In:
Beilstein Journal of Nanotechnology, Beilstein Institut, Vol. 7 ( 2016-12-09), p. 1960-1970
Abstract:
Nanocomposites of Li 1.4 Ni 0.5 Mn 0.5 O 2+ x and amorphous carbon were obtained by the pyrolysis of linear and cross-linked poly(vinyl alcohol) (PVA) in presence of Li 1.4 Ni 0.5 Mn 0.5 O 2+ x . In the case of linear PVA, the formation of nanostructured carbon coatings on Li 1.4 Ni 0.5 Mn 0.5 O 2+ x particles is observed, while for cross-linked PVA islands of mesoporous carbon are located on the boundaries of Li 1.4 Ni 0.5 Mn 0.5 O 2+ x particles. The presence of the carbon framework leads to a decrease of the polarization upon cycling and of the charge transfer resistance and to an increase in the apparent Li + diffusion coefficient from 10 −16 cm 2 ·s −1 (pure Li 1.4 Ni 0.5 Mn 0.5 O 2+ x ) to 10 −13 cm 2 ·s −1 . The nanosized carbon coatings also reduce the deep electrochemical degradation of Li 1.4 Ni 0.5 Mn 0.5 O 2+ x during electrochemical cycling. The nanocomposite obtained by the pyrolysis of linear PVA demonstrates higher values of the apparent lithium diffusion coefficient, a higher specific capacity and lower values of charge transfer resistance, which can be related to the more uniform carbon coatings and to the significant content of sp 2 -hybridized carbon detected by XPS and by Raman spectroscopy.
Type of Medium:
Online Resource
ISSN:
2190-4286
DOI:
10.3762/bjnano.7.187
Language:
English
Publisher:
Beilstein Institut
Publication Date:
2016
detail.hit.zdb_id:
2583584-1
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