Synthesis, crystal structure, characterization and electrochemical properties of a new cyclohexaphosphate: Li2Na2CoP6O18·12H2O

• New mixed cobalt (II) lithium sodium cyclohexaphosphta Li2Na2CoP6O18·12H2O, was synthesized.
• The atomic arrangement shows three-dimensional network.
• FT-IR and UV–vis spectra were measured.
• This material was also investigated by cyclic voltammetry and impedance spectroscopy.

A new cyclohexaphosphate with the Li2Na2CoP6O18·12H2O (LNCP) composition was prepared via a simple process at room temperature. This compound was characterized using X-ray diffraction (XRD), Infrared and UV–visible spectroscopy, Thermal analysis (TG), Cyclic voltammetry and Impedance spectroscopy. The results show that the LNCP was phased with a monoclinic structure and C2/c space group. The crystal structure was solved by using 3893 independent reflections with a final R value of 0.055. The P6O18 ring is centrosymmetrical. Its main geometrical features are those commonly observed in the atomic arrangements of cyclohexaphosphate. The atomic arrangement of this compound can be described by an organization in a three-dimensional framework, formed by the anions (P6O18)6− and polyhedra of lithium and sodium. This structure has channels where octahedral cobalt is housed. By means of a cyclic voltammetry study, it is shown that this substrate undergoes a multistep anodic oxidation, leading to a thin and compact electroactive deposit. The electrical conductivity was studied using two-probe impedance spectroscopy and results showed that the conductivity of LNCP at 518 K was equal to 1.74 × 10−4 Scm−1.

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