CHEMISTRY AND MATERIAL SCIENCE

Formation of 2:1 Li–Fe-phyllosilicate with montmorillonite-like structure in hydrothermal conditions

A. A. Iyakhmaeva^a, E. K. Khrapova^a, L. A. Lebedev^a, N. V. Glebova^a, V. G. Semenov^b, A. V. Kopylov^c, A. A. Krasilin<sup>a

a</sup> Ioffe Institute, St. Petersburg, Russia
^b Institute of Chemistry, St. Petersburg State University, St. Petersburg, Russia
^c RITVERC JSC, St. Petersburg, Russia

Abstract: We report on hydrothermal synthesis and structural characterization of Li–Fe-montmorillonite (MMT). To date, this 2:1 type phyllosilicate attracts attention due to such properties as high ion mobility, hydrophilicity, electrical and thermal resistance. Due to that, various MMTs may serve as perspective components of Li-ion batteries (electrolyte and separator fillers, as well as protective buffer layer on top of Li metal anode). Scarce data on synthetic Li–Fe$^{3+}$-MMTs motivated us to investigate formation process and structure features of such phyllosilicate by X-ray diffraction, UV-visible and Mössbauer spectroscopy, and other methods. We established critical Fe$^{3+}$ content and temperature range needed for almost single-phase MMTs formation. Around 20% of total Fe may occupy tetrahedral site of MMT layer. Thermal behavior of Li–Fe-MMT strongly depends on hydrothermal synthesis conditions because of different Li$^+$ amount present in the interlayer space and in the layer vacancies.

Keywords: phyllosilicate, hydrothermal synthesis, isomorphism, X-ray diffraction, Mössbauer spectroscopy.

Received: 14.11.2025
Accepted: 02.12.2025

Language: English

DOI: 10.17586/2220-8054-2025-16-6-837-849