Solid State Electrochemistry I: Thermodynamics and Kinetics of Charge Carriers in Solids
About: This article is published in ChemInform.The article was published on 2005-01-01. It has received 17 citations till now. The article focuses on the topics: Space charge.
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TL;DR: The thermodynamics of electrochemical lithium storage are examined by taking into account that it is the point defects that enable storage, and the relationship between reversible cell voltage and lithium content is derived for the novel job-sharing mechanism.
Abstract: The thermodynamics of electrochemical lithium storage are examined by taking into account that it is the point defects that enable storage. While the Li defects are mobile, most of the other point defects have to be considered as frozen owing to the performance temperature being low compared to the melting point of the electrode materials. The defect chemistry needs to be considered to fully understand equilibrium charge/discharge curves. On this basis, single phase and multiphase storage mechanisms can be discussed in terms of theoretical storage capacity and theoretical voltage. Of paramount interest in the field of Li batteries are metastable materials, in particular nanocrystalline and amorphous materials. The thermodynamics of storage and voltage, also at interfaces, thus deserve a special treatment. The relationship between reversible cell voltage and lithium content is derived for the novel job-sharing mechanism. With respect to the classic storage modes, thermodynamic differences for cathodes and anodes are elaborated with a special attention being paid to the search for new materials. As this contribution concentrates on the equilibrium state, current-related phenomena (irreversible thermodynamics) are only briefly touched upon.
165 citations
TL;DR: In this paper, the formation and evolution of LiCoO2-LiPON interfaces upon annealing using photoelectron spectroscopy was investigated and the results of a combined Li-ion and electron interface energy level scheme providing insights into fundamental charge transfer processes.
Abstract: In this contribution, we investigate the formation and evolution of LiCoO2–LiPON interfaces upon annealing using photoelectron spectroscopy. We identify interlayer compounds related to the deposition process and study the chemical reactions leading to interlayer formation. Based on the structure of the pristine interface as well as on its evolution upon annealing, we relate reaction layer and space charge layer formation to chemical potential differences between the two materials. The results are discussed in terms of a combined Li-ion and electron interface energy level scheme providing insights into fundamental charge transfer processes. In constructing the energy level alignment, we take into account calculated defect formation energies of lithium in the cathode and solid electrolyte.
75 citations
04 Mar 2019
TL;DR: In this article, a facile and scalable method for nitrogen doping of carbon paper electrodes, leading to superior electrocatalytic activity was demonstrated, and the effects of pyrolytic pretreatments under different conditions on the performance of carbon papers were also studied to elucidate their intrinsic electron transfer kinetics, using Raman spectroscopy.
Abstract: Carbon paper electrodes are employed for different electrochemical applications such as flow batteries and fuel cells. However, redox reactions such as VO2+/VO2+ in a vanadium redox flow battery have been found to possess relatively slow kinetics, resulting in significant activation losses during operation. In this work, we demonstrate a facile and scalable method for nitrogen doping of carbon paper electrodes, leading to superior electrocatalytic activity. The effects of pyrolytic pretreatments under different conditions on the performance of carbon paper were also studied to elucidate their electrocatalytic activity from a material physics perspective, using Raman spectroscopy. The 2D Raman signature, a specific feature of the carbon structures, was employed to understand the effect of different pretreatments on the Fermi level of the carbon papers, which could help us elucidate their intrinsic electron transfer kinetics. The full wave half-maximum of the 2D Raman band and the intensity ratio I2D/IG wer...
42 citations
24 citations
TL;DR: In this paper, an extension of the continuum elasticity model combined with the classical lattice-gas (LG) model was proposed to describe guest ion insertion into various host materials, and the analysis of the (chemical) differential intercalation capacitance, Cdif, and of the chemical diffusion coefficient, D, on the concentration of Li-ions in graphite in the course of electrochemical lithiation/delithiation of these electrodes.
