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<h4>A generalized physics-based modeling framework is presented to analyze: (a) the effects of temperature on identified degradation mechanisms, (b) interfacial debonding processes, including deterministic and stochastic mechanisms, and (c) establishing model performance benchmarks of electrochemical porous electrode theory models, as a necessary stepping stone to perform valid battery degradation analyses and designs. Specifically, the effects of temperature were incorporated into a physics-based, reduced-order model and extended for a LiCoO₂ -graphite 18650 cell. Three dimensionless driving forces were identified, controlling the temperature-dependent reversible charge capacity. The identified temperature-dependent irreversible mechanisms include homogeneous SEI, at moderate to high temperatures, and the chemomechanical degradation of the cathode at low temperatures. Also, debonding of a statistically representative electrochemically active particle from the surrounding binder-electrolyte matrix in a porous electrode was modeled analytically, for the first time. The proposed framework enables to determine the space of C-Rates and electrode particle radii that suppresses or enhances debonding and is graphically summarized into performance–microstructure maps where four debonding mechanisms were identified, and condensed into power-law relations with respect to the particle radius. Finally, in order to incorporate existing or emerging degradation models into porous electrode theory (PET) implementations, a set of benchmarks were proposed to establish a common basis to assess their physical reaches, limitations, and accuracy. Three open source models: dualfoil, MPET, and LIONSIMBA were compared, exhibiting significant qualitative differences, despite showing the same macroscopic voltage response, leading the user to different conclusions regarding the battery performance and possible degradation mechanisms of the analyzed system.</h4>

The rate of degradation of a lithium-ion battery depends on its use i.e. how it is charged and discharged. Physics-based models are used to represent the processes inside a cell as well as the degradation mechanisms. This thesis aimed to compare how the battery lifetime is affected when charging with different charging protocols using different battery models and degradation mechanisms. The investigated models are the Single Particle Model (SPM), the Single Particle Model with electrolyte (SPMe), and the Doyle-Fuller Newman model (DFN). The degradation mechanisms are solid electrolyte interphase (SEI), and lithium plating (LP). The used charging protocols are constant-current constant voltage(CCCV), positive pulsed current (PPC), and constant current (CC). Pulsed charging was included to investigate if the battery lifetime can be improved as in an experiment by Huang where pulsed charging increased the battery lifetime by 60%. To perform the simulations using the physics-based models, PyBaMM (PythonBattery Mathematical Modeling) was used. The simulations were performed for a lithium cobalt oxide (LCO) cell. Two types of SEI were implemented, solvent-diffusion limited and reaction limited. For the LP only irreversible LP was used.1200 cycles were simulated. Comparing the PPC and CC protocols, there were no significant changes between the degradation mechanisms for the different protocols. The results were the same for all the models, except for the results of the internal resistance. The conclusion is that for the PPC and CC protocols, the cell degrades the same although the PPC protocol used twice the C-rate. The PPC charging did not increase the battery lifetime. For the CCCV and CC protocols, there were some bigger differences between the protocols, but between the different models, there weren’t any significant differences. The CCCV degrades the cell faster for all degradation mechanisms and all models. Simulating one degradation submodel at a time resulted in a very small capacity fade for some submodels. Therefore, for future work, it is suggested to use several degradation submodels at the same time but also to try other degradation mechanisms or try PPC protocols with different frequencies and duty cycles. / Hur snabbt litiumjonbatterier degraderas beror på hur de används, laddas och laddas ur. Fysikbaserde modeller används för att representera processerna inuti cellen och även degraderingsmekanismerna. Denna studie har genomförts för att undersöka hur batteriets livslängd påverkas av olika laddningsprotokoll genom att använda olika batterimodeller och degraderingsmekanismer. Modellerna som användes är Singel-partikelmodellen (SPM), Singel-partikelmodellen med elektrolyt (SPMe) och Doyle-Fuller Newman-modellen (DFN). Degraderingsmekanismerna är fast elektrolytinterfas (SEI) och litiumplätering (LP). Laddningsprotokollen som användes är konstant ström konstant spänning (CCCV), positiv pulserande ström (PPC) och konstant