Development and testing of an integrated model for sustainable material strategies

Abstract

Raw materials have a significant impact on climate change mitigation. They are vital for many low carbon technologies, but can contribute to high cost, environmental emissions and supply chain risks. Sustainable material strategies are increasingly recognised as important levers to improve the technical, socio-economic and environmental aspects of low carbon technologies. Decisions on such strategies need to be supported by quantitative assessments to evaluate potential trade-offs and identify optimal strategies. Due to the multidisciplinary nature of these assessments, different- discipline specific models such as life cycle assessment, life cycle costing, engineering process models and multi-objective optimisation need to be integrated. While the need for such integrated modelling is well recognised, the lack of operational and practical guidance to establish accessible tools prohibits their widespread use. This thesis aims to contribute to this knowledge gap by developing and testing a general methodological framework for Integrated Modelling of Sustainable Material Strategies (IM-SMS). The IM-SMS framework combines several analytical models and includes procedural steps, general mathematical formulas, a database structure, and suggestions for an open source software implementation. The IM-SMS framework was tested using the case of electric vehicle batteries. A parameterised model for lithium-ion battery design was es tablished to assess the cost, emissions, material criticality and energy density of 20,736 different design options. The results show a significant trade-off between energy density and the other objectives . Strategies from a cost, emissions and criticality point of view reduce the energy density by 46% compared to optimal strategies for the performance. However, energy density as the main decision variable in battery design can lead to new material challenges. A balance between these objectives is essential to establish sustain able material systems for electric vehicle batteries. As such, the IM-SMS framework is presented as a useful tool to support policy and industrial decisions for the low carbon transition.