Strong stress-composition coupling in lithium alloy nanoparticles

• Published in: Nature communications Vol. 10; no. 1; pp. 3428 - 8
• Main Authors: Seo, Hyeon Kook, Park, Jae Yeol, Chang, Joon Ha, Dae, Kyun Sung, Noh, Myoung-Sub, Kim, Sung-Soo, Kang, Chong-Yun, Zhao, Kejie, Kim, Sangtae, Yuk, Jong Min
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 31.07.2019; Nature Publishing Group UK; Nature Portfolio
• Subjects: Alloys; Binary alloys; Chemical reactions; Composition; Core-shell particles; Coupling; Density functional theory; Electrochemistry; Electron microscopy; Graphene; Lithium; Lithium base alloys; Morphology; Nanoalloys; Nanoparticles; Stress; Stress concentration; Tin; Tin oxide; Tin oxides
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-019-11361-z

The stress inevitably imposed during electrochemical reactions is expected to fundamentally affect the electrochemistry, phase behavior and morphology of electrodes in service. Here, we show a strong stress-composition coupling in lithium binary alloys during the lithiation of tin-tin oxide core-shell nanoparticles. Using in situ graphene liquid cell electron microscopy imaging, we visualise the generation of a non-uniform composition field in the nanoparticles during lithiation. Stress models based on density functional theory calculations show that the composition gradient is proportional to the applied stress. Based on this coupling, we demonstrate that we can directionally control the lithium distribution by applying different stresses to lithium alloy materials. Our results provide insights into stress-lithium electrochemistry coupling at the nanoscale and suggest potential applications of lithium alloy nanoparticles.