ström konstant (CC). Protokollet för pulsad laddning inkluderades för att undersöka om batteriets livslängd kan förbättras som i ett experiment av Huang, där pulsad laddning ökade batteriets livslängdmed 60%. För att utföra simuleringar med fysikbaserade modeller användes PyBaMM(Pyhton Battery Mathematical Modeling). Simuleringarna utfördes för en lithiumkobaltoxid-cell (LCO). Två typer av SEI implementerades, lösningsmedelsdiffusion-begränsad och reaktions-begränsad SEI. För LP användes endast irreversibel LP.1200 cykler simulerades. Jämförande PPC- och CC-protokollen fanns det inga signifikanta förändringar mellan degraderingsmekanismerna för de olika protokollen. Resultaten vardesamma för alla modellerna, förutom resultaten av den interna resistansen. Slutsatsen är att för både PPC- och CC-protokollen så degraderades cellen på samma sätt, trots att PPC-protokollet använde dubbelt så hög C-faktor. PPC-protokollet ökade inte batteriets livslängd. För CCCV- och CC-protokollen fanns det några större skillnader mellan protokollen, men mellan de olika modellerna fanns det inga signifikanta skillnader. CCCV-protokollet försämrade cellen snabbare för alla degraderingsmekanismer och alla modeller. Att simulera en degraderingsmodell i taget resulterade i mycket små kapacitetsförluster. Därmed föreslås det att i framtida arbete använda flera degraderingsmodeller samtidigt men även testa andra degraderingsmekanismer eller PPC-protokoll med olika frekvenser och arbetscykler

The increasing adoption of electric vehicles (EVs) brings forth the challenge of effectively managing the second-life and end-of-life cycles for lithium-ion batteries. Augmented Reality (AR) offers a promising solution to sustainably and efficiently dismantle these batteries. This thesis explores the development and evaluation of an AR mobile app specifically designed for guiding the dismantling process of a Volkswagen (VW) ID.4 lithium-ion EV battery. Subsequently, a detailed end-to-end development pipeline is presented, spanning from identifying the correct dismantling steps and building complete 3D reconstructions of the ID.4 battery using photogrammetry and CAD or 3D modelling, to creating an AR mobile application in Unity with the help of Vuforia allowing users to visualize the disassembly steps through an interactive guide. Tracking recognition testing results for each model indicates that simpler models exhibit a higher chance of producing false positives, while composite models have a greater minimum recognition distance compared to the faithfulto-real-life one-piece counterparts. User testing is conducted using a hybrid approach, combining a Figma prototype with video recordings to replicate the app’s behavior in a safe environment, without the physical presence of a high voltage battery. Results show positive user feedback, demonstrating the app’s usability and effectiveness in guiding the dismantling process. Furthermore, the thesis evaluates the app’s performance through the System Usability Scale (SUS) and the Technology Acceptance Model. The obtained SUS score of 80 (Grade B - Good) indicates favorable usability, while the Technology Acceptance Model provides insights into potential users’ perceptions. / Den ökande användningen av elektriska fordon (EV) frambringar utmaningen att effektivt hantera andra livscykler och slutlivscykler för litiumjonbatterier. För att hållbart och effektivt demontera dessa batterier erbjuder Augmented Reality (AR) en lovande lösning. Denna uppsats utforskar utvecklingen och utvärderingen av en AR-mobilapplikation som specifikt är utformad för att guida demonteringsprocessen av ett Volkswagen (VW) ID.4 litiumjon EVbatteri. Därefter presenteras en detaljerad genomgående utvecklingsprocess, som sträcker sig från att identifiera korrekta demonteringssteg och skapa kompletta 3D-rekonstruktioner av ID.4-batteriet med hjälp av fotogrammetri och CAD eller 3D-modellering, till att skapa en AR-mobilapplikation i Unity med hjälp av Vuforia, som tillåter användare att visualisera demonteringsstegen genom en interaktiv guide. Resultaten bättre identifieringstester för varje modell indikerar att enklare modeller har större chans att producera falska positiva resultat, medan komplexa modeller har större minsta igenkänningsavstånd jämfört med helhetsmodeller som är trogna verkligheten. Användartester genomförs med hjälp av en hybridmetod som kombinerar en Figma-prototyp med videoinspelningar för att återskapa appens beteende i en säker miljö, utan att behöva ha ett högspänningsbatteri fysiskt närvarande. Resultaten visar positivt användarfeedback och bekräftar appens användarvänlighet och effektivitet vid guidning av demonteringsprocessen. Uppsatsen utvärderar också appens prestanda genom System Usability Scale (SUS) och Technology Acceptance Model. Den erhållna SUS-poängen på 80 (Betyg B - Bra) indikerar en god användbarhet, medan Technology Acceptance Model ger insikter om potentiella användares uppfattningar.

