Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: In situ Measurement of Biaxial Modulus of Si Anode for Li-ion Batteries   We report in situ measurement of biaxial moduli of a Si thin-film electrode
as a function of its lithium concentration. During lithiation, biaxial
compressive stress is induced in the Si film and it undergoes plastic flow. At
any state-of-charge (SOC), a relatively small delithiation-relithiation
sequence unloads and reloads the film elastically. From the stress and strain
changes during a delithiation-relithiation cycle, the biaxial modulus of the
film is calculated. Stress change is obtained by measuring the change in
substrate curvature using a Multi-beam Optical Sensor; the elastic strain
change is obtained from the change in SOC. By repeating these measurements at
several different values of SOC, the biaxial modulus was seen to decrease from
ca. 70 GPa for Li0.32Si to ca. 35 GPa for Li3.0Si. Such a significant reduction
in elastic modulus has important implications for modeling stress evolution and
mechanical degradation in Si-based anodes.

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The categories of this paper are: nucl-ex
28
The categories of this paper are: alg-geom
18
The categories of this paper are: econ
35
The categories of this paper are: mtrl-th
7
The categories of this paper are: hep-th
10
The categories of this paper are: q-bio
26
The categories of this paper are: bayes-an
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The categories of this paper are: dg-ga
30
The categories of this paper are: q-alg
5
The categories of this paper are: gr-qc
8
The categories of this paper are: hep-ex
12
The categories of this paper are: nucl-th
19
The categories of this paper are: eess
37
The categories of this paper are: supr-con
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The categories of this paper are: cmp-lg
32
The categories of this paper are: atom-ph