L’électrification des moyens de transport est de plus en plus importante. Sa mise en œuvre nécessite des systèmes de stockage de l’énergie plus performants, moins coûteux, et plus sûrs. Actuellement, les batteries lithium-ion équipent la majorité de ces véhicules innovants. Toutefois, ces systèmes sont complexes, onéreux, et leur performance se dégrade au cours du temps. Leur durabilité constitue donc un enjeu majeur.Son estimation est complexe car elle ne dépend pas que des kilomètres parcourues mais des conditions d’usage. Actuellement, les outils de prédiction de durée de vie des batteries sont simplificateurs ou pas compatible avec l’usage automobile.L’objet de ces travaux consiste à développer un outil de simulation capable de reproduire le comportement électrique, thermique, et de vieillissement d’un pack batteries au cours de sa vie. Cet outil doit permettre l’optimisation de la conception et l’usage des packs afin d’augmenter leur durabilités. Des campagnes d’essais ont permis de calibrer et de valider des modèles électrothermiques au niveau de la cellule puis à l’échelle de l’assemblage. De même, la mise en place et l’analyse de tests de vieillissement accélérés ont permis de développer une loi de vieillissement et de mettre en avant un optimum d’usage.Le comportement du pack a été par la suite testé dans différentes conditions d’usage par l’intermédiaire d’un simulateur de scénario. Des stratégies de conception et de recharges ont été donc proposées et vérifiées par simulation. / Lithium batteries are key solutions as power storage systems for several applications including portable devices, aviation, space, and electrified vehicles. Their success is principally due to their high power and energy density. Therefore, several researchers are attempting to develop more powerful, cheaper, longer-lived and more secure batteries. One drawback of lithium batteries is their durability: lithium batteries’ energy and power capability decrease over time. The degradation rate is sensitive to operating conditions. A crucial step towards the large-scale introduction of electrified vehicles in the market is to reduce the cost of their energy storage devices.The aim of this study is to develop a simulation tool at the pack level able to reproduce its electro-thermal-aging behavior overtime. Thanks to an accelerated aging tests and experimental approach the models are calibrated and coupled with a usage scenario simulator at the vehicle level. The behavior of the pack is thus studied under different conditions and simulations were compared and discussed. Strategies of usage and charging were then proposed and validated by simulation.

The electric vehicle market has rapidly expanded due to technological advancements for the last decade and a key enabler is the development of high-performance batteries with greater energy density, faster charging, and longer lifespan. The construction equipment sector faces unique challenges in electrification, including high power demands, extended operating hours, and the need for minimal downtime. To address these challenges Volvo Construction Equipment is investigating a battery swap system solution that allows for quick battery swaps, reducing downtime and a decoupled lifetime from the machines. The aim for this study is to design a battery pack used for the battery swap system while answering the following research questions: RQ1: What configuration of battery modules, rack and auxiliary systems achieve the highest energy density when designing a battery pack for construction equipment? RQ2: What factors should be considered when designing the battery modules, rack, and auxiliary systems to achieve the highest energy density of a battery pack for construction equipment? This project followed a limited version of Ulrich et al.'s (2019) product development process, focusing on concept development and system-level design for a battery swapping system. An inductive research approach was taken, gathering qualitative and quantitative data from interviews, literature, documents, and meetings to create a holistic understanding of the project challenges. A structured literature review was conducted using relevant keywords across multiple databases, employing techniques like forward and backward snowballing. Data analysis methods, including conversation analysis, were employed to structure and analyze collected data, ensuring validity and reliability through triangulation, and cross-referencing with experts at Volvo. Empirical studies were conducted through benchmarking and a case study, providing quantitative data on specifications and qualitative insights from internal documentation and communication with product developers. The findings formed an iterative concept generation process, emphasizing the importance of exploring diverse possibilities in the early stages. The design process involved evaluating previous battery pack solutions, working within predefined constraints like using a specific shell, internally developed battery modules, auxiliary components while satisfying a set of stakeholder needs. Some auxiliary components and a rack that supports the battery modules were also developed as there is a new internal layout of the battery pack. This resulted in a conceptual battery pack that theoretically have a 30% higher energy density than the previous battery pack solutions. The proposed solution enables Volvo Construction Equipment to offer machines with longer runtimes and increased productivity by maximizing the energy storage capacity within the given constraints.

