Electronic and Ionic Conduction in Cu2-δSe, Cu2-δS and Cu2-δ(Se, S)

Ishikawa, T.; Miyatani, Shin-ya

doi:10.1143/jpsj.42.159

Cited by 63 publications

(25 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Lithium insertion changes to the worse ionic transport facilities in both copper sulfide and copper selenide, and the energy of the ionic conductivity increases considerably. For the coarse-grained Li 0.25 Cu 1.75 S compound (with grain sizes around 100 μm), the E a value was observed to be equal (0.33± 0.01 eV) in the temperature interval 625-700 K [20], while for copper sulfide, the E a value lies in the interval 0.16-0.22 eV from various sources [11,21].…”

Section: Resultsmentioning

confidence: 99%

“…phase of copper selenide has low activation energy of the cation diffusion of about 0.15 eV [11,12]; this magnitude is comparable with the energy of the thermal motion of ions, and so it is interesting to investigate the influence of grain sizes on the ionic conductivity of the compound. Thus, the purpose of the paper is to study the effect of grain sizes on the overall ionic conductivity of superionic materials with highly disordered crystal structure using copper selenide as a model system.…”

Section: Introductionmentioning

confidence: 99%

“…The ionic conductivity of copper selenide was investigated thoroughly [11], but grain size influence on ionic conductivity was not studied. It is clearly established that the extremely fast bulk ionic diffusion in the superionic f.c.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Influence of grain sizes on the ionic conductivity and the chemical diffusion coefficient in copper selenide

Балапанов

Уразаева

Zinnurov

et al. 2006

Ionics

View full text Add to dashboard Cite

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Influence of grain sizes on the ionic conductivity and the chemical diffusion coefficient in copper selenide

Балапанов

Уразаева

Zinnurov

et al. 2006

Ionics

View full text Add to dashboard Cite

show abstract

“…We focused on two types of copper sulfides with heteromorphic S 2¹ sublattice structures: high-temperature phases of cubic digenite (c-Cu 2¹x S) and hexagonal chalcocite (h-Cu 2¹x S), where x represents position defects. 16,17 c-Cu 2¹x S has an fcc sublattice formed by S 2¹ ions, in which Cu + ions with a small amount of Cu 2+ ions and position defects occupy statistically lowsymmetry interstitial sites (Figure 1a), whereas h-Cu 2¹x S comprises a hexagonal close-packed (hcp) sublattice of S 2¹ ions with Cu + ions and a small amount of Cu 2+ ions and defects at the interstitial sites (Figure 1b). 18 The x value of their homogeneous phases ranges from 0.08 to 0.24 for c-Cu 2¹x S and from 0 to 0.01 for h-Cu 2¹x S, at temperatures below 250°C.…”

mentioning

confidence: 99%

“…19 Both these copper sulfides are superionic conductors of Cu + ions. 17,20 Achieving high mobility for the Cu + ions could be advantageous for a rapid conversion reaction involving the rearrangement of metal ions in secondary battery electrodes. In addition, the S 2¹ and Se 2¹ ions are soft Lewis bases as per the HSAB theory, which form only weak chemical bonds with hard Lewis acids like the Mg 2+ ion.…”

mentioning

confidence: 99%

The Effect of Anion-sublattice Structure on the Displacement Reaction in Copper Sulfide Cathodes of Rechargeable Magnesium Batteries

