Vacancy-Enabled O3 Phase Stabilization for Manganese-Rich Layered Sodium Cathodes.
Angew Chem Int Ed Engl
; 60(15): 8258-8267, 2021 Apr 06.
Article
em En
| MEDLINE
| ID: mdl-33480154
ABSTRACT
Manganese-rich layered oxide materials hold great potential as low-cost and high-capacity cathodes for Na-ion batteries. However, they usually form a P2 phase and suffer from fast capacity fade. In this work, an O3 phase sodium cathode has been developed out of a Li and Mn-rich layered material by leveraging the creation of transition metal (TM) and oxygen vacancies and the electrochemical exchange of Na and Li. The Mn-rich layered cathode material remains primarily O3 phase during sodiation/desodiation and can have a full sodiation capacity of ca. 220â
mAh g-1 . It delivers ca. 160â
mAh g-1 specific capacity between 2-3.8â
V with >86 % retention over 250â
cycles. The TM and oxygen vacancies pre-formed in the sodiated material enables a reversible migration of TMs from the TM layer to the tetrahedral sites in the Na layer upon de-sodiation and sodiation. The migration creates metastable states, leading to increased kinetic barrier that prohibits a complete O3-P3 phase transition.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Angew Chem Int Ed Engl
Ano de publicação:
2021
Tipo de documento:
Article
País de afiliação:
Estados Unidos