改性膨润土的介电性能：钠、铜和锌对介电弛豫的影响

There is a growing need for environmentally friendly materials for energy storage devices that will be widely available and inexpensive. Since bentonite is a promising material with respect to all these requirements, in this study we examined the potential of bentonite doped with sodium, copper, and zinc separately and together in different concentrations for energy storage applications. X-ray diffraction (XRD) showed that the dominant component of the samples is montmorillonite, which makes up the majority of the bentonite composition. It is confirmed that dopants will cause a change in the interplanar distances corresponding to the family of crystallographic planes (001). Fourier transform infrared spectroscopy (FTIR) was used to investigate the influence of doping on the structure of the bentonite. Dielectric spectroscopy was performed in a frequency range from 30 Hz to 120 kHz. All samples showed high dielectric permittivity values, with all modified bentonites showing higher dielectric permittivity values ​​compared to natural bentonite. According to the dielectric loss tangent dependence on frequency, two potential relaxations were observed. The Havriliak–Negami equation was used to analyze these relaxations, based on which the relaxation times were determined. As an important factor for dielectrics, conductivity values ​​were also examined, considering which of these modified samples would have the optimal combination of low conductivity, high dielectric permittivity, and small dielectric losses.