From Zinc Clusters to One-Dimensional Crystals on Quasi-Free Sustained Substrates

Investigating structural and electronic properties of neutral zinc clusters: a G0W0 and G0W0Г0(1) benchmark

The structural and electronic properties of zinc clusters (Znn) for a size range of n = 2-15 are studied using density functional theory. The particle swarm optimization algorithm is employed to search the structure and to determine the ground-state structure of the neutral Zn clusters. The structural motifs are optimized using the density functional theory approach to ensure that the structures are fully relaxed. Results are compared with the literature to validate the accuracy of the prediction method. The binding energy per cluster is obtained and compared with the reported literature to study the stability of these structures. We further assess the electronic properties, including the ionization potential, using the all-electron FHI-aims code employing G0W0 calculations, and the G0W0Г0(1) correction for a few smaller clusters, which provides a better estimation of the ionization potential compared to other methods.

Selective Shielding of the (002) Plane Enabling Vertically Oriented Zinc Plating for Dendrite-Free Zinc Anode

Uncontrolled growth of Zn dendrites hinders the future development of aqueous Zn-ion batteries. Despite that the (100) plane possesses better zincophilic ability and fast kinetics, dendrites are generally suppressed via (002) plane-oriented Zn deposition in previous reports; the ordered (100) plane-dominant Zn deposition, especially under high current density has not yet been realized. Herein, vertically-oriented Zn plating with preferential growth of (100) plane is reported using disodium lauryl phosphate (DLP) as an electrolyte additive. DLP is preferentially anchored on the Zn (002) crystal plane via the polar phosphate group, then the deposition of Zn atoms on the (002) plane is retarded by the long alkyl chain, finally promoting the preferred growth of the (100) plane. This unique growth pattern results in ultrastable Zn plating/stripping at a super-high current density of 50 mA cm-2 , with a cumulative capacity of 8500 mAh cm-2 . The Zn//Zn symmetric cell also cycles steadily for 700 h with a large areal capacity of 10 mAh cm-2 at a current density of 10 mA cm-2 . This study provides new insights into the realization of dendrite-free Zn anodes by crystal plane modulation.

Catalyst-free growth of zinc nanocrystals with various morphologies on ionic liquid surfaces

We report a catalyst-free growth of zinc nanocrystals with various morphologies on ionic liquid surfaces at room temperature.

Are zinc clusters really amorphous? A detailed protocol for locating global minimum structures of clusters

We report the results of a conjoint experimental/theoretical effort to assess the structures of free-standing zinc clusters with up to 73 atoms. Experiment provides photoemission spectra for ZnN- cluster anions, to be used as fingerprints in structural assessment, as well as mass spectra for both anion and cation clusters. Theory provides both a detailed description of a novel protocol to locate global minimum structures of clusters in an efficient and reliable way, and its specific application to neutral and charged zinc clusters. Our methodology is based on the well-known hybrid EP-DFT (empirical potential-density functional theory) approach, in which the approximate potential energy surface generated by an empirical Gupta potential is first sampled with unbiased basin hopping simulations, and then a selection of the isomers so identified is re-optimized at a first-principles DFT level. The novelty introduced in our paper is a simple but efficient new recipe to obtain the best possible EP parameters for a given cluster system, with which the first step of the EP-DFT method is to be performed. Our method is able to reproduce experimental measurements at an excellent level for most cluster sizes, implying its ability to locate the true global minimum structures; meanwhile, if exactly the same method is applied based on the existing Gupta potential (fitted to bulk properties), it leads to wrong predicted structures with energies between 1 and 2 eV above the correct ones. Opposite to what was claimed in the past, our work unequivocally demonstrates that Zn clusters are not amorphous, and they rather adopt high symmetry structures for most sizes. We show that Zn clusters have a number of exotic, unprecedented structural and electronic properties which are not expected for clusters of a metallic element, and describe them in detail.

DFT study of nano zinc/copper voltaic cells

To facilitate the development of new materials for use in batteries, it is necessary to develop ab initio full-electron computational techniques for modeling potential new battery materials. Here, we tested density functional theory procedures that are accurate enough to obtain the energetics of a zinc/copper voltaic cell. We found the magnitude of the zero-point energy correction to be 0.01-0.2 kcal/mol per atom or molecule and the magnitude of the dispersion correction to be 0.1-0.6 kcal/mol per atom or molecule for Zn _n , (H₂O) _n , [Formula: see text], [Formula: see text], and Cu _n . Counterpoise correction significantly affected the values of ∆[Formula: see text], ∆[Formula: see text], and ∆E^solv by 1.0-3.1 kcal/mol per atom or molecule at the B3PW91/6-31G(d) level of theory, but by only 0.04-0.4 kcal/mol per atom or molecule at the B3PW91/cc-pVTZ level of theory. The application of B3PW91/6-31G(d) yielded results that differed from macroscopic experimental values by 0.1-7.1 kcal/mol per atom or molecule, whereas applying B3PW91/cc-pVTZ produced results that differed from macroscopic experimental values by 0.1-4.8 kcal/mol per atom or molecule, with the smallest differences occurring for reactions with a small macroscopic experimental ∆E and the largest differences occurring for reactions with a large macroscopic experimental ∆E, implying size consistency.