Effect of Sintering on Structural Modification and Phase Transition of Al-Substituted LLZO Electrolytes for Solid State Battery Applications

2021 ◽  
Vol 18 (3) ◽  
Author(s):  
K. Ganesh Kumar ◽  
P. Balaji Bhargav ◽  
C. Balaji ◽  
Ahmed Nafis ◽  
K. Aravinth ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Solid State ◽  
Solid Electrolyte ◽  
Photoelectron Spectroscopy ◽  
Lithium Ion ◽  
Impedance Analysis ◽  
Chemical Compositions ◽  
X Ray ◽  
Reitveld Refinement ◽  
Solid State Battery

Abstract Owing to high lithium ion conductivity and good stability with lithium metal, Li7La3Zr2O12 (LLZO—a solid electrolyte) has emerged as a viable candidate for solid-state battery applications. In the current study, Al-substituted LLZO (Al-LLZO) powder is synthesized using a typical solid-state reaction. The pellets are made with the synthesized powder and are subjected to annealing for different durations and its effect on the structural properties of the Al-LLZO is investigated in detail. Reitveld refinement of the powder X-ray diffraction pattern reveals that the sintered Al-LLZO belong to the cubic system with the Ia-3d space group at room temperature. Morphology and microstructural properties of sintered powder are analyzed using field emission scanning electron microscopy (FESEM) and high-resolution transmission electron microscopy (HRTEM)/selected area electron diffraction (SAED), respectively. The FESEM image of LLZO pellets shows well-structured cubic grains spread evenly over on the surface after sintering. The chemical compositions of the sample are identified using energy dispersive X-ray analysis (EDAX). The surface chemistry of the prepared samples is examined by X-ray photoelectron spectroscopy (XPS), which states that the observed photoelectron signals from O 1s at about 531 eV and Li1s at 54.52 eV correspond to the Li-O bond in Al-LLZO. Raman spectra have been analyzed and the observed Raman peaks appearing at 299 cm−1, 393 cm−1, 492 cm−1, and 514 cm−1 were assigned to Eg, F2g, A1g, and F2g, respectively. Phase transformation from C-LLZO to the pyrochore LZO phase is noticed when the sample is sintered for 12 h at 1100 °C. The impedance analysis is carried out to measure the conductivity of the Al-LLZO pellet and is found to be 0.3 × 10−5 S cm−1, which is suitable for solid electrolyte applications in lithium ion batteries.

scholarly journals Structure and Characterization of TiC/GLC Multilayered Films with Various Bilayers Periods

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 787
Author(s):  
Weiqi Wang ◽  
Xiaoming Ling ◽  
Rui Wang ◽  
Wenhao Nie ◽  
Li Ji ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Chemical Compositions ◽  
Closed Field ◽  
Multilayered Structures ◽  
Multilayered Films ◽  
Sputtering Deposition ◽  
X Ray ◽  
Mechanical And Tribological Properties ◽  
Self Organizing

The spontaneously self-organizing multilayered graphite-like carbon (denoted as GLC) /TiC films with various bilayer periods in the range of 13.3–17.5 nm were deposited on silicon and 1Cr18Mn8Ni5N stainless steel substrates using closed field magnetron sputtering deposition facility. The microstructures and chemical compositions of the prepared multilayered films were characterized by scanning electron microscopy, high resolution transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy respectively. The self-organizing multilayered structures in all of the films consisted of titanium carbide layers and sp2-rich carbon layers periodically alternate arrangement. The TiC contents and bilayer periods of the multilayered films can be controlled by means of adjusting of sputtering current of graphite target. Furthermore, the mechanical and tribological performances of the prepared films were appraised by nano-indentor, scratch measures, and ball-on-plate tribometer respectively. The results indicated that multilayer structure endowed the as-deposited TiC/GLC films outstanding mechanical and tribological properties, especially the multilayer film with 15.9 nm bilayer period deposited at 10 A sputtering current showed the excellent adhesion strength and hardness; Simultaneously it also exhibited the lowest average friction coefficient in the humid environment owing to its high content of sp2 hybrid carbon.

scholarly journals Operando hard X-ray photoelectron spectroscopy of LiCoO2 thin film in an all-solid-state lithium ion battery

2020 ◽  
Vol 118 ◽  
pp. 106790
Author(s):  
Hisao Kiuchi ◽  
Kazuhiro Hikima ◽  
Keisuke Shimizu ◽  
Ryoji Kanno ◽  
Fukunaga Toshiharu ◽  
...  
Keyword(s):  
Thin Film ◽  
Solid State ◽  
Lithium Ion Battery ◽  
Photoelectron Spectroscopy ◽  
Lithium Ion ◽  
X Ray

Thickness of carbon coatings on silicon materials determined by hard X-ray photoelectron spectroscopy at multiple photon energies

2019 ◽  
Vol 26 (6) ◽  
pp. 1936-1939 ◽  
Author(s):  
Noritake Isomura ◽  
Naoko Takahashi ◽  
Satoru Kosaka ◽  
Hiroyuki Kawaura
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Secondary Electron ◽  
Lithium Ion ◽  
Cross Sectional ◽  
Carbon Coatings ◽  
X Ray ◽  
Negative Electrodes ◽  
Silicon Materials ◽  
Microscopy Images

Hard X-ray photoelectron spectroscopy at multiple photon energies is used to investigate the surface structure of carbon coatings on silicon materials destined for use as negative electrodes in lithium-ion batteries. The photoelectron intensity from the carbon coatings decreases with an increase in the kinetic energy of the photoelectron. By fitting the photoelectron intensity versus energy to numerically derived curves, the thickness and coverage of the carbon coatings can be obtained. The results are in agreement with the values suggested by the cross-sectional secondary-electron microscopy images of the carbon coatings, although the thickness should be corrected by accounting for the rectangular parallelepiped structure of the silicon material.

Synthesis of MoO3/V2O5/C Composite as Novel Anode for Li-Ion Battery Application

2020 ◽  
Vol 20 (5) ◽  
pp. 2911-2916
Author(s):  
Zhen Zhang ◽  
Xiao Chen ◽  
Guangxue Zhang ◽  
Chuanqi Feng
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Specific Capacity ◽  
Lithium Ion ◽  
Li Ion Battery ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Li Ion ◽  
Battery Application

The MoO3/V2O5/C, MoO3/C and V2O5/C are synthesized by electrospinning combined with heat treatment. These samples are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy and thermogravimetric analysis (TG) techniques. The results show that sample MoO3/V2O5/C is a composite composed from MoO3, V2O5 and carbon. It takes on morphology of the nanofibers with the diameter of 200~500 nm. The TG analysis result showed that the carbon content in the composite is about 40.63%. Electrochemical properties for these samples are studied. When current density is 0.2 A g−1, the MoO3/V2O5/C could retain the specific capacity of 737.6 mAh g−1 after 200 cycles and its coulomb efficiency is 92.99%, which proves that MoO3/V2O5/C has better electrochemical performance than that of MoO3/C and V2O5/C. The EIS and linear Warburg coefficient analysis results show that the MoO3/V2O5/C has larger Li+ diffusion coefficient and superior conductivity than those of MoO3/C or V2O5/C. So MoO3/V2O5/C is a promising anode material for lithium ion battery application.

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