New materials for Li-ion batteries: synthesis and spectroscopic characterization of Li2(FeMnCo)SiO4 cathode materials.
Improving cathode materials is mandatory for next-generation Li-ion batteries. Exploring polyanion compounds with high theoretical capacity such as the lithium metal orthosilicates, Li2MSiO4 is of great importance. In particular, mixed silicates represent an advancement with practical applications. Here we present results on a rapid solid state synthesis of mixed Li2(FeMnCo)SiO4 samples in a wide compositional range. The solid solution in the P21/n space group was found to be stable for high iron concentration or for a cobalt content up to about 0.3 atom per formula unit. Other compositions led to a mixture of polymorphs, namely Pmn21 and Pbn21. All the samples contained a variable amount of Fe(3+) ions that was quantified by Mössbauer spectroscopy and confirmed by the TN values of the paramagnetic to antiferromagnetic transition. Preliminary characterization by cyclic voltammetry revealed the effect of Fe(3+) on the electrochemical response. Further work is required to determine the impact of these electrode materials on lithium batteries.
WMG, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK.
Stefania
S
Ferrari
Dept. of Physics and CNISM, University of Pavia, via Bassi 6, 27100 Pavia, Italy.
Maria Cristina
MC
Mozzati
Istituto dei Sistemi Complessi - CNR, Via Madonna del Piano 10, 50019 Sesto Fiorentino (FI), Italy.
Marco
M
Lantieri
Dept. of Physics and Astronomy, University of Florence, Via Sansone 1, 50019 Sesto Fiorentino (FI), Italy.
Gabriele
G
Spina
Dept. of Chemistry, University of Pavia, viale Taramelli 16, 27100 Pavia, Italy.
Doretta
D
Capsoni
Dept. of Chemistry, University of Pavia, viale Taramelli 16, 27100 Pavia, Italy.
Marcella
M
Bini