Towards the I n-Operando Observation of Lithium Dendrite Growth Via X-Ray Computed Tomography

Abstract

The formation of lithium dendrites causes significant safety concerns in current lithium ion cells and prevents the implementation of commercial lithium metal batteries. To better understand this phenomenon, we are using nanoresolution x-ray computed tomography (nano-CT) to observe the in-operando nucleation and growth of dendrites during lithium deposition. Preliminary results of lithium films deposited ex-situ reveal that different deposition conditions affect not only the surface morphology but also subsurface features. Figure 1 displays the results of cycling the lithium film at high rates: the higher rate sample shows a dramatic increase in thickness and porosity within the film. The observational cell can also be used to observe other degradation processes occurring within lithium-ion batteries such as the deposition of copper dendrites during an overdischarge event. We will show preliminary results on the effect of deposition conditions (rate, temperature, etc.) on the surface and subsurface morphology of the lithium. From this, we are able to investigate how suppression methods such as electrolyte composition affect these features and develop more targeted strategies at dendrite prevention. Figure 1