Irreversible Structural Changes in Lithium Electrodes Accelerate Capacity Fading in Lithium-Metal-Based Rechargeable Batteries

High Resolution Image Download MS PowerPoint Slide Lithium-metal-based rechargeable batteries (LMBs) are promising candidates for next-generation energy storage devices because of their high energy density potentials. However, for the practical implementation of LMBs, an in-depth understanding of the degradation mechanism at the lithium-metal electrode is necessary. Although recent studies have revealed that macroscopic volume changes in lithium electrodes are associated with the repeated lithium dissolution/deposition reaction, the detailed degradation mechanism remains unclear. Thus, we demonstrate that the solid-state product layer composed of isolated lithium particles covered by solid–electrolyte interface (SEI) components has a significant impact on the electrode volume. Notably, this volume change increases the overpotential during the lithium deposition process, resulting in capacity fading during repeated cycles. We believe that this clarified degradation mechanism will aid the research and development of LMBs with high energy densities and long cycle lives.