title: Polymorphism and magnetic properties of Li2MSiO4 (M = Fe, Mn) cathode materials.
abstract: Transition metal-based lithium orthosilicates (Li2MSiO4, M = Fe, Ni, Co, Mn) are gaining a wide interest as cathode materials for lithium-ion batteries. These materials present a very complex polymorphism that could affect their physical properties. In this work, we synthesized the Li2FeSiO4 and Li2MnSiO4 compounds by a sol-gel method at different temperatures. The samples were investigated by XRPD, TEM, (7)Li MAS NMR, and magnetization measurements, in order to characterize the relationships between crystal structure and magnetic properties. High-quality (7)Li MAS NMR spectra were used to determine the silicate structure, which can otherwise be hard to study due to possible mixtures of different polymorphs. The magnetization study revealed that the Néel temperature does not depend on the polymorph structure for both iron and manganese lithium orthosilicates.
authors: Dept. of Chemistry, University of Pavia, viale Taramelli 16, 27100 Pavia, Italy.
authors: Marcella
authors: M
authors: Bini
authors: Stefania
authors: S
authors: Ferrari
authors: Chiara
authors: C
authors: Ferrara
authors: Maria Cristina
authors: MC
authors: Mozzati
authors: Doretta
authors: D
authors: Capsoni
authors: Andrew J
authors: AJ
authors: Pell
authors: Guido
authors: G
authors: Pintacuda
authors: Patrizia
authors: P
authors: Canton
authors: Piercarlo
authors: P
authors: Mustarelli