2026-04-08 ヒューストン大学（UH）
Lithium-ion batteries power everything from smartphones to electric vehicles. Photo courtesy: GettyImages
＜関連情報＞
- https://www.uh.edu/news-events/stories/2026/april/04082026-lithium-battery-weakness.php
- https://www.science.org/doi/10.1126/science.adu9988
- https://www.nature.com/articles/s41467-025-59567-8
強靭で脆いリチウムデンドライ Strong and brittle lithium dendrites
Qing Ai, Boyu Zhang, Xing Liu, Bongki Shin, […] , and Jun Lou
Science Published:12 Mar 2026
DOI:https://doi.org/10.1126/science.adu9988
Editor’s summary
As a bulk material, lithium is a soft metal with the ability to deform, enabling good electrical contact to solid electrolyte surfaces. Ai et al. performed a nanomechanical study on lithium dendrites that grew on a copper transmission electron microscopy (TEM) grid in a working lithium-ion battery with liquid electrolytes. Lithium dendrites were transferred from the TEM grid to a testing device using an air-free procedure. Tensile tests performed in a scanning electron microscope showed that the dendrites have remarkably high fracture strength, high modulus, and brittle fracture. These observations may help to explain solid electrolyte penetration, poor interfacial contact, and the presence of “dead lithium” in solid-state batteries. —Marc S. Lavine
Abstract
The growth and penetration of lithium dendrites through electrolytes and separators remain key challenges to realizing high–energy density lithium-metal batteries. Using mechanically strong electrolytes and separators has been considered a promising strategy based on the commonly believed softness of lithium. However, dendrite formation persists in stiff solid electrolytes, suggesting distinct mechanical behaviors. We measured the mechanical properties of individual lithium dendrites using an air-free protocol. We found that lithium dendrites are unexpectedly strong and brittle, with fracture stress greater than ~150 megapascals, unlike the ductile bulk metal. Cryo–transmission electron microscopy and mechanical modeling showed that this behavior arises from solid electrolyte interface constraints and nanoscale strengthening. These findings provide alternative mechanisms for dendrite penetration and dead lithium formation as well as guidance for design strategies for lithium-metal batteries.
オペランド走査型電子顕微鏡を用いたリチウム固体電解質界面の進化の画像化 Imaging the evolution of lithium-solid electrolyte interface using operando scanning electron microscopy
Lihong Zhao,Min Feng,Chaoshan Wu,Liqun Guo,Zhaoyang Chen,Samprash Risal,Qing Ai,Jun Lou,Zheng Fan,Yue Qi & Yan Yao
Nature Communications Published:08 May 2025
DOI:https://doi.org/10.1038/s41467-025-59567-8
Abstract
The quality of Li–solid electrolyte interface is crucial for the performance of solid-state lithium metal batteries, particularly at low stack pressure, but its dynamics during cell operation remain poorly understood due to a lack of reliable operando characterization techniques. Here, we report the evolution of Li–electrolyte interface with high spatial resolution using operando scanning electron microscopy under realistic operating conditions. By tracking the stripping process of both Li and Li-rich Li-Mg alloy anodes, we show that multiple voids coalesce into a single gap and eventually delaminate the interface in Li, whereas the voids split and collapse to partially recover interfacial contact in Li-Mg. Density functional theory calculations show that the stronger Mg-S interaction at the metal–electrolyte interface attracts Mg toward the interface and repels Li-vacancies into the bulk, resulting in a reduced number of voids. The pressure-dependent voltage profiles of Li and Li-Mg stripping suggest that loss of contact due to void formation, rather than Mg accumulation at the interface, is the origin of high overpotential that limits the utilization of metal anodes. Improved interfacial contact enables stable cycling of all-solid-state lithium full cell at low stack pressure (1 MPa) and moderate rate (2 mA cm−2) simultaneously. The real-time visualization of Li–electrolyte interface dynamics provides critical insights into the rational design of solid-state battery interfaces.
