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The voltammetric behavior of Li+ intercalation/deintercalation in/from LiMn2O4 thin films and single particles is simulated, supporting very recent experimental results. Experiments and calculations both show that particle size and geometry are crucial for the electrochemical response. A remarkable outcome of this research is that higher potential sweep rates, of the order of several millivolts per second, may be used to characterize nanoparticles by voltammetry sweeps, as compared with macroscopic systems. This is in line with previous conclusions drawn for related single particle systems using kinetic Monte Carlo simulations. The impact of electrode kinetics and finite space diffusion on the reversibility of the process and the finiteness of the diffusion in ion Li / LiMn2O4 (de)intercalation is also discussed in terms of preexisting modeling. [ABSTRACT FROM AUTHOR]

This work presents key modeling aspects that are central to the manipulation of the decoration of metallic nanoparticles by a thin shell of a metal of different chemical nature. The concept of underpotential deposition is generalized to nanoparticles. An all-atom model, taking into account many-body interactions by means of the embedded atom potential, was used to represent nanoparticles of different sizes and atomic adsorbates on them. A full set of state-of-the-art computer simulations are performed for a model system, showing that selective decoration of facets is possible. The trends observed in the present work are in good qualitative agreement with experimental data reported very recently. [ABSTRACT FROM PUBLISHER]

Abstract: The electrochemical decoration of Au and Pd nanoparticles by Pd and Au atoms respectively is discussed in a statistical mechanical framework. It is found that depending on precursor nanoparticle size and shape, controlled decoration may be achieved in undersaturation or oversaturation conditions. Multilayer deposition is also considered, with the finding that this phenomenon is also size dependent. [Copyright &y& Elsevier]

Abstract: A thermodynamic model predicting the disappearance of the underpotential deposition phenomenon in the limit of small nanoparticles is proposed and developed for selected families of geometric bodies. The key parameters are the binding energy of adatoms on the flat foreign substrate and at the edges of the nanoparticle. [Copyright &y& Elsevier]

Abstract: The meaning of underpotential shift is discussed for free nanoparticles, where a redox couple is used to set potential control on them. Atomistic Monte Carlo simulations are performed to study their decoration in the submonolayer regime. The resulting configurations are used to simulate their plasmon spectra by means of a state-of-the art quantum mechanical atomistic model. [Copyright &y& Elsevier]

Abstract: Electrochemical deposition of a metal on a foreign substrate may occur before or after the Nernst reversible potential, depending on the chemical nature of the substrate and adsorbate in question. Statistical mechanical treatment and a proper description of interactions between the particles of the system are necessary for an adequate theoretical representation of the electrochemical systems. In the present work, changes in relevant thermodynamic properties due to adsorption of a metal on a foreign single crystal (h k l) metallic surface are studied for a number of systems of electrochemical interest by means of quasi-harmonic (QH) lattice dynamics calculations with embedded atom method potentials at 300K. The metal couples considered involve silver, gold, platinum, palladium and copper. Underpotential and overpotential deposition trends observed for this set of transition metal systems are analyzed taking into account the changes in the internal energies and the entropic contributions due to deposition processes. The possibility of obtaining entropic information from measurements at different temperatures is also discussed. [Copyright &y& Elsevier]

Abstract: In order to contribute to the understanding of metal electrodeposition on real surfaces, we consider in the present work the deposition of Ag, Cu and Pd on a Pt(111) surface with defects. Off lattice Monte-Carlo simulations were performed using embedded atom method Potentials in the canonical ensemble at 300 K. Structural and energetic properties of deposits on surface defects of low dimension (iD=0,1,2) were studied. Among others, we consider vacancies (0D), steps (1D) and holes (2D). The results obtained are in qualitative agreement with experimental data in the literature. [Copyright &y& Elsevier]

Kinetic Monte Carlo simulations are applied to simulate the insertion of lithium ions into graphite. The present results show how the kinetics of lithium ion intercalation in graphite rules the global process, leading to metastable phases. The relatively slow rate of the events of insertion (deinsertion) of lithium ions into (from) graphite is found to yield the intercalation structures proposed by Daumas and Hérold. These arrangements can be considered as frustrated, metastable structures, with a higher energy than that of the equilibrium state. [ABSTRACT FROM AUTHOR]