As an efficient energy storage technology, lithium-ion batteries play a key role in the ongoing electrification of the mobility sector. However, the required modelbased design process, including hardware in the loop solutions, demands precise battery models. In this work, an encoder-decoder model framework based on recurrent neural networks is developed and trained directly on unstructured battery data to replace time consuming characterisation tests and thus simplify the modelling process. A manifold pseudo-random bit stream dataset is used for model training and validation. A mean percentage error (MAPE) of 0.30% for the test dataset attests the proposed encoder-decoder model excellent generalisation capabilities. Instead of the recursive one-step prediction prevalent in the literature, the stage-wise trained encoder-decoder framework can instantaneously predict the battery voltage response for 2000 time steps and proves to be 120 times more time-efficient on the test dataset. Accuracy, generalisation capability and time efficiency of the developed battery model enable a potential online anomaly detection, power or range prediction. The fact that, apart from the initial voltage level, the battery model only relies on the current load as input and thus requires no estimated variables such as the state-of-charge (SOC) to predict the voltage response holds the potential of a battery ageing independent LIB modelling based on raw BMS signals. The intrinsically ageingindependent battery model is thus suitable to be used as a digital battery twin in virtual experiments to estimate the unknown battery SOH on purely BMS data basis.

The purpose of this diploma thesis is to describe the impact of compaction pressure on the electrochemical parameters of lithium-sulfur batteries. Theoretical part of this thesis contains briefly described terminology and general issues of batteries and their division. Every kind of battery is provided with a closer description of a specific battery type. A separate chapter is dedicated to lithium cells, mainly lithium-ion batteries. Considering various composition of lithium-ion batteries, this chapter deeply analyzes mostly used active materials of electrodes, used electrolytes and separators. Considering that the electrochemical principle of Li-S and Li-O batteries is different to Li-ion batteries, these accumulators of new generation are included in individual subhead. In the experimental part of this thesis are described methods used to measure electrochemical parameters of Li-S batteries. Next chapter contains description of preparing individual electrodes and their composition. Rest of the experimental part of my thesis is dedicated to the description of individual experiments and achieved results.

Indiana University-Purdue University Indianapolis (IUPUI) / There is a strong urge for advanced diagnosis method, especially in high power battery packs and high energy density cell design applications, such as electric vehicle (EV) and hybrid electric vehicle segment, due to safety concerns. Accurate and robust diagnosis methods are required in order to optimize battery charge utilization and improve EV range. Battery faults cause significant model parameter variation affecting battery internal states and output. This work is focused on developing diagnosis method to reliably detect various faults inside lithium-ion cell using electrochemical model based observer and fuzzy logic algorithm, which is implementable in real-time. The internal states and outputs from battery plant model were compared against those from the electrochemical model based observer to generate the residuals. These residuals and states were further used in a fuzzy logic based residual evaluation algorithm in order to detect the battery faults. Simulation results show that the proposed methodology is able to detect various fault types including overcharge, over-discharge and aged battery quickly and reliably, thus providing an effective and accurate way of diagnosing li-ion battery faults.

