In Situ Characterization and Phase‐Filed Modeling of the Interaction between Dendrites and Gas Bubbles during an Electrochemical Process

The extrusion of dendrites and gas bubbles can lead to the appearance of dead lithium, which seriously reduces the coulomb efficiency, hindering the rapid development of high‐energy batteries. Therefore, it is very important to study the internal mechanism of the interaction between lithium dendrites and gas bubbles during electrochemical processes. In this paper, we have designed and developed a special in situ observation device for investigating the dendrite behavior. We also modified the phase‐field model to study the growth of lithium dendrites on the electrode with bubbles. The cantilever beam theory was applied to study the interaction between lithium dendrites and gas bubbles. The observed effects comprise the coalescence of gas bubbles, changing of lithium‐ion transport path on graphite electrode surface near the gas bubble, and bending of dendrites in front of the bubble. The local variation in the lithiation speed can be attributed to the insulating properties of the gas bubbles. Phase‐field simulation results of the interaction between dendrites and gas bubbles were consistent with the experimental results. A deeper insight into the gas‐bubble behaviors during dendrite growth with the presented simulation and experiment techniques becomes possible, which could be helpful to choose an appropriate structural design for reducing bubbles and lithium dendrites. A special in situ observation device for investigating dendrite behavior has been designed and developed.