61 |
Study and improve the electrochemical behaviour of new negative electrodes for li-ion batteries / Etude et amélioration des propriétés électrochimiques des nouvelles électrodes négatives pour les batteries li-ionTesfaye, Alexander Teklit 14 November 2017 (has links)
Les accumulateurs commerciaux à base de lithium-ion (LIB) utilisent des matériaux à base de carbone (graphite) comme électrode négative; cependant, la technologie atteint sa limite en raison de la faible capacité spécifique théorique. L'objectif de cette thèse est d'étudier le comportement électrochimique de trois nouvelles anodes à haute capacité (SnSb microsturé, Ti3SiC2 anodisé et nanotubes de Si poreux) comme alternatives au graphite, d'identifier les principaux paramètres responsables de la perte de capacité et de proposer une solution commune pour améliorer leurs performances électrochimiques. Ces matériaux d'électrode présentent une bonne performance électrochimique qui les rend prometteurs pour remplacer le carbone en tant qu'électrode négative pour batteries au Li-ion. Cependant, ils présentent une perte de capacité initiale importante qui doit être résolue avant la commercialisation. Les limitations observées sont attribuées à de nombreux facteurs, et en particulier à la formation et la croissance d’une SEI à la surface des matériaux. En raison de la forte perte de la capacité et du manque d’études détaillées sur les matériaux à base d’étain, en particulier le SnSb, nous avons concentré la suite du travail à la formation et la croissance de la SEI sur cette électrode négative. L'évolution des propriétés électriques, de la composition chimique et de la morphologie du SnSb microstructuré a été étudiée en détail pour comprendre son comportement électrochimique. Pour limiter l’effet de la SEI, nous avons proposé d’appliquer un film protecteur à la surface de l'électrode. / Currently, commercial lithium ion batteries (LIBs) use carbon based materials as negative electrode; however the technology is reaching its limit because of the low theoretical specific capacity. The objective of this thesis is to study the electrochemical behaviour of three different new high capacity anodes (SnSb alloy, anodized Ti3SiC2, and Si nanotubes) as alternative to graphite, identify the main parameters responsible for the capacity fading, and propose a versatile solution to improve their electrochemical performance. These electrode materials exhibit good electrochemical performance which makes them promising candidates to replace carbon as a negative electrode for LIBs. However, their limitation due to capacity fading and the large initial irreversible capacity loss must be resolved before commercialization. The observed limitations are attributed to many factors, and particularly, to the formation and growth of SEI layer which is the common factor for all the three electrode materials. Because of the strong capacity fade and lack of many detailed studies on the Sn-based materials, specifically SnSb, we focus our study to investigate the formation and growth of SEI layer on SnSb electrode. The evolution of the electrical, compositional, and morphological properties have been investigated in detail to understand the electrochemical behavior of micron-sized SnSb. To limit the capacity fade, we propose the use of a protective film on the electrode surface. The electrochemical performance of micron-sized SnSb electrode coated with thermoplastic elastomer protective film, namely poly(styrene-b-2-hydroxyethyl acrylate) PS-b-PHEA has been achieved.
|
62 |
Study of highly conductive, flexible polymer electrolyte membranes and their novel flexoelectric effectRendon Piedrahita, Camilo January 2018 (has links)
No description available.
|
63 |
Strategies for enhancing the circularity of Lithium-ion Batteries.Malik, Tanveer Ahmad January 2023 (has links)
Li-ion batteries have gained great popularity among researchers and practitioners as an environmentally friendly energy storage solution for more environmentally friendly electric vehicles (EVs). However, because of the increased demand for Li-ion battery-powered EVs, and some issues with battery design, legislation, collection and sorting, recycling, and material recovery, achieving sustainable mobility through the circularity of Li-ion batteries is a major challenge. This study aims to identify the challenges as well as develop strategies for enhancing the circularity of Li-ion batteries in Sweden. Following a systematic literature review, two primary research questions were investigated: 1) what are the current challenges and opportunities for the circular economy in lithium-ion battery end-of-life management? 2) how the circularity of LIBs in Sweden could be enhanced? This study employed PEST and SWOT analysis, as well as 11 interviews with industry experts and researchers are performed, to determine the strengths, weaknesses, opportunities, and threats in the circularity of lithium-ion batteries in Sweden. Following that, various strategies were developed to address the identified challenges and improve the circular economy of these batteries. Finally, the developed strategies are validated through expert interviews, and various recommendations are outlined. The study's findings are significant and can assist policymakers, investors, and industry professionals concerned with the circularity of lithium-ion batteries in developing appropriate decisions and better planning for the Swedish transportation sector.
|
64 |
Parameter Identification Methodology for Thermal Modeling of Li-ion BatteriesKhanna, Yatin 06 September 2022 (has links)
No description available.
