Initial stages of oxide formation on the Zr surface at low oxygen pressure: An in situ FIM and XPS study

Bespalov, Ivan; Datler, Martin; Buhr, S.; Drachsel, W.; Rupprechter, Günther; Suchorski, Yuri

doi:10.1016/j.ultramic.2015.02.016

Cited by 109 publications

(65 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…9A 2 ) present two bands 181.2 and 183.5 eV which are in accordance with bands at 181.3 and 183.6 eV of White ZrO 2 (Fig. 9B 2 ) corresponding to 3d electrons of suboxides Zr (4 − x)+ [33]. Similarly, to other reports, none of the samples present any indication for the presence of metallic Zr (~178 eV) [34,35].…”

Section: Blackening Phenomenon Of Zrosupporting

confidence: 87%

See 1 more Smart Citation

Effect of sintering pressure on microstructure and mechanical properties of hot-pressed Ti6Al4V-ZrO2 materials

et al. 2017

View full text Add to dashboard Cite

This study proposes a bilayered materials design approach obtained by hot pressing for biomedical applications. • The effect of sintering pressure on chemical composition and mechanical properties (namely H and E) was studied. • Interface reaction and mechanical properties are strongly dependent on sintering pressure. • The highest hardness and modulus were found for materials produced at P=100 MPa. • An interesting blackening phenomenon on ZrO 2 layer was described and discussed in light of the variation of O/ Zr ratio.

show abstract

Section: Blackening Phenomenon Of Zrosupporting

confidence: 87%

“…Moreover, the regions spectra of White ZrO 2 sample show, in addition to suboxides, also ZrO 2 contribution, probed by the two more bands appearance which are related to Zr 4+ electrons [33]. This is in accordance with the high-resolution O1s XPS region spectrum.…”

Section: Blackening Phenomenon Of Zrosupporting

confidence: 84%

Effect of sintering pressure on microstructure and mechanical properties of hot-pressed Ti6Al4V-ZrO2 materials

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Both Zr peaks remained with the increased relative intensity of the side peak at 179.7 eV, after the LLZO was discharged to 0 V. In addition, another peak at a lower binding energy of 178.2 eV also appears for the discharged LLZO. It is known that various Zr suboxides exist and their binding energy will shift to a lower value as the oxidation state of Zr decreases . The increase in the relative intensity of side peak at 179.7 eV as well as the appearance of a new peak at a lower binding energy (178.2 eV, ascribed to Zr 3 O herein) confirmed the reduction of Zr in the discharged LLZO, which agrees with the calculation result.…”

Section: Resultsmentioning

confidence: 73%

“…We believe that the coloration is related to the reduction of Zr and/or the dopant (Al) in LLZO. The undetected oxidation change of Zr in their XPS result may be caused by the re‐oxidation of the top‐surface of the sample stored in dry room, since the surface of Zr is very sensitive to oxygen and will be gradually oxidized to ZrO 2 after long time exposure of air …”

Section: Resultsmentioning

confidence: 95%

Electrochemical Stability of Li₁₀GeP₂S₁₂ and Li₇La₃Zr₂O₁₂ Solid Electrolytes

Han

Zhu

et al. 2016

Advanced Energy Materials

850

531

View full text Add to dashboard Cite

electrochemical stability window, and (3) chemical compatibility with the anode and cathode. In the past few years, major advances have been achieved in increasing the Li ionic conductivity of the solid electrolytes. The state-of-the-art solid electrolyte materials, such as Li-garnet Li 7 La 3 Zr 2 O 12 (LLZO) and Li 10 GeP 2 S 12 (LGPS) have achieved an ionic conductivity of 10 −3 to 10 −2 S cm −1 , [ 1,2 ] which are comparable to commercial organic liquid electrolytes. The high ionic conductivity in solid electrolytes has ignited the research of all-solid-state Li-ion batteries. After achieving adequate Li ionic conductivity in the solid electrolyte materials, current research efforts turned to enhancing the electrochemical stability of the solid electrolytes and chemical compatibility between the solid electrolytes and electrodes, so that Li metal anode and high voltage cathode materials can achieve higher energy density in all-solid-state Li-ion batteries. To enable the highest voltage output of the solid-state battery by coupling a lithium metal anode with a high voltage cathode material, a very wide electrochemical stability window (0.0-5.0 V) is desired for an ideal solid electrolyte. The electrochemical stability window of solid electrolyte was typically obtained by applying the linear polarization on the Li/solid electrolyte/ inert metal (e.g., Pt) semiblocking electrode. Tested by this method, very wide electrochemical stability windows of 0.0 to 5.0 V were reported for both LGPS and LLZO. [ 2,3 ] However, the electrochemical performances of the bulk-type all-solid-state battery batteries assembled with these solid electrolytes [ 2,4 ] are far worse than the liquid-electrolyte based batteries even though the solid electrolyte has a comparable ionic conductivity to the liquid electrolyte. The high interfacial resistance is often blamed as the main limiting factor for the performance of the solid state battery. [ 5 ] The origin of the interfacial resistance, though still not fully understood, is often attributed to the poor physical interfacial contact, the formation of space charge layers, [ 6 ] and/or the formation of interphase layers due to the chemical reactions between the electrolyte and electrode. [ 7 ] Although a variety of interfacial processing techniques, such as dynamic pressing, [ 8 ] nanosizing, [ 9 ] cosintering, [ 10 ] screen printing, [ 11 ] surface coatings [ 12,13 ] have been attempted to engineer the interfaces between the electrodes and electrolytes, the performances of the solid-state battery are still much lower than the liquidelectrolyte based batteries. The limited electrochemical stabilityThe electrochemical stability window of solid electrolyte is overestimated by the conventional experimental method using a Li/electrolyte/inert metal semiblocking electrode because of the limited contact area between solid electrolyte and inert metal. Since the battery is cycled in the overestimated stability window, the decomposition of the solid electrolyte at the interfaces occurs but has be...

