Neutron Imaging of Lithium Ion Batteries

Principal Investigators: Anna Stefanopoulou, University of Michigan, annastef(at)
Co-PI Jason Siegel, University of Michigan, siegeljb(at)
Student: Shankar Mohan, University of Michigan
Government: Yi Ding, David Gorsich, U.S. Army TARDEC
Dan Hussey, NIST
Industry: Patrick Hagans, Navitas Advanced Solutions Group

Project began in 2010 and was completed in 2013.

Neutron imaging, also known as neutron radiography, is a valuable tool for in-situ measurements, similar to x-ray radiography. The change in attenuation of a neutron beam passing through a sample can be used to measure a change in the material over time. As lithium concentration inside a battery electrode change, there is a direct and measureable change in the associated neutron attenuation. Moreover, the largest change in molar concentration of lithium occurs within the intercalation materials. Therefore, the change in detected beam intensity is related to the change in Li concentration in the solid electrodes.

The long term goal of this project is use neutron radiography for measuring in situ lithium concentration in lithium-ion battery cells and hence validate mathematical models of Li-ion cells. These models can then be used for real-time state of charge estimation and efficient cell-to-cell balancing using nonlinear predictive control theoretic techniques. The in situ measurements can provide critical information needed to understand, quantify, and model mechanisms associated with battery degradation.


  • Jason B. Siegel, Anna G. Stefanopoulou, Patrick Hagans, Yi Ding, and David Gorsich. Expansion of Lithium Ion Pouch Cell Batteries: Observations from Neutron Imaging. J. Electrochem. Soc., 160 (8), 2013. doi:10.1149/2.011308jes
  • C. Speltino, A. G. Stefanopoulou, and G. Fiengo. Parameterisation and estimation of surrogate critical surface concentration in lithium-ion batteries. In Special Issue on Int’l Journal of Vehicle Dynamics, Vol. 61, No. 1 - 234, pp. 128-156, Jan. 2013. doi:10.1504/IJVD.2013.050843
  • Jason B. Siegel, Xinfan Lin, and Anna G. Stefanopoulou. On the accuracy and simplifications of battery models using in situ measurements of lithium concentration in operational cells. In Proceedings of the 2012 American Control Conference, pp. 1362 - 1367, Montreal, Canada, June 2012. doi:10.1109/ACC.2012.6315414
  • Jason B. Siegel, Xinfan Lin, and Anna G. Stefanopoulou. Neutron imaging of degraded LFP pouch cells illustrate dendrite formation and internal shorts. In ECS Meeting Abstracts, volume 1201, page 506, Seattle, Washington, May 2012. ECS.
  • J. B. Siegel, X. Lin, A. G. Stefanopoulou, D. S. Hussey, D. L. Jacobson. Neutron Imaging of Lithium Concentration in LFP Pouch Cell Battery. J. Electrochem. Soc. 158, A523 (2011), doi: 10.1149/1.3566341.
    Publication is supplemented by:
  • Xinfan Lin, Anna Stefanopoulou and David Gorsich Jason B. Siegel. Neutron Imaging of Lithium Concentration in Battery Pouch Cells. American Controls Conference, Invited, San Francisco, CA, June 2011. doi:10.1109/ACC.2011.5990883
  • Jason B. Siegel, Xinfan Lin, Anna Stefanopoulou, Daniel Hussey, and David Jacobson. Neutron imaging LFP pouch cells: Spatially resolved changes in lithium concentration. In ECS Meeting Abstracts, volume 1101, page 515, Montreal, QC, Canada, May 2011. ECS.
  • Jason B. Siegel, and Anna G. Stefanopoulou Xinfan Lin. Quantifying Lithium Concentration in a Li-Ion Battery Using Neutron Radiography. Battery Congress, Ann Arbor, MI, April 2011.
  • Xinfan Lin, Anna G. Stefanopoulou, and David Gorsich Jason B. Siegel. Neutron Imaging of Lithium Concentration for Validation of Li-Ion Battery State of Charge Estimation. Army Science Conference, Orlando, FL, December 2010.