Lithium-ion batteries have transformed energy storage and technological applications. They stand poised to convert transportation from combustion to electric engines. The discharge/charge rate is a key parameter that determines battery power output and recharge time; typically, operation is on the timescale of hours but reducing this would improve existing applications and open up new possibilities. Conventionally, the rate at which a battery can operate has been improved by synthetic strategies to decrease the solid-state diffusion length of lithium ions by decreasing particle sizes down to the nanoscale. In this work, a different approach is taken toward next-generation high-power and fast charging lithium-ion battery electrode materials. The phenomenon of high-rate charge storage without nanostructuring is discovered in niobium oxide and the mechanism is explained in the context of the structure–property relationships of Nb2O5. Three polymorphs, T-Nb2O5, B-Nb2O5, and H-Nb2O5, take bronze-like, rutile-like, and crystallographic shear structures, respectively. The bronze and crystallographic shear compounds, with unique electrochemical properties, can be described as ordered, anion-deficient nonstoichiometric defect structures derived from ReO3. The lessons learned in niobia serve as a platform to identify other compounds with related structural motifs that apparently facilitate high-rate lithium insertion and extraction. This leads to the synthesis, characterisation, and electrochemical evaluation of the even more complicated composition–structure–property relationships in ternary TiO2–Nb2O5 and Nb2O5–WO3 phases. Advanced structural characterisation including multinuclear solid-state nuclear magnetic resonance spectroscopy, density functional theory, X-ray absorption spectroscopy, operando high-rate X-ray diffraction, and neutron diffraction is conducted throughout to understand the evolution of local and long-range atomic structure and changes in electronic states.

[ES] La presente Tesis Doctoral se centra en la síntesis, caracterización y optimización de nanoestructuras de óxido de wolframio (WO3) y nanoestructuras híbridas de WO3-MoO3 mediante anodizado electroquímico. Estas nanoestructuras se emplean como fotocatalizadores para la degradación de contaminantes y como ánodos para baterías de ion de litio. El WO3 destaca por sus propiedades semiconductoras, ópticas y eléctricas excepcionales. En aplicaciones medioambiental, las nanoestructuras de WO3 son de gran interés para la fotoelectrocatalisis, un proceso prometedor para la degradación de contaminantes en el agua. El WO3 destaca como fotoánodo debido a su fotoestabilidad, alta conductividad eléctrica y capacidad de absorción de la luz visible. En el campo energético, el WO3 muestra un gran potencial como ánodo en baterías de ion de litio ya que su estructura cristalina permite la inserción y extracción eficiente de iones de litio, mejorando la capacidad de almacenamiento y la durabilidad de las baterías gracias a su estabilidad electroquímica. Para mejorar las nanoestructuras de WO3, se ha estudiado su combinación con óxido de molibdeno (MoO3). El molibdeno, con propiedades químicas y estructurales similares al wolframio, facilita la deposición efectiva en las nanoestructuras de WO3, ajusta el ancho de banda prohibida, mejora la conductividad, la difusión iónica y reduce la recombinación de portadores de carga. Esta combinación de óxidos resulta en una mayor eficiencia electroquímica, haciendo de las nanoestructuras híbridas WO3-MoO3 una solución prometedora para aplicaciones energéticas. En primer lugar, se sintetizaron las nanoestructuras de WO3, estudiando la influencia de la temperatura de calentamiento tras la síntesis y la adición de disolventes en el electrolito de síntesis. La temperatura óptima fue de 600 °C, obteniendo nanoestructuras cristalinas con excelentes propiedades fotoelectroquímicas. Además, se demuestra que la incorporación de disolventes en el electrolito de síntesis influye significativamente en las propiedades de las nanoestructuras, obteniendo que la adición de un 50 % de isopropanol en el electrolito mejora notablemente sus propiedades electroquímicas. En segundo lugar, se sintetizaron nanoestructuras híbridas de WO3- MoO3·añadiendo diferentes concentraciones de molibdato al electrolito de síntesis. La concentración de 0,1 M de molibdato produjo nanoestructuras con propiedades electroquímicas superiores, destacándolas como prometedoras para su uso como ánodo en baterías. Las nanoestructuras fueron exhaustivamente caracterizadas morfológica, estructural, química, electroquímica