show abstract

“…[19] However, Li deposition onto polished, Nb-doped samples ( Figure 2, middle row) leads to a clear reduction of Nb 5+ to Nb 4+ and Nb 3+ , as evidenced by the presence of new peaks at 206.4 and 205.3 eV, respectively, with no apparent reactivity of Zr 4+ species. [31] This result is particularly surprising, as both Al-and Ta-doped LLZO are generally assumed to be stable in contact with Li metal. [31] This result is particularly surprising, as both Al-and Ta-doped LLZO are generally assumed to be stable in contact with Li metal.…”

Section: Surface Chemistry and Dopant-dependent LI Reactivitymentioning

confidence: 99%

Dopant‐Dependent Stability of Garnet Solid Electrolyte Interfaces with Lithium Metal

Zhu

Connell

Tepavcevic

et al. 2019

Advanced Energy Materials

247

282

View full text Add to dashboard Cite

materials are a particularly promising class of solid electrolytes for all-solidstate lithium metal batteries, as they are predicted to have a wide electrochemical stability window, [5,6] can be synthesized with very high density (>97%) [7,8] and, through aliovalent doping, can achieve room temperature Li-ion conductivities as high as ≈1.0 mS cm −1 with negligible electronic conductivity. [9] However, significant fundamental issues remain unresolved for garnet-based all-solid-state batteries, including low accessible current densities, [10] the persistence of Li dendrite formation, [11,12] and perhaps most importantly, ambiguities as to whether the interfaces between LLZO and both Li metal [13,14] and high voltage oxide cathodes [15,16] are stable over extended cycling. Indeed, developing deep understanding of the intrinsic reactivity between solid electrolytes and relevant electrode materials is crucial to developing high voltage solidstate batteries with long lifetimes, as the presence of any significant (electro)chemical reactivity will ultimately lead to premature cell failure during extended cycling.Understanding interfacial stability is an especially challenging issue common to all solid-state battery systems due to the inability of many experimental techniques to adequately interrogate the chemical properties of buried interfaces. Such studies are further complicated when one or both materials at the interface are unstable to exposure to air, water, etc., as Li 7 La 3 Zr 2 O 12 (LLZO) garnet-based materials doped with Al, Nb, or Ta to stabilize the Li + -conductive cubic phase are a particularly promising class of solid electrolytes for all-solid-state lithium metal batteries. Understanding of the intrinsic reactivity between solid electrolytes and relevant electrode materials is crucial to developing high voltage solid-state batteries with long lifetimes. Using a novel, surface science-based approach to characterize the intrinsic reactivity of the Li-solid electrolyte interface, it is determined that, surprisingly, some degree of Zr reduction takes place for all three dopant types, with the extent of reduction increasing as Ta < Nb < Al. Significant reduction of Nb also takes place for Nb-doped LLZO, with electrochemical impedance spectroscopy (EIS) of Li||Nb-LLZO||Li symmetric cells further revealing significant increases in impedance with time and suggesting that the Nb reduction propagates into the bulk. Density functional theory (DFT) calculations reveal that Nb-doped material shows a strong preference for Nb dopants toward the interface between LLZO and Li, while Ta does not exhibit a similar preference. EIS and DFT results, coupled with the observed reduction of Zr at the interface, are consistent with the formation of an "oxygen-deficient interphase" (ODI) layer whose structure determines the stability of the LLZO-Li interface.

show abstract

Initial stages of oxide formation on the Zr surface at low oxygen pressure: An in situ FIM and XPS study

Cited by 109 publications

References 35 publications

Effect of sintering pressure on microstructure and mechanical properties of hot-pressed Ti6Al4V-ZrO2 materials

Effect of sintering pressure on microstructure and mechanical properties of hot-pressed Ti6Al4V-ZrO2 materials

Electrochemical Stability of Li₁₀GeP₂S₁₂ and Li₇La₃Zr₂O₁₂ Solid Electrolytes

Dopant‐Dependent Stability of Garnet Solid Electrolyte Interfaces with Lithium Metal

Contact Info

Product

Resources

About

Initial stages of oxide formation on the Zr surface at low oxygen pressure: An in situ FIM and XPS study

Cited by 109 publications

References 35 publications

Effect of sintering pressure on microstructure and mechanical properties of hot-pressed Ti6Al4V-ZrO2 materials

Effect of sintering pressure on microstructure and mechanical properties of hot-pressed Ti6Al4V-ZrO2 materials

Electrochemical Stability of Li10GeP2S12 and Li7La3Zr2O12 Solid Electrolytes

Dopant‐Dependent Stability of Garnet Solid Electrolyte Interfaces with Lithium Metal

Contact Info

Product

Resources

About

Electrochemical Stability of Li₁₀GeP₂S₁₂ and Li₇La₃Zr₂O₁₂ Solid Electrolytes