Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Singlet Oxygen Generation as a Major Cause for Parasitic Reactions
  during Cycling of Aprotic Lithium-Oxygen Batteries   Non-aqueous metal-oxygen batteries depend critically on the reversible
formation/decomposition of metal oxides on cycling. Irreversible parasitic
reactions cause poor rechargeability, efficiency, and cycle life and have
predominantly been ascribed to the reactivity of reduced oxygen species with
cell components. These species, however, cannot fully explain the side
reactions. Here we show that singlet oxygen forms at the cathode of a
lithium-oxygen cell during discharge and from the onset of charge, and accounts
for the majority of parasitic reaction products. The amount increases during
discharge, early stages of charge, and charging at higher voltages, and is
enhanced by the presence of trace water. Superoxide and peroxide appear to be
involved in singlet oxygen generation. Singlet oxygen traps and quenchers can
reduce parasitic reactions effectively. Awareness of the highly reactive
singlet oxygen in non-aqueous metal-oxygen batteries gives a rationale for
future research towards achieving highly reversible cell operation.

22
The categories of this paper are: chao-dyn
3
The categories of this paper are: physics
16
The categories of this paper are: stat
34
The categories of this paper are: chem-ph
21
The categories of this paper are: adap-org
37
The categories of this paper are: supr-con
33
The categories of this paper are: plasm-ph
9
The categories of this paper are: nlin
5
The categories of this paper are: gr-qc
12
The categories of this paper are: nucl-th
19
The categories of this paper are: eess
25
The categories of this paper are: patt-sol
27
The categories of this paper are: comp-gas
1
The categories of this paper are: cs
8
The categories of this paper are: hep-ex
35
The categories of this paper are: mtrl-th