Hybrid organic-inorganic ; Lithium ion-batteries; In situ methods; Synthesis; Insertion materials
Schmidt Sebastian, Sheptyakov Denis, Jumas Jean-Claude, Medarde Marisa, Benedek Peter, Novák Petr, Sallard Sébastien, Villevieille Claire (2015), Litihum iron metylenediphosphonate: A model material for new organic-inorganic hybrid positive electrode materials for Li-ion batteries, in Chemistry of Materials
, 27(23), 7889-7895.
Schmidt Sebastian, Sallard Sébastien, Sheptyakov Denis, Nachtegaal Maarten, Novák Petr, Villevieille Claire, Fe and Co methylenediphosphonates as conversion materials for Li-ion batteries, in Journal of Power Sources
The goal of this project is to open the perspectives for hybrid organic-inorganic anions as a component of insertion materials, in particular materials able to reversibly accommodate Li-ion. We want to understand and to tune the electrochemical properties (potential, specific charge, reduction/oxidation mechanisms…) of the hybrid organic-inorganic insertion materials. The primary objective is to determine the influence of the possible different organic groups R in Li2M(O3P-R-PO3) compared to the lithium metal pyrophosphate Li2MP2O7 as inorganic material reference. The secondary objective is to understand the role of the P and/or Si atoms in the anionic part (hybrid phosphonate-silanes P-R-Si and disilanes Si-R-Si) and the role of the cationic composition (Li2M, Li3M and Li2M2) on the electrochemical properties of the hybrid organic-inorganic insertion materials.The metal M(n+) present in the insertion materials is essential because it is where the oxidation/reduction takes place. But the choice of the proper anion is also critical for the electrochemical properties of the material, examples include the lithium metal oxides LixMyOz, the lithium metal phosphates LiMPO4, and the lithium metal silicates Li2MSiO4. In the recent years, new syntheses of insertion materials using molecular precursors in solutions and soft conditions (below 300°C) have been published. The hybrid organic-inorganic insertion materials are not anymore fantasies. The introduction of an organic part opens quasi-infinite possibilities on the synthesizable materials due to the high number of R-groups usable, their location in the material, and their combination with different inorganic parts. The Li2M(O3P-R-PO3) materials will be synthesized preferentially by the classical solvothermal method. Ionothermal or benzyl alcohol routes are planned as possible backup. Exhaustive characterizations (X-rays diffraction, elemental analysis, N2-sorption, electronic microscopy…) will be performed to correlate the influence of the R group on the structure and the electrochemical properties of the hybrid organic-inorganic materials. In situ characterization (Infra-Red, Raman, X-ray, and neutron diffraction) techniques available in our laboratory will be applied when needed to investigate the mechanisms of Li+ intercalation/deintercalation in the different hybrid materials. The synthesis of the needed phosphonate-silanes P-R-Si and disilanes Si-R-Si anionic precursors will be performed by the adaptation of an established recipe from the literature. The syntheses, purifications, characterizations, and electrochemical studies of the insertion materials based on the P-R-Si and the Si-R-Si anions will be done using the knowledge acquired in the first steps of the project from the Li2M(O3P-R-PO3) hybrid organic-inorganic reference materials.