Effect of nanostructured carbon coatings on the electrochemical performance of Li 1.4 Ni 0.5 Mn 0.5 O 2+ x -based cathode materials.

Autor: Kurilenko KA; Department of Chemistry, M. V. Lomonosov Moscow State University, 119991 Moscow, Russia., Shlyakhtin OA; Department of Chemistry, M. V. Lomonosov Moscow State University, 119991 Moscow, Russia., Brylev OA; Department of Chemistry, M. V. Lomonosov Moscow State University, 119991 Moscow, Russia; Department of Materials Sciences, M. V. Lomonosov Moscow State University, 119991 Moscow, Russia., Petukhov DI; Department of Chemistry, M. V. Lomonosov Moscow State University, 119991 Moscow, Russia; Department of Materials Sciences, M. V. Lomonosov Moscow State University, 119991 Moscow, Russia., Garshev AV; Department of Chemistry, M. V. Lomonosov Moscow State University, 119991 Moscow, Russia; Department of Materials Sciences, M. V. Lomonosov Moscow State University, 119991 Moscow, Russia.
Jazyk: angličtina
Zdroj: Beilstein journal of nanotechnology [Beilstein J Nanotechnol] 2016 Dec 09; Vol. 7, pp. 1960-1970. Date of Electronic Publication: 2016 Dec 09 (Print Publication: 2016).
DOI: 10.3762/bjnano.7.187
Abstrakt: 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.
Databáze: MEDLINE
Externí odkaz: