Road vehicles represent a vital part of the world‟s mobility network. However significant concerns surrounding the energy supply and emissions associated with these vehicles have led to many alternative powertrains being proposed. Much research has been conducted evaluating how the in-use impacts of these compare to incumbent powertrains. This has shown that battery electric vehicles (BEV) have great potential to address many of the concerns, but assessments that go beyond the use phase suggest that changes in other stages, e.g. production, could abate these benefits. The large battery packs of BEVs may incur substantial production impacts. However their reported impacts vary dramatically in the literature, which can introduce significant variations into whole life assessments of BEVs. To evaluate this uncertainty, a new life cycle assessment (LCA) for lithium-ion battery production and end-of-life processing was developed. This was combined with further models to permit studies of battery variables such as efficiency, lifetime, materials and specific energy, along with the trade-offs between them, on the whole life impacts of BEVs. The inclusion of battery production impacts are vital in assessments of BEVs and can significantly alter the findings relative to incumbent vehicles. Different lithium-ion variants were shown to alter a BEVs lifetime impacts and to necessitate the normalisation of vehicle range to fully quantify their effects. A sensitivity analysis of the new battery LCA revealed less variability than in the current literature and indicated that assessments are hampered by limited production data, along with unrepresentative inventories for various specialist materials. Trade-offs between parameters may result in batteries with superior lifetimes only offering whole life CO2e emissions reductions under limited scenarios when used in BEVs. The research also showed that for BEVs, increasing battery losses with power demands exacerbate the higher energy usage exhibited over many realworld driving situations compared to the European test cycle. Overall this research has generated improved lifecycle models for lithium-ion batteries and incorporated many additional factors/scenarios to generate a framework that permits enhanced whole life sustainability assessments of alternative powertrains.
Sweeting, W
Department of Mechanical Engineering and Mathematical SciencesFaculty of Technology, Design and Environment
Year: 2013
© Sweeting, W Published by Oxford Brookes UniversityAll rights reserved. Copyright © and Moral Rights for this thesis are retained by the author and/or other copyright owners. A copy can be downloaded for personal non-commercial research or study, without prior permission or charge. This thesis cannot be reproduced or quoted extensively from without first obtaining permission in writing from the copyright holder(s). The content must not be changed in any way or sold commercially in any format or medium without the formal permission of the copyright holders.