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Effect of the synthesis temperature on the structure and electrochemical behaviour of the LiNi0.65Co0.25Mn0.1O2 positive electrode material
Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Materials Chemistry, Structural Chemistry.
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2008 (English)In: Solid State Ionics, ISSN 0167-2738, E-ISSN 1872-7689, Vol. 178, no 31-32, 1668-1675 p.Article in journal (Refereed) Published
Abstract [en]

Three kinds of LiNi0.65Co0.25Mn0.1O2 samples were prepared using a combustion method at different synthetic conditions (C1: 900 °C/1 h; C2: 900 °C/12 h and C3: 1000 °C/12 h). The samples were characterized using X-ray diffraction, scanning electron microscopy and magnetization measurements before their use as positive electrode material in lithium-ion batteries. Sample C1 presents the most ordered structure with less than 3% of nickel ions in the lithium plane. Increasing synthesis temperature and/or time lead to an increase of the Li/Ni disorder. The amount of extra-nickel ions in the lithium plane strongly affects the magnetic behaviour and the electrochemical performances of the prepared material. LiNi0.65Co0.25Mn0.1O2 prepared at 900 °C for 1 h presents the best cycling properties.

Place, publisher, year, edition, pages
2008. Vol. 178, no 31-32, 1668-1675 p.
Keyword [en]
Layered oxides, Magnetization, Crystal structure, Li-ion batteries, Electrochemical cycling
National Category
Chemical Sciences Engineering and Technology
Research subject
Engineering Science with specialization in Solid State Physics
URN: urn:nbn:se:uu:diva-12778DOI: 10.1016/j.ssi.2007.10.019ISI: 000252531200007OAI: oai:DiVA.org:uu-12778DiVA: diva2:40547
Available from: 2008-01-15 Created: 2008-01-15 Last updated: 2016-04-13Bibliographically approved
In thesis
1. Fundamental Properties of Functional Magnetic Materials
Open this publication in new window or tab >>Fundamental Properties of Functional Magnetic Materials
2010 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Magnetic properties of powders, thin films and single crystals have been investigated using magnetometry methods. This thesis provides analysis and conclusions that are supported by the results obtained from spectroscopic and diffraction measurements as well as from theoretical calculations.

First, the magnetic behavior of transition metal (TM) doped ZnO with respect to doping, growth conditions and post annealing has been studied. Our findings indicate that the magnetic behavior stems from small clusters or precipitates of the dopant, with ferromagnetic or antiferromagnetic interactions. At the lowest dopant concentrations, the estimated cluster sizes are too small for high resolution imaging. Still, the clusters may be sufficiently large to generate a finite spontaneous magnetization even at room temperature and could easily be misinterpreted as an intrinsic ferromagnetic state of the TM:ZnO compound.

Second, influence of lattice strain on both magnetic moment and anisotropy has been investigated for epitaxial MnAs thin films grown on GaAs substrates. The obtained magnetic moments and anisotropy values are higher than for bulk MnAs. The enhanced values are caused by highly strained local areas that have a stronger dependence on the in-plane axis strain than out-of plane axis strain.

Finally, spin glass behavior in Li-layered oxides, used for battery applications, and a double perovskite material has been investigated. For both Li(NiCoMn)O2 and (Sr,La)MnWO6, a mixed-valence of one of the transition metal ions creates competing ferromagnetic and antiferromagnetic interactions resulting in a low temperature three-dimensional (3D) spin glass state. Additionally, Li(NiCoMn)O2 with large cationic mixing exhibits a percolating ferrimagnetic spin order in the high temperature region and coexists with a two-dimensional (2D) frustrated spin state in the mid temperature region. This is one of the rare observations where a dimensional crossover from 2D to 3D spin frustration appears in a reentrant material.

Place, publisher, year, edition, pages
Uppsala: acta universitatis upsaliensis, 2010. 74 p.
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 790
Magnetic anisotropy, magnetic aging, magnetic semiconductors, exchange interactions, magnetic oxides, spin glasses, lithium-ion batteries, short-range magnetic order
National Category
Physical Sciences
Research subject
Engineering Science with specialization in Solid State Physics
urn:nbn:se:uu:diva-133257 (URN)978-91-554-7953-4 (ISBN)
Public defence
2010-12-17, Polhemsalen, Ångströmlaboratoriet, Lägerhyddsvägen 1, Uppsala, 09:15 (English)
Felaktigt tryckt som Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 720Available from: 2010-11-25 Created: 2010-11-04 Last updated: 2011-03-21Bibliographically approved

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Wikberg, MagnusGustafsson, TorbjörnSvedlindh, PeterEdström, Kristina
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