Development of a health-aware fast-charging strategy based on feedback from pressure sensors. The work will be focused on compensation for thermal expansion, including simulation-based validation and experimental investigation.

Knowledge of lithium-ion battery internal states is essential for developing fast and safe charging strategies. Graphite, widely used as the negative electrode, stores lithium through intercalation. When cycled, graphite transitions through a series of phases differentiated by the number carbon layers between each lithium layer. Reaching the final phase increases the risk of severe degradation, such as lithium plating, making it interesting to track the phase composition.
Lithium intercalation causes electrode expansion, with rates that vary across phases. Therefore, measuring expansion, e.g., using pressure sensors, can provide insight into the current intercalation state. This forms the basis for my research, which aims to use pressure measurements to enable faster and safer charging.
During my secondment at the University of Bristol, the focus will be on thermal compensation. Since temperature changes can increase battery swelling, especially at high currents, separating thermal and phase-related expansion is necessary for accurate phase estimation.

Proof-of-concept for differential pressure-based feedback:
doi.org/10.1038/s41467-022-33486-4
Expansion-based charging strategy, including thermal compensation:
doi.org/10.1016/j.jpowsour.2018.04.095
Estimating phase content from the electrode potential:
doi.org/10.1016/j.matdes.2026.116218
Description of simulation model:
doi.org/10.1016/j.ensm.2026.104997

Isac Borghed

Chalmers University of Technology

Department of Electrical Engineering / Division of Systems and Control