|
65 |
Operando detection of Li-plating by online gas analysis and acoustic emission monitoringEspinoza Ramos, Inti January 2023 (has links)
Lithium ion batteries (LIBs) are widely used for storing and converting chemical energy into electrical energy. During battery operation, lithium ions move between electrode materials, enabling energy storage. However, aging mechanisms like lithium plating can negatively impact battery performance and lifetime. Lithium plating occurs when lithium ions are reduced to metallic lithium on the graphite electrode. The undesired Li plating in LIBs leads to dendrite formation that may puncture the separator, causing internal short-circuit and ultimately thermal runaway. This study aims to investigate the internal processes of LIBs during charge and discharge. Two analysis methods are employed: online electrochemical mass spectrometry (OEMS) and acoustic emission monitoring (AEM). OEMS is a gas analysis technique that combines electrochemical measurements with mass spectrometry to provide real-time testing of cells. OEMS allows identifying and quantifying gas evolution/consumption of chemical species. AE is a diagnostic tool, offering monitoring the health of LIBs through detection and characterisation of stress waves produced by parasitic mechano-electrochemical events. The results indicates that the formation of SEI thin film layer, generated gases like hydrogen and ethylene, while consuming carbon dioxide. During induced lithium plating, hydrogen and carbon dioxide were consumed, and ethylene gas was produced, due to new SEI film formation process. The acoustic emission analysis indicated that lithium plating was an active process, whereas SEI formation was less AE active. Further research is needed to understand the relationships and significance of these processes for battery performance and safety. Overall, this study highlighted the importance of investigating aging mechanisms in LIBs to enhance their performance and longevity. By combining OEMS and AE, it was possible to analyse the batteries behaviour during cycling. The evolution of gas and acoustic signals provided insights into the reactions and processes occurring inside the battery during cycling.
|
66 |
Highly Ion Conductive Polymer Electrolyte Networks For Energy Storage ApplicationsNarute, Suresh Tanaji 24 July 2022 (has links)
No description available.
|
67 |
Investigating the Effects of Mechanical Damage on the Electrical Response of Li-ion Pouch CellsStacy, Andrew January 2019 (has links)
Li-ion batteries (LIB) are used in many applications because of their high-power/energy density, long life cycling, and low self-discharge rate. The use of LIB continues to grow every day, and the necessity for proper safety standards grows as well. A key aspect for safe utilization of LIB is determining their safety and remaining useful life (RUL). Battery characteristics degrade over time under normal and extreme operating conditions and modeling the electrochemical processes can improve RUL estimations. Extreme operating conditions such as abnormal temperatures and charge/discharge rates are believed to exacerbate the rate of degradation. Li-ion batteries are also susceptible to mechanical damage, which may lead to an electrical short. In severe cases, mechanical damage causes a thermal run away, and possibly explosions or fires. In the event of a car accident, battery packs can be damage without an electrical short or immediate thermal run away. Currently, there is no reliable batt / Mechanical Engineering
|
68 |
Studies on Electrochemical Properties of Positive Electrodes for Use in Aqueous Li-ion and Ca-ion Batteries / 水系リチウムイオンおよびカルシウムイオン電池用正極の電気化学特性に関する研究LEE, CHANGHEE 24 September 2021 (has links)
京都大学 / 新制・課程博士 / 博士(工学) / 甲第23515号 / 工博第4927号 / 新制||工||1769(附属図書館) / 京都大学大学院工学研究科物質エネルギー化学専攻 / (主査)教授 安部 武志, 教授 陰山 洋, 教授 作花 哲夫 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
|
69 |
Combined Experimental and Numerical Study of Active Thermal Control of Battery ModulesHe, Fan 16 April 2015 (has links)
Lithium ion (Li-ion) batteries have been identified as a promising solution to meet the increasing demands for alternative energy in electric vehicles (EVs) and hybrid electric vehicle (HEVs). This work describes experimental and numerical study of thermal management of battery module consisting of cylindrical Li-ion cells, with an emphasis on the use of active control to achieve optimal cooling performance with minimal parasitic power consumption. The major contribution from this work is the first experimental demonstration (based on our review of archival journal and conference literature) and the corresponding analysis of active thermal control of battery modules. The results suggest that the active control strategy, when combined with reciprocating cooling flow, can reduce the parasitic energy consumption and cooling flow amount substantially. Compared with results using passive control with unidirectional cooling flow, the parasitic energy consumption was reduced by about 80%. This contribution was achieved in three steps, which was detailed in this dissertation in chapters 2, 3, and 4, respectively. In the first step, an experimental facility and a corresponding CFD model were developed to capture the thermal behavior of multiple battery cells. Based on the experimental and CFD results, a reduced-order model (ROM) was then developed for active monitoring and control purposes. In the second step, the ROM was parameterized and an observer-based control strategy was developed to control the core temperature of battery cells. Finally, based on the experimental facility and the ROM model, the active control of a battery module was demonstrated. Each of these steps represents an important facet of the thermal management problem, and it is expected that the results and specifics documented in this dissertation lay the groundwork to facilitate further study. / Ph. D.
|
70 |
IMPROVING THE CAPACITY, DURABILITY AND STABILITY OF LITHIUM-ION BATTERIES BY INTERPHASE ENGINEERINGZhang, Qinglin 01 January 2016 (has links)
This dissertation is focus on the study of solid-electrolyte interphases (SEIs) on advanced lithium ion battery (LIB) anodes. The purposes of this dissertation are to a) develop a methodology to study the properties of SEIs; and b) provide guidelines for designing engineered SEIs. The general knowledge gained through this research will be beneficial for the entire battery research community.
|
Page generated in 0.0941 seconds