Quantifying Bulk Electrode Strain and Material Displacement within Lithium Batteries via High‐Speed Operando Tomography and Digital Volume Correlation

• Published in: Advanced science Vol. 3; no. 3; pp. 1500332 - n/a
• Main Authors: Finegan, Donal P., Tudisco, Erika, Scheel, Mario, Robinson, James B., Taiwo, Oluwadamilola O., Eastwood, David S., Lee, Peter D., Di Michiel, Marco, Bay, Brian, Hall, Stephen A., Hinds, Gareth, Brett, Dan J. L., Shearing, Paul R.
• Format: Journal Article
• Language: English
• Published: Germany John Wiley & Sons, Inc 01.03.2016; John Wiley and Sons Inc
• Subjects: Annan kemiteknik; Architectural engineering; Chemical Engineering; degradation; digital volume correlation; Electrodes; Engineering and Technology; High speed; Kemiteknik; Lithium; lithium batteries; Morphology; operando imaging; Other Chemical Engineering; Teknik; Three dimensional imaging; Tomography; X-ray computed tomography; degradation; digital volume correlation; lithium batteries; operando imaging; X‐ray computed tomography
• ISSN: 2198-3844; 2198-3844
• DOI: 10.1002/advs.201500332

Tracking the dynamic morphology of active materials during operation of lithium batteries is essential for identifying causes of performance loss. Digital volume correlation (DVC) is applied to high‐speed operando synchrotron X‐ray computed tomography of a commercial Li/MnO2 primary battery during discharge. Real‐time electrode material displacement is captured in 3D allowing degradation mechanisms such as delamination of the electrode from the current collector and electrode crack formation to be identified. Continuum DVC of consecutive images during discharge is used to quantify local displacements and strains in 3D throughout discharge, facilitating tracking of the progression of swelling due to lithiation within the electrode material in a commercial, spiral‐wound battery during normal operation. Displacement of the rigid current collector and cell materials contribute to severe electrode detachment and crack formation during discharge, which is monitored by a separate DVC approach. Use of time‐lapse X‐ray computed tomography coupled with DVC is thus demonstrated as an effective diagnostic technique to identify causes of performance loss within commercial lithium batteries; this novel approach is expected to guide the development of more effective commercial cell designs. High speed synchrotron X‐ray computed tomography is used to capture the morphological evolution of active materials within a commercial Li/MnO2 battery during discharge. Temporal 3D strain profiles of the MnO2 electrode are generated via digital volume correlation of sequential 3D tomograms, providing insight into local Li+ transport and interactions between the active material and the cell's mechanical design.