Abstract

The development of highly efficient batteries is a critical need in automotive industry in order to enable the future success of Electric Vehicles (EV). Active material with higher insertion potential in association with a compliant electrolyte is a way to increase Li-ion cell energy density and so EV autonomy. Moreover, green process like aqueous process for positive electrode manufacturing allows significant reduction of battery cost. This work in the framework of the European SPICY project presents results obtained on polyanionic chemistry in association with sulfolane or adiponitrile electrolyte solvent and water soluble binder stable at high voltage. Results at cell level are also presented with 17 Ah cells having same components but different formats. Models for electrochemical and thermal behavior at the levels of particles, electrodes and cells are finally presented and allow identification of the optimized cell design in terms of loading and porosity.

Abstract

The number of battery electric vehicle models available in the market has been increasing, as well as their battery capacity, and these trends are likely to continue in the future as sustainable transportation goals rise in importance, supported by advances in battery chemistry and technology. Given the rapid pace of these advances, the impact of new chemistries, e.g., lithium-manganese rich cathode materials and silicon/graphite anodes, has not yet been thoroughly considered in the literature. This research estimates life cycle greenhouse gas and other air pollutants emissions of battery electric vehicles with different battery chemistries, including the above advances. The analysis methodology, which uses the greenhouse gases, regulated emissions, and energy use in transportation (GREET) life-cycle assessment model, considers 8 battery types, 13 electricity generation mixes with different predominant primary energy sources, and 4 vehicle segments (small, medium, large, and sport utility vehicles), represented by prototype vehicles, with both battery replacement and non-replacement during the life cycle. Outputs are expressed as emissions ratios to the equivalent petrol internal combustion engine vehicle and two-way analysis of variance is used to test results for statistical significance. Results show that newer Li-ion battery technology can yield significant improvements over older battery chemistries, which can be as high as 60% emissions reduction, depending on pollutant type and electricity generation mix. This research was funded by Fundação para a Ciência e a Tecnologia, grant number UID/Multi/00308/2019, INESC-Coimbra R&D project “Alternative Fuel Vehicles”. info:eu-repo/semantics/publishedVersion Document type: Article

Abstract

Battery thermal management is essential to efficienct and safe operation of Li-ion batteries, particularly in challenging applications such as fast charging. This work proposes a thermal management control framework based on MPC. The novelty of this approach resides in the focus on incorporating disturbance prediction into the control decision. Simulations show that this methodology allows for (1) lower peak and mean battery temperatures during fast charging for a similarly sized battery thermal management system; or (2) battery thermal management system downsizing for similar thermal performance.

Abstract

Model based development methodologies have strong potential in reducing development effort of complex automotive systems. This paper presents a model based development methodology used to develop battery state estimation algorithms, and steps through all the steps required for this. The benefits of the mixed simulation and testing methodology are outlined using a State of Charge estimation algorithm development example. Overall, this development methodology leads to safer, more efficient and more affordable battery packs, enabling faster market update of electric vehicles.

Abstract

Interest in electric vehicles (EVs) and hybrid electric vehicles (HEVs) has risen dramatically on account of environmental and energy concerns. The biggest issues that must be addressed in order to popularize these advanced vehicles are related to the battery.We have been promoting vigorous R& D work on batteries for application to environmental vehicles since the beginning of the 1990s. Attention was focused on lithium-ion batteries early on as a fundamental solution to the critical issue mentioned above. The conclusion was reached that the development of those potentialities to their fullest extent would create completely new forms of value unobtainable with conventional batteries. As a result of extensive theoretical studies and many experimental demonstrations, we successfully showed ahead of others that those potentialities did in fact exist and could be achieved.This paper makes clear the various performance requirements of advanced batteries for EV or HEV application, focusing in particular on the critical aspects of the battery thermal design and construction for system stability. It also explains how the power output of the lithium-ion battery has been substantially improved for application to HEVs. Document type: Article