Functionally constructed magnetic-dielectric mineral microspheres for efficient thermal energy storage and microwave absorption

To solve the problem of electromagnetic interference and equipment heat dissipation of advanced electronic equipment. We provide an innovative strategy for the composite microsphere with the magnetic-dielectric-microsphere structure for encapsulated paraffin synergistically enhanced efficient energy storage, conversion, and microwave absorption. [Display omitted] •Magnetic-electric mineral microspheres were constructed by spray drying method.•Mineral microspheres could enhance microwave absorption and heat energy storage.•The melting enthalpy of composite PCMs reaches 111.6 J/g.•The effective microwave absorption bandwidth of composite PCMs can reach 5.76 GHz. Electromagnetic interference (EMI) and equipment heat dissipation problems are becoming increasingly prominent in advanced applications such as modern wireless communications, driverless cars, and portable devices. Multifunctional composites with efficient energy storage, conversion, and microwave absorption are urgently needed. We reported an effective strategy to construct attapulgite (ATP), carbon nanotubes (CNT), and NiCo alloys composite mineral microspheres (ACNC). Urchin-like TiO2 was coated on the surface of ACNC to form composite microspheres (ACNCT), which was compounded with paraffin (P-ACNCT) to prepare thermal energy storage and microwave absorption integrated material. The urchin-like TiO2 morphology possesses unique advantages in encapsulating paraffin. The results show that the melting and solidification enthalpy of the P-ACNCT reaches 111.6 J/g and 108.1 J/g, respectively, which indicates excellent thermal energy storage capacity. Combining a dielectric TiO2 shell with a magnetic composite microsphere core can produce a core–shell microsphere mechanism that allows for adjustable reflection loss and promotes impedance matching. The effective microwave absorption bandwidth of P-ACNCT can reach 5.76 GHz when the thickness is only 1.6 mm in the 2–18 GHz range. P-ACNCT is significant for synchronous microwave absorption and thermal energy regulation of advanced electronic equipment.