Influence of Iron on the Structural Evolution of LiNi0.4Fe0.2Mn1.4O4 during Electrochemical Cycling Investigated by in situ Powder Diffraction and Spectroscopic Methods

Yavuz, Metin; Kiziltas-Yavuz, Nilüfer; Bhaskar, Aiswarya; Scheuermann, Marco; Indris, Sylvio; Fauth, François; Knapp, Michael; Ehrenberg, Helmut

doi:10.1002/zaac.201400247

Cited by 18 publications

(25 citation statements)

References 42 publications

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“…This is an important factor for insertion kinetics and a necessary requirement for the use as electrode material. A recent review of a state-of-the-art synchrotron beamline for Li-ion battery research and a description of an application to high-voltage spinels are given by Herklotz et al 11 and Yavuz et al, 12 respectively. Extrapolation of the data to room temperature conditions yields values which reach the order of magnitude of commercially established LiFePO 4 cathode material (10 −9 S cm −1 ).…”

Section: Introductionmentioning

confidence: 99%

Unravelling the mechanism of lithium insertion into and extraction from trirutile-type LiNiFeF₆ cathode material for Li-ion batteries

et al. 2015

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LiNiFeF 6 was used as cathode material in lithium-ion cells and studied by in situ X-ray diffraction (XRD), in operando X-ray absorption spectroscopy (XAS) and 7 Li MAS NMR spectroscopy. An optimised electrochemical in situ cell was employed for the structural and electrochemical characterisation of LiNiFeF 6 upon galvanostatic cycling. The results for the first time reveal the lithium insertion process into a quaternary lithium transition metal fluoride with a trirutil-type host structure (space group P4 2 /mnm). The in situ diffraction experiments indicate a preservation of the structure type after repeated lithium insertion and extraction. The lithium insertion reaction can be attributed to a phase separation mechanism between Li-poor Li 1+x1 NiFeF 6 and Li-rich Li 1+x2 NiFeF 6 (x1 ≲ 0.16 ≲ x2), where not only the weight fractions, but also the lattice parameters of the reacting phases change. The insertion of Li ions into [001]-channels of the trirutile structure causes an anisotropic lattice expansion along the tetragonal a-axes. An overall increase in the unit cell volume of~6% and a reduction in the c/a ratio of~4% are detected during discharge. Changes of atomic coordinates and distances suggest the accommodation of intercalated lithium in the empty six-fold coordinated 4c site. This is confirmed by 7 Li MAS NMR spectroscopy showing two Li environments with similar intensities after discharging to 2.0 V. Furthermore, in operando XAS investigations revealed that only Fe 3+ cations participate in the electrochemical process via an Fe 3+ /Fe 2+ redox reaction, while Ni 2+ cations remain electrochemically inactive. CrystEngCommThis journal is

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Section: Introductionmentioning

confidence: 99%

Unravelling the mechanism of lithium insertion into and extraction from trirutile-type LiNiFeF₆ cathode material for Li-ion batteries

et al. 2015

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“…A large change in the lattice strain during cycling usually leads to cracks in the crystal structure and eventually to a loss of electrical contact and finally to quick capacity fading. In this cathode material the lattice parameter difference between the two cubic spinel phases is smaller than in the undoped LiNi 0.5 Mn 1.5 O 4 spinel cathode material (Yavuz et al, 2014). The smaller the difference between the lattice parameters of the two phases, the smaller the stress induced into the structure, finally resulting in an improved cycling performance.…”

Section: Figurementioning

confidence: 84%

A novel high-throughput setup forin situpowder diffraction on coin cell batteries

et al. 2016

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A new setup for in situ experiments with up to eight electrochemical cells, especially battery coin cells, and the corresponding custom‐made in situ cells are presented. The setup is primarily optimized for synchrotron powder diffraction measurements. As a newly constructed experimental setup, the in situ coin cell holder was tested for positional errors of the cells and the reliability of the diffraction as well as electrochemical measurements. The overall performance characteristics of the sample holder are illustrated by measurements on LiMn2O4 and LiNi0.35Fe0.3Mn1.35O4 spinel‐based positive electrode materials.

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“…1. This holder is usually used for in situ experiments and has been described in previous papers (Herklotz et al, 2013;Yavuz et al, 2014).…”

Section: Methodsmentioning

confidence: 99%

X-ray total scattering investigation of Al_0.57Sn_0.43O_1.71nanoparticles

et al. 2015

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X‐ray pair distribution function (PDF) analysis of Al0.57Sn0.43O1.71, a promising candidate as anode material for Li ion batteries, has been carried out using synchrotron radiation at 60 keV. The average and short‐range ordering of nanocrystalline Al0.57Sn0.43O1.71 was investigated both with the traditional Rietveld refinement method and with X‐ray PDF analysis. The instrumental parameters of the high‐resolution powder diffraction beamline P02.1, Petra III, have been characterized. Reverse Monte Carlo (RMC) refinements based on PDF data indicate that Al substitution induces local distortions around the Al/Sn atoms and that oxygen vacancies, induced by the Al substitution, are mostly located on an anion site around the Al atoms. Additionally, RMC refinements hint at a clustering of Al atoms.

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Influence of Iron on the Structural Evolution of LiNi_0.4Fe_0.2Mn_1.4O₄ during Electrochemical Cycling Investigated by in situ Powder Diffraction and Spectroscopic Methods

Cited by 18 publications

References 42 publications

Unravelling the mechanism of lithium insertion into and extraction from trirutile-type LiNiFeF₆ cathode material for Li-ion batteries

Unravelling the mechanism of lithium insertion into and extraction from trirutile-type LiNiFeF₆ cathode material for Li-ion batteries

A novel high-throughput setup forin situpowder diffraction on coin cell batteries

X-ray total scattering investigation of Al_0.57Sn_0.43O_1.71nanoparticles

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Influence of Iron on the Structural Evolution of LiNi0.4Fe0.2Mn1.4O4 during Electrochemical Cycling Investigated by in situ Powder Diffraction and Spectroscopic Methods

Cited by 18 publications

References 42 publications

Unravelling the mechanism of lithium insertion into and extraction from trirutile-type LiNiFeF6 cathode material for Li-ion batteries

Unravelling the mechanism of lithium insertion into and extraction from trirutile-type LiNiFeF6 cathode material for Li-ion batteries

A novel high-throughput setup forin situpowder diffraction on coin cell batteries

X-ray total scattering investigation of Al0.57Sn0.43O1.71nanoparticles

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Product

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Influence of Iron on the Structural Evolution of LiNi_0.4Fe_0.2Mn_1.4O₄ during Electrochemical Cycling Investigated by in situ Powder Diffraction and Spectroscopic Methods

Unravelling the mechanism of lithium insertion into and extraction from trirutile-type LiNiFeF₆ cathode material for Li-ion batteries

Unravelling the mechanism of lithium insertion into and extraction from trirutile-type LiNiFeF₆ cathode material for Li-ion batteries

X-ray total scattering investigation of Al_0.57Sn_0.43O_1.71nanoparticles