2017

View full text Add to dashboard Cite

Copper sulfides (Cu 2¹x S, where x denotes position defects) with different structures of the S 2¹ sublattice, such as cubic digenite and hexagonal chalcocite, have been investigated as cathode materials for magnesium (Mg) batteries. Rechargeable performance is only achieved using a cubic digenite cathode; however, using hexagonal chalcocite cathode yields poor rechargeable performance. The face-centered cubic S 2¹ sublattice in cubic digenite, which enables Cu + and Mg 2+ ions to be displaced from each other without causing the lattice to collapse, could play a key role in improving the performance of rechargeable cathodes.Keywords: Rechargeable magnesium battery | Anion-sublattice structure | Copper sulfide cathodeCurrently, a rechargeable lithium (Li)-ion battery is one of the key systems for energy storage.1,2 However, the growing demand for reduced cost and safety in energy storage for largescale applications has motivated the development of secondary batteries using non-Li cations. For this purpose, a magnesium (Mg) battery is one of the promising alternatives owing to its relatively high stability of magnesium metal upon air exposure and high terrestrial abundance. Despite their promising characteristics, the development of Mg batteries has been slow. In fact, although relevant materials have been extensively researched, only a limited number of transition metal compounds have been found as suitable materials for the insertion-type cathode of rechargeable Mg batteries. 312 One of the reasons for this is that Mg 2+ ions travel through the electrodes too slowly. This is due to the bivalent nature of Mg 2+ ions and their highly stable coordination with hard Lewis bases, as per the hard and soft Lewis acids and bases (HSAB) theory. 13 A new type of cathode materials should be developed for Mg batteries other than the insertion-type one.One promising approach is to research materials that enable the displacement reaction, which is a type of conversion reaction found in the study of Li-ion batteries.14 In this reaction, the insertion of guest cations induces the displacement and extrusion of transition metal cations from the original lattice sites, while maintaining the sublattice of anions. In this situation, the energy barrier caused by lattice strains should be suppressed such that the exchange of cations proceeds more smoothly in the reaction process than in most conversion reactions that require a reconstruction of the anion sublattice. Recently, based on the displacement reaction, we reported that β-Cu 2 Se is suitable as a cathode material for rechargeable Mg batteries. 15 In the discharge process for this material, Mg 2+ ions diffuse to the face-centered cubic (fcc) sublattice composed of Se 2¹ anions (i.e. a Se 2¹ sublattice) to induce a position displacement of Cu + ions that are reduced to Cu 0 (i.e., Cu metal) at the outside of the lattice, leading to the formation of MgSe (+2Cu 0 ). Importantly, the Se 2¹ sublattice in MgSe also has an fcc structure. This result suggested that a key factor for suc...

show abstract

Are Binary Copper Sulfides/Selenides Really New and Promising Thermoelectric Materials?

Dennler

Chmielowski

Jacob

et al. 2014

Advanced Energy Materials

248

185

View full text Add to dashboard Cite

weighted by cyclical constrains. Furthermore, the approach proposed by Schumpeter embodies another fundamental idea, which is the competition between innovators. Indeed, these players pursue the monopoly rents that accrue to new proprietary technologies, and, as such, intend to be the fi rst to fi nd the right solution to the right problem at the right moment. Economists have been studying the relationship between innovation and competition for many years, trying to understand more specifi cally whether competition fosters innovation or not. As a matter of fact, some concluded on a negative infl uence of competition upon innovation and some on a positive effect. [ 2,5 ] But it appears that many economists and marketers converge toward the idea that the innovation versus competition curve shows an inverted U shape. [ 6 ] In other words some competition is constructive, yet aggressive competition tends to hamper the innovation process.It is interesting to place in this context the concept of duplication. Historians and sociologist often refer to multiple discoveries for cases in which similar discoveries are made simultaneously by scientists working independently from each other. [ 7 ] The wide literature of scientifi c discovery can be classifi ed into three basic categories: [ 8 ] the genius model, [ 9 ] the model based on chance, [ 10 ] and the model relying on cultural maturation. [ 11 ] The latter type, which is the more prone to multiplicity, suggests that the contributions of individual researcher are epiphenomenal. This school of thought advocates the infl uence of social determinism and zeitgeist. [ 12 ] As a consequence, it proposes that the change in science is strongly infl uenced by cultural priorities and research programs. [ 8 ] This very type of duplication can be considered benefi cial for society as a higher number of independent experiments does maximize the probability of the accuracy and the reality of a given discovery. [ 11 ] This point of view is easily applicable to paradigm shifting, major discoveries, especially if they occurred before the era of easily accessible information via the internet, gigantic centralized databases, and ultrafast search engines. However, nowadays it may appear obvious that the replication of the effort to generate innovation is socially suboptimal and reduces the overall return on investment for entities that fi nance research. None of the studies mentioned above accounts for that phenomenon because of the diffi culty to quantify modern duplication. Thus, despite its acknowledged relevance [ 13 ] and occurrence, the share and infl uence of modern duplication in academic and industrial research remains largely underexplored. The European Patent Offi ce (EPO) affi rms that "up to 30% of all expenditure in R&D is wasted on redeveloping existing Copper sulfi des and copper selenides have recently been reported as new and promising low-cost and environmentally friendly thermoelectric materials. Here, it is shown that these materials have actually been studied for mo...

show abstract

Electronic and Ionic Conduction in Cu_2-δSe, Cu_2-δS and Cu_2-δ(Se, S)

Cited by 63 publications

References 14 publications

Influence of grain sizes on the ionic conductivity and the chemical diffusion coefficient in copper selenide

Influence of grain sizes on the ionic conductivity and the chemical diffusion coefficient in copper selenide

The Effect of Anion-sublattice Structure on the Displacement Reaction in Copper Sulfide Cathodes of Rechargeable Magnesium Batteries

Are Binary Copper Sulfides/Selenides Really New and Promising Thermoelectric Materials?

Contact Info

Product

Resources

About