2023-05-09 ワシントン大学セントルイス校
◆固体電解質の厚さが小さくなると、電池内部での樹状突起の成長を防ぎ、内部短絡を回避できるため、固体電解質の臨界電流密度（CCD）を解決する可能性がある。この研究は、実際の電池での電解質の使用可能性を高めるために、樹状突起発生の統計的傾向を明らかにすることができるという。
＜関連情報＞
- https://engineering.wustl.edu/news/2023/New-study-shows-similarity-between-solid-state-and-liquid-state-electrolytes-used-in-batteries.html
- https://pubs.acs.org/doi/full/10.1021/acsenergylett.3c00499
セラミック電解質における過渡分極とデンドライト発生ダイナミクス Transient Polarization and Dendrite Initiation Dynamics in Ceramic Electrolytes
Rajeev Gopal, Longan Wu, Youngju Lee, Jinzhao Guo and Peng Bai
ACS Energy Letters Published:April 12, 2023
DO:Ihttps://doi.org/10.1021/acsenergylett.3c00499
Abstract
Solid-state electrolytes combined with lithium-metal anodes have the potential to improve the energy density of lithium-ion batteries. However, soft Li metal can still penetrate these stiff electrolytes above a critical current density (CCD). Prevailing methods to determine CCD suffer inconsistencies due to void formations after repeated stripping and plating, leaving significant variations in reported data. Here, we combine one-way linear sweep voltammetry (LSV) with electrochemical impedance spectroscopy (EIS) to uncover the existence of significant polarization in ceramic electrolytes, which can fully relax even without stacking pressure. At high scan rates, LSV experiments showed metal penetration with a diverging transient current, similar to CCD values. However, at a lowered scan rate, the transient current reaches a maximum, suggesting a dynamic electrochemical limiting mechanism. The results and analysis of many consistent samples suggest that polarization of mobile charge carriers preceding the maximum current is critical for accurately understanding dendrite penetration in ceramic electrolytes.
