Comparative Life Cycle Assessment of Second Life NMC Batteries
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Typ
Examensarbete för masterexamen
Program
Industrial ecology (MPTSE), MSc
Publicerad
2022
Författare
Bergqvist, Nadja
Talakoob, Bahare
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
As the EV batteries reach their end of life, a large number of batteries will be
available post 2030. One solution for retired batteries is to consider them for second
life applications in Battery Energy Storage Systems (BESS). The viability of second
life Nickel Manganese Cobalt (NMC) batteries, however, is a balancing act between
their reliability due to fading performance and safety issues, costs and environmental
impacts.
This Master’s thesis investigates the viability by breaking it down into two research
questions. Firstly, from the viewpoint of the impact categories energy demand
and climate change, how the second life NMC battery compares to a new Lithium
Iron Phosphate (LFP) battery for BESS applications. And secondly, regarding the
material scarcity impact category, how beneficial it is to delay the recycling of the
NMC battery by adding a second life. The first question is answered in a break-
even analysis with LFP as a reference point by considering three different scenarios.
The scenarios represent different allocations of environmental impacts between the
first and second life of the NMC. Each scenario is further comprised of different
recycling percentages. For the second question, the crustal scarcity indicator is used
as a proxy to address the material scarcity hot-spots at the battery pack, cell and
cathode level. Moreover, the supply risks and geopolitics surrounding the critical
metals used in the battery chemistries are discussed.
According to the break-even analysis, it is only when 0% of the energy requirement
for production and recycling are allocated to the second life that a second-life NMC
battery can outperform a new LFP battery in terms of energy use. This is mainly
due to a lower efficiency of the aged battery. In terms of climate change, the second-
life NMC battery can potentially be a viable choice for both 0% and 20% allocation,
depending on the local electricity mix. The carbon intensity of the electricity mix
in the BESS was indicated as the most significant parameter. Regarding materials
scarcity it was observed that in some situations second life use of NMCs could
aggravate supply risks of nickel and cobalt. However, this depends on the existence
and efficiency of recycling infrastructure, and hence on the time horizon.
Beskrivning
Ämne/nyckelord
second life battery , lithium-ion battery , life cycle assessment , battery energy storage system , end of life management