![]() Results obtained from ultra-pure electrolyte suggest preferred crystal growth towards well-mixed orientation in the concentration field caused by slight differences in crystallization overpotential. Morphological observations revealed the major influence of trace lead ions on the amplifications of surface roughness through coalescence and preferred growth of more » initial protrusions. ![]() Logarithmic spiral markings, which reflect the hydrodynamic flow on a rotating disk, appear in a certain region of current density well below the limiting current density. The development of macromorphology of zinc deposits has been investigated under galvanostatic conditions on a rotating plantinum disk electrode by use of photomacrography, scanning electron microscopy, electron probe microanalysis and Auger microprobe analysis. The morphology of zinc as it is electrodeposited from acid solutions demonstrates a remarkable imprint of electrolyte flow conditions. At low over potentials, the current transients were not consistent with theory, and AFM images confirmed that nuclei did not overlap. At high over potentials, the current transients were consistent with theory, and AFM images indicated that nucleation was three-dimensional with overlap. The current transients and AFM images recorded during the deposition experiments were compared with theory for 3-D, solution-diffusion-controlled, multiple nucleation with overlap. At over potentials =]200 mV), uniform nucleation and overlap were observed. On Pt(111), three-dimensional nucleations of copper was monitored at the nanoscale level during cathodic deposition from 0.25M CuSO/0.5M HSO. From solutions containing 100 m BTA, deposition occurred without regard to substrate features. more » From solutions containing 10M BTA, copper deposited in clumps along the steps. ![]() In the absence of BTA, copper selectively deposited on the larger step sites rather than on the smaller steps or terrace regions. Deposit morphology was monitored primarily during growth at current densities between 1 and 15 mA/cm under stagnant conditions. The Pt(100) crystal was misoriented 2 to give terraces that were approximately 1 m in length and 25 to 50 high. In situ atomic force microscopy (AFM) was used to observe growth morphology during copper electrodeposition on Pt(100) and Pt(111) surfaces from 0.25 M CuSO/0.5M HSO containing 0, 10, and 100 M benzotriazole (BTA). (LLNL), Livermore, CA (United States) Sponsoring Org.: USDOE National Nuclear Security Administration (NNSA) USDOE Office of Science (SC) OSTI Identifier: 1811787 Alternate Identifier(s): OSTI ID: 1702329 Report Number(s): LLNL-JRNL-813115 Journal ID: ISSN 0013-4686 1019897 Grant/Contract Number: AC52-07NA27344 AC02-06CH11357 Resource Type: Accepted Manuscript Journal Name: Electrochimica Acta Additional Journal Information: Journal Volume: 342 Journal Issue: na Journal ID: ISSN 0013-4686 Publisher: Elsevier Country of Publication: United States Language: English Subject: 36 MATERIALS SCIENCE materials science condensed matter physics storage ultra-small-angle X-ray scattering in situ atomic force microscopy electrodeposition ionic liquid electrolyte zinc anode = , Publication Date: Research Org.: Lawrence Livermore National Lab. of California, Berkeley, CA (United States) of California, Berkeley, CA (United States) Lawrence Livermore National Lab. ![]() Finally, a more detailed analysis suggests that there is little change in the aspect ratio of the individual Zn crystals – this is consistent with a growth mechanism in which more » previously deposited plates grow in diameter as new plates nucleate on their surface and then coalesce into one crystal. Analysis of the key features observed by USAXS indicates that the growth of the domain size is non-linear with the charge passed and that at least some of this non-linearity can be attributed to increased coalescence of the individual plates as the deposit thickens. Imaging reveals two dominant features: a hexagonal plate-like morphology associated with individual Zn crystals and larger domains in which the individual crystals appear co-aligned. In this work, we evaluate the evolution of zinc morphology as a function of the deposition thickness using in situ atomic force microscopy (AFM), in situ ultra-small angle X-ray scattering (USAXS) and ex situ electron microscopy. However, the underlying mechanisms that control deposition and morphology are not well understood. In recent years, researchers have demonstrated that the Zn morphology can be tuned by electrodepositing from an ionic liquid often leading to morphologies that improve cyclability. Zinc (Zn) is a low-cost material that is widely used in plating and is under consideration as a reversible deposit for a range of energy storage applications. ![]()
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