Park, Jun-Hyoung Choi, Yong-Seok Byeon, Young-Woon Ahn, Jae-Pyoung Lee, Jae-Chul 2024-01-19T19:00:37Z 2024-01-19T19:00:37Z 2022-01-25 2019-11 2211-2855 https://pubs.kist.re.kr/handle/201004/119355 Diffusion in alloying anode materials was previously viewed as solute diffusion in conventional alloys. However, solute diffusion, neglecting the presence of a thin intermediate reaction layer between the unreacted anode material and inflowing carrier ions, is insufficient to account for the diffusion kinetics in alloying anodes and their influence on the electrochemical properties of batteries. Here, by performing a comparative study on Na-Sb and Na-Sn battery systems displaying differing diffusion kinetics, we establish the relationship between diffusion kinetics and electrochemical properties for batteries. In situ microelectrochemical experiments show that sodiation in Na-Sb and Na-Sn systems is governed by an interface-controlled reaction (ICR) and a diffusion-controlled reaction (DCR), respectively, causing them to display significantly different diffusion rates, diffusion anisotropy, and possibly self-limiting diffusion of carrier ions. Density functional theory calculations are performed to elucidate the structural origin of the observed diffusion behaviors. It is found that the different degrees of structural stability evaluated for the propagating interfaces of the two systems are responsible for the differing diffusion kinetics, which in turn determine the respective diffusion rates and diffusion anisotropy of the anode materials. The present study provides crude yet quantitative guidelines for selecting battery materials and can be used to develop fast-charging batteries with high stability and improved cycle life. English ELSEVIER Diffusion kinetics governing the diffusivity and diffusion anisotropy of alloying anodes in Na-ion batteries Article 10.1016/j.nanoen.2019.104041 1 NANO ENERGY, v.65 NANO ENERGY 65 N scie scopus 000496445600023 2-s2.0-85070987560 Chemistry, Physical Nanoscience & Nanotechnology Materials Science, Multidisciplinary Physics, Applied Chemistry Science & Technology - Other Topics Materials Science Physics Article CRYSTALLINE SILICON ELECTROCHEMICAL LITHIATION LITHIUM SODIATION EVOLUTION SOLUBILITY NANOWIRES GERMANIUM MECHANISM EXPANSION Sodium-ion battery Diffusion kinetics Interface-controlled reaction Diffusion-controlled reaction In situ sodiation experiment Density functional theory calculations