Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Understanding the electronic and ionic conduction and lithium
  over-stoichiometry in LiMn$_2$O$_4$ spinel   We report a first-principles study of defect thermodynamics and transport in
spinel-type lithium manganese oxide LiMn$_2$O$_4$, an important lithium-ion
battery electrode material, using density-functional theory and the
Heyd-Scuseria-Ernzerhof screened hybrid functional. We find that intrinsic
point defects in LiMn$_2$O$_4$ have low formation energies and hence can occur
with high concentrations. The electronic conduction proceeds via hopping of
small polarons and the ionic conduction occurs via lithium vacancy and/or
interstitialcy migration mechanisms. The total conductivity is dominated by the
electronic contribution. LiMn$_2$O$_4$ is found to be prone to lithium
over-stoichiometry, i.e., lithium excess at the manganese sites, and
Mn$^{3+}$/Mn$^{4+}$ disorder. Other defects such as manganese antisites and
vacancies and lithium interstitials may also occur in LiMn$_2$O$_4$ samples. In
light of our results, we discuss possible implications of the defects on the
electrochemical properties and provide explanations for the experimental
observations and guidelines for defect-controlled synthesis and defect
characterization.

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The categories of this paper are: math
15
The categories of this paper are: nucl-ex
10
The categories of this paper are: q-bio
32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
25
The categories of this paper are: patt-sol
7
The categories of this paper are: hep-th
21
The categories of this paper are: adap-org
24
The categories of this paper are: dg-ga
9
The categories of this paper are: nlin
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The categories of this paper are: cs
20
The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
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The categories of this paper are: gr-qc
22
The categories of this paper are: chao-dyn
13
The categories of this paper are: quant-ph