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Grechnev, G. E.; Ahuja, Rajeev; Johansson, Börje; Eriksson, Olle

doi:10.1103/physrevb.65.174408

Cited by 59 publications

(35 citation statements)

References 31 publications

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“…The elastic parameters for the Li x Mn 2 O 4 phase were compiled from several sources ͑see Table II͒. 31,32 The electrolyte phase is assumed to be a compliant gel with negligible resistance to deformation and zero Vegard coefficient.…”

Section: Model Validation and Limitationsmentioning

confidence: 99%

Microstructural Modeling and Design of Rechargeable Lithium-Ion Batteries

Garcı́a

Chiang

Carter

et al. 2005

J. Electrochem. Soc.

300

244

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The properties of rechargeable lithium-ion batteries are determined by the electrochemical and kinetic properties of their constituent materials as well as by their underlying microstructure. In this paper a method is developed that uses microscopic information and constitutive material properties to calculate the response of rechargeable batteries. The method is implemented in OOF, a public domain finite element code, so it can be applied to arbitrary two-dimensional microstructures with crystallographic anisotropy. This methodology can be used as a design tool for creating improved electrode microstructures. Several geometrical two-dimensional arrangements of particles of active material are explored to improve electrode utilization, power density, and reliability of the Li y C 6 ͉Li x Mn 2 O 4 battery system. The analysis suggests battery performance could be improved by controlling the transport paths to the back of the positive porous electrode, maximizing the surface area for intercalating lithium ions, and carefully controlling the spatial distribution and particle size of active material. Important advances in materials have paved the way to the introduction of new devices of ever-increasing functionality. 1 In many cases, however, the full potential of these devices remains unreachable due to limitations of the batteries that power them. These limitations find their origin on the constituents of the battery: the different ohmic contributions, the low diffusivity of the involved charged species, the underlying oxidation-reduction processes, etc. Thus, battery technology improvement is critical to the development of many electric-based applications.In this context, modeling the galvanostatic cycling of a rechargeable battery provides valuable insight into optimizing the performance of the device. Furthermore, an analysis that simultaneously resolves the microstructural details and includes the nonlinearities and history from successive charge-discharge cycles will be useful for improving cell design.The discharging and recharging process involves electronic and ionic flow and their spatial relationships to conductivity in multiple phases as well as interfacial contact potential. Stress distributions that arise due to concentration-induced strains and resistive heating affect battery performance and reliability. Fundamentally, these processes depend on the structure, size, and spatial distribution of electrolyte and active material phases. The incorporation of microstructure into battery models can provide design criteria for improved battery performance. In this paper, a two-dimensional microstructural model for battery discharge is presented and accounts for geometry, connectivity, electrochemical properties of the component phases as well as elastic stresses that develop during battery use. The model presented in this paper links previously developed models for the homogeneous behavior of individual battery components and interfaces. The models are coupled together in a way that geometrically and physica...

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Section: Model Validation and Limitationsmentioning

confidence: 99%

Microstructural Modeling and Design of Rechargeable Lithium-Ion Batteries

Garcı́a

Chiang

Carter

et al. 2005

J. Electrochem. Soc.

300

244

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“…Tetragonal Li 2 Mn 2 O 4 phase has been observed by high-resolution transmission electron microscopy on the surface of Li-rich electrodes. 11 Theoretical studies of LiMn 2 O 4 have been limited to the bulk crystal [12][13][14][15][16][17] and have not been extended to its surfaces nor to its interfaces with other oxides, despite their relevance for the functionality of the material. In the present work, we report the results of ab initio studies of the atomic and electronic structure of clean and Al 2 O 3 covered Li x Mn 2 O 4 (001) surfaces (x ) 0 or 1).…”

Section: Introductionmentioning

confidence: 99%

Oxidation States of Mn Atoms at Clean and Al₂O₃-Covered LiMn₂O₄(001) Surfaces

Ouyang¹,

Zeng²,

Šljivančanin³

et al. 2010

J. Phys. Chem. C

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The electronic structures of bulk and (001) surfaces of λ-MnO 2 and LiMn 2 O 4 have been studied with density functional theory. In λ-MnO 2 , the Mn oxidation state is +4 both in the bulk and at the (001) surface. In LiMn 2 O 4 , however, Mn atoms exhibit mixed Mn 3+ /Mn 4+ oxidation states in the bulk, while only Mn 3+ at the (001) surface, due to lower coordination with O atoms. The technically undesired Mn 3+ ions form at Li x Mn 2 O 4 (001) even for very small Li concentrations. Upon covering the LiMn 2 O 4 (001) surface with Al 2 O 3 , the oxidation state of surface Mn atoms changes from +3 to +4, which explains the improved performance of coated LiMn 2 O 4 cathodes in Li-ion batteries.

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“…In fact, a lot of previous publications in the field of ab initio calculation have showed that relaxation is not always necessary and neglecting the relaxation is a general operation, especially when the doping (or Li-deintercalation) ratio is not large (see Refs. [13,17,[21][22][23]26]). Requested k-point spacing was set as 0.05 Å À1 , which corresponded to 32 k-points for m-LiMnO 2 and 8 k-points for 6.25% Al-doped m-LiMnO 2 in the irreducible Brillouin zone generated by the Monkhorst-Pack scheme.…”

Section: Methodsmentioning

confidence: 99%