Low-density ordered mesoporous carbon−silica nanocomposites with different Fe contents have been prepared by a facile solvent-evaporation-induced self-assembly approach. Magnetic metal nanocrystallines are highly dispersed in the composites due to in situ carbothermal reduction. The optimal reflection loss calculated from the measured permittivity and permeability is −34.4 dB at 13.1 GHz. Moreover, the electromagnetic wave absorption less than −10 dB is found to exceed 5.0 GHz for an absorber thickness of 2 mm. The microwave enhancement absorption of the mesoporous C−SiO2−Fe nanocomposites is contributed to the better match between dielectric loss and magnetic loss, which originates from the high absorption by the incorporation of magnetic species as well as the multiple reflections by the ordered mesoporous structure. The mesoporous C−SiO2−Fe nanocomposites also exhibit a lower infrared emissivity in the wavelength from 8 to 14 μm than that of Fe-free powder.

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The excellent electronic conductivity and high surface area are two crucial factors for electrode materials to achieve high energy and power capabilities in lithium ion batteries. This article presents a feasible method to obtain nanospherical electrode materials in the versatile carbon framework. A facile synthesis has been developed to prepare LiFePO 4 nanospheres with an average diameter of ∼300 nm lodged in the tridimensional (3D) porous carbon structure. This LiFePO 4 /C composite possesses the considerably enhanced electronic conductivity of ∼10 -2 Scm -1 and amazing high surface area of 200.5 m 2 g -1 , and the lithium ion diffusion coefficient of ∼10 -15 -10 -14 cm 2 s -1 is calculated. The LiFe-PO 4 /C cathode material delivers discharge capacities of 155.0 mAhg -1 at 0.1 C and 69.5 mAhg -1 at 20 C. Furthermore, the pristine LiFePO 4 /C entity has exhibited discharge capacity of 127.8 mAhg -1 at 0.1 C without conductive carbon additives.

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