In connection to the increasing awareness of vehicles and its impact on the environment, the interest in the electric vehicle market has shown a significant growth in the recent years. According to forecasts, it is also projected to increase further in the future. These electric vehicles are driven by lithium-ion batteries with an expected service life of 5-15 years depending on different technology generations and design concepts. After the given service life, the battery has lost approximately 20 percent of its capacity and is no longer permitted to be used in its original application area again, out of safety reasons. Although the retired battery pack is not suitable for vehicles, its remaining capacity can still be utilized in other applications. Hence, the term second life has become a common subject in the automotive industry, where companies are trying to find new application areas for the retired electric vehicle battery packs. Common methods regarding second life of electric vehicle batteries are processes such as remanufacturing, repurposing and re-use. These presented second life methods are from a reverse logistics perspective. Second life alternatives enable a better sustainability and reduces the environmental impact by re-using and recycling existing materials.   In this thesis, the authors examined different second life concepts with the same prerequisite, an electric vehicle lithium-ion battery pack with an energy capacity of 20 kWh. The project has been conducted in a company that is one of the leading manufacturers in the heavy-duty industrial vehicle industry, which currently is developing their electric vehicle machines. Several different concepts have been generated and analysed to find the most applicable business model concepts from a second life perspective. The purpose has been to investigate and calculate which of these business model concepts are most feasible from an economic and a reverse logistics perspective. In order to fulfil the purpose, the following research questions have been formulated:   RQ1: Which secondary use business model concepts are feasible for battery packs of electrified machines? RQ2: Out of the above identified concepts, which business model concept is economically feasible and how can its reverse logistic be composed?   In order to answer the research questions, the authors have analysed different cost aspects and forecasts based on existing research and case company data. This is performed to develop the most profitable concepts based on the collected data, where the generated ideas concluded in three final concepts. For these concepts, individual business model canvases were created to illustrate all important parts of the concepts. The thesis resulted in an economic analysis of the three concepts, visualizing function diagrams and comparing them to each other, to identify the most applicable concept for the case company. The remanufacturing concept proved to be the most applicable one, where its associated reverse logistics and recycling process were investigated and determined. In conclusion the thesis can firstly contribute to future research by the created process map that companies can use and apply in their second life process, correlated to the managerial implications. Secondly, the remanufacturing concept can be a potential future investment for the case company, considering all valuable factors that have been analysed throughout the thesis.     Keywords: Battery pack, Battery secondary use, Business model, Reverse logistic, ESS, Remanufacturing, Battery repurposing, re-use, Battery second life economic analysis.

Dans le cadre du développement des véhicules électriques et hybrides, la connaissance et la gestion de l'énergie du pack de batteries est une problématique majeure. Pour cela, les constructeurs automobiles ont besoin de modèles numériques pour représenter le comportement dynamique des batteries. L'objectif de cette thèse est de développer, d'une part une méthodologie de caractérisation du comportement dynamique des cellules de batterie et de leurs assemblages et d'autre part des modèles numériques associés qui soient simples, rapides, robustes, présentant le meilleur compromis précision/simplicité. La première partie du travail de la thèse a consisté à développer une nouvelle méthode de caractérisation expérimentale avec un modèle de circuit électrique équivalent, qui permet de s'appliquer facilement à différentes batteries et de calibrer la complexité du modèle (nombre de circuits utilisés) en fonction de la durée des mesures de la phase de repos après une sollicitation. Le modèle généré est capable de suivre les évolutions rapides et lentes de la tension de la batterie, ce qui peut améliorer l'estimation de la tension dans les applications BMS (Battery Management System). Des essais de validations sur différentes batteries ont montré que les modèles générés permettent une prédiction précise du comportement dynamique de la batterie. Ensuite, le manuscrit aborde les assemblages des cellules en série avec la méthode de caractérisation élaborée. Elle commence par une définition énergétique de l'assemblage. Puis, la modélisation de l'assemblage avec la méthode de caractérisation est discutée. Les essais de validation ont été menés sur différents assemblages et ont montré que le comportement dynamique de l'assemblage peut aussi être bien représenté avec les modèles identifiés / As part of the development of electric and hybrid vehicles, energy management in the battery pack is a major issue. Car manufacturers need a numerical model to represent the dynamic behavior of batteries. The objective of this work is to develop, on the one hand, a characterization method of the dynamic behavior of battery cells and their assemblies, and on the other hand the combined numerical models which are simple, fast, robust and with the best accuracy/simplicity compromise. The first part of the work is dedicated to develop a new experimental characterization method with an equivalent circuit model, which can be applied easily to different battery cells and allows calibrating the complexity of the model (number of the RC circuits) according to the measurement duration of the resting phase after a solicitation. Therefore, the generated model is able to follow the rapid and slow voltage change of the battery cell, which improves voltage and state of charge estimation for the BMS (Battery Management System) applications. The validation tests on different battery cells show that the generated model allows accurate prediction of the battery cell’s dynamic behavior. The second part of the work studies the cell assemblies with cells connected in series. It begins with an energy definition of the cell assembly. Then modelling of the assembly with the developed characterization method is discussed. The validation tests were carried out on different assemblies and show that the dynamic behavior of the assembly can be also well represented with the identified models