Synthesis, Characterization, and Electrochemical Behavior of LiMnxFe(1-x)PO₄ Composites Obtained from Phenylphosphonate-Based Organic-Inorganic Hybrids

Alessandro Dell'Era; Mauro Pasquali; Elvira Maria Bauer; Stefano Vecchio Ciprioti; Francesca A Scaramuzzo; Carla Lupi

doi:10.3390/ma11010056

Synthesis, Characterization, and Electrochemical Behavior of LiMn_xFe_(1-x)PO₄ Composites Obtained from Phenylphosphonate-Based Organic-Inorganic Hybrids

Materials (Basel). 2017 Dec 30;11(1):56. doi: 10.3390/ma11010056.

Authors

Alessandro Dell'Era^{1

2}, Mauro Pasquali³, Elvira Maria Bauer⁴, Stefano Vecchio Ciprioti⁵, Francesca A Scaramuzzo⁶, Carla Lupi⁷

Affiliations

¹ Department of Basic and Applied Sciences for Engineering (SBAI), Sapienza University of Rome, Via del Castro Laurenziano 7, 00161 Rome, Italy. alessandro.dellera@uniroma1.it.
² Istituto di Struttura della Materia ISM-CNR, Via Salaria, km. 29.300, C.P. 10, 00015 Rome, Italy. alessandro.dellera@uniroma1.it.
³ Department of Basic and Applied Sciences for Engineering (SBAI), Sapienza University of Rome, Via del Castro Laurenziano 7, 00161 Rome, Italy. mauro.pasquali@uniroma1.it.
⁴ Istituto di Struttura della Materia ISM-CNR, Via Salaria, km. 29.300, C.P. 10, 00015 Rome, Italy. elvira.bauer@ism.cnr.it.
⁵ Department of Basic and Applied Sciences for Engineering (SBAI), Sapienza University of Rome, Via del Castro Laurenziano 7, 00161 Rome, Italy. stefano.vecchio@uniroma1.it.
⁶ Department of Basic and Applied Sciences for Engineering (SBAI), Sapienza University of Rome, Via del Castro Laurenziano 7, 00161 Rome, Italy. francesca.scaramuzzo@uniroma1.it.
⁷ Department Chemical Engineering Materials Environment DICMA, University Sapienza Rome, Via Eudossiana 18, 00184 Rome, Italy. carla.lupi@uniroma1.it.

Abstract

The synthesis of organic-inorganic hybrid compounds based on phenylphosphonate and their use as precursors to form LiMn_xFe_(1-x)PO₄ composites containing carbonaceous substances with sub-micrometric morphology are presented. The experimental procedure includes the preliminary synthesis of Fe²⁺ and/or Mn²⁺ phenylphosphonates with the general formula Fe_(1-x)Mn_x[(C₆H₅PO₃)(H₂O)] (with 0 < x < 1), which are then mixed at different molar ratios with lithium carbonate. In this way the carbon, obtained from in situ partial oxidation of the precursor organic part, coats the LiMn_xFe_(1-x)PO₄ particles. After a structural and morphological characterization, the electrochemical behavior of lithium iron manganese phosphates has been compared to the one of pristine LiFePO₄ and LiMnPO₄, in order to evaluate the doping influence on the material.

Keywords: LiMnxFe(1−x)PO4; carbon coating; electrochemical impedance spectroscopy; lithium-ion battery; potential step voltammetry; pseudo-diffusion coefficient.