Abstract: This work is devoted to an extension of the continuum elasticity model combined with the classical lattice-gas (LG) model that recently appeared in the literature and described guest ion insertion into various host materials. The extension involves two important aspects: (i) derivation of intercalation isotherms with four different elastic parameters with the purpose to find their critical combination, leading to first-order phase transitions, and (ii) quantitative treatment of the first-order phase transition reactions controlled by slow external kinetics. This analysis helps to understand properly an important issue of the mechanism of electrochemically driven first-order phase transitions in various ion-insertion electrodes often disregarded in the literature: whatever the concerned electrochemical characteristics are measured, the underlying (often hidden, in practice) kinetic limitations must be considered. The analysis described herein refers to the dependence of the (chemical) differential intercalation capacitance, Cdif, and of the chemical diffusion coefficient, D, on the concentration of Li-ions in graphite in the course of electrochemical lithiation/delithiation of these electrodes.
24 citations
References
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Book•
01 Jan 1982
TL;DR: This book is a blend of erudition, popularization, and exposition, and the illustrations include many superb examples of computer graphics that are works of art in their own right.
Abstract: "...a blend of erudition (fascinating and sometimes obscure historical minutiae abound), popularization (mathematical rigor is relegated to appendices) and exposition (the reader need have little knowledge of the fields involved) ...and the illustrations include many superb examples of computer graphics that are works of art in their own right." Nature
24,199 citations
Book•
31 Dec 1959
TL;DR: In this paper, a classic account describes the known exact solutions of problems of heat flow, with detailed discussion of all the most important boundary value problems, including boundary value maximization.
Abstract: This classic account describes the known exact solutions of problems of heat flow, with detailed discussion of all the most important boundary value problems.
21,807 citations
IBM1
TL;DR: In this paper, Ba−La−Cu−O system, with the composition BaxLa5−xCu5O5(3−y) have been prepared in polycrystalline form, and samples with x=1 and 0.75,y>0, annealed below 900°C under reducing conditions, consist of three phases, one of them a perovskite-like mixed-valent copper compound.
Abstract: Metallic, oxygen-deficient compounds in the Ba−La−Cu−O system, with the composition BaxLa5−xCu5O5(3−y) have been prepared in polycrystalline form. Samples withx=1 and 0.75,y>0, annealed below 900°C under reducing conditions, consist of three phases, one of them a perovskite-like mixed-valent copper compound. Upon cooling, the samples show a linear decrease in resistivity, then an approximately logarithmic increase, interpreted as a beginning of localization. Finally an abrupt decrease by up to three orders of magnitude occurs, reminiscent of the onset of percolative superconductivity. The highest onset temperature is observed in the 30 K range. It is markedly reduced by high current densities. Thus, it results partially from the percolative nature, bute possibly also from 2D superconducting fluctuations of double perovskite layers of one of the phases present.
10,272 citations
TL;DR: It is reported that electrodes made of nanoparticles of transition-metal oxides (MO), where M is Co, Ni, Cu or Fe, demonstrate electrochemical capacities of 700 mA h g-1, with 100% capacity retention for up to 100 cycles and high recharging rates.
Abstract: Rechargeable solid-state batteries have long been considered an attractive power source for a wide variety of applications, and in particular, lithium-ion batteries are emerging as the technology of choice for portable electronics. One of the main challenges in the design of these batteries is to ensure that the electrodes maintain their integrity over many discharge-recharge cycles. Although promising electrode systems have recently been proposed, their lifespans are limited by Li-alloying agglomeration or the growth of passivation layers, which prevent the fully reversible insertion of Li ions into the negative electrodes. Here we report that electrodes made of nanoparticles of transition-metal oxides (MO, where M is Co, Ni, Cu or Fe) demonstrate electrochemical capacities of 700 mA h g(-1), with 100% capacity retention for up to 100 cycles and high recharging rates. The mechanism of Li reactivity differs from the classical Li insertion/deinsertion or Li-alloying processes, and involves the formation and decomposition of Li2O, accompanying the reduction and oxidation of metal nanoparticles (in the range 1-5 nanometres) respectively. We expect that the use of transition-metal nanoparticles to enhance surface electrochemical reactivity will lead to further improvements in the performance of lithium-ion batteries.
7,404 citations