Dynamics of the lithium metal electrodeposition: Effects of a gas bubble

TL;DR

This study uses a phase-field model to analyze how a static gas bubble influences lithium dendrite growth during electrodeposition, revealing that bubbles accelerate dendrite formation and affect their morphology, which is crucial for battery safety.

Contribution

The paper introduces a grand potential-based phase-field model to investigate the impact of gas bubbles on lithium dendrite growth, highlighting the role of bubble size and position.

Findings

Gas bubbles accelerate dendrite growth.

Larger and closer bubbles lead to longer dendrites.

Bubbles cause dendrite bending and tilting.

Abstract

Rechargeable lithium metal batteries have been widely investigated recently, driven by the global trend for the electrification of transportation. Understanding the dynamics of lithium metal electrodeposition is crucial to design safe and reliable lithium metal anodes. In this study, we developed a grand potential-based phase-field model to investigate the effect of a static gas bubble, which forms due to the complicated internal side reactions, on the dynamics of the dendrite growth during electrodeposition. It is observed that with the presence of a gas bubble, the dendrite growth is largely accelerated, due to the accumulation of lithium ions on the far side of the bubble away from the anode surface, which could serve as an ion "reservoir" for the dendrite growth, leading to the bending/tilting of the lithium dendrites toward the bubble. Meanwhile, the effects of the bubble size and distance to the anode are further studied, demonstrating that the larger the bubble size and the closer to the anode, the longer the lithium dendrites grow. We hope this study could serve as an example to exploit the effect of extrinsic factors on the dendrite growth dynamics.