the mechanism as a coating material for performance improvement was investigated. Inspired by the application of HEO as a conversion electrode material as an anode, high-entropy fluorides (HEFs), as conversion materials, were synthesized and used as cathode materials for LIBs and their underlying storage mechanisms were investigated. Due to the elemental dissolution of metal fluorides during cycling, high entropy oxides have also been studied as a coating for HEFs. The application and research of high entropy materials in electrode materials provide new guidelines for designing and manufacturing new electrode materials for LIBs. |
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Status: | Publisher's Version | ||||
URN: | urn:nbn:de:tuda-tuprints-242091 | ||||
Classification DDC: | 500 Science and mathematics > 540 Chemistry | ||||
Divisions: | 11 Department of Materials and Earth Sciences > Material Science | ||||
Date Deposited: | 14 Jul 2023 11:06 | ||||
Last Modified: | 29 Sep 2023 14:18 | ||||
URI: | https://tuprints.ulb.tu-darmstadt.de/id/eprint/24209 | ||||
PPN: | 510552560 | ||||
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