Kinetically-Driven Phase Transformation during Lithiation in Copper Sulfide Nanoflakes.

Title Kinetically-Driven Phase Transformation during Lithiation in Copper Sulfide Nanoflakes.
Authors K. He; Z. Yao; S. Hwang; N. Li; K. Sun; H. Gan; Y. Du; H. Zhang; C. Wolverton; D. Su
Journal Nano Lett
DOI 10.1021/acs.nanolett.7b02694
Abstract

Two-dimensional (2D) transition metal chalcogenides have been widely studied and utilized as electrode materials for lithium ion batteries due to their unique layered structures to accommodate reversible lithium insertion. Real-time observation and mechanistic understanding of the phase transformations during lithiation of these materials are critically important for improving battery performance by controlling structures and reaction pathways. Here, we use in situ transmission electron microscopy methods to study the structural, morphological, and chemical evolutions in individual copper sulfide (CuS) nanoflakes during lithiation. We report a highly kinetically driven phase transformation in which lithium ions rapidly intercalate into the 2D van der Waals-stacked interlayers in the initial stage, and further lithiation induces the Cu extrusion via a displacement reaction mechanism that is different from the typical conversion reactions. Density functional theory calculations have confirmed both the thermodynamically favored and the kinetically driven reaction pathways. Our findings elucidate the reaction pathways of the Li/CuS system under nonequilibrium conditions and provide valuable insight into the atomistic lithiation mechanisms of transition metal sulfides in general.

Citation K. He; Z. Yao; S. Hwang; N. Li; K. Sun; H. Gan; Y. Du; H. Zhang; C. Wolverton; D. Su.Kinetically-Driven Phase Transformation during Lithiation in Copper Sulfide Nanoflakes.. Nano Lett. 2017. doi:10.1021/acs.nanolett.7b02694

Related Elements

Sulfur

See more Sulfur products. Sulfur (or Sulphur) (atomic symbol: S, atomic number: 16) is a Block P, Group 16, Period 3 element with an atomic radius of 32.066. Sulfur Bohr ModelThe number of electrons in each of Sulfur's shells is 2, 8, 6 and its electron configuration is [Ne] 3s2 3p4. In its elemental form, sulfur has a light yellow appearance. The sulfur atom has a covalent radius of 105 pm and a Van der Waals radius of 180 pm. In nature, sulfur can be found in hot springs, meteorites, volcanoes, and as galena, gypsum, and epsom salts. Sulfur has been known since ancient times but was not accepted as an element until 1777, when Antoine Lavoisier helped to convince the scientific community that it was an element and not a compound.

Copper

See more Copper products. Copper Bohr Model Copper (atomic symbol: Cu, atomic number: 29) is a Block D, Group 11, Period 4 element with an atomic weight of 63.546. The number of electrons in each of copper's shells is 2, 8, 18, 1 and its electron configuration is [Ar]3d10 4s1. The copper atom has a radius of 128 pm and a Van der Waals radius of 186 pm. Copper was first discovered by Early Man prior to 9000 BC. In its elemental form, copper has a reddish-orange metallic and lustrous appearance. Of all pure metals, only silver Elemental Copperhas a higher electrical conductivity. The origin of the word copper comes from the Latin word 'cuprium' which translates as "metal of Cyprus," as the Mediterranean island of Cyprus was known as an ancient source of mined copper..

Related Forms & Applications