Supervised Theses

Thesis and reports of Carl von Ossietzky University Oldenburg


Resource Constraints for the Diffusion of Fuel Cell Vehicles: Assessing the Role of Recycling in Meeting Future Platinum Demand (Master Thesis by Rikka Wittstock)

AWARDED by the VDI !

Classified as ‘zero emission vehicles’, fuel cell vehicles do not emit any greenhouse gases while driving, but still offer the familiar convenience of conventional vehicles. For this reason, they are expected to play a major role in combating climate change un-der the European Union’s quest for reducing greenhouse gas emissions.
However, the widespread deployment of fuel cell vehicles entails trade-offs and unin-tended rebound effects, especially concerning the depletion of non-renewable resources. The excessive platinum requirement is of major concern, as this metal is used as the predominant catalyst material in automotive proton exchange membrane fuel cells. Platinum recycling is viewed as a vital strategy for mitigating environmental and re-source-related impacts of extraction, as well as enhancing security of supply.
This thesis thus aims to assess to what extent the recycling of fuel cell vehicles can con-tribute to meeting this industry’s future platinum demand. Following a theoretical basis that provides the fundamental principles of current proton exchange membrane fuel cell technology, the market status of fuel cell vehicles and the global platinum market, a literature review examines the potential recycling chain of fuel cell vehicles in qualita-tive terms. Analysing possible deficits in the recycling chain that could lead to sub-optimal platinum recovery rates in the future, this part concludes that the recycling of fuel cell vehicles is still in its early stages and many aspects require further research.
Using the software STAN 2.5, a dynamic material flow analysis is prepared to deter-mine in quantitative terms the expected platinum requirements resulting from the diffu-sion of fuel cell vehicles in Europe, as well as the platinum flows resulting from the recycling of end-of-life fuel cell vehicles.
In the course of this research it is shown that the diffusion of fuel cell vehicles in Europe is unlikely to cause a depletion of primary platinum deposits, but could have severe impacts on the global platinum market and exacerbate structural and temporal scarcities. These effects could not only impede the market adoption of fuel cell vehicles, but also impact on other platinum-dependant technologies. The co-development of re-cycling technologies and frameworks is hence considered a prerequisite, and sugges-tions for the mitigation of deficits in the recycling chain of end-of-life vehicles are given. Further research on all steps of the recycling chain of fuel cell vehicles is deemed essential.

You can download this thesis here.


Sustainable Resource Management – Challenges regarding the powertrain of electric vehicles (Master-Thesis from Sabine Albach)


Electric vehicles are considered to be a promising alternative to conventional combustion engine based vehicles in the transition to a more sustainable individual mobility. Their broad implementation is expected to substantially contribute to a necessary reduction of greenhouse gas emissions (GHG) from road transport, which are threatening Earth’s intake capacity and accelerating anthropogenic climate change.

However, the associated shift in resource requirements towards so-called special, respectively technology metals has been given reason to suspect that trade-offs could threaten the desired merits of e-mobility with regard to sustainability. This study is aimed to obtain a more comprehensive understanding of challenges that the broad implementation of e-mobility could place on the sustainable management of special metals for high voltage traction batteries.

Accordingly, general claims, targets and challenges of a sustainable resource, respectively metals management are analysed, followed by a technological review on battery technologies to determine the state-of-the-art.

Latter reveals that Lithium-Ion technology is most promising in the short- and medium term. Material development within Lithium-Ion technology is currently still highly dynamic. Among the specific positive electrode chemistries that currently show the applicable performances are lithium-iron-phosphate (LiFePO4, LFP), lithium-nickel-cobalt manganese-oxide (LiNiCoMnO2, NMC) and the spinel prototype lithium-manganese-oxide (LiMnO4, LMO), each paired with a graphite anode (negative electrode) . Based on these three battery chemistries and two scenarios for e-mobility development, a dynamic Material Flow Analysis (MFA) is conducted to gain insights on expected lithium and cobalt flows, as well as required quantities and recycling potentials between 2014 and 2050.

Download here

Comparative Life Cycle Assessment of Stationary Battery Storage Technologies for Balancing Fluctuations of Renewable Energy Sources (Master-Thesis from Mitavachan Hiremath)


Many governments all over the world have already started inducing ambitious targets for the development and deployment of renewable energy sources, especially, wind and solar. But, the intermittent nature of these energy sources leads to a series of technical challenges at various levels in the electricity grid network, especially when their shares increase in the power grid mix. These technical challenges are already being observed in the countries like Germany. Among others, battery storage technologies are considered as promising candidates to tackle some of these challenges caused by these fluctuating renewable energy sources. This has led to a renewed interest among industries, R&D institutions and academia alike to develop and deploy better batteries in the electricity market.

Therefore, more information on the environmental performance of the available battery technologies is needed at this hour, so as to make sure that the battery technologies that are going to be deployed in the near future are really the sustainable ones. This thesis tries to address this matter by undertaking the comparative life cycle assessment of promising near future stationary battery storage technologies.

The life cycle assessment was carried out in two stages. In the first stage of analysis, four battery technologies, such as, Lithium Ion, Lead Acid, Sodium Sulfur and Vanadium Redox-flow were compared for their cradle-to-gate and overall life cycle impacts on cumulative energy demand (CED) and global warming potential (GWP) impact categories. Further, the comparative study was extended to assess the effect of battery use scenarios on their relative ranking by modeling six different stationary application scenarios. In the second stage, a detailed analysis of Lithium Ion process chains was carried out to assess the impacts of these process chains on CED, GWP and 17 mid-point environmental indicators (using ReCiPe 2008 methodology), and also the key battery components/processes that have significant impact on the environment were identified.

(Changed: 19 Jan 2024)  | 
Zum Seitananfang scrollen Scroll to the top of the page