Lithium intercalation into amorphous-silicon thin films: An electrochemical-impedance study

Кулова, Т. Л.; Pleskov, Yu. V.; Скундин, А. М.; Terukov, E. I.; Kon’kov, O. I.

doi:10.1134/s1023193506070032

Cited by 45 publications

(33 citation statements)

References 5 publications

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“…This fact, which is indirectly confirmed in the experiment [26], is apparently explained by the presence of a large number of potential barriers for hopping of lithium atoms in amorphous silicon and the ease of diffusion of lithium atoms through barriers of minimum height.…”

Section: Theoretical Study Of the Diffusion 145mentioning

confidence: 62%

Theoretical study of the diffusion of lithium in crystalline and amorphous silicon

et al. 2012

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143Modern ideas about the mechanisms of diffusion in crystals and liquids were formed in the 1960s, mainly owing to computer simulation by the molecular dynamics and Monte Carlo methods. The problem of diffusion mechanisms in amorphous media is much more complicated than that in crystals and has not yet been completely solved. In particular, this refers to the diffusion of particles in systems that form a low mobile frame and are coupled either by strong cova lent bonds (as in amorphous silicon) or by strong Cou lomb interaction (as in silica). The methods of the the oretical analysis of the diffusion processes in these sys tems have been elaborated insufficiently (see [1]). In contrast to the case of diffusion in crystalline media with low potential barriers (V barrier ≈ (1-10)kT) for hopping of particles, when the molecular dynamics method can be applied, the hopping frequency of atoms through barriers becomes extremely low in structures with high potential barriers (the rare event problem). Therefore, these systems, particularly in the amorphous state, cannot be studied directly by the molecular dynamics method. To speed up the simula tion of the processes of activation hopping for these cases, an activation-relaxation technique (ART) was elaborated recently. It makes it possible to simulate the structure and activation processes in amorphous com pounds (see [2,3]). This method is based on the calcu lation of the transition states (saddle points) of the sys tem (activation) at arbitrarily chosen vectors of motion of atoms by means of the calculation of the forces acting on atoms, and also motion in the direc tion to the nearest saddle point. Atoms arbitrarily relaxed (relaxation) from the transition states to the nearest energy minima defining the amorphous state. The further development of this approach was the uni fication of the kinetic Monte Carlo algorithm and the ART method (the kinetic activation-relaxation tech nique (k ART)), which accelerates the convergence of this algorithm (see [4]). When the method of acceler ated dynamics is developed, it is necessary to mention also the recently elaborated bias potential method [5], the hyperdynamics method [6], and the temperature accelerated dynamics method [7]. The WootenWiner-Weaire algorithm [8], which is based on the random rearrangements of the nearest atoms, is also used to simulate the amorphous structure. It leads to the change in the number and directions of the chem ical bonds between the nearest environment of atoms and the subsequent relaxation of the structure by numerical annealing. The result of the simulation of silicon and germanium by this method showed good coincidence with the experiment for the radial distri bution function of atoms [8]. Unfortunately, all these methods have been applied exclusively to systems that are described either by the simplified embedded atom model or by empirically selected potentials with the The effect of the lattice deformation on potential barriers for the motion of a lithium atom in crystalline sili con has ...

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Section: Theoretical Study Of the Diffusion 145mentioning

confidence: 62%

Theoretical study of the diffusion of lithium in crystalline and amorphous silicon

et al. 2012

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“…Since the penetration depth propagates deeper in the more-curved geometry, given an identical frequency, the transition in Effect of particle size distribution -The effect of heterogeneity in solid-state diffusion length, l , in particles appears in the overall impedance, Z , given by Equation (19). The dimensionless parameters required in the model are taken from literature values [15,27], and a lognormal PDF is employed to describe the distribution in l .…”

