Deepening the understanding of cracking during electrode drying
One of the key aims of the Nextrode project is to enable increased energy and power density in lithium-ion batteries by producing thicker electrodes with optimised microstructures. Methods such as ice templating and laser cutting have been used by the project to introduce vertical pores through battery electrodes, which enable faster ion diffusion and consequently improve energy density and fast charging performance. Researchers at UCL have advanced the understanding of how spontaneous electrode cracking during drying may serve a similar purpose while theoretically eliminating the need for additional process steps and capital costs.
Electrode cracking occurs as a consequence of stresses that build during the drying process and are particularly prevalent in thicker electrodes or those with smaller active particles (such as LFP or LMFP – lithium manganese iron phosphate). To study the cracking process dynamically, researchers used synchrotron X-ray computed tomography (CT) imaging at the European Synchrotron Research Facility (ESRF) to capture the electrode drying process and crack formation in 3D. This enabled the prediction of crack position before they became visible, using digital volume correlation.
A follow-on study, also at the ESRF, used localised multi-channel collimator X-ray diffraction to infer the lithium content of lithium nickel manganese cobalt oxide particles from their crystal structure in different regions of cracked electrodes. By applying the technique during battery operation, researchers developed an understanding of how vertical pores impact electrode active material utilisation at a microstructural level. This research, paired with a previous study published in Batteries and Supercaps, contributed key insights to the understanding and optimisation of structural design for thick electrodes, potentially leading to increased energy density and longer EV range.
Image: A 3D volume renderings of crack growth during the Li-ion electrode drying process taken from in situ X-ray CT imaging.
Case study published December 2025.