Ionic Hall effect in crystals: Independent versus cooperative hopping in AgBr and α-AgI

Liou, Y. J.; Hudson, R. A.; Wonnell, S. K.; Slifkin, Lawrence

doi:10.1103/physrevb.41.10481

Cited by 14 publications

(7 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Interestingly, previous work on the AgI family of superionic conductors suggests that highly interacting charge carriers may be a necessary condition for superionic conduction. [ 48 ] Carrier-carrier coulombic interactions caused by short LiLi separation distance driven by the change in site occupancy seem to be critical for the high Li-ion conductivity of the garnet family of materials, however, there is a limit to how much destabilization of the Li sublattice can occur. As discussed in the literature previously, as the Li content is increased past 6.5 moles, the system undergoes a reduction of symmetry from the cubic to the tetragonal phase in order to relieve coulombic repulsion in the Li sublattice.…”

Section: Resultsmentioning

confidence: 99%

“…[ 29 ] The fi nding that only a small fraction of the ions may be participating in the conduction is reminiscent of the discussion surrounding other families of ionic conductors. [23][24][25][26][27]48 ] As a consequence, it is important to discuss how the carriers are defi ned in the garnet family of ionic conductors. This work proposes that the Li site occupancy is an important factor for defi ning the effective carrier concentration.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

A Tale of Two Sites: On Defining the Carrier Concentration in Garnet‐Based Ionic Conductors for Advanced Li Batteries

Thompson

Sharafi

Johannes

et al. 2015

Advanced Energy Materials

148

159

View full text Add to dashboard Cite

energy storage. While the primary strategy for improving performance has focused on electrode materials, the development of new solid state ionic conducting electrolytes has been overlooked as a potential means to revolutionize electrochemical energy storage. Examples of some of the technologies ( Figure 1 ) could include: (i) dual electrolyte Li-S batteries, (ii) solidstate batteries employing Li metal anodes, and (iii) all oxide, solid-state Li-ion batteries. Indeed, the need for ionic conducting solid-state electrolytes is clear, but relatively few have been identifi ed as promising candidates. The garnet mineral structure represents a family of complex oxides spanning a broad range of natural and synthetic compositions.Initial work identifi ed Li 5 La 3 M 2 O 12 (M = Nb 5+ , Ta 5+ ) as a promising formulation having a total conductivity of 0.04 mS cm −1 at room temperature. [5][6][7] Recently, Weppner and co-workers discovered a formulation exhibiting up to 0.4 mS cm −1 at room temperature: Li 7 La 3 Zr 2 O 12 (also known as LLZO). [ 8 ] For comparison, conventional battery separators soaked in liquid electrolyte have a total conductivity of 0.4 mS cm −1 at room temperature. [ 9 ] In LLZO, edge-sharing ZrO 6 octahedra and LaO 8 dodecahedra form an isotropic skeleton framework through which Li-ions and Li-ion vacancies form a percolative network of tetrahedral and distorted octahedral sites (Figure 1 ). In addition to high conductivity, LLZO has been reported to have the unprecedented combination of stability against metallic Li, and stability in dry air. [ 8,[10][11][12] LLZO is also referred to as a "stuffed" garnet because of its relatively high Li concentration (7 moles) compared to Li 3 La 3 M 2 O 12 . In the garnet family of materials, as the Li content is increased from Li = 3 mols toward Li = 7 mols, the ionic conductivity increases by several orders of magnitude. [ 13 ] At Li contents near Li = 6.5 mols, the cubic structure undergoes a reduction of symmetry to a tetragonal polymorph and the ionic conductivity again decreases. [ 14,15 ] A maximum in the ionic conductivity at room temperature has been observed for compositions near the critical Li concentration to stabilize the cubic phase. [16][17][18][19] As such, the majority of the work in the literature has focused on understanding how the cubic phase is stabilized at high Li concentrations. [14][15][16][17][18][19][20][21] However, the understanding of the fundamental parameters that control the Li conductivity has Solid electrolytes based on the garnet crystal structure have recently been identifi ed as a promising material to enable advance Li battery cell chemistries because of the unprecedented combination of high ionic conductivity and electrochemical stability against metallic Li. To better understand the mechanisms that give rise to high conductivity, the goal of this work is to correlate Li site occupancy with Li-ion transport. Toward this goal, the Li site occupancy is studied in cubic garnet as a function of Li concentration over the com...