Section:  mentioning

confidence: 99%

“…While theoretical formulae of the BD impedance have been derived for a thin film electrode and nanoparticle electrodes with some model particle geometries [2,6,12,13,15,16], they have not been widely applied by experimentalists. In most applications, only the original Warburg impedance model and an one-dimensional BD impedance model have been exclusively used without considering the actual curved particle shape and particle size distribution in interpreting diffusion impedance [7][8][9][10][17][18][19]. Likewise, only these two models are built into commercial data-processing software products (e.g.…”

Section: Introductionmentioning

confidence: 99%

Effects of Nanoparticle Geometry and Size Distribution on Diffusion Impedance of Battery Electrodes

Song¹,

Bazant

2012

J. Electrochem. Soc.

235

195

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The short diffusion lengths in insertion battery nanoparticles render the capacitive behavior of bounded diffusion, which is rarely observable with conventional larger particles, now accessible to impedance measurements. Coupled with improved geometrical characterization, this presents an opportunity to measure solid diffusion more accurately than the traditional approach of fitting Warburg circuit elements, by properly taking into account the particle geometry and size distribution. We revisit bounded diffusion impedance models and incorporate them into an overall impedance model for different electrode configurations. The theoretical models are then applied to experimental data of a silicon nanowire electrode to show the effects of including the actual nanowire geometry and radius distribution in interpreting the impedance data. From these results, we show that it is essential to account for the particle shape and size distribution to correctly interpret impedance data for battery electrodes. Conversely, it is also possible to solve the inverse problem and use the theoretical "impedance image" to infer the nanoparticle shape and/or size distribution, in some cases, more accurately than by direct image analysis. This capability could be useful, for example, in detecting battery degradation in situ by simple electrical measurements, without the need for any imaging.2

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“…Схема представляет собой последовательное соединение сопротивления R 0 , двух параллельных комбинаций сопротивления и элементов с постоянным сдвигом фазы (R 1 CPE 1 ) и (R 2 CPE 2 ), а также последовательно включенного элемента CPE 3 . Такие же или близкие эквивалентные схемы для кремниевых или композитных электродов использовались в работах [12,[18][19][20]. Импеданс элемента с постоянным сдвигом фазы рассчитывается по формуле…”

Section: импедансные измерения кремниевых образцовunclassified

“…Измеренный в таких условиях коэффициент диффузии является концентрационнозависимой величиной, и для него используется термин химический, или эффективный, коэффициент диффузии D [11]. Для корректного нахождения D стараются использовать электроды из чистого кремния без дополнительных компонент, чаще всего в виде пленок аморфного Si [12,13].…”

Section: Introductionunclassified

Импедансная Спектроскопия Пористых Кремниевых И Кремний-Углеродных Анодов, Полученных Спеканием

Ложкина¹,

Румянцев²,

Астрова³

2020

Физика И Техника Полупроводников

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Dry sintered macroporous Si electrodes for Li-ion batteries are first studied using spectral impedance measurements (EIS). The obtained EIS spectra in the lithiated and delithated state are modeled by an equivalent electrical circuit, the parameters of which make it possible to determine the main stages of the electrochemical process of lithium incorporation / extraction caused by the surface layer of solid-state electrolyte (SEI), a double electric layer, and diffusion in the solid phase of the electrode material. It was shown that the effective diffusion coefficient of Li in Si increases with rising degree of lithiation from D = 6.5·10 ^ (-12) cm2/s to D = 2.6·10^ (-10) cm2/s. The effect of carbonization by sucrose pyrolysis was studied, which led to a decrease in impedance and an increase in the diffusion coefficient of lithium to D = 2.2·10^(-10) - 1.7·10^(-9) cm2/s.

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Lithium intercalation into amorphous-silicon thin films: An electrochemical-impedance study

Cited by 45 publications

References 5 publications

Theoretical study of the diffusion of lithium in crystalline and amorphous silicon

Theoretical study of the diffusion of lithium in crystalline and amorphous silicon

Effects of Nanoparticle Geometry and Size Distribution on Diffusion Impedance of Battery Electrodes

Импедансная Спектроскопия Пористых Кремниевых И Кремний-Углеродных Анодов, Полученных Спеканием

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