A Comparative Study on the Influences of Various Nickel Powders on the EMI Shielding Performance of Conductive Polymer Composites

The morphology of filler has an important effect on the electrical conductivity and electromagnetic shielding properties of conductive polymer composites (CPCs). In this work, three different nickel powders include spherical nickel (S-Nickel) powder, flaky nickel (F-Nickel) powder, and chain spherical nickel (CS-Nickel) powder were mixed into two-component silica gel and epoxy resin to obtain CPCs, respectively. The electrical conductivity, electromagnetic interference shielding effectiveness (EMI SE), compressibility, and tensile strength of CPCs were investigated. The results show that CPCs with CS-Nickel have the best electrical conductivity and EMI SE, due to the excellent dimensional structure of CS-Nickel result in the denser conductive network. At the same time, compared with silica gel, epoxy resin has a higher cohesion force to fillers, and epoxy resin CPCs show better electromagnetic shielding performance with lower filler content. We believe that our work can provide some experimental support for the selection of filler and matrix for high performance electromagnetic shielding materials.