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

A Tale of Two Sites: On Defining the Carrier Concentration in Garnet‐Based Ionic Conductors for Advanced Li Batteries

Thompson

Sharafi

Johannes

et al. 2015

Advanced Energy Materials

148

159

View full text Add to dashboard Cite

show abstract

“…The ratio μ/μ Br represents the ratio between the sample Hall mobility to that of strictly Brownian motion and is hence indicative of the ion transport mechanism. Liou et al , argued that strong correlation effects of mobile ions are prerequisites for an ionic Hall voltage to be generated in a crystal. According to previous works, the Hall effect may not be observable in ionic conductors associated with uncorrelated ion transport.…”

Section: Discussionmentioning

confidence: 99%

Classical and Emerging Characterization Techniques for Investigation of Ion Transport Mechanisms in Crystalline Fast Ionic Conductors

et al. 2020

View full text Add to dashboard Cite

Ion transport in crystalline fast ionic conductors is a complex physical phenomenon. Certain ionic species (e.g., Ag+, Cu+, Li+, F–, O2–, H+) in a solid crystalline framework can move as fast as in liquids. This property, although only observed in a limited number of materials, is a key enabler for a broad range of technologies, including batteries, fuel cells, and sensors. However, the mechanisms of ion transport in the crystal lattice of fast ionic conductors are still not fully understood despite the substantial progress achieved in the last 40 years, partly because of the wide range of length and time scales involved in the complex migration processes of ions in solids. Without a comprehensive understanding of these ion transport mechanisms, the rational design of new fast ionic conductors is not possible. In this review, we cover classical and emerging characterization techniques (both experimental and computational) that can be used to investigate ion transport processes in bulk crystalline inorganic materials which exhibit predominant ion conduction (i.e., negligible electronic conductivity) with a primary focus on literature published after 2000 and critically assess their strengths and limitations. Together with an overview of recent understanding, we highlight the need for a combined experimental and computational approach to study ion transport in solids of desired time and length scales and for precise measurements of physical parameters related to ion transport.

show abstract

“…Successful Hall measurements on ionic systems however have been done in the past in systems where ionic conduction is highly correlated. 43 Further study of the structure and chemical composition of asdeposited ALD and annealed films is currently underway, in particular to explore means to tune electronic vs. ionic conductivities in situ during ALD.…”

Section: Discussionmentioning

confidence: 99%

Mixed mode, ionic-electronic diode using atomic layer deposition of V2O5 and ZnO films

et al. 2011

View full text Add to dashboard Cite

We demonstrate high current rectification in a new system comprising 30 nm of hydrated vanadium pentoxide and 100 nm of zinc oxide (V 2 O 5 $nH 2 O-ZnO) thin film structures. The devices are prepared using a low temperature (<150 C), all atomic layer deposition process. A key element in the rectifying properties comes from anomalous p-type conductivity in V 2 O 5 -an otherwise well known n-type semiconductor. Experimental evidence points to protonic (H + ) conductivity due to intercalated water in V 2 O 5 as the source for p-type behaviour, while the ZnO is known to be electronically n-type. Thus, the diode behaves as a novel, mixed mode ionic-electronic rectifier. Further, we show that the diode characteristics are strongly dependent on the electrode material in contact with V 2 O 5 $nH 2 O. A high I on /I off ratio (598) at AE 2 V is obtained for oxygen-free Pt electrodes, whereas a low I on /I off ratio ( 19) is obtained for oxygen-rich ITO electrodes, suggesting the deleterious effects of oxygen atom reactivity to device characteristics.

show abstract

Ionic Hall effect in crystals: Independent versus cooperative hopping in AgBr and α-AgI

Cited by 14 publications

References 21 publications

A Tale of Two Sites: On Defining the Carrier Concentration in Garnet‐Based Ionic Conductors for Advanced Li Batteries

A Tale of Two Sites: On Defining the Carrier Concentration in Garnet‐Based Ionic Conductors for Advanced Li Batteries

Classical and Emerging Characterization Techniques for Investigation of Ion Transport Mechanisms in Crystalline Fast Ionic Conductors

Mixed mode, ionic-electronic diode using atomic layer deposition of V2O5 and ZnO films

Contact Info

Product

Resources

About