Direct evidence of concurrent solid-solution and two-phase reactions and the nonequilibrium structural evolution of LiFePO4.
J Am Chem Soc
; 134(18): 7867-73, 2012 May 09.
Article
em En
| MEDLINE
| ID: mdl-22482702
ABSTRACT
Lithium-ion batteries power many portable devices and in the future are likely to play a significant role in sustainable-energy systems for transportation and the electrical grid. LiFePO(4) is a candidate cathode material for second-generation lithium-ion batteries, bringing a high rate capability to this technology. LiFePO(4) functions as a cathode where delithiation occurs via either a solid-solution or a two-phase mechanism, the pathway taken being influenced by sample preparation and electrochemical conditions. The details of the delithiation pathway and the relationship between the two-phase and solid-solution reactions remain controversial. Here we report, using real-time in situ neutron powder diffraction, the simultaneous occurrence of solid-solution and two-phase reactions after deep discharge in nonequilibrium conditions. This work is an example of the experimental investigation of nonequilibrium states in a commercially available LiFePO(4) cathode and reveals the concurrent occurrence of and transition between the solid-solution and two-phase reactions.
Texto completo:
1
Base de dados:
MEDLINE
Idioma:
En
Ano de publicação:
2012
Tipo de documento:
Article