Hydrothermal synthesis of Zn2Sn1 − x Ti x O4 as anode material for lithium-ion batteries

Yuan, W. S.; Yan-wen, Tian; Liu, G. Q.

doi:10.1134/s1023193511020182

Cited by 8 publications

(12 citation statements)

References 8 publications

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“…The spinel phase exists as a metastable structure and tends to transform to the more stable rock-salt phase. The formation of this intermediate spinel-like phase is not completely necessary because the Ni 3+ and Ni 4+ cations in the Ni-rich layered cathode studied here are highly oxidative and can be directly reduced to the Ni 2+ cations, , thereby leading to the direct formation of the rock-salt phase by bypassing the metastable, intermediate spinel phase. However, the spinel phase does reduce the energy barrier for the phase transformation, offering a kinetically feasible pathway for the layered → rock-salt transformation. , Because the formation of rock-salt domains in the bulk is kinetically more difficult compared with the formation of the surface rock-salt phase, which has a more intensive degrading environment, ,, the formation of the spinel-like phase is a kinetically favored intermediate reaction that accelerates the formation of rock-salt domains and leads to the anti-core–shell configuration.…”

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confidence: 99%

Formation of an Anti-Core–Shell Structure in Layered Oxide Cathodes for Li-Ion Batteries

et al. 2017

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The layered → rock-salt phase transformation in the layered dioxide cathodes for Li-ion batteries is believed to result in a "core−shell" structure of the primary particles, in which the core region remains as the layered phase while the surface region undergoes a phase transformation to the rock-salt phase. Using transmission electron microscopy, here we demonstrate the formation of an "anti-core−shell" structure in cycled primary particles with a formula of Li-Ni 0.80 Co 0.15 Al 0.05 O 2 , in which the surface and subsurface regions remain as the layered structure while the rock-salt phase forms as domains in the bulk with a thin layer of the spinel phase between the rock-salt core and the skin of the layered phase. Formation of this anti-core−shell structure is attributed to oxygen loss at the surface that drives the migration of oxygen from the bulk to the surface, thereby resulting in localized areas of significantly reduced oxygen levels in the bulk of the particle, which subsequently undergoes phase transformation to the rock-salt domains. The formation of the anti-core−shell rock-salt domains is responsible for the reduced capacity, discharge voltage, and ionic conductivity in cycled cathodes.

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confidence: 99%

Formation of an Anti-Core–Shell Structure in Layered Oxide Cathodes for Li-Ion Batteries

et al. 2017

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“…Thus, even if the starting powder has the expected Li:La:V ratio, any inhomogeneity would create regions with either rich or poor lithium content. In addition, Li loss may happen, because of sublimation or evaporation at high synthesis temperature (lithium evaporation occurs at 950 °C and accelerates at 1050 °C). As long as the cationic tunnels are not filled in the structure, the cationic backbone is probably modified and, as a consequence, the general periodicity is potentially locally changed.…”

Section: Resultsmentioning

confidence: 98%

On the Use of Dynamical Diffraction Theory To Refine Crystal Structure from Electron Diffraction Data: Application to KLa₅O₅(VO₄)₂, a Material with Promising Luminescent Properties

et al. 2016

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A new lanthanum oxide, KLa5O5(VO4)2, was synthesized using a flux growth technique that involved solid-state reaction under an air atmosphere at 900 °C. The crystal structure was solved and refined using an innovative approach recently established and based on three-dimensional (3D) electron diffraction data, using precession of the electron beam and then validated against Rietveld refinement and denisty functional theory (DFT) calculations. It crystallizes in a monoclinic unit cell with space group C2/m and has unit cell parameters of a = 20.2282(14) Å, b = 5.8639(4) Å, c = 12.6060(9) Å, and β = 117.64(1)°. Its structure is built on Cresnel-like two-dimensional (2D) units (La5O5) of 4*3 (OLa4) tetrahedra, which run parallel to (001) plane, being surrounded by isolated VO4 tetrahedra. Four isolated vanadate groups create channels that host K(+) ions. Substitution of K(+) cations by another alkali metal is possible, going from lithium to rubidium. Li substitution led to a similar phase with a primitive monoclinic unit cell. A complementary selected area electron diffraction (SAED) study highlighted diffuse streaks associated with stacking faults observed on high-resolution electron microscopy (HREM) images of the lithium compound. Finally, preliminary catalytic tests for ethanol oxidation are reported, as well as luminescence evidence. This paper also describes how solid-state chemists can take advantages of recent progresses in electron crystallography, assisted by DFT calculations and powder X-ray diffraction (PXRD) refinements, to propose new structural types with potential applications to the physicist community.

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“…A proton trap cathode allows the high potential proton-coupled quinone redox chemistry to be used with any type of anode, including conventional LIB anodes, decoupling the cell cycling chemistry from the anodic redox reaction. The result is a type of dual-ion battery operating with a nonrocking-chair mechanism, similar to when, for example, graphite is used as both anode and cathode with cations and anions being intercalated/deintercalated into/from each corresponding side during charging or discharging. − Apart from the sustainability aspect as motivation for new battery technologies, safety is also of great concern regarding LIBs and the reason why polymeric electrolytes, , ionic liquids (ILs), − and various combinations thereof , are currently investigated as alternative electrolytes to the conventional ones.…”

Section: Introductionmentioning

confidence: 99%

In situ Investigations of a Proton Trap Material: A PEDOT-Based Copolymer with Hydroquinone and Pyridine Side Groups Having Robust Cyclability in Organic Electrolytes and Ionic Liquids

Åkerlund

Emanuelsson

Hernández

et al. 2019

ACS Appl. Energy Mater.

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A conducting redox polymer based on PEDOT with hydroquinone and pyridine pendant groups is reported and characterized as a proton trap material. The proton trap functionality, where protons are transferred from the hydroquinone to the pyridine sites, allows for utilization of the inherently high redox potential of the hydroquinone pendant group (3.3 V versus Li0/+) and sustains this reaction by trapping the protons within the polymer, resulting in proton cycling in an aprotic electrolyte. By disconnecting the cycling ion of the anode from the cathode, the choice of anode and electrolyte can be extensively varied and the proton trap copolymer can be used as cathode material for all-organic or metal-organic batteries. In this study, a stable and nonvolatile ionic liquid was introduced as electrolyte media, leading to enhanced cycling stability of the proton trap compared to cycling in acetonitrile, which is attributed to the decreased basicity of the solvent. Various in situ methods allowed for in-depth characterization of the polymer’s properties based on its electronic transitions (UV–vis), temperature-dependent conductivity (bipotentiostatic CV-measurements), and mass change (EQCM) during the redox cycle. Furthermore, FTIR combined with quantum chemical calculations indicate that hydrogen bonding interactions are present for all the hydroquinone and quinone states, explaining the reversible behavior of the copolymer in aprotic electrolytes, both in three-electrode setup and in battery devices. These results demonstrate the proton trap concept as an interesting strategy for high potential organic energy storage materials.

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Hydrothermal synthesis of Zn2Sn1 − x Ti x O4 as anode material for lithium-ion batteries

Cited by 8 publications

References 8 publications

Formation of an Anti-Core–Shell Structure in Layered Oxide Cathodes for Li-Ion Batteries

Formation of an Anti-Core–Shell Structure in Layered Oxide Cathodes for Li-Ion Batteries

On the Use of Dynamical Diffraction Theory To Refine Crystal Structure from Electron Diffraction Data: Application to KLa₅O₅(VO₄)₂, a Material with Promising Luminescent Properties

In situ Investigations of a Proton Trap Material: A PEDOT-Based Copolymer with Hydroquinone and Pyridine Side Groups Having Robust Cyclability in Organic Electrolytes and Ionic Liquids

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Hydrothermal synthesis of Zn2Sn1 − x Ti x O4 as anode material for lithium-ion batteries

Cited by 8 publications

References 8 publications

Formation of an Anti-Core–Shell Structure in Layered Oxide Cathodes for Li-Ion Batteries

Formation of an Anti-Core–Shell Structure in Layered Oxide Cathodes for Li-Ion Batteries

On the Use of Dynamical Diffraction Theory To Refine Crystal Structure from Electron Diffraction Data: Application to KLa5O5(VO4)2, a Material with Promising Luminescent Properties

In situ Investigations of a Proton Trap Material: A PEDOT-Based Copolymer with Hydroquinone and Pyridine Side Groups Having Robust Cyclability in Organic Electrolytes and Ionic Liquids

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On the Use of Dynamical Diffraction Theory To Refine Crystal Structure from Electron Diffraction Data: Application to KLa₅O₅(VO₄)₂, a Material with Promising Luminescent Properties