Enhanced dielectric and microwave absorption properties of LiCoO ₂ powders by magnesium doping in the X-band

The solid-state reaction was adopted to prepare a series of LiCo _1−x Mg _x O ₂ powders doped with different amount of Mg ²⁺ . The XRD patterns reveal single phase for all the prepared materials. The shift of the electronic structure of LiCo _1−x Mg _x O ₂ has been investigated by X-ray photoelectron spectroscopy to confirm the single phase for material. Influence of dopant amount on the electromagnetic properties of LiCoO ₂ powders was analyzed. The dielectric and the microwave absorption properties were evaluated. Results showed that with the increase in Mg the complex permittivity decreased after increasing. Maximum values of both real part (ε′ = 16.2 at 8.2 GHz) and imaginary part (ε″ = 4.1 at 8.2 GHz) were obtained for x = 0.06. Monolayer absorbent containing 75 wt% LiCo _0.94 Mg _0.06 O ₂ had the peak microwave absorption properties in a thickness of 2.1 mm. The available bandwidth (<−10 dB) was obtained in 8.4-10.2 GHz and the minimum reflection loss was −50.4 dB, which indicated that LiCo _1−x Mg _x O ₂ powders would be potential materials as microwave absorption.