title: High-pressure investigation of Li2MnSiO4 and Li2CoSiO4 electrode materials for lithium-ion batteries.
abstract: In this work, the high-pressure behavior of Pmn2(1)-Li(2)MnSiO(4) and Pbn2(1)-Li(2)CoSiO(4) is followed by in situ X-ray diffraction at room temperature. Bulk moduli are 81 and 95 GPa for Pmn2(1)-Li(2)MnSiO(4) and Pbn2(1)-Li(2)CoSiO(4), respectively. Regardless of the moderate values of the bulk moduli, there is no evidence of any phase transformation up to a pressure of 15 GPa. Pmn2(1)-Li(2)MnSiO(4) shows an unusual expansion of the a lattice parameter upon compression. A density functional theory investigation yields lattice parameter variations and bulk moduli in good agreement with experiments. The calculated data indicate that expansion of the a lattice parameter is inherent to the crystal structure and independent of the nature of the transition-metal atom (M). The absence of pressure-driven phase transformation is likely associated with the incapability of the Li(2)MSiO(4) composition to adopt denser structures while avoiding large electrostatic repulsions.
authors.affiliation: Departamento de Química Física, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Madrid, Spain. dsantamaria@quim.ucm.es
authors.forename: D
authors.initials: D
authors.lastname: Santamaría-Pérez
authors.forename: U
authors.initials: U
authors.lastname: Amador
authors.forename: J
authors.initials: J
authors.lastname: Tortajada
authors.forename: R
authors.initials: R
authors.lastname: Dominko
authors.forename: M E
authors.initials: ME
authors.lastname: Arroyo-de Dompablo
mesh_terms: D003035:Cobalt / Q000737:chemistry*; D003460:Crystallization; D011211:Electric Power Supplies; D004566:Electrodes; D008094:Lithium / Q000737:chemistry*; D008274:Magnesium / Q000737:chemistry*; D008958:Models, Molecular; D044367:Phase Transition; D011312:Pressure; D017640:Silicates / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D017640:Silicates; D003035:Cobalt; D008094:Lithium; D008274:Magnesium