Jens F. Peters

The Issue of Metal Resources in Li-Ion Batteries for Electric Vehicles

The worldwide development and market penetration of electric vehicles (EVs) and hybrid cars has lagged far behind initial expectations and prognoses. However, more recent discussions about petrol and diesel car emissions seem to accelerate the market penetration of battery-based mobility and other alternative options. Many big car manufacturers have announced that they will offer a broad EV fleet by between 2020 and 2024 at the latest, and some even plan to abandon the production of petrol- and diesel-powered cars completely. This might result in a sharp increase in EV market shares and, consequently, in a significant amount of resources needed to produce traction batteries. At present, EVs are produced mainly using different types of Li-ion batteries (LIBs) and only to a lesser extent other battery systems like NiMH. Also in a midterm perspective, LIBs will probably continue to be the preferred energy storage technology for EVs due to their excellent technical performance. This raises the question of whether we will have enough reserves or resources of key metals such as Li, Co, Ni, Cu, Al, Mn or P required for Li-ion traction batteries. In answering this question, a dynamic material flow analysis (dMFA) was conducted to quantify the global demand for these key metals driven by the increasing number of battery vehicles. The calculations also take into account potential recycling of metals from batteries after the use phase, which significantly reduces the pressure on reserves and resources.

The Importance of Recyclability for the Environmental Performance of Battery Systems

While several studies about the environmental impacts of batteries exist, the end-of-life stage is often disregarded and the relevance of battery reuse or recycling not quantified. However, the end-of-life phase of battery storage systems is highly relevant for their overall environmental performance. In order to quantify this relevance, we extend existing LCA studies by an end-of life model and assess the influence of battery recycling for the life cycle impact of three different battery types. These include a lithium-ion battery (LIB), a vanadium-redox-flow battery (VRFB) and an aqueous hybrid ion battery (AHIB), all for stationary energy storage services (renewable support). The results show that a high recyclability can improve the environmental performance of the batteries over their life cycle significantly. This underlines the need for a design for recyclability of batteries for minimising environmental impacts of battery systems and the corresponding loss of valuable resources.

Biorefinery Modeling and Optimization

Most biorefinery processes are still in an early stage of development. Some pilot and demonstration plants exist, but little or no information is available from real installations at commercial scale, which is needed to determine their economic and environmental feasibility. Process simulation is a powerful tool to address this issue, since it is possible to determine mass and energy balances without the necessity of those industrial facilities. From this information, consumption of biomass and other chemicals or auxiliary services can be estimated, and plant equipment can be sized, allowing the identification of the main drawbacks and bottlenecks, the necessity of layouts modification and their optimization. This chapter reviews the different stages to carry process simulation out. As well, the main thermochemical (combustion, pyrolysis, and gasification), biochemical (fermentation) and chemical (fractionation, lignin depolymerization, and platform molecules obtaining) processes for biomass processing are discussed in terms of best approaches to simulate them. Finally, some common aspects like pinch analysis, process optimization, and upscaling are studied.