Identifying soft breakdown in all-solid-state lithium battery

Summary

Recent years have witnessed significant advances in all-solid-state lithium batteries (ASSLBs). However, soft breakdown hidden in ASSLBs has been overlooked in most previous research. Moreover, existing assessment criteria are insensitive to detecting soft breakdown. Here, we first discuss the current status of ASSLBs and highlight the challenges of evaluating the soft breakdown phenomenon with the existing evaluation method. A simple but effective strategy—cyclic voltammetry—is then proposed to diagnose soft breakdown in all-solid-state symmetric cells. To establish a standard testing protocol, several critical parameters that have not been well emphasized thus far, including areal capacity, thickness, and porosity of solid electrolytes, are numerically analyzed to understand their significant effect on the energy density of practical all-solid-state pouch cells. With these understandings, we establish a definitive testing benchmark with the aim of guiding the research efforts toward in-depth scientific understanding and practical engineering design.