y fotoelectroquímicamente. Por último, las nanoestructuras con mejores propiedades fotoelectroquímicas y electroquímicas se emplearon como ánodo en aplicaciones medioambientales y energéticas, respectivamente. En el ámbito medioambiental, se evaluó la eficiencia de las nanoestructuras en la degradación de disruptores endocrinos pertenecientes a diferentes familias químicas, así como sus mezclas y su toxicidad. Las nanoestructuras de WO3 demostraron ser efectivas, logrando una degradación del 100 % de pesticidas, parabenos y fenoles en menos de 4 horas. Sin embargo, la técnica no fue eficiente para eliminar ftalatos, generando productos finales más tóxicos. En el ámbito energético, se estudió el rendimiento de las nanoestructuras como ánodos en baterías de ion de litio, considerando también el impacto del electrolito. La nanoestructura híbrida WO3-MoO3 mostró el mejor rendimiento cuando se utilizó un electrolito que combinaba bisoxalato borato de litio (LiBOB) con aditivos y solventes adicionales. Este trabajo ofrece una contribución significativa al desarrollo de soluciones sostenibles para problemas medioambientales y energéticos, subrayando el potencial de las nanoestructuras de WO3 y WO3-MoO3. / [CA] La present Tesi Doctoral se centra en la síntesi, caracterització i optimització de nanoestructures d'òxid de wolframi (WO3) i nanoestructures híbrides de WO3-MoO3 mitjançant anodització electroquímica. Aquestes nanoestructures s'utilitzen com a fotocatalitzadors per a la degradació de contaminants i com a ànodes per a bateries d'ió de liti. El WO3 destaca per les seues propietats semiconductores, òptiques i elèctriques excepcionals. En aplicacions mediambientals, les nanoestructures de WO3 són de gran interès per a la fotoelectrocatalisi, un procés prometedor per a la degradació de contaminants en l'aigua. El WO3 destaca com a fotoànode per la seua fotoestabilitat, alta conductivitat elèctrica i capacitat d'absorció de la llum visible. En el camp energètic, el WO3 mostra un gran potencial com a ànode en bateries d'ió de liti ja que la seua estructura cristal·lina permet la inserció i extracció eficient d'ions de liti, millorant la capacitat d'emmagatzematge i la durabilitat de les bateries gràcies a la seua estabilitat electroquímica. Per a millorar les nanoestructures de WO3, s'ha estudiat la seua combinació amb òxid de molibdè (MoO3). El molibdè, amb propietats químiques i estructurals similars al wolframi, facilita la deposició efectiva en les nanoestructures de WO3, ajusta l'amplada de banda prohibida, millora la conductivitat, la difusió iònica i redueix la recombinació de portadors de càrrega. Això resulta en una major eficiència electroquímica, fent de les nanoestructures híbrides WO3-MoO3 una solució prometedora per a aplicacions energètiques. En primer lloc, es van sintetitzar les nanoestructures de WO3, estudiant la influència de la temperatura de calentament després de la síntesi i l'addició de dissolvents en l'electròlit de síntesi. La temperatura òptima va ser de 600 °C, obtenint nanoestructures cristal·lines amb excel·lents propietats fotoelectroquímiques. A més, es demostra que la incorporació de dissolvents en l'electròlit de síntesi influeix significativament en les propietats de les nanoestructures, obtenint que l'addició d'un 50 % d'isopropanol en l'electròlit millora notablement les seues propietats electroquímiques. En segon lloc, es van sintetitzar nanoestructures híbrides de WO3-MoO3 afegint diferents concentracions de molibdat a l'electròlit de síntesi. La concentració de 0,1 M de molibdat va produir nanoestructures amb propietats electroquímiques superiors, destacant-les com a prometedores per al seu ús com a ànode en bateries. Les nanoestructures van ser exhaustivament caracteritzades morfològicament, estructuralment, químicament, electroquímicament i fotoelectroquímicament. Finalment, les nanoestructures amb millors propietats fotoelectroquímiques i electroquímiques s'utilizaren com a ànode en aplicacions mediambientals i energètiques, respectivament. En l'àmbit mediambiental, s'avaluà l'eficiència de les nanoestructures en la degradació de disruptors endocrins pertanyents a diferents famílies químiques, així com una mescla d'ells i la seua toxicitat. Les nanoestructures de WO3 demostraren ser efectives, aconseguint una degradació del 100 % de pesticides, parabens i fenols en menys de 4 hores. No obstant això, la tècnica no va ser eficient per a eliminar ftalats, generant productes finals més tòxics. En l'àmbit energètic, s'estudià el rendiment de les nanoestructures com a ànodes en bateries d'ió de liti, considerant també l'impacte de l'electròlit. La nanoestructura híbrida WO3-MoO3 mostrà el millor rendiment quan s'utilitzà un electròlit que combinava bis(oxalat)borat de liti (LiBOB) amb additius i dissolvents addicionals. Aquest treball ofereix una contribució significativa al desenvolupament de solucions sostenibles per a problemes mediambientals i energètics, subratllant el potencial de les nanoestructures de WO3 i WO3-MoO3. / [EN] This Doctoral Thesis focuses on the synthesis, characterization, and optimization of tungsten oxide (WO3) nanostructures and hybrid WO3-MoO3 nanostructures through electrochemical anodization. These nanostructures are used as photocatalysts for contaminant degradation and as anodes for lithium-ion batteries. WO3 stands out for its exceptional semiconductor, optical, and electrical properties. In environmental applications, WO3 nanostructures are of great interest for photoelectrocatalysis, a promising process for contaminant degradation in water. WO3 is highly effective as a photoanode due to its photostability, high electrical conductivity, and visible light absorption capacity. In the energy field, WO3 shows great potential as an anode in lithium-ion batteries because its crystalline structure allows efficient insertion and extraction of lithium ions, improving storage capacity and battery durability thanks to its electrochemical stability. To improve WO3 nanostructures, their combination with molybdenum oxide (MoO3) has been studied. Molybdenum, with chemical and structural properties similar to tungsten, facilitates effective deposition in WO3 nanostructures, adjusts the bandgap, improves conductivity, ionic diffusion, and reduces charge carrier recombination. This results in greater electrochemical efficiency, making hybrid WO3-MoO3 nanostructures a promising solution for energy applications. Firstly, WO3 nanostructures were synthesized, studying the influence of the annealing temperature and the addition of solvents to the synthesis electrolyte. The optimal temperature was 600 °C, obtaining crystalline nanostructures with excellent photoelectrochemical properties. Additionally, it was demonstrated that the incorporation of solvents in the synthesis electrolyte significantly influences the properties of the nanostructures, showing that the addition of 50 % isopropanol in the electrolyte notably improves their electrochemical properties. Secondly, hybrid WO3-MoO3 nanostructures were synthesized by adding different concentrations of molybdate to the synthesis electrolyte. The concentration of 0.1 M molybdate produced nanostructures with superior electrochemical properties, making them promising for use as anodes in batteries. The nanostructures were exhaustively characterized morphologically, structurally, chemically, electrochemically, and photoelectrochemically. Finally, the nanostructures with the best photoelectrochemical and electrochemical properties were used as anodes in environmental and energy applications, respectively. In the environmental field, the efficiency of the nanostructures in the degradation of endocrine disruptors from different chemical families, as well as their mixtures and toxicity, was evaluated. WO3 nanostructures proved to be effective, achieving 100 % degradation of pesticides, parabens, and phenols in less than 4 hours. However, the technique was not efficient in eliminating phthalates, generating more toxic final products. In the energy field, the performance of the nanostructures as anodes in lithium-ion batteries was studied, also considering the impact of the electrolyte. The hybrid WO3-MoO3 nanostructure showed the best performance when an electrolyte combining Lithium bis(oxalate)borate (LiBOB) with additional additives and solvents was used. This work offers a significant contribution to the development of sustainable solutions for environmental and energy problems, highlighting the potential of WO3 and WO3-MoO3 nanostructures. / Agradezco al Ministerio de Universidades por la ayuda predoctoral recibida para la realización de la presente Tesis Doctoral (FPU19/02466). También al Ministerio de Economía, Industria y Competitividad, por la concesión de los proyectos CTQ2016-79203-R (2016) y PID2019-105844RB-I00 (2019) en los cuales he podido participar durante la Tesis Doctoral. Además, agradezco la financiación a la Red Española de Investigación E3TECH-PLUS (RED2022- 134552-T, MICINN/AEI). / Cifre Herrando, M. (2024). Nanotecnología con WO3 y aplicaciones: Degradación fotoelectroquímica de disruptores endocrinos y ánodos avanzados para baterías de ion de litio [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/211319