The increasing use of lithium-ion batteries across different scales and applications has made understanding the degradation mechanisms that affect their aging behavior increasingly important. Conditions such as high C-rates, extreme temperatures, and high depth of discharge (DoD) lead to rapid capacity loss, increased internal resistance, and voltage stress at the cell level. In addition, differences in state of charge (SOC) and state of health (SOH) between cells, along with uneven current distribution, result in thermal imbalance and energy losses at the system level. These stress factors further accelerate cell degradation, leading to the development of a reciprocal degradation cycle. This PhD project aims to investigate the interconnection between system and cell degradation by experimental and numerical methods, contributing to the development of stable, safe, and high-performance battery systems under real operating conditions.

This work focuses on sustainability by developing high-resolution environmental assessments of the lithium-ion battery value chain. Using bottom-up and process-based modeling, the project analyzes key stages: upstream processes like mining and material refining, battery production in giga-factories, and downstream steps such as second-life applications and recycling. While the main goal is to understand environmental impacts, the work also includes techno-economic analysis to evaluate costs and performance using the same detailed modeling approach in order to build an integrated assessment model that covers both current and next-generation battery chemistries. This model will provide valuable insights for making more sustainable technology and policy decisions. In addition, the project supports collaboration across other work packages within the center, helping to create a more complete picture of battery systems and their role in a clean energy future for Norway.