In Situ Visualization of Lithium Penetration through Solid Electrolyte and Dead Lithium Dynamics in Solid-State Lithium Metal Batteries

作者：Haiming Sun, Qiunan Liu, Jingzhao Chen, Yanshuai Li, Hongjun Ye, Jun Zhao, Lin Geng, Qiushi Dai, Tingting Yang, Hui Li, Zaifa Wang, Liqiang Zhang, Yongfu Tang, Jianyu Huang · 发表于：ACS Nano · 年份：2021 · DOI：10.1021/acsnano.1c04864 · 被引用次数：114 · 研究领域：Advanced Battery Materials and Technologies、Advancements in Battery Materials、Advanced Battery Technologies Research

The two biggest promises of solid-state lithium (Li) metal batteries (SSLMBs) are the suppression of Li dendrites by solid-state electrolyte (SSE) and the realization of a high-energy-density Li anode. However, LMBs have not met their expectations due to Li dendrite growth causing short-circuiting. In fact, Li dendrites grow even more easily in SSE than in liquid electrolyte, but the reason for this remains unclear. Here we report in situ transmission electron microscopy observations of Li dendrite penetration through SSE and “dead” Li formation dynamics in SSLMBs. We show direct evidence that large electrochemomechanical stress generates cracks in the SSE and drives Li through the SSE directly. We revealed that fresh Li nucleation sites emerged in every discharge cycle, creating new “dead” Li in the following charging cycle and becoming the dominant Coulombic efficiency decay mechanism in SSLMBs. These results indicate that engineering flaw size and reducing electronic conductivity in SSEs are essential to improve the performance of SSLMBs.