Making Stress Work For You: Advanced Battery Management Based on Novel Stress/Strain Models and Measurements

Case study was conducted in 2016.

Contributors (TA 3 & 4): Jason Siegel, Bogdan Epureanu, Anna Stefanopoulou, Jau-Ching Lu†, Ki-Yong Oh†, Nassim Samad† (UM), Charles Monroe (Oxford University), Yi Ding, Matt Castanier (GVSC), Brian Eagle (Amphenol), Aaron Knobloch, Jason Karp, Chris Kapusta (General Electric), Dyche Anderson, Arnold Mensah-Brown, XinFan Lin Sung-Kwon Hong (Ford Motor Company)

This case study presented a success story of combining basic research results from multiple ARC projects to launch a multi-disciplinary 4-year program funded by ARPA-E with industrial support. Enabled by structural models for predicting vibrations of stacked battery cells, health monitoring methods for estimating cell aging, and experimental techniques using neutron imaging for visualizing electrode expansion, the ARC investigators constructed a phenomenological thermo-mechanical battery model describing cell swelling due to Lithium intercalation and thermal expansion.

Model-based estimation of critical states—using data from thin-film temperature and strain sensors developed by GE—led to multiple innovations in real time power limits, fast warm-up, and state of health estimation of capacity fading based on monitoring shifts in bulk stress.

These innovations could allow downsizing of the battery with associated increase in energy utilization by 19% per cell and a projected decrease in capacity of only 0.5% after 100,000 miles. Testing and validation with a hybrid-electric vehicle battery pack